2005 memoria

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

MEMÒRIA ANUAL Exercici 2005

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

PRESENTACIÓN........................................................................................ 3 1.

LÍNEAS DE INVESTIGACIÓN EN DESARROLLO......................... 4 1.1 Proyecto Unión Europea..........................................................................................4 1.1.1 Presentación de los resultados en Bruselas ..............................................................4 1.1.2 Resumen de los resultados.......................................................................................8 1.1.3 Evaluación científica ...............................................................................................9 1.2 Proyecto Phaco Ersatz ........................................................................................... 12 1.2.1 Aparato para simular la acomodación ex vivo........................................................13 1.2.2 Cámara de Scheimpflug para la simulación de la acomodación..............................14 1.2.3 Prevención de la opacificación de la cápsula posterior...........................................15 1.3 Otros proyectos....................................................................................................... 16 1.3.1 Osteo-odonto Queratoprotesis..............................................................................16 1.3.2 Estudio de la calidad óptica del ojo .......................................................................17

2. ACTIVIDADES DOCENTES..............................................................18 2.1 Tesis de doctorado en desarrollo........................................................................... 18 2.2 Tesis de doctorado realizadas 2005....................................................................... 18 2.3 Trabajos de investigación Máster ......................................................................... 21 2.3.1 Master de segmento anterior .................................................................................21 2.3.2 Master de segmento posterior ...............................................................................22 2.4 Transparency Club Meetings ................................................................................23 2.5 Actividades en organizaciones internacionales....................................................25 2.6 Curso de Estadística...............................................................................................32

3. PUBLICACIONES 2005.......................................................................34 3.1 Monográficos ..........................................................................................................34 3.2 Presentaciones en congresos .................................................................................34 3.3 Publicaciones del Dr. Rafael I. Barraquer............................................................35 3.3.1 Libro .....................................................................................................................35 3.3.2 Capítulos de libro..................................................................................................35 3.3.3 Artículos en revistas indexadas..............................................................................36

4. APÉNDICE..........................................................................................58 4.1 4.2 4.3

Actividades Ralph Michael....................................................................................58 Propuesta de actividades 2006...............................................................................64 Próximas líneas de investigación ..........................................................................65

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Presentació Amb la normalitat que donen els anys de treball continuat, podem presentar la Memòria d’activitats del 2005 parlant, en primer lloc, de la segona fase d’aprofundització de la investigació encarregada per la Unió Europea sobre “ La visió dels conductors europeus” que, amb una mostra de 2.422 ciutadans conductors, ha estat realitzada a Centres de Amsterdam, Amberes, Salzburg, Tübingen i Barcelona.

També tractarem del disseny i desenvolupament d’una càmera especial pel Projecte “Phaco Ersatz”. Aquesta càmera fa possible, durant la simulació del procés d’ acomodació, la mesura dels canvis de profunditat del cristal.lí. Tanmateix és important l’estudi desenvolupat sobre la qualitat òptica de l’ull i el que, aprofitant l’ experiència del Centre d’Oftalmologia Barraquer, s’ha fet sobre els resultats a llarg termini de les queratoplasties.

Ha estat rellevant la nostra participació en el Congrés Anual de la European Association for Vision and Eye Research (EVER), celebrat a Vilamoura (Portugal), on ens ha estat concedida l’organització del “Workshop: Measurement of Accommodation”.

Per no ser exhaustius en el resum de presentació d’ una Memòria que considerem prou complerta, tant sols un apunt, sobre la tasca de formació continuada, fent esment del Curs d’Estadística organitzat per els Col.laboradors i MIR del Centre d’Oftalmología Barraquer.

Doctor Rafael I. Barraquer 3.IV.06

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1. Líneas de investigación en desarrollo 1.1 Proyecto Unión Europea Importancia de la sensibilidad al deslumbramiento y de los trastornos de la función visual en los conductores europeos 1.1.1 Presentación de los resultados en Bruselas Presentación a la Unión Europea el 27 de Abril de 2005

EU project: SUB-B27020-E3-GLARE-2002-S07.18091

Relevance of glare sensitivity and impairment of visual function among European drivers

Netherlands Ophthalmic Research Institute

The Netherlands

The Netherlands

Austria

Belgium

Spain

Germany

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EUROPEAN COMMISSION DIRECTORATE-GENERAL FOR ENERGY AND TRANSPORT DIRECTORATE E - Inland Transport Road Safety

Brussels, 04/03/2005 TREN E3/JV/cl/L0143/D(2005)103065

MEETING ON WEDNESDAY 27

APRIL AND THURSDAY 28 APRIL 2005

STARTING 10.00 A.M.(05.04.27)- ENDING FORESEEN AT 17.00 P.M.

(05.04.28)

LOCATION: CENTRE BORSCHETTE RUE FROISSART

JOINT MEETING ON “FITNESS TO DRIVE” OF

The Driving Licence Committee, The experts group on Alcohol, drugs, medicines and driving The three experts working groups on: eyesight, epilepsy and diabetes in collaboration with the consortia of the following projects: - AGILE, ALCOLOCK, CONSENSUS, IMMORTAL, MEDRIL, QUAVADIS and in collaboration of the coordinators of the campaigns: - EUROBOB, NESA

Commission européenne, B-1049 Bruxelles / Europese Commissie, B-1049 Brussel - Belgium. Telephone: (32-2) 299 11 11.

Office: DM28-01/414. Telephone: direct line (32-2) 2963809. Fax: (32-2) 2965196.

Internet: http://europa.eu.int/comm/dgs/energy_transport/index_en.html

DRAFT AGENDA

27 APRIL 2005

(1) 10:00-10:30:

General presentation of the meeting by Mr Enrico Grillo Pasquarelli, Director Inland Transport (EC) Adoption of the agenda;

(2) 10:30-11:15:

Driving licence, fitness to drive, driving under influence, by Mr JoĂŤl Valmain (Road Safety Unit, EC)

(3) 11:15-11:45:

Tour de table (members of the Driving Licence Committee)

(4) 11:45-12:00:

Updating of the legislation on the medical examination for driving licence in the Member States, by Mr Daniel Vandenberghe

(5) 12:00-12:30:

Presentation of the MEDRIL project, a practical study of the medical examination for driving licence holders in 4 MS, by Mr Nick Sanders

12:30: Lunch

(6) 14:00-15:15:

Eyesight - Report of the eyesight working group results, by Mr RenĂŠ Van Rijn - Final report of the Glare study, by Mr Tom Van den Berg - Cost-benefits analysis of an eyesight test, by TOI/SWOV (tbc)

(7) 15:15-15:45:

Tour de table and discussion

15:45-16:15: coffee-break

(8) 16:15-16:45:

Report of the Mr Eric Schmedding

epilepsy

(9) 16:45-17:15:

Tour de table and discussion

(10)17:15-17:30: Summary of the first day 2

working

group

results,

by

28 APRIL 2005

(1) 9:00-11:00: Driving under influence (alcohol, drugs and medicines) - the experts group on “Alcohol, drugs, medicines and driving”, speaker to be confirmed - the campaigns: EuroBob (by Mr Peter De Neve), NESA (by Mr Johan Chiers) - the “Alcolock” project (by Mr Ward Vanlaar) - the Rosita 2 project (speaker to be confirmed) - the Immortal project, on issues about driving under influence of alcohol and drugs (by Ms Inger-Marie Bernhoft and/or Mr Javier Alvarez, tbc) - reminder of the FP6 research project which title is “Influence of alcohol, drugs and medicines”, by Mr Joël Valmain (2)11:00-11:30: Tour de table and discussion (3)11:30-12:00: Progress Report of the diabetes working group, by Mr Christian Berne (4)12:00-12:30: Tour de table and discussion

12:30: Lunch

(5) 14:00-14:45: Disabled people - Report of the Consensus project, speaker to be confirmed - Report of the Quavadis project, by Ms Aleid Hekstra - Future actions in this field (6) 14:45-15:15: Tour de table and discussion (7) 15:15-16:15: Elderly drivers - the AGILE project, speaker to be confirmed - the Immortal project, by Lily Read (tbc) (8) 16:15-16:45: Tour de table and discussion (9) 16:45-17:00: Conclusions

17:00: End of the meeting

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.1.2 Resumen de los resultados Importancia de la sensibilidad al deslumbramiento y de los trastornos de la función visual en los conductores europeos - Resultados Ralph Michael, Marco Alvarez Fischer, Jose Gálvez, Manel Aguiló, Laura Garassino, Andres Pico, Rafael I. Barraquer Institut Universitari Barraquer En este estudio realizado durante el año 2004 participaron 2422 conductores de edad avanzada en los centros colaboradores en Amsterdam, Antwerpen (Amberes), Salzburg, Tübingen y Barcelona. En Barcelona participaron 346 conductores, que vinieron a través de familiares y amigos del personal del Centro de Oftalmología Barraquer y otros seleccionados aleatoriamente de miembros del RACC Automóvil Club.

Resultados: La prevalencia de la agudeza visual deteriorada es de 0.9% en el grupo de 45-54 años y sube hasta 5.3% en el grupo de 75-84 años con sus gafas habituales. Son conductores que no cumplen los estándares europeos actuales para el permiso de conducir, que requiere una agudeza visual de 0.5 en el mejor ojo. En la mayoría de estos casos de agudeza visual deteriorada, una agudeza visual de 0.5 o superior se puede alcanzar con la corrección apropiada del error refractivo. En un 10.2% de todos los conductores la agudeza visual se puede mejorar 2 líneas o más con la mejor corrección de sus gafas.

La prevalencia del campo visual defectuoso es de 0.5% en el grupo de 45-54 años y 2.7% en el grupo de 75-84 años. Son conductores que no cumplen los estándares europeos actuales para el permiso de conducir que requiere una extensión horizontal del campo visual de 120 grados. La prevalencia de la sensibilidad al contraste deteriorada es de 0.2% en el grupo de 45-54 años y sube hasta 6.3% en el grupo de 75-84 años. Se ha considerado valores por debajo de 1.25 en la tabla de Pelli-Robson como deteriorados. Actualmente no hay estándares europeos para los conductores con respecto a la sensibilidad al contraste.

La prevalencia de valores altos de luz dispersa en el ojo son un 0.8% en el grupo de 45-54 años y 29.5% en el grupo de 75-84 años. Se ha considerado valores sobre 1.4 en el Stray light meter como deteriorados. Actualmente no existen exigencias oficiales respecto a la luz dispersa en el ojo. La prevalencia de la catarata clínicamente relevante es de un 14% en el grupo de 75-84 años.

Un 23.7% de este grupo han sido operados de cataratas.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació Un 12% de todos los conductores del estudio tiene antecedentes de accidentes de tráfico en los últimos 3 años. Sin embargo, no hemos encontrado ninguna relación entre trastornos visuales y accidentes de tráfico en el grupo estudiado. La diferencia entre el promedio de la edad de conductores con y sin accidentes es insignificativo como también la diferencia entre el promedio de la suma de kilómetros conducidos de conductores con y sin accidentes. Conductores que admiten una mayor velocidad de conducir (en comparación con los demás) tienen mejores funciones visuales. Hemos descubierto que las personas de edad avanzada, que sufren cambios en la función visual, aparentemente reconocen sus limitaciones y se ponen autolimitaciones en su conducción.

1.1.3 Evaluación científica

Prevalence of impairments of visual function among elderly European drivers Distribution of analysis and writing of papers Amsterdam, VUMC Prevalence of impairments Prevalence of impaired visual functions Prevalence of eye diseases, eye disorders Sreening issues Antwerpen Quality of life Relation to quality of life with ocular disorders (literature) Relation with driving behaviour / driving difficulties Accident incidence Tübingen (and 2. Salzburg (and 3. Amsterdam VUMC)) Ufov, visual field Relation between UFOV and visual field outcome Relation between UFOV and other visual functions (acuity CS) Relation between automated visual field assessment and expert visual field assessment: development of criteria for automated assessement

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació Barcelona (and Salzburg and Amsterdam NORI) Straylight vs LOCS vs Contrast sensitivity Relation between “objective”assessment of cataract and outcome of visual function tests, in particular straylight and contrast sensitivity Salzburg (and Barcelona) Straylight and contrast sensitivity before and after cataract surgery Tübingen Glasses, what is wrong with them Sources and types of improperly corrected refractive errors Amsterdam NORI Development of straylight meter Simulation of cataract Wavelength dependency Fundamental psychophysics

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Analysis in Barcelona Evaluación científica de la relación entre el grado de luz dispersa en el ojo con la medición de sensibilidad al contraste y la agudeza visual Intraocular stray light measurements compared with contrast sensitivity and visual acuity in elderly European drivers R. Michael, R.I. Barraquer, G. Grabner, T.J.T.P. van den Berg, L.J. van Rijn, H. Wilhelm, T. Coeckelbergh, M. Emesz, P. Marvan, Ch. Hufnagl, N. Nischler 1 2 3 4 5 6

Institut Universitari Barraquer, Barcelona, Spain Landesklinik für Augenheilkunde, St. Johanns-Spital, Salzburg, Austria The Netherlands Ophthalmic Research Institute, Amsterdam, The Netherlands Vrije Universiteit Medical Center, Dept. of Ophthalmology, Amsterdam, The Netherlands Universitäts-Augenklinik, Universität Tübingen, Tübingen, Germany Universitair Ziekenhuis Antwerpen, Antwerpen, Belgium

PURPOSE: To study the relation between objective stray light measurement with conventional visual function tests.

METHODS: We investigated 2422 random selected elderly drivers in 5 clinics in different EU member states aging between 45 to 85 years and a control group (20 to 30 years). Subjects with prior cataract surgery were excluded (5.7%). Intraocular stray light was measured psychophysically applying flicker stray light in a central test field which had to be compensated by another light using a two alternative forced choice strategy. Contrast sensitivity was measured with a Pelli-Robson chart and visual acuity with an ETDRS chart. Cataract was graded with the LO CS III without pupillary dilation. Subjects answered the NEI questionnaire VFQ-25.

RESULTS: There is a linear relationship for intraocular stray light with contrast sensitivity, with best corrected visual acuity and with mean LOCS values. Self reported night driving difficulty could be related only to some extend to measured stray light values. Stray light was not different in drivers with or without ocular disorder, including amblyopic eyes versus non-amblyopic fellow eyes.

CONCLUSIONS: Objective stray light measurements are better correlated with conventional cataract grading (LOCS) than contrast sensitivity or visual acuity and relatively independent to mild forms of general ocular disorders.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.2 Proyecto Phaco Ersatz Reemplazamiento del material cristaliniano para recuperar la acomodación tras la cirugía de cataratas

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.2.1 Aparato para simular la acomodación ex vivo Ralph Michael, Rodolfo Carretié, Rafael I. Barraquer Institut Universitari Barraquer Hemos diseñado un aparato para medir las características mecánicas y ópticas dinámicas del cristalino durante la simulación de la acomodación ex vivo. El aparato se puede utilizar para el cristalino de ojos de donantes y para el cristalino después de la operación de catarata donde se rellena la cápsula del cristalino con un polímero.

El globo donante se secciona dejando el cristalino y el cuerpo ciliar para poner encima de un dispositivo. El dispositivo permite el estiramiento circunferencial del cristalino simulando la acomodación. El estiramiento se crea por un motor de pasos conectado a un micrómetro y a una balanza que permite medir el desplazamiento y la fuerza. La sección corneal del ojo se va a conectar mediante ocho suturas de Prolene al conjunto del micrómetro y de la balanza. El conjunto funciona haciendo pequeños desplazamientos de 1 a 100 µm con una resolución de 2 µm. El micrómetro tiene una salida digital que permite la medición del desplazamiento con una resolución de 1 µm. El núcleo de una balanza digital sirve para la medición de la fuerza de los estiramientos ligeros (1 a 500 mN) con una resolución de 0.1 mN. Hemos desarrollado programas informáticos para manejar todas las partes mecánicas y la toma de imágenes a través de un solo programa principal (LabView).

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.2.2 Cámara de Scheimpflug para la simulación de la acomodación Ralph Michael, Rafael I. Barraquer Institut Universitari Barraquer La cámara de Scheimpflug nos da la imagen del corte transversal del cristalino. La cámara funciona como una lámpara de hendidura con una camera fotográfica. El especifico es el principio de Scheimpflug que requiere que los ejes de la iluminación de hendidura, el plano principal del objetivo y el plano del CCD o de la película se cruzan en un solo punto. Así se consigue una foto con todas las partes del cristalino bien enfocado. Hemos diseñado una cámara de Scheimpflug miniaturizada a base de una webcam:

Durante de la simulación de la acomodación este cámara nos permite medir el cambio de la profundidad del cristalino. Así podemos estudiar la relación entre la fuerza del músculo ciliar necesario para un cambio óptico del cristalino definido.

Ejemplo de una foto con al camera de Scheimpflug a base de una webcam.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.2.3 Prevención de la opacificación de la cápsula posterior José Lamarca, Ralph Michael, Rafael I. Barraquer Institut Universitari Barraquer Este trabajo aporta un modelo de cultivo celular para células epiteliales de la cápsula posterior que permitirá estudios de toxicidad para el estudio de la prevención de la opacificación con diferentes fármacos. Para conseguir esta finalidad el trabajo se dividirá fundamentalmente en dos partes. La primera se basa en la teoría básica del cultivo celular y la segunda en un modelo de trabajo tanto desde el punto de vista logístico como práctico.

El trabajo con cultivos nos permite trabajar con células parecidas a las que existen en el tejido de donde proceden, de modo que en cierta forma trabajaríamos exvivo. Además podemos disponer de un tipo celular concreto donde se pueden repetir ensayos. La ventaja que se obtiene con la investigación exvivo es la posibilidad de experimentar obteniendo datos objetivos sin producir daño sobre el organismo del que proceden las células.

Experimento ejemplo con células CHO: El objetivo de este experimento es mostrar un experimento de toxicidad típico practicado por el autor con camptothecina, ciclosporina A, dexametasona y etanol con células CHO -K1. La toxicidad será medida mediante técnica de ELISA y el reactivo utilizado el MTT. Este modelo ayudará a diseñar un posible modelo para el estudio de toxicidad de diferentes fármacos sobre células epiteliales capsulares para evitar la opacificación de la cápsula posterior.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.3 Otros proyectos 1.3.1 Osteo-odonto Queratoprotesis Evaluacion estadística de mas de 300 casos de cirugia del Dr. Jose Temprano en el Centro de Oftalmologia Barraquer durante de los ultimos 40 años.

Osteo-odonto Keratoprosthesis: A 40-Year Review José Temprano, Juan Alvarez de Toledo, Victor Charoenrook, María Fideliz de la Paz, Ralph Michael, Rafael I. Barraquer PURPOSE: To study short and long term functional results after Osteo-odonto Keratoprosthesis (OOKP).

METHODS: We reviewed the charts of 287 patients who underwent osteo-odonto keratoprosthesis at the Barraquer Centre of Ophthalmology from January 1964 to May 2005. A total of 337 cases, 100 of which were bilateral were reviewed; 219 were male and 116 were female. All surgeries were done by a single surgeon using Strampelli´s technique with a variation using tibia (Temprano's technique) if patient was edentulous. Functional success was defined as visual acuity > 0.05 (legal blindness as defined by the WHO). Survival rates were calculated using life tables and the Kaplan-Meier estimator.

RESULTS: Mean follow-up time was 74 months (range: 1-585 months). Mean age of patients was 42 years (range: 4 – 86 years). Prior to intervention all patients were legally blind (VA < 0.05) and at final follow-up 153 patients had visual acuity better than 0.05. Overall survival rate was 86% at 1 month, 71% at 1 year, 50% in 5 years, 38% in 10 years and 18% in 25 years. Complications encountered were cataract (61%), vitritis (36%), expulsion (35%), glaucoma (19%), aseptic necrosis (19% cases), retinal detachment (16%). Survival rates for chemical burn (135 cases), Stevens-Johnson Syndrome (39 cases), Ocular cicatricial pemphigoid (16 cases) and other aetiologies are presented.

CONCLUSION: A 50% functional success rate after 5 years is quite satisfactory for these end-stage ocular-surface diseases.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

1.3.2 Estudio de la calidad óptica del ojo Las aberraciones de un sistema óptico como el ojo humano pueden ser evaluadas con la ayuda de un análisis de frente de ondas. Durante la operación de catarata, las aberraciones producidas por el cristalino serán prácticamente eliminadas al reemplazar el cristalino por una lente intraocular artificial (LIO) de menores aberraciones. Por otra lado, las aberraciones inducidas por la córnea pueden ser incrementadas por las incisiones en el borde de la córnea necesarias en la operación de la catarata. La información referida a la topografía corneal tiene que ser transformada y ser expresada en forma de datos de frente de onda corneal. Estos datos de frente de onda de la cornea serán extraídos de los datos del frente de onda del ojo entero para calcular los datos del frente de onda del cristalino o de la LIO. De esta forma, las aberraciones de la córnea y de la lente podrán ser evaluadas de forma independiente, antes y después de la cirugía de la catarata.

Para preparar este proyecto hemos estudiado y evaluado un aparato de análisis de frente de onda (TRACEY) y un aparato que mide la luz dispersa en el ojo (C-Quant):

Una empresa en Holanda nos ha ayudado a desarrollar un programa que nos calcule la Modulation Transfer Function desde las coeficientes (Zernike) de frente de ondas. La Modulation Transfer Function describe la cualidad de un sistema óptica y se puede relacionar con la agudeza visual.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2. Actividades docentes 2.1 Tesis de doctorado en desarrollo Astigmatismo inducido en la cirugía de la catarata con pequeña incisión.

Dr. Andrés Picó García, Centro de Oftalmología Barraquer Evolución del astigmatismo a largo plazo tras queratoplastia penetrante en queratocono.

Dr. Juan P. Alvarez de Toledo Elizalde, Centro de Oftalmología Barraquer Resultados funcionales de la fotocoagulación láser mediante rejilla del edema macular diabético difuso.

Dr. Jerónimo Nadal Reus, Centro de Oftalmología Barraquer Lentes precristalinianas para la corrección de alta miopía.

Dr. Tahsin Martini, Hospital Martini, Aleppo, SIRIA Tutor: Prof. Joaquín Barraquer, Centro de Oftalmología Barraquer Endoftalmitis de etiología exogena. Revisión de datos clínicos.

Dra. Simona Nossa, Bergamo, ITALIA Tutor: Dr. Santos Muiños, Centro de Oftalmología Barraquer

2.2 Tesis de doctorado realizadas 2005 Influence of exposure patterns in UVR-induced cataract.

Dr. Marcelo Ayala, Örebro University Hospital, Örebro, SUECIA Lectura: 20 de Mayo 2005 Tutor: Prof. Per Söderberg, Karolinska Institutet; Dr. Ralph Michael, Institut Universitari Barraquer

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Disputation vid Karolinska Institutet

Ayala, Marcelo Influence of exposure patterns and oxidation in UVR-induced cataract Fredagen den 20 maj 2005, kl. 13.00.

Föreläsningssalen, Universitetssjukhuset, Örebro, SWEDEN ISBN: 91-7140-263-2

Diss: 05:211

Tutors: Prof. Per Söderberg, St. Erik's Eye Hospital, Karolinska Institutet, Stockholm, Sweden Dr. Ralph Michael, Institut Universitari Barraquer, Barcelona, Spain Abstract: Background: Ultraviolet radiation (UVR) is one among a number of possible factors that may lead to the development of cataract. Whereas induction of cataract as the result of onetime exposure to UVR has been studied extensively, the data on lens damage resulting from repeated exposures to UVR are scarce. The Bunsen-Roscoe law of photochemical reaction (also known as the reciprocity law) states that if the products of time of exposure and irradiance are equal, then the quantities of material undergoing change will be equal. Vitamin E is an antioxidant with essentially unknown effects during lens aging and cataractogenesis. The p53 gene is related to apoptosis, an important phenomenon in cells, incuding the lens cells.

Aims: 1. To investigate the additive effects of radiation exposure in UVR-induced cataract. 2. To evaluate the validity of the reciprocity law for UVR-induced cataract. 3. To deter mine whether vitamin E may protect against UVR-induced cataract. 4. To investigate the influence of vitamin E in the application of the reciprocity law for UVR induced cataract. 5. To investigate whether p53 expression increases after UVR exposure.

Methods: Common for all five studies was the unilateral use of 300 nm UVR in vivo exposure of Sprague-Dawley rats. The degree of cataract was quantified by measurement of forward light scattering in the lenses. In the first study (additivity), rats received two UVR exposures of 4 kJ/M2 at increasing intervals (6 hours, 1 day, 3 days, 9 days and 30 days). In the second study

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació (reciprocity), each rat was exposed to 8 kJ/m2 UVR for a different length of time (5, 7.5, 11, 15, 30, 60, and 120 minutes). In the third study (vitamin E and cataract) rats were fed vitamin E or not and then exposed to UVR. In the fourth study (vitamin E and reciprocity), vitamin E was added and rats were exposed to UVR for 5 or 15 minutes. In the fifth and final study rats were exposed to UVR and p53 gene expression was measured using reverse transcriptase polymerase chain reaction (RT-PCR).

Results: In the first study (additivity), highest light scattering was found in the group with a 3-day interval between exposures. In the second study (reciprocity), the group exposed to UVR for 15 minutes showed the highest level of light scattering. In the third study (vitamin E and cataract), the vitamin E-treated group showed less light scattering than the control group. In the fourth study (vitamin E and reciprocity), no significant difference in forward light scattering was found among the lenses treated with vitamin E and exposed for 5 versus 15 minutes. In the fifth study p53 expression was 147% higher in the lenses exposed to UVR compared with the nonexposed lenses.

Conclusions: Additivity does not always hold true for UVR-induced cataract. The reciprocity law cannot be applied to UVR-induced cataract for exposures between 5 -120 minutes. Vitamin E protects the lens against UVR induced cataract. The inapplicability of the reciprocity law for shorter periods of time can be attributed to oxidation. Apoptosis in the lens due to UVR exposure may be mediated through increased p53 expression.

Keywords: Cataract, ultraviolet radiation, lens, in vivo, rats, oxidative process, time List of papers In vivo cataract after repeated exposure to ultraviolet radiation.

Ayala MN, Michael R, Soderberg PG Exp Eye Res, 2000; 70(4): 451-6 Influence of exposure time for UV radiation-induced cataract.

Ayala MN, Michael R, Soderberg PG Invest Ophthalmol Vis Sci, 2000; 41(11): 3539-43 Vitamin E can protect against ultraviolet radiation-induced cataract in albino rats.

Ayala MN, Soderberg PG Ophthalmic Res, 2004; 36(5) Reversal of reciprocity failure for UVR-induced cataract with vitamin E. Ayala M, Soderberg PG Ophthalmic Research, Accepted p53 in the lens after ultraviolet radiation exposure.

Ayala M, Strid H, Jacobsson U, Dong X, Soderberg PG Manuscript

20

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2.3 Trabajos de investigación Máster 2.3.1 Master de segmento anterior NOMBRE DR . ALVAREZ DRA. SRIPATTANAWAT DR . ARCARI

TÍTULO

COORDINADOR

Estudio comparativo entre injerto de tibia y diente en la Dr. J. Temprano osteo-odonto-queratoprótesis Indicaciones de las queratoplastias 1995-2005

Dr. J. Álvarez de Toledo

DR . C HIARELLI DR . ARTEAGA DR . RAMÍREZ

Urgencias del segmento anterior dentro del Centro de Dr. J. Villanueva Oftalmología Barraquer en el año 2004 Dr. R.I. Barraquer

DR . BELLIZZI

La pseudoaccomodazione nei soggetti giovani

Dr. R.I. Barraquer

DR. BOLEAS

Anillos intracorneales

Dr. R.I. Barraquer

Queratitis por acanthamoeba

Dr. Álvarez de Toledo

DRA. M ARTINEZ DR . BUCHACRA DRA. G IAGANTE DR . C AMACHO DR . G ARCÍA-FRANCO

Estudio de la reparación corneal después de cirugía lasik Dr. R. I. Barraquer mediante microscopía confocal Dr. A. Picó

DR . L AMARCA

Opacificación de la cápsula posterior

DR. LÓPEZ

Actualidad en los estudios de las bases neurales de la Dr. R. I. Barraquer sensación corneal y su aplicación en mejoras en el tratamiento del malestar corneal en pacientes postoperados de cirugía refractiva, usuarios de lentes de contacto y con ojo seco

DR . L UQUE

La posibilidad de realización de queratoplastias en un Dr. Álvarez de Toledo Hospital Comarcal

DRA. M ALOUFI

Morfología corneal con queratocono

Dr. Álvarez de Toledo

DR . SÁNCHEZ

Queratoplastia penetrante (QPP) en niños

Dr. R.I. Barraquer

Dr. R.I. Barraquer

DRA. VASQUEZ DRA. VAZQUEZ

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2.3.2 Master de segmento posterior NOMBRE

TÍTULO

COORDINADOR

DR . ACEBES

Edema macular quístico, patogenia, relación con cirugía Dr. Escoto de segmento anterior (faco Mics, faco 2’75, queratoplastias, cirugía filtrante). Tratamiento y pronóstico

DR . ARTEAGA

El papel del OCT en el diagnóstico de las enfermedades Dr. S. Abengoechea de la mácula

DR . RAMOS DR . SÁNCHEZ DR . BOLEAS

Maculopatía diabética

Dr. S. Abengoechea

DR . BUCHACRA

Endoftalmitis de Clínica Barraquer de Barcelona

Dr. R. Escoto

DR . D EBRI

Vitrectomía en la retinopatía diabética

Dr. S. Abengoechea

DRA. G ARCÍA ROLDÁN

Uveítis posterior asociada a enfermedades sistémicas no Dr. R. Escoto infecciosas

DR . L AMARCA

Estudio epidemiológico sobre enucleación por melanoma en Dr. J. Elizalde C.O.B.

DR . LOPEZ

Prótesis e implantes biomicroelectrónicos intraoculares Dr. S. J. Muiños aplicables en retina, nuevas ofertas terapéuticas, presente y futuro de la biomedicina intraocular

DR . PRIETO

Desprendimiento de retina con vitrectomía primaria sin Dr. J. Nadal posicionamiento

DR . RODRIGUEZ HUELTES

Estudio descriptivo sobre patología hemorrá-gica retiniana Dr. S.J. Muiños en gestantes

DRA. RODRIGUEZ

Estudio experimental y morfométrico del efecto Dr. J. Nadal neuroprotector de los antagonistas del calcio sobre la isquemia retiniana transitoria en rata.

DRA. SRIPATTANAWAT

Terapia fotodinámica en el tratamiento de neovascularización coroidea asociada a miopía alta

DRA. G IAGANTE

DRA. VASQUEZ

la Dr. R. Escoto

DRA. VAZQUEZ

22

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2.4 Transparency Club Meetings Anterior Segment Research Group Cada mes se ha organizado una reunión llamada "Transparency Club" o "Club de Transparencia". El nombre es debido a una de las características más importantes de la córnea y del cristalino. Participan los oftalmólogos especializados en segmento anterior, los residentes y alumnos máster interesados en el segmento anterior y el equipo del departamento de cirugía refractiva. Se tratan temas clínicos y experimentales en forma de discusión, "brain storming" y ponencias.

Meetings 2005: Tuesday, 11. January 2005, 20:00 at Research Department, COB Francisco: Aplicaciones de la oxigenoterapia hiperbárica en la oftalmología Ralph: Statistics course and software at COB Tuesday, 1. February 2005, 20:00 at Research Department, COB - Comparative results of driver's vision in Holland, Belgium, Germany, Austria and Spain (EU project at COB 2004) - Progress Lens Stretching Device for Phaco Ersatz - Short info about: Weekend Statistics Course Tuesday, 1. March 2005, 20:00 at Research Department, COB Experimental design of a new research projects: - José Lamarca: Posterior Capsular Opacification - Cell culture Tuesday, 12. April 2005, 20:00 at Research Department, COB Experimental design of a new research projects: - Rodrigo Abreu: Edema macular diabético Tuesday, 10. May 2005, 20:00 at Research Department, COB Discussion of possible research project with: TRACEY, Scheimpflug Camera, Confocal Microscopy of the Cornea Tuesday, 14. June 2005, 14:00 at Research Department, COB Discussion of possible research project with: TRACEY, Scheimpflug Camera, and Straylight meter

23

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació Tuesday, 5. July 2005, 14:00 at Research Department, COB - Short demonstration of Straylight meter C-Quant - Maria de la Paz: Experimental design of Yellow IOL project - How to do statistics with Visual Acuity data? (PDF summary) Tuesday, 6. September 2005, 14:00 at Research Department, COB - Practical experience with TRACEY and Straylight meter (EduTRACE demo) - Cornea Confocal Microscopes: HRT module versus Nidek - Info about simple data export OCT retinal thickness Tuesday, 8. November 2005, 14:00 - Phaco Ersatz: Lens stretching device and results from Japan and Australia - Common statistical software at COB and planning for second part of statistics course Tuesday, 29. November 2005, 14:00 - Presentation and discussion of seven Master projects, one group about Accommodation and another about Visual Quality in patients with cataract.

24

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2.5 Actividades en organizaciones internacionales •

Actividades en el European Association for Vision and Eye Research (EVER) o Dr. Ralph Michael trabaja en la junta del EVER como "Board Member" y "Chair of the Lens and Cataract section" o Organización y moderación de dos Special Interest Symposium durante el congreso EVER 2005

25

Posterior capsular opacification Session type Special Interest Symposium Moderators for this session Albert GALAND, Rafael I. BARRAQUER Time and place of session This session will take place on Friday 7 October 2005 from 08:30 till 10:00 in room Gemini III. Abstracts assigned to this session (6) 08:30

15'

3121

After-Cataract Dilemmas

VRENSEN G

08:45

15'

3122

Clinical aspects of Posterior Capsular Opacification

TETZ M

09:00

15'

3123

Are the lens epithelial cells the capsular bag's enemy or ally?

TASSIGNON MJ

09:15

15'

3124

Surgical options for PCO prevention

BARRAQUER RI

09:30

15'

3125

Intra- & post-operative abrasion of the lens epithelial cells by the IOL

GALAND A

09:45

15'

3126

A human capsular bag model for PCO evaluation after IOL implantation - prognostic power?

LIEKFELD A

Posterior capsular opacification ■ 3121 After-Cataract Dilemmas

■ 3122 Clinical aspects of Posterior Capsular Opacification

VRENSEN G Ophthalmology, Univ. Medical Center, Leiden

TETZ M Berlin

Purpose PCO is caused by unrestrained proliferation of LECs left in the bag after ECCE. LECs migrate to the posterior capsule causing wrinkles and fibrotic plaques or differentiate into lens fibres forming the ring of Soemmering. Escaping fibres form Elschnig’s pearls. Plaques and pearls obstruct light and capsulotomy is needed to restore vision.Efforts to overcome LEC proliferation and migration by cleaning the capsule, by mitotic inhibition and killing of LECs, by creating a barrier between the peripheral and central PC with special IOL designs or by removal of the central PC have reduced the prevalence of PCO but it is still at a disappointing level of 10-20%. Dilemmas: careful cleaning considerably extends the ECCC procedure, and mitotic inhibition or cell killing should be 100% effective in a short per-operative period and should not affect other anterior chamber tissues. Even in the 80ties ECCE and IOL implantation were uncomplicated in 40-50% of cases. A probable reason for this is the formation of the ring of Soemmering consisting of a monolayer of slowly proliferating LECs and a core of lens fibres. As long as Soemmering’s ring remains closed nothing seems to happen. It was shown in vitro that lens fibres left after ECCE reduce the proliferation of LECs. The ‘bagin-the-lens’ implantation of IOLs (Tassignon et al., JCRS 2002), in which a closed ring is intrinsic to the procedure, proves this point. Up till now no PCO has been observed after this procedure.The ‘bag-in-the-lens’ procedure seems an excellent solution for PCO prevention but its surgery is rather complicated. Alternatively we could intentionally leave a rim of equatorial lens fibres during ECCC or try to find the lens fibre factors controlling the proliferation and differentiation in the intact lens.

ABSTRACT NOT PROVIDED

■ 3123 Are the lens epithelial cells the capsular bag’s enemy or ally?

■ 3124 Surgical options for PCO prevention

TASSIGNON MJ Department of Ophthalmology, Antwerp

BARRAQUER RI J. Barraquer Chair of Eye Research - UAB, Barcelona

Purpose The last decade, the lens epithelial cells (LECs) have received full responsibility for the occurrence of PCO after cataract surgery. We would like to prove that this is only partially true.

Purpose To review the current status of posterior capsule opacification (PCO) prevention strategies and surgical options.

Methods - Clinical evaluation of the capsular bag of 300 eyes implanted with the bagin-the-lens were evaluated.- Capsular bags equipped with a bag-in-the-lens IOL were put in culture and compared to capsular bags equipped with a lens-in-the-bag IOL. Results The capsular bags of 123 eyes could be monitored on the presence of Elschnig pearls, fibrosis, wrinkles and Soemerring.The response of the LECs on TGF-β was much lower for the bag-in-the-lens capsules compared to the lens-in-the-bag capsules.

Conclusion The bag-in-the-lens implantation presents the advantage to have full control over the LEC transformation by allowing only LEC proliferation. The physiological conditions for the maintenance of the capsular bag are better preserved using the bagin-the-lens implantation technique. This is a major advantage.

Methods Literature review and meta-analysis of the factors influencing PCO. Longterm retrospective study of personal series comparing rates of PCO with and without lens epithelial cell aspiration (LECA). Retrospective study of the incidence of retinal complications of planned posterior capsulorhexis (PPC) versus Nd:YAG capsulotomy (YAG).

Results A number of pathological conditions, surgical techniques, IOL designs and materials, and pharmacological treatments have been described to influence the rate of PCO. With IOLs of classical design and materials (PMMA, silicone), we found a significant reduction in PCO at over 3 years of follow-up, from ECCE and no LECA (61.8%), to phacoemulsification (PE) without LECA (36.6%), to PE+LECA (17.2%, p<0.01). In another study, retinal detachment (RD) occurred in 1.05% of cases after PPC versus 2.14% after YAG (OR=2.05 but p=0.31). Both groups were significantly worse than the intact capsule group (IC, 0.24% RD) and significantly better than the unplanned capsular rupture group (8.12% RD). Rates of cystoid macular edema and new retinal tears were non significantly different between IC, PPC and YAG. Conclusion PCO remains the most frequent postoperative complication after cataract surgery. LECA is an effective surgical method for the reduction of PCO incidence.

Further studies are required to evaluate its possible additivity with the documented beneficial effect of the newer IOL designs and materials. PPC is a viable option in the younger patients with high risk of PCO, appearing to be at least as safe as YAG capsulotomy.

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EVER 2005 - Abstract book

Posterior capsular opacification ■ 3125 Intra- & post-operative abrasion of the lens epithelial cells by the IOL

■ 3126 A human capsular bag model for PCO evaluation after IOL implantation - prognostic power?

GALAND A Centre d’Ophtalmologie, Liège

LIEKFELD A Charité, Ophthalmology, Berlin

Purpose To get partial or total elimination of the lens epithelial cells in order to reduce the rate of posterior capsular opacification.

Purpose To evaluate the transferability of a human capsular bag model to clinical situations concerning the development of posterior capsule opacification after intraocular lens (IOL) implantation.

Methods I observed by slit lamp examinations that eyes with intraocular lenses implants smaller than the capsular bag had sometimes no posterior capsule opacification (PCO), up to ten years postoperatively.In those eyes, a rotation of the implant within the capsular bag, after the surgery, was either documented or supposed. So, I assumed that a relative freedom of the implant can result in abrasion of the lens epithelial cells. “Sine Tensione” intraocular lenses allow some, limited, pseudo-accommodation by anterior shifting. By intra and post-operative rotation of such implants (AccoRing), we hope a reduction of the PCO rate.

Results After a one year follow-up, eyes which received the implant, with intraoperative rotational manoeuvre, present a lower PCO rate than eyes with conventional implantation.However the respective role of the implant design and of the surgical method are difficullt to assess.Data and their discussion will be bring at the SIS PCO.

Methods 120 intraocular lenses were compared in pairs in the capsular bag model. The behaviour of the lens epithelial cells (LEC) was documented in terms of the time needed to form a complete monolayer on the posterior capsule. The results were compared to data from the literature and from own clinical studies.

Results Depending on the type of IOL the LEC growing was significantly different in speed. A LEC monolayer was formed between day 8 at the earliest and more than 60 days at the latest.

Conclusion The human capsular bag model employed allows short-term evaluation of secondary cataract formation for different IOLs. This model’s correlation with clinical results is good.

Conclusion Intra- and post- operative implant rotation could be a way to reduce PCO. Textured haptics are suggested to improve this possible mechanism of abrasion of the lens epithelial cells.

EVER 2005 - Abstract book

133

Workshop: Measurement of accommodation Session type Workshop Moderators for this session Adrian GLASSER, Ralph MICHAEL Time and place of session This session will take place on Friday 7 October 2005 from 17:30 till 19:00 in room Fenix III. Abstracts assigned to this session (5) 17:30

15'

3461

Introduction to measurement of accommodation

GLASSER A

17:45

15'

3462

Optical techniques to measure natural accommodation

SCHAEFFEL F

18:00

15'

3463

Accommodation Measurement with Shin-Nippon Autorefractors

WOLFFSOHN JS

18:15

15'

3464

Wavefront Measurement of Accommodation

LOPEZ-GIL N

18:30

30'

3465

Hands-on practice: Accommodation measurement

GLASSER A, SCHAEFFEL F, MICHAEL R, LOPEZ-GIL N, WOLFFSOHN JS

Workshop: Measurement of accommodation ■ 3461 Introduction to measurement of accommodation

■ 3462 Optical techniques to measure natural accommodation

GLASSER A Optometry, Houston

SCHAEFFEL F University Eye Hospital, Section Neurobiology of the Eye, Tübingen

Purpose Accommodation is a dioptric change in power of the eye. Although accommodation is usually measured clinically with a subjective push-up test, this overestimates the true accommodative response and is inadequate to unequivocally demonstrate accommodation.

Purpose Although it is possible to observe biometrical changes in lens geometry or the ciliary body during accommodation by Scheimpflug imaging, MRI, or high resolution ultrasonography, one can never be sure about the resulting dioptric changes.

Furthermore, since natural accommodation may be different from artifically stimulated accommodation, techniques that can measure natural accommodation are preferred.

Methods Several methods to both stimulate and measure accommodation exist. Low concentrations of pilocarpine administered topically produce a direct contraction of the ciliary muscle and an ensuing involuntary accommodative response. Real, self illuminated targets viewed binocularly at far (6 meters) and at various near distances present compelling stimuli that contain blur, convergence and proximal cues. Far targets viewed through minus powered trial lenses present blur cues. The accommodative response can be measured objectively with static refractometers (Hartinger coincidence refractometer), autorefractors (Grand Seiko WR5500K) and wavefront aberrometers (TRACEY iTrace).

Results The subjective push-up test overestimates the true accommodative amplitude relative to objective measures. Pharmacologically stimulated accommodation occurs over 30 minutes and the response amplitude depends on iris color. An accommodative response can be elicited when compelling blur and/or proximity cues are presented. A variety of clinical instruments are available for objective measurement of accommodation.

Methods Techniques are described that measure accommodation based on Scheiner’s principle, direct measurement of retinal image contrast, automated dynamic retinoscopy, retinal image size, photorefraction and wavefront analysis.

Results Most of the measurements principles have been developed to permit dynamic recordings of refraction. They still vary (1) with regard to their dioptric resolution, (2) the possibilities for calibration, (3) the possibility to measure both eyes at the same time, and (4) to record also pupil size and the direction of gaze.

Conclusion Measurement techniques that work from a distance, under open field viewing condiitions, are particularly valuable. A further advantage is if they can record the refractions of both eyes, pupil size and convergence.

Conclusion Accommodation can and should be measured objectively to unequivocally demonstrate if accommodation occurs. A variety of different methods to both stimulate and measure accommodation are available.

■ 3463 Accommodation Measurement with Shin-Nippon Autorefractors

■ 3464 Wavefront Measurement of Accommodation

WOLFFSOHN JS Life and Health Sciences, Aston University, Birmingham

LOPEZ-GIL N Fisica. Grupo de Ciencias de la Visión, Murcia

Purpose To provide an overview on how to measure accommodation clinically with Shin-Nippon autorefractors and to examine their potential to assess the dynamics of ocular accommodation.

Purpose Accommodation modifies ocular wavefront which can be measured objectively by means of aberrometers. Our purpose is to show how accommodation can be measured from wave-front outcomes; to present the changes in wavefront error that can be typically found during accommodation; and to show the potential use of this technique to obtain objective measures of accommodation and pseudophakic accommodation in subjects wearing multifocal and accommodative intraocular lenses.

Methods Shin-Nippon autorefractors, also marketed under Grand Seiko, use infrared light reflected off the retina to assess the ocular refracting power of the eye. As with the extensively utilised Canon R-1 autorefractor, they offer an objective measurement of refractive error/ocular accommodation, and an open and binocular field of view.

However, unlike the Canon R-1 which measured the overall intensity of infrared light reflected from the retina, the Shin-Nippon autorefractors project a pattern (ring or lines) of light and image analyse the change in shape after it has been reflected through the ocular refracting elements. Measurements can be made with pupil sizes as small as 23mm.

Results Static measurements of refractive error/ocular accommodation can be made in approximately 1 second by the instruments. However, with the SRW-5000 and FR5000 the infrared light can be switched permanently on and the video image tapped to be analysed by an external computer at up to 60Hz. This allows the dynamics of accommodation to be assessed and is fairly robust to small eye movements and focusing adjustments. However, the newer model (NVision-K, SRW5001) has had an autokeratometer added and the refractive video output can no longer be tapped.

Conclusion Shin-Nippon autorefractors offer the ability to provide robust, objective measures of ocular accommodation at up to 60Hz while the patient maintains an open field of view.

EVER 2005 - Abstract book

Methods For the last three years, a few aberrometers have made it possible to stimulate the accommodation by positioning optically a stimulus at different distances, and to obtain accurate and objective measurements of the accommodation response. An objective measure of accommodation can be obtained by computing specific metrics from the resulting Zernike coefficients. In particular, a combination between defocus and spherical aberration is related to the subject’s accommodation state. The effect of accommodative miosis is also analyzed.

Results Results obtained in several studies show that ocular wavefront aberrations change with accommodation. Although those changes exhibit inter-subject variability, there is a significant decrease in spherical aberration with increasing accommodation in young subjects that could influence the lag of accommodation. Recent measurements obtained with an Imagine Eyes irx3 aberrometer have shown that the change in ocular aberrations during accommodation is different in the young (pre-presbyope) and the old (presbyope) eye. Accurate measurements on intraocular implants (monofocal, multifocal and pseudo-accommodative) are also presented.

Conclusion Dynamic aberrometry is a valuable technique to investigate accommodation and evaluate various presbyopic corrections modalities.

171

Workshop: Measurement of accommodation â&#x2013; 3465 Hands-on practice: Accommodation measurement GLASSER A, SCHAEFFEL F, MICHAEL R, LOPEZ-GIL N, WOLFFSOHN JS Purpose To allow audience participants to gain hands on experience in objective measurement of accommodation.

Methods We anticipate that several autorefractors, wavefront aberrometers and other commercially available clinical instruments will be on display to do objective accommodation measurements. The session speakers will interact with audience participants to demonstrate and explain how accommodation can be measured objectively with these instruments.

Results The experience will provide participants with hands on experience in objective accommodation measurement with several commercially available clinical instruments.

Conclusion Several commercial instruments are available for objective accommodation measurements. These can readily be introduced in clinical practice to do objective accommodation measurements.

172

EVER 2005 - Abstract book

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

2.6 Curso de Estadística Estadística per a oftalmòlegs Destinataris:

Personal facultatiu del Centre d'Oftalmologia Barraquer SA

Objectius Formatius: • Poder aplicar l'estadística dins de l'àmbit de l'oftalmologia • Adquirir els coneixements necessaris per fer un anàlisi estadístic, a partir d'un vocabulari senzill.

• Saber utilitzar un programa estadístic, el qual facilitarà els complexos càlculs matemàtics.

Lloc d'impartició:

EUIF Blanquerna ( Universitat Ramon Llull) C/ Padilla, 326,332 - 08025 Barcelona

Programa (Durada·16 hores) DISSABTE,16 ABRIL 2005.

09.00 Lliurament de documentació i presentació del curs.

09.15 Introducció al Mètode Científic i a l'Estadística 10.00 Anàlisi exploratori de les dades I 11.00 Descans 11.30 Anàlisi exploràtori de les dades II 12.30 Inferència estadística.

13.30 Menjar 15.00 Elecció de la prova estadística 15.30 Fases d'una anàlisi estadística.

16.00 Descans.

16.30 Comparança de mitjanes 17.30 Comparança de proporcions 18.30 Fi de la jornada

32

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

DISSABTE 7 MAIG 2005.

09.00 Introducció SPSSWIN 11.00 Elecció de la prova estadística 11.30 Descans 11.00 Anàlisi exploratori de les dades 13.30 Menjar 15.00 Comparança de mitjanes 16.30 Descans.

17.00 Comparança de proporcions.

18.30 Fi de la jornada.

Docents Dr. Félix Muñiz. Cap del servei de Pediatria i Neonatologia . Hospital General de Catalunya Dr. Julián Roldán. Cap del servei d'Anestesiologia , Reanimació i Tractament del Dolor. Hospital General de Catalunya.

33

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

3. Publicaciones 2005 3.1 Monográficos T.J.T.P. van den Berg1, L.J. van Rijn2, G. de Wit1, L. Franssen1, J. Coppens1, G. Grabner3, H. Wilhelm4, T. Coeckelbergh5, R. Michael6, R.I. Barraquer6 Relevance of glare sensitivity and impairment of visual function among European drivers.

Report EU project: SUB-B27020B-E3-GLARE-2002-S07.18091 1 The Netherlands Ophthalmic Research Institute, Amsterdam, The Netherlands 2 Vrije Universiteit Medical Center, Dept. of Ophthalmology, Amsterdam, The Netherlands 3 Landesklinik für Augenheilkunde, St. Johanns-Spital, Salzburg, Austria 4 Universitäts-Augenklinik, Universität Tübingen, Tübingen, Germany 5 Universitair Ziekenhuis Antwerpen, Antwerpen, Belgium 6 Centro de Oftalmología Barraquer, Institut Universitari Barraquer, Barcelona, Spain

3.2 Presentaciones en congresos Michael R, Carretié R, Barraquer RI. Development of a computer controlled device for simulation of accommodation ex vivo. Societas Ophtalmologica Europeae 2005, Berlin, D. Oral presentation.

Michael R, Wegener A, Barraquer RI. Safety estimation for optical radiation from an operation microscope with and without protective filters. Societas Ophtalmologica Europeae 2005, Berlin, D. Poster presentation. van Rijn LJ, van den Berg TJTP, Grabner G, Wilhelm H, Michael R, Coeckelbergh T. The prevalence of impairments of visual function amongst European drivers. Societas Ophtalmologica Europeae 2005, Berlin, D. Oral presentation.

Michael R, Barraquer RI, Emesz M, Nischler Ch, Hufnagl Ch, Grabner G, Coppens J, van den Berg TJTP, Coeckelbergh T, Wilhelm H, van Rijn LJ. Comparison of intraocular stray light measurements with conventional cataract grading and contrast sensitivity estimation in elderly European drivers. European Association for Vision and Eye Research 2005, Vilamoura, P. Oral presentation. Ophthalmic Research 2005;37 (suppl 1):213 #4446 Michael R, Sripattanawat R, Alvarez A, Temprano J, de la Paz M, Charoenrook V, Alvarez de Toledo J, Barraquer RI. Osteo-odonto Keratoprosthesis: A 40-Year Review. European Association for Vision and Eye Research 2005, Vilamoura, P. Poster presentation. Ophthalmic Research 2005;37 (suppl 1):24 #228 / 2427

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

3.3 Publicaciones del Dr. Rafael I. Barraquer editadas durante el Año 2005 3.3.1 Libro Barraquer RI, De Toledo MC, Torres E. Corneal Dystrophies and Degenerations. Atlas and Textbook (English edition). Barcelona, Institut Universitari Barraquer, 2005-6. (en prensa)

3.3.2 Capítulos de libro Barraquer RI. Penetrating keratoplasty in irregular astigmatism. In: Alió JL, Belda JI (eds.), Treating Irregular Astigmatism and Keratoconus. Panama (Rep. of Panama), Highlights of Ophthalmology International, 2004. pp 187-193.

Barraquer RI. Penetrating keratoplasty in keratoconus. In: Alió JL, Belda JI (eds.), Treating Irregular Astigmatism and Keratoconus. Panama (Rep. of Panama), Highlights of Ophthalmology International, 2004. pp 305-333.

Barraquer RI, Alvarez de Toledo JP, de la Paz MF. Pterigion y pinguécula. In: Benitez del Castillo JM et al. (eds.), Superficie Ocular. LXXX Ponencia Oficial de la Sociedad Española de Oftalmología 2004.

Barraquer RI. Hydromaneuvers. In: Gutierrez Carmona F (ed.), Phaco without the Phaco.

Vaypajee, Bombay 2005.

Barraquer J, Barraquer RI. Foreword. In: Gutierrez Carmona F (ed.), Phaco without the Phaco.

Vaypajee, Bombay 2005.

Barraquer RI, Elizalde J. La photographie en ophtalmologie. Encyclopédie Médico-Chirurgicale 2006 (en prensa).

Barraquer RI, Picó A. Wavefront and aberrometry analysis. In: Boyd S, ed., Diagnostic and Imaging Techniques. Highlights of Ophthalmology, Panamá 2006. (en prensa).

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

3.3.3 Artículos en revistas indexadas Alvarez-Fischer M, de Toledo JA, Barraquer RI. Lisch corneal dystrophy. Cornea 2005; 24:494495.

Barraquer, RI, Barraquer E. Manifestraciones corneales de las enfermedades sistémicas. Annals d'Oftalmología (Barc) 2005.

Barraquer RI, Michael R, Abreu R, Lamarca J, Tresserra F. Human lens capsule thickness as a function of age and location along the sagittal lens perimeter. Invest Ophthalmol Vis Sci 2006 (en prensa).

36

EU project: SUB-B27020B-E3-GLARE-2002-S07.18091

Relevance of glare sensitivity and impairment of visual function among European drivers

Netherlands Ophthalmic Research Institute

The Netherlands

The Netherlands

Austria

Belgium

Spain

Germany

January 2005

Contact information and involved institutes Grant holder: The Netherlands Ophthalmic Research Institute (NORI) of The Royal Netherlands Academy of Arts and Sciences Dr. P van ‘t Klooster, director CW van Leeuwen, administrative officer

Project leaders and contact persons:

Dr. T.J.T.P. van den Berg and Dr. L.J. van Rijn Meibergdreef 47 1105 BA Amsterdam The Netherlands Tel. (+31)20-5665185 Fax. (+31)20-5666121 E-mail: T.J.vandenBerg@ioi.knaw.nl vanRijn@vumc.nl

Involved institutes: Netherlands Ophthalmic Research Institute Contact information: see above Landesklinik für Augenheilkunde und Optometrie Prof. Dr. G. Grabner St. Johanns-Spital Müllner Hauptstraße 48 A-5020 Salzburg Austria Vrije Universiteit Medical Center, Department of Ophthalmology Dr L.J. van Rijn PO Box 7057 NL-1007 MB Amsterdam The Netherlands

Centro de Oftalmología Barraquer Càtedra de Recerca en Oftalmologia J. Barraquer Dr. R.I. Barraquer and Dr. R. Michael Muntaner, 314 E-08021 Barcelona Spain

Universitäts-Augenklinik Prof. Dr. H. Wilhelm Schleichstraße 12-16 D-72076 Tübingen Germany

Universitair Ziekenhuis Antwerpen Dr. T. Coeckelbergh Wilrijkstraat 10 2650 Edegem Belgium 3

Persons involved in the project Netherlands Ophthalmic Research Institute (Amsterdam) Dr. T.J.T.P. van den Berg local and overall project leader Dr. G.C. de Wit project coordinator, researcher J.E. Coppens senior researcher L. Franssen researcher Vrije Universiteit Medical Center (Amsterdam) Dr L.J. van Rijn, ophthalmologist, local and overall project leader Prof dr H.J. Völker-Dieben, ophthalmologist E. Gutker, ophthalmic nurse R. Kaper, ophthalmic assistant D.J. Vonhoff, ophthalmic assistant F. Huizing-Chapel, ophthalmic assistant D. Dijkstra (van Hellemond) recruitment Staff opthalmologists and residents Co-workers outpatient department Centro de Oftalmología Barraquer (Barcelona) Dr. R.I. Barraquer, director Centro de Oftalmología Barraquer Dr. R. Michael, local project leader M. Alvarez Fischer, ophthalmologist J. Gálvez, optometrist, head optometry dept.

M. Aguiló, optometrist, head visual field dept.

V. Rojo, optometrist L. Garassino, ophthalmologist Universitair Ziekenhuis Antwerpen (Antwerpen) Prof. dr. M.J. Tassignon, head of the department Dr. T. Coeckelbergh, local project leader Dr. K. Verbruggen, ophthalmology resident Dr. D. Verhelst, ophthalmology resident Dr. S. Ceuterick, ophthalmology resident Dr. J. Van Looveren, ophthalmology resident Dr. B. Reyntjens, ophthalmology resident Dr. P. Schraepen, ophthalmology resident Dr. S. Kiekens, ophthalmology resident Dr. K. Mgaieth, ophthalmology resident D. Godts, orthoptist C. Ferdinandus, nurse G. Vandeweyer, nurse B. Swenters, nurse

4

Landesklinik f체r Augenheilkunde und Optometrie (Salzburg) Prof. dr. G. Grabner ophthalmologist, local project leader Dr. M. Emesz ophthalmologist Dr. P. Marvan ophthalmologist in training Dr. N. Nischler ophthalmologist in training Dr. Ch. Hufnagl ophthalmologist in training Universit채ts-Augenklinik (T체bingen) Prof. Dr. med. H. Wilhelm Dr. med. C. Heine B. Meyer Cand. med . B. Matthiesen Cand.med. B. Voykov Cand. med E. Guenova stud. med. A. Kasperkowiak G. Wilhelm I. Mildenberger A. Ene Cand. med. M. Sell

ophthalmologist, local project leader resident ophthalmology ophthalmic assistant, optician student, assistant student, assistant student, assistant student, assistant student, assistant student, assistant student, assistant student, assistant

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Contents

Contact information and involved institutes.......................................................................... 3 Contents..................................................................................................................................... 6 General introduction and summary ....................................................................................... 8 1

Prevalence of impairments of visual function among European drivers.................. 13 1.1 Introduction .............................................................................................................. 15 1.2 Methods.................................................................................................................... 17 1.3 Results ...................................................................................................................... 21 1.3.1 The driving habits questionnaire...................................................................... 22 1.3.2 Visual function tests in relation to age............................................................. 25 1.3.3 Visual function tests: regional differences ....................................................... 34 1.3.4 Eye diseases and structural eye abnormalities ................................................ 35 1.3.5 Relation between driving habits and visual functions...................................... 36 1.3.6 Relation between quality of life and visual function ........................................ 38 1.4 Discussion ................................................................................................................ 39 1.5 Acknowledgements .................................................................................................. 47 1.6 Proprietary interests.................................................................................................. 47 1.7 References ................................................................................................................ 47 1.8 Appendix : The driving questionnaire...................................................................... 51

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Measuring glare sensitivity ........................................................................................... 53 2.1 Introduction .............................................................................................................. 55 2.2 Compensation Comparison method for assessment of retinal straylight ................. 57 2.3 Measurement reliability of the Compensation Comparison method........................ 58 2.4 Commercialization of the straylight meter............................................................... 58 2.5 References ................................................................................................................ 60 2.6 Appendix A: Explanation of the Straylight Meter based on the Compensation Comparison method ................................................................................................. 62 2.6.1 Introduction / Direct compensation method..................................................... 62 2.6.2 Measurement principle: Compensation Comparison method.......................... 64 2.6.3 Psychometric function ...................................................................................... 68 2.6.4 Actual implementation of the straylight meter ................................................. 72 2.7 Appendix B: Spectral dependence of retinal straylight............................................ 76

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Glare sensitivity and visual impairment ...................................................................... 77 3.1 Introduction .............................................................................................................. 80 3.2 Cataract simulation................................................................................................... 81 3.3 On the relationship straylight â&#x20AC;&#x201C; driver performance ................................................ 81 3.3.1 Static blinding: basic considerations of straylight effects during driving ....... 82 3.3.2 Dynamic aspects of glare in a driving situation............................................... 85 3.3.3 Straylight â&#x20AC;&#x201C; driver performance simulation study............................................ 85 3.4 References ................................................................................................................ 91 3.5 Appendix A: References belonging to section 3.3.1 ................................................ 92

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General introduction and summary Written by T.J.T.P. van den Berg E-mail: T.J.vandenBerg@ioi.knaw.nl The present report is the result of work over the years 2003 and 2004 performed for the European Community in the field of transport safety. In response to the “call for proposals with a view to obtaining grants in the field of transport” (2001/C 202/12) published 18 July 2001, especially paragraph 3.4 on safety of Inland Transport, a consortium named GLARE was formed at the end of 2002 to study questions related to driving safety, more in particular to the danger of glare. Participants were ophthalmological university clinics in Amsterdam, Barcelona, Salzburg and Tübingen, as well as a research lab in Amsterdam. Later, the clinic in Antwerp joined the group. A grant was obtained from the Directorate-General for Energy and Transport of the European Community. For safe driving, eyesight is beyond doubt a major issue, and we propose to improve upon eyesight testing and upon awareness of eyesight problems. Point 6 of annex III of directive 91/439/EEG, gives minimum demands for the visual capacity of applicants for driver licensing. These demands should be based on proper knowledge of their relation to driver safety. Their definition and way of measurement should be unambiguous. Moreover, several visual functions are not included, notably disability glare.

It was the intention of the present investigation to further our knowledge with respect to these questions. The efforts of several groups are combined in a European-broad project. One methodological group and 5 ophthalmological groups all over Europe joined forces to assess the potential of glare testing and the prevalence of visual deficits among European drivers in order to gather data needed for European decision making upon driver licensing.

Although this report reflects the joined efforts of many individuals, most of the actual writing was in the hands of: Gerard de Wit (compilation, intro’s and summaries of chapters 2&3, sections 2.4, 3.2 and 3.3.2), René van Rijn (chapter 1), Luuk Franssen (sections 2.2, 2.6 and 3.5), Joris Coppens (section 2.3) and Tom van den Berg (sections 2.7, 3.2, 3.3.1 and 3.3.3).

Relations between impaired vision and increased rates of traffic accidents and violations have been found on many occasions (for a review, see van Rijn and Völker-Dieben, 1999). It is therefore not surprising that demands are being placed upon the visual functions of drivers (Council directive 91/439/EEC). Impairments of visual functions are mainly problems of the elderly driver. Many studies have shown that visual functions decline with age. This holds for visual acuity, but also for visual field and other modalities of visual function, such as glare sensitivity and visual attention. For this reason, testing of the visual functions is of particular relevance in elderly drivers. In the years 2001-2002 several members of the present group joined in a combined project to study the technologies available for visual function testing.

Important conclusions were that (1) retinal straylight offers added value to the tests that already exist and that a practical instrument is needed to assess retinal straylight in the large population (2) for decision making on what tests to include in driver licensing regulation, and at what cut off level, Europe wide prevalence values are needed.

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Relevance of glare sensitivity and impairment of visual function among European drivers

The subsequent GLARE project aimed to give a better hold on the danger of glare in driving.

Although the general belief is that glare is a serious thread for driving safety, it has escaped up till now proper evaluation. The reason is that no reliable method was available to determine glare sensitivity in (candidate) drivers. The project started by designing a suitable instrument to measure glare sensitivity (i.e. retinal straylight) for driver licensing application, working from the experience of the earlier collaborative project during the years 2001-2002. At the same time a measurement protocol was set up to determine the percentages of visual impairments among European drivers (the prevalence part of the study). The old visual functions (visual acuity and visual field) as well as new ones (in particular retinal straylight, but also contrast sensitivity, and â&#x20AC;&#x153;Useful Field Of Viewâ&#x20AC;?) were included. Also basic studies to elucidate the relationship between retinal straylight and actual visual handicap during driving took place.

CHAPTER 1. PREVALENCE OF VISUAL FUNCTION IMPAIRMENT. In this chapter the results are presented from the prevalence part of the study. Insight in the prevalence of vision impairments in the driving population is important, both for evaluating the effectiveness of the current regulations on visual functions of drivers and for estimating the impact of possible new regulations. We investigated 2422 drivers in 5 different countries Netherlands, Spain, Germany, Austria and Belgium in the following age categories: 45-54 years, 55-64 years, 65-74 years and 75- years of age and older. In addition, there was a smaller group with ages between 20 and 30 years, to serve as a reference group. Many visual functions were tested, in particular retinal straylight using a method designed in this same project (Chapter 2). In addition, subjects were asked to fill in two questionnaires. One questionnaire was about driving habits, driving difficulties and self reported accidents. The other questionnaire was the NEI-VFQ25 into vision related quality of life. All subjects underwent an ophthalmological examination, comprising the evaluation of current and past ocular diseases and abnormalities.

Prevalence of impairments of visual functions was found to be low in the younger age groups, and raises to relevant percentages in the higher age groups. This counts for all modalities of visual function, but especially for those functions that are not included in the current regulations, such as straylight and Useful Field of View. The percentage of subjects with inadequate correction of their refractive error is rather high and about equal in all age groups.

Quite a number of subjects do not meet the current European standards on visual acuity and visual field, particularly in the highest age groups. The requirements on visual acuity could be met in the majority of cases if refractive errors were adequately corrected. In all age groups, acuity can be improved in a significant number of subjects by optimization of correction of refractive errors, although in the younger groups, the majority of subjects, even with their (sub-optimal) habitual driving correction, still meet the current standards.

Our findings regarding the higher prevalence of impairments of contrast sensitivity and stray light in the elderly groups are in concordance with the larger number of eye diseases and abnormalities that are found in these age groups. Past research has demonstrated the importance of adequate contrast sensitivity for driving safety. This suggests, in combination with our results, that contrast sensitivity could have a more important role in the assessment of drivers than in the current regulations. For such role, a better establishment of cut-off values would be necessary. Past research into the role of stray light in traffic safety has been hampered by the lack of an adequate measurement method. Our results demonstrate that stray 9

Relevance of glare sensitivity and impairment of visual function among European drivers

light sensitivity can be adequately measured in the majority of subjects in a population study, facilitating future research into its relevance.

CHAPTER 2. STRAYLIGHT MEASUREMENT TECHNIQUE. Glare sensitivity is considered an important parameter for traffic safety. Studies by Von Hebenstreit and Lachenmayr show a relatively strong relationship between glare sensitivity and road traffic accidents. Basically what happens in a glare situation is that light from the glare source (e.g. headlights) does not only follow geometric optical rules to form an image of the glare source on the retina, but also some of the light is scattered in the eye creating a veil of light on top of the image of the rest of the visual field. This light is called retinal straylight.

So a technique is needed to determine an individual’s retinal straylight level. In fact, in the earlier study (van Rijn et al. 2005) several conventional glare tests and straylight meters were evaluated for their ability to discriminate clinically evaluated cataract from non-cataract patients. This study showed that a straylight meter is better in several aspects such as discriminative ability than the conventional glare tests.

In the current study the straylight meter was further developed to make it suitable for large scale application such as in the prevalence study of chapter 1 and for driver licensing testing. The new method is called “compensation comparison” method. Central is the application of the so called 2 alternatives forced choice method (2AFC method). This method is well known from psychophysics for its reliability. Reproducibility that was finally achieved during the study is around 0.07 log units for the majority of individuals, and 0.1 log units overall. See figure 2.19. Furthermore, the task has become more intuitive and comfortable for the subject. An important consequence has been that the German firm OCULUS, well established in ophthalmology has chosen this approach to design a straylight meter for the commercial market, called C-Quant.

CHAPTER 3. RELATION STRAYLIGHT – DRIVING SAFETY For straylight testing in driver licensing, ultimately we would like to understand the relationship between a certain straylight outcome and road safety. This relationship involves a very complex set of intermediate steps and separate issues. In the present chapter we set out to contribute on a few points to this understanding. From simple to more complex, and more close to the actual driving situation, the following 3 steps were approached: The simple static blinding situation. Straylight induces sensitivity loss and blinding, depending on the relationship between visual task and glare source. Especially important are the luminance relationships. In this chapter we will review the luminances encountered during night driving and the glare induced blinding (equivalent) luminances. The simple dynamic blinding situation. Driving is a dynamic process. Also blinding is a dynamic process. Glare sources are often encountered suddenly while driving, and for a short period. Blinding is more strong if the blinding source is presented in such a dynamic fashion. Experimentally this increment was determined, and proved to be around a factor of 2. The complex blinding effects during driving. Although ideally steps 1 and 2 could predict what drivers may or may not be able to see, one would like this to be demonstrated in actual road tests. Because of several practical, legal and ethical reasons this might better be studied with simulation. We entered in to a largely FDA funded study using the NADS system in Iowa. The first pilot experiments have been done, but not the real test. We will continue to participate after closure of the present European project, and the data will become available also for Europe.

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Relevance of glare sensitivity and impairment of visual function among European drivers

In this chapter also the search for realistic (early) cataract simulation filters is reported. The importance of such filters is for education/demonstration, to improve public awareness, to show policy makers what driving looks like with increased straylight, etc. We also use these filters to increase straylight in a realistic manner in experimental subjects performing the visual- and driving performance tests.

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Chapter 1

Prevalence of impairments of visual function among European drivers

1

Prevalence of impairments of visual function among European drivers Written by: L.J. van Rijn on behalf of the GLARE study group E-mail: vanRijn@vumc.nl

Summary Insight in the prevalence of vision impairments in the driving population is important, both for evaluating the effectiveness of the current regulations on visual functions of drivers and for estimating the impact of possible new regulations. In past research, attention has been focussed on demonstrating the direct relation between impairments of visual function and driving (in)capacity. The prevalence of impairments has been infrequently addressed. Large studies on this issue date from several years back and were not performed in Europe. In the present research, we aimed at investigating the prevalence of impairments of a number of visual functions in a variety of European countries.

Methods: We investigated 2422 drivers in 5 participating clinics: the Vrije Universiteit medical centre in Amsterdam; the Landesklinik für Augenheilkunde und Optometrie in Salzburg; the Universitäts-Augenklinik in Tübingen; the Centro de Oftalmología Barraquer in Barcelona and the Universitair Ziekenhuis Antwerpen.

Participants belonged to either one of the following age categories: 45-54 years, 5564 years, 65-74 years and 75- years of age and older. In addition, we recruited a smaller group with ages between 20 and 30 years, to serve as a reference group.

Subjects participated in the measurement of a large number of visual functions: visual acuity, both with driving correction and with best correction, visual field, contrast sensitivity, straylight and Useful Field of View. In addition, subjects were asked to fill in two questionnaires. One questionnaire was about driving habits, driving difficulties and self reported accidents. The other questionnaire was the NEIVFQ25 into vision related quality of life. All subjects underwent an ophthalmological examination, comprising the evaluation of current and past ocular diseases and abnormalities.

Results: We found that the prevalence of impairments of visual functions is low in the younger age groups, and raises to relevant percentages in the higher age groups. This counts for all modalities of visual function, but especially for those

13

Relevance of glare sensitivity and impairment of visual function among European drivers

functions that are not included in the current regulations, such as straylight and Useful Field of View. The percentage of subjects with inadequate correction of their refractive error is rather high and about equal in all age groups. This inadequate correction results in a lower than optimal visual acuity. The major results are listed in the next paragraph.

Conclusions: The present study is the largest study into the prevalence of visual impairments that has been performed in Europe so far. The results demonstrate that there are quite a number of subjects that do not meet the current European standards on visual acuity and visual field, particularly in the highest age groups. The requirements on visual acuity could be met in the majority of cases if refractive errors were adequately corrected. In all age groups, acuity can be improved in a significant number of subjects by optimization of correction of refractive errors, although in the younger groups, the majority of subjects, even with their (sub-optimal) habitual driving correction, still meet the current standards.

Our findings regarding the higher prevalence of impairments of contrast sensitivity and straylight in the elderly groups are in concordance with the larger number of eye diseases and abnormalities that are found in these age groups. Past research has demonstrated the importance of adequate contrast sensitivity for driving safety. This suggests, in combination with our results, that contrast sensitivity could have a more important role in the assessment of drivers than in the current regulations. For such role, a better establishment of cut-off values would be necessary. Past research into the role of straylight in traffic safety has been hampered by the lack of an adequate measurement method. Our results demonstrate that straylight sensitivity can be adequately measured in the majority of subjects in a population study, facilitating future research into its relevance.

General conclusions 1. The prevalence of impaired visual acuity (presenting visual acuity less than 0.5 in the best eye) rises from 0.9% in the group from 45-54 years of age to 5.3% in the group, aged 75 years and older. These are subjects that do meet the current European standards on vision (council directive 91/439/EEC, 1991, annex III).

2. In the majority of cases with impaired presenting visual acuity, an acuity of 0.5 or more can be reached after proper correction of the refractive error.

3. The prevalence of visual field defects, such that driving would not be allowed according to the current European standards, rises from 0.5% in the group from 45-54 years of age to 2.7% in the group, aged 75 years and older. These are subjects that do not meet the current European standards on visual field. In an additional 2.4% in the eldest group, the results are questionable.

4. Currently, there are no criteria regarding the (absence) of central visual field defects. If such criterion would be: No more than 2 overlapping relative visual field defects within the central 20 degrees of visual field and no more than 3 overlapping absolute defects within a zone extending 60 degrees left and right and 20 degrees up and down, then all but 3 of the 2076 subjects that are fit according to the current standards would still be classified as fit. 21 of the 36 subjects that are unfit or questionable according to the current standards would still be classified as unfit. This demonstrates that such criterion could be a useful additional but not a sole criterion for the assessment of visual fields. Note that the effectiveness of this criterion depends on the visual field measurement strategy.

5. The prevalence of impaired contrast sensitivity values, defined as values below 1.25, measured with the Pelli-Robson chart, rises from 0.2% in the group from 45-54 years of age to 6.3% in the group, aged 75 years and older.

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Chapter1: Prevalence of impairments of visual function among European drivers

6. The prevalence of impaired straylight measurements, defined as measurement values above 1.4 (three times more than normal) rises from 0.8% in the group, aged 45-54 years to 29.5% in the group, aged 75 years and older. The prevalence of straylight values above 1.8 (8 times more than normal) is 1.7% in the eldest group.

7. In 10.2% of all subjects, a significant and relevant improvement of visual acuity (improvement 2 lines or more on the visual acuity chart) can be achieved by proper adjustment of spectacle correction. This percentage is only slightly higher in older than in younger drivers.

8. The prevalence of impaired results of the Useful Field of View measurements (impairments defined as risk categories “high” and “very high” according to the definitions of the manufacturer), rises from 0.7% in the group, aged 45-54 years to 21.6% in the group, aged 75 years and older.

9. The percentage of subjects with prior cataract surgery rises with age: in the highest age group (75 years and older) 23.7% of subjects had prior cataract surgery in at least one eye. This may explain the fact that the prevalence of impairments of visual functions, as reported in our study, is somewhat lower than that reported in some (older) literature studies.

10. Despite the high percentage of subjects that had prior cataract surgery, the prevalence of (clinically relevant) cataract rises with age to 14% in the highest age group.

11. Restricted driving (self reported, in terms of frequency and distance) is associated with lesser visual functions. In contrast with this finding: higher driving speed (self reported, as compared to fellow drivers) is associated with better visual functions.

12. Vision related quality of life is best correlated to visual acuity, contrast sensitivity and straylight. There is only a weak correlation with Useful Field of View and no significant correlation with visual field.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Development of a computer controlled device for simulation of accommodation ex vivo Michael R., Carretié R., Barraquer R. I. Institut Universitari Barraquer, Barcelona Objective: To design an instrument to measure the mechanical and dynamic optical properties of human donor lenses and refilled lenses during simulated accommodation exvivo.

Methods: Based on previous designs by Fisher, Glasser, Campbell and Parel our device consists of a rigid bench for holding and stretching coronal eye sections including the ciliarylens zone, while allowing front and back axial, as well as oblique observation and measuring.

Circumferential stretching is created by a stepper motor coupled to a digital outside micrometer for linear displacement and distance measurement, and a digital balance for load measuring. This is attached to the specimen through 8 Prolene sutures. One web cam is placed above the crystalline lens to monitor the coronary diameter changes and another web cam will be rebuilt to take low resolution Scheimpflug images to monitor sagittal diameter changes during stretching.

Results: We have desinged a compact, portable lens stretching device with direct measurement of displacement with a precision of 1 µm (one step movement of the stepper motor), and of load with precision of 0.1 mN (0.01g). All operating and measuring parts have data output and are computer controlled through LabView routines with a single program, also integrating image acquisition.

Conclusions: Our device offers precision, integrated control and measurement, and portability for lens accommodation studies.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Safety estimation for optical radiation from an operation microscope with and without protective filters Michael R.1, Wegener A.2, Barraquer R. I.1 1 Institut Universitari Barraquer, Barcelona; 2Department of Ophthalmology, Rheinische Friedrich-Wilhelms-University, Bonn Objective: To investigate the hazards from the optical radiation by an operating microscope to cause damage at the corneal, lenticular and retinal level, considering in particular ultraviolet radiation (UVR) and blue light.

Methods: The spectral irradiance from a Zeiss Operation Microscope OPMI visu 200 was measured in the corneal plane between 300 and 1100 nm. Effective irradiance and radiance were calculated using relative spectral effectiveness data from The American Conference for Governmental and Industrial Hygienists.

Results: Safe exposure time to avoid UVR injury to lens and cornea was found to be 2 h without filter, 4 h with UVR filter, 200 h with yellow filter and 400 h with filter combination.

Safe exposure time to avoid retinal photochemical injury was found to be 3 min without filter and with UVR filter, 10 min with yellow filter and 49 min with filter combination. The effective radiance limit for retinal thermal injury was not exceeded.

Conclusions: Hazard due to the UVR component from the operating microscope is not critical and operation time can be safely prolonged with the use of appropriate filters. Retinal photochemical hazard appears critical without appropriate filters, permitting only some minutes of safe exposure time. The calculated safe exposure times are for worst case conditions, maximal light output and include a safety factor.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

The prevalence of impairments of visual function amongst European drivers van Rijn L. J.1, van den Berg T. J. T. P.2, Grabner G.3, Wilhelm H.4, Michael R.5, Coeckelbergh T.6 1 VUMC Amsterdam, 2IOI Amsterdam, 3Landesklinik f. Augenheilkunde u. Optometrie Salzburg, 4Univ.Augenklinik Tübingen, 5 Inst Barraquer Barcelona, 6UZA Antwerpen Insight in the prevalence of vision impairments in the driving population is important, both for evaluating the effectiveness of the current regulations on visual functions of drivers and for estimating the impact of possible new regulations. In past research, attention has been focused on demonstrating the direct relation between impairments of visual function and driving (in)capacity.

Methods: We investigated 2422 drivers in 5 European countries, belonging to one of the age categories: 45-54 years, 55-64 years, 65-74 years and 75- years of age and older. A group between 20 and 30 years served as a reference group. Measurements involved several visual functions (acuity, visual field, contrast sensitivity, stray light and UOFV), questionnaires into driving habits and quality of life (NEI-VFQ25) and a structural eye examination.

Results: The prevalence of impairments of visual functions is low in the younger age groups, and raises to relevant percentages in the higher age groups. This counts especially for stray light, contrast sensitivity and Useful Field of View. The percentage of subjects with inadequate correction of their refractive error is rather high and about equal in all age groups.

Conclusions: The results demonstrate that there are quite a number of subjects that do not meet the current European standards on visual acuity and visual field, particularly in the highest age groups. The requirements on visual acuity could be met in the majority of cases if refractive errors were adequately corrected. In all age groups, acuity can be improved in a significant number of subjects by optimization of correction of refractive errors, although in the younger groups, the majority of subjects, even with their (sub-optimal) habitual driving correction, still meet the current standards.

Our findings suggest that contrast sensitivity could have a more important role in the assessment of drivers than in the current regulations. For such role, a better establishment of cut-off values would be necessary. Past research into the role of stray light in traffic safety has been hampered by the lack of an adequate measurement method. Our results demonstrate that stray light sensitivity can be adequately measured in the majority of subjects in a population study, facilitating future research into its relevance.

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Comparison of intraocular stray light measurements with conventional cataract grading and contrast sensitivity estimation in elderly European drivers Ralph Michael, Rafael I. Barraquer Institut Universitari Barraquer Martin Emesz, Christian Nischler, Christine Hufnagl, Günther Grabner Landesklinik für Augenheilkunde und Optometrie Joris Coppens, Tom van den Berg Netherlands Ophthalmic Research Institute Tanja Coeckelbergh Universitair Ziekenhuis Antwerpen Helmut Wilhelm Universitäts-Augenklinik Tübingen René van Rijn Vrije Universiteit Medical Center PURPOSE: To study the relation between objective stray light measurement with conventional visual function tests.

METHODS: We investigated 2422 random selected elderly drivers in 5 clinics in different EU member states aging between 45 to 85 years and a control group (20 to 30 years). Subjects with prior cataract surgery were excluded (5.7%). Stray light was measured psychophysically applying flicker stray light in a central test field which had to be compensated by another light using a two alternative forced choice strategy. Cataract was graded with the LOCS III without pupillary dilation and contrast sensitivity was measured with a Pelli-Robson chart. Subjects answered the NEI questionnaire VFQ-25 and driving habit questions.

55

Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació RESULTS: Stray light values increase from 0.95 (lowest LOCS) to 1.50 (highest LOCS) and decrease from 1.40 (Pelli-Robson <1.20) to 1.00 (P-R >1.80). Both relationships are significant and the dependencies have a linear shape. However, drivers reporting night driving difficulties have equal stray light values as drivers without difficulties.

CONCLUSIONS: Objective stray light measurement is well correlated with conventional cataract grading and contrast sensitivity estimation. Individual elevated stray light values are not consistently perceived by the drivers.

EU project: SUB-B27020B-E3-GLARE-2002-S07.18091

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Càtedra de Recerca en Oftalmologia "Joaquim Barraquer" Departament d'Investigació

Osteo-odonto Keratoprosthesis: A 40-Year Review Ralph Michael, Rossukon Sripattanawat, Alejandro Alvarez, Jose Temprano, María Fideliz de la Paz, Victor Charoenrook, Juan Alvarez de Toledo, Rafael I Barraquer Centro de Oftalmologia Barraquer, Barcelona PURPOSE: To study short and long term functional results after Osteo-odonto Keratoprosthesis (OOKP).

METHODS: We reviewed the charts of 287 patients who underwent osteo-odonto keratoprosthesis at the Barraquer Centre of Ophthalmology from January 1964 to May 2005. A total of 337 cases, 100 of which were bilateral were reviewed; 219 were male and 116 were female. All surgeries were done by a single surgeon using Strampelli´s technique with a variation using tibia (Temprano's technique) if patient was edentulous. Functional success was defined as visual acuity > 0.05 (legal blindness as defined by the WHO). Survival rates were calculated using life tables and the Kaplan-Meier estimator.

RESULTS: Mean follow-up time was 74 months (range: 1-585 months). Mean age of patients was 42 years (range: 4 – 86 years). Prior to intervention all patients were legally blind (VA < 0.05) and at final follow-up 153 patients had visual acuity better than 0.05. Overall survival rate was 86% at 1 month, 71% at 1 year, 50% in 5 years, 38% in 10 years and 18% in 25 years. Complications encountered were cataract (61%), vitritis (36%), expulsion (35%), glaucoma (19%), aseptic necrosis (19% cases), retinal detachment (16%). Survival rates for chemical burn (135 cases), Stevens-Johnson Syndrome (39 cases), Ocular cicatricial pemphigoid (16 cases) and other aetiologies are presented.

CONCLUSION: A 50% functional success rate after 5 years is quite satisfactory for these end-stage ocular-surface diseases.

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