90) Efficasy of mydriatic cocktailsoaked sponge pupil dilation in patients using tamsulosin due to benign prostatic hypertrophy Forfattere: János Hargitai, Laszló Vezendi, Jørgen Vigstrup, Finn Eisgart, Bálint Hargitai, Henrik Vorum Abstract: Purpose: To investigate the effect of a mydriatic-cocktail soaked cellulose sponge on perioperative pupil diameter in tamsulosin-treated patients undergoing elective cataract surgery. Methods: 30 eyes of 30 patients using tamsulosin were dilated using mydriatic-cocktail soaked sponge (group 1) along with 28 eyes of 28 tamsulosin-treated patients using conventional eyedrop regiment (group 2). 31 eyes of 31 aged mathced control patients not using any α1 adrenergic receptor inhibtors were also dilated using mydriatic sponge (group 3). In all groups oxybuprocain, cocain, tropicamide, phenylephrine, diclophenac and chloramphenicol drops were used preoperatively. In the two sponge groups a 4mmx5mm piece of soaked wick was inserted in the lower fornix for 30 minutes. In the conventional group we applied the above drops 3 times with 10 minutes intervals. Pupil diameter was measured preoperatively, after nucleus delivery, and before IOL implantation using caliper. Adverse effects associated with the use of sponge were recorded. Results: Preoperative mean pupil diameter in group 1 was 7,52±1,21 compared 7,30±1,55 in group 2 and 7,99±0,96 in group 3. There was no statistically significant difference preoperatively between the three groups. After nucleus delivery pupil mean pupil diameters were: group 1: 6±1,20; group 2: 6,29±1,12 and group 3: 6,52±0,81. Before IOL implantation mean pupil diameters were as follows: group 1: 5,46±1,06; group 2: 5,83±1,088 and group 3: 6,17±0,89. No adverse effect related to sponge use was detected. Conclusion: The use of mydraitic cocktail-soaked sponge is an effective and timesaving way to achieve perioperative mydriasis even in high risk patients using tamsulosin. Indsendt af: Overlæge Janos Hargitai, (Øjenafdeling/Thy-Mors Sygehus, Aalborg Sygehus) Uddannelse: læge E-mail: janos.hargitai@rn.dk / Telefon: 2335 3854 Forskningsansvarlig på afdelingen: Henrik Vorum
91) Oxygen is a key regulator of limbal epithelial stem cell growth and differentiation Forfattere: Chris Bath (1, 2), Sufang Yang (2), Danson Muttuvelu (1), Jeppe Emmersen (2), Henrik Vorum (1), Jesper Hjortdal (3) & Vladimir Zachar (2) Department of Ophthalmology, Aalborg University Hospital (1), Laboratory for Stem Cell Research, Aalborg University (2), Department of Ophthalmology, Aarhus University Hospital (3) Abstract: Purpose: Transplantation of ex vivo expanded limbal epithelial stem cells (LESCs) is emerging as a new treatment of choice for diseases with associated limbal epithelial stem cell deficiency. It is expected, that O2 (oxygen) concentrations vary from below 5% in the stem cell niche to 17% below the tear film. We hypothesized that exposure to a gradient of O2 concentrations during expansion of limbal epithelial cells (LECs) could selectively promote different epithelial cell phenotypes. Methods: Human LECs were expanded in parallel on either γ-irradiated 3T3 cells using serum-rich medium, or on plastic using serum-free EpiLife medium. Growth and phenotype of cells were examined in O2 concentrations of 2%, 5%, 10%, 15%, and 21%. Results: A bimodal growth pattern was observed with slow growth in 2-5% O2 and in 15% O2. cLECs expanded in 2-5% O2 exhibited a significant decrease of cells in replicative phase with increasing time in culture. ABCG2 (stem cell marker) and CK3 (differentiation marker) were inversely related across O2 concentrations with high ABCG2 and low CK3 expression in hypoxia. Highest level of clonogenicity was observed in hypoxic oxygen concentrations. Conclusions: Human LESCs and their progeny are selectively expanded in different physiologically relevant oxygen concentrations irrespective of the culture system employed. cLESCs are supported in 2-5% O2, transient accelerating cells in 10% O2, and terminal differentiated cells in 15% O2. The specific O2 concentrations used are very similar to layer-specific concentrations measured in vivo. Preparing grafts in a controlled hypoxic environment could enhance future outcome of transplantation. Indsendt af: Klinisk assistent Chris Bath Søndergaard, (Øjenafdelingen, Aalborg Sygehus) Uddannelse: Læge E-mail: c.bath@me.com / Telefon: 5154 3110 Forskningsansvarlig på afdelingen: Professor Henrik Vorum 63