Trabulectomyerview Trabulectomy overview © Michelle Baker This overview provides general information related to trabeculectomy to Trabulectomysurgery and does and doestake not not into takeaccount into account your your personal personal circumstances circumstances
Diagram showing flow of aqueous humour through a trabeculectomy
TRABULECTOMY TRABULECTOMY SURGERY INFORMATION TRABULECTOMY SURGERY INFORMATION SHEET
Trabeculectomy
TABLE OF CONTENTS What Is Glaucoma? 3 Eye Appearance After Trabeculectomy Surgery 3 When Is Trabeculectomy Surgery Indicated? 3 Pre-operative Assessment 4 The Surgery Itself 4 Anaesthetic 5 Anti-metabolite Drugs 5 After Surgery: Post-operative Care 6 Immediately After Your Surgery 6 Day 1 After Your Surgery 6 Eye Drops 7 Post-operative Clinic Visits 7 Activities After Surgery 8 When Can I Go Back To Work 10 What Are Success Rates? 10 Are There Any Risks Or Complications? 11 Longer Term Complications 12 Remember 13 Where Can I Get Further Information On Trabeculectomy Surgery? 13 Glossary 13
2
Trabeculectomy
Where can I get more information on Trabeculectomy surgery? 1. From your ophthalmologist (eye specialist) - Ask me! 2. Glaucoma Australia 3. Glaucoma UK 4. American Academy of Ophthalmology
WHAT IS GLAUCOMA?
Glaucoma is the name given to a group of eye disease processes which damage the optic nerve and can lead to vision loss and blindness. Glaucoma typically, but not always, produces elevated pressure inside the eyeball, termed raised intraocular pressure which can damage the optic nerve. If glaucoma is detected early, treatment to reduce the intraocular pressure can prevent or reduce vision loss in most patients.
EYE APPEARANCE AFTER TRABECULECTOMY SURGERY
Initially after surgery, your eyelid can slightly droop and your eye will be red and swollen, to a variable degree. This normally resolves over a period of weeks to months. The surgery is not usually visible to the naked eye after trabeculectomy surgery but the drainage bleb may be seen, if you look downwards in the mirror, and you raise your upper eyelid at the same time. Most patients feel no sensation from the presence of the surgery.
WHEN IS TRABECULECTOMY SURGERY INDICATED?
Trabeculectomy (trab-ec-u-lec-tomy) surgery is indicated for patients whose glaucoma continues to progress despite using glaucoma eye drops and/or having had laser treatment, or if you are intolerant of glaucoma eye drops or laser. The aim of trabeculectomy surgery is to help lower the intraocular pressure by draining aqueous humour (natural fluid inside the eye), in a controlled way, through a newly created alternative drainage channel and bypassing the impaired natural drain (trabecular meshwork) of your eye. Your intraocular pressure is reduced because the aqueous humour can drain more easily through the newly created drainage channel. This reduces the intraocular pressure on the optic nerve and prevents or slows further damage and further loss of vision from glaucoma. This operation will not improve your vision or cure glaucoma, but aims to prevent or slow down further vision loss from glaucoma damage.
3
Trabeculectomy
PRE - OPERATIVE ASSESSMENT
A pre-operative assessment of your general health will be carried out prior to your surgery. For this assessment please have available an up to date list of your current medications, including blood thinners, and a brief summary of your medical history, available from your GP, if you are unsure. Your general health and suitability for anaesthetic will be assessed. Underlying medical conditions including cardiac disease, uncontrolled high blood pressure or diabetes will need to be addressed, prior to scheduling of your surgery. You should continue any eye drops and tablets for your glaucoma, as prescribed, until the time of your surgery. Blood thinning medications such as aspirin and clopidogrel should also be continued, unless directed otherwise. If you take Warfarin this may need adjusting before your operation to ensure it is within the correct therapeutic range. You will receive instructions about fasting prior to your surgery.
THE SURGERY ITSELF
Trabeculectomy surgery typically lasts around one hour. A tiny opening is made in the white of the eye (sclera) which is covered by a thin layer of the sclera called a flap (Figure 1). This opening allows the aqueous humour to drain through into a reservoir called a bleb (Figure 2). The aqueous humour is then absorbed by the body. View video of trabeculectomy surgery here.
4
Trabeculectomy
ANAESTHETIC
Trabeculectomy surgery can be carried out under either local anaesthetic or a general anaesthetic. These choices will be discussed with you prior to your admission to hospital. Patients who have their surgery under local anaesthetic are awake during the surgery but will have the option of light sedation.
ANTI - METABOLITE DRUGS
The main reason for failure after trabeculectomy surgery is the newly created drainage site can scar. It is a natural for the body to want to heal. Anti-metabolite drugs prevent scar tissue forming, and this enhances the success rate of a trabeculectomy. The most commonly used anti-metabolite drugs with trabeculectomy surgery are Mitomycin C (MMC) and 5 Fluorouracil (5-FU). These can be used at the time of surgery or after surgery. Usually MMC is applied on the scleral surface over the area to be treated during surgery. The use of MMC in glaucoma surgery is ‘off licence’ which means that the manufacturers have never applied for this use to be registered. Over many years MMC has been shown to be safe and effective in trabeculectomy surgery. 5-FU is usually given as an injection around the bleb in the outpatient clinic, if required, to prevent scar formation in the post-operative visits. Bevacizumab (Avastin) is another drug which is widely used in treating eye conditions and sometimes this drug is injected into the eye at the time of surgery to prevent scar formation, in addition to MMC.
5
Trabeculectomy
AFTER SURGERY: POST OPERATIVE CARE IMMEDIATELY AFTER YOUR SURGERY
Following your eye surgery, your eye will be covered by an eye pad and a protective clear plastic shield. If the unoperated eye does not see well, then only the clear shield will be placed on the operated eye, then it is still possible to see after surgery, once the anaesthetic has worn off. Patients are usually discharged home from hospital on the same day as the surgery. Eye drops are not usually required in your operated eye until the day after surgery. Rest with both eyes closed as much as possible in the days following your trabeculectomy surgery so the wounds rapidly heal. You might wish to take pain relieving medication, e.g. paracetamol, to relieve any discomfort. If you are already taking pain relief for a different condition continue with those, but do not take both.
DAY 1 AFTER YOUR SURGERY
Your eye will be examined one day after surgery. At that appointment the eye pad and protective shield will be removed and your eye will be cleaned and examined. Initially your eye is likely to be red and swollen after surgery. It is normal for the vision to be blurred and for the eye to be uncomfortable after surgery. The period of blurring is variable but the vision may be particularly blurred for one to two weeks following the surgery, and then should then start to improve. You will be asked to wear the shield at night for the first two weeks, or so. This is to prevent any accidental harm to the operative site whilst sleeping. Soreness in the eye after trabeculectomy surgery is partly due to the surgery itself, and partly due to the stitches. Some of the stitches dissolve and others are usually removed in the clinic a few weeks after surgery (this takes a couple of minutes
6
Trabeculectomy
with the eye numbed using eye drops). The eye usually starts to feel more comfortable after the stitches have been removed.
EYE DROPS
New eye drops will be prescribed to be used regularly for approximately three months from the day after your surgery, after the post-operative examination. Previous glaucoma drops to the operated eye or Acetazolamide (Diamox) tablets should be ceased. It is important any glaucoma drops to the unoperated eye are continued, including on the day of your surgery, unless advised otherwise. The post-surgery eye drops consist of an antibiotic drop (e.g. Chloramphenicol) and a steroid anti-inflammatory drop (e.g. Prednefrin Forte). The antibiotic drop needs to be instilled four times per day and the steroid eye drop will initially be used intensively, every 2 hours or about 8 times per day, during the day only. These drops need to be instilled when lying down flat on your back, on one pillow to improve drop retention. The Chloramphenicol needs to be instilled first, followed by the Prednefrin Forte 5 to 10 minutes later, to prevent drop dilution. Prednefrin Forte is in a suspension and the bottle needs to be shaken first. You may notice white particles on your eyelashes, or in the corner of your eye, which are the particles from the Prednefrin Forte drop which allows the drop to continue working. You will be initially be given a prescription for a supply of the post-operative drops which lasts about one month. At each post-surgery visit you will be advised whether a change of dosage or drop is required. If you are running out of drops you must obtain a repeat prescription, usually from the clinic.
POST - OPERATIVE CLINIC VISITS
You will be reviewed at least weekly for the first four weeks but may be seen more frequently, if the intraocular pressure is either too high or too low. Your intraocular pressure can vary in the first few weeks after surgery. Success with trabeculectomy surgery depends on the aftercare just as much as the operation itself. There are many
7
Trabeculectomy
adjustments which may need to be made during your clinic visits, depending on the rate and extent of your conjunctival healing process, to maximise the success of your surgery. This may include changes to eye drop medications, adjustments to, or removal of stitches and possibly anti-scarring injections such as 5-FU or steroids. It is sometimes necessary to massage the bleb or carry out a procedure called a bleb needling, if it appears that the wound is healing too much. A bleb needling is considered to be a safe and effective way of re-opening the drainage site. For these reasons it is critical to the success of your surgery for you attend all your clinic appointments and use your eye drops, as prescribed.
WHEN WILL MY EYE FEEL BACK TO NORMAL?
In most cases, it takes 2 to 3 months for the eye to feel back to normal, and sometimes longer in more complicated cases.
ACTIVITIES AFTER SURGERY
Following trabeculectomy surgery it is important to rest your eyes for the first couple of days with both eyes mostly closed so the wounds rapidly heal. Then you are able to read and watch television, as normal, as these activities will not harm your eye. It is however, important to avoid strenuous/ water-based activities during the early post-operative period including swimming, jogging, gardening and contact sports. Avoid heavy lifting or bending, including activities such as yoga that require head-down posturing. As a general rule, keep your head above the level of your heart until I advise you it is safe to resume normal activities. It is most important that you do not bump, rub or press on your eye after surgery. Avoid coughing and sneezing, if possible. It is recommended you consult with me before commencing any strenuous activity. The following table is a general guide but is altered depending upon how each individual’s eye recovers. If in doubt, please ask.
8
Trabeculectomy
ACTIVITY
ADVICE
Hair washing
No need to avoid but back wash advised to avoid getting shampoo and water into your eye. It may be easier to have someone else wash your hair for you.
Showering and bathing
No need to avoid but don’t allow soapy or dirty water to go into your eye.
Sleeping
Try to sleep on your un-operated side. Tape the clear plastic eye shield provided over your eye every night for 2 weeks to avoid accidentally rubbing your eye whilst asleep.
Walking
No restrictions.
Wearing spectacles
No restrictions. Avoid buying new spectacles until 3 months after surgery, as your spectacle prescription can change during this time, as your eye heals.
Wearing sunglasses
Wear for comfort if your eye feels sensitive to light and wear sunglasses in bright sunlight with UV protection.
Wearing contact lenses
Cannot be worn due to the bleb.
Driving
This is dependent on your vision in both eyes and you will be advised by me during your post op follow up in clinic
Flying
No restrictions but bear in mind your frequent post-operative visits to ensure that the trabeculectomy is functioning properly and that the intraocular pressure is at the correct level.
Going away on holiday
Discuss with me first as it is critical to your trabeculetomy success, to attend your follow up appointments. In the 3 month post-operative period I prefer you to be in close proximity, so if problems arise, I can review you properly.
Wearing eye make up
Avoid for 1 month, then use new make-up. Never share eye make-up with someone else.
Household chores e.g. cleaning, ironing, vacuum cleaning
Avoid for 1 – 2 weeks but this depends upon your intraocular pressure.
Sexual activity
Avoid for 1 -2 weeks.
Gym workout
Avoid for 3 months.
Playing sports e.g. football, tennis, golf
Avoid for 3 months.
Running / jogging
Avoid for 3 months.
Swimming
Avoid until all your stitches have been removed, and for approximately 3 months, (check with me first) then after that wear goggles with a horizontal internal diameter of at least 52mm.
9
Trabeculectomy
WHEN CAN I GO BACK TO WORK?
The length of time you will need off work depends upon a number of factors. These include the nature of your job, your vision and the intraocular pressure in your operated eye. Typically, most people require two weeks off work after surgery, if their postoperative course is smooth. If your occupation involves heavy manual work or you work in a dusty/dirty environment (e.g. builder or farmer) you may require longer off work. This can be discussed at any clinic visit. You may need to make your employer aware of your need to attend for frequent follow up appointments after surgery.
WHAT ARE THE SUCCESS RATES?
Long-term studies suggest most people will achieve a low intraocular pressure without the need for additional glaucoma medication after trabeculectomy surgery.(1) In clinical trials trabeculectomy surgery has proven to be more successful at achieving a consistent low intraocular pressure than medication, laser or minimally invasive glaucoma surgery (MIGS). The success rate of trabeculectomy is dependent upon many things. Factors which can reduce the success of trabeculectomy surgery are: • • • • •
Younger age Ethnic group Uveitis (inflammation within the eye) Previous severe eye injury Rubeotic glaucoma where there are abnormal blood vessels on the iris • Natural healing processes which cause scarring • Diabetes • Previous use of some eye drops, including multiple use of eye drops, particularly containing preservative
10
Trabeculectomy
In one study(1) on the success rate of trabeculectomy surgery based upon a patients’ intraocular pressure being less than 21 mmHg a year after surgery, after 20 years, almost 90 per cent were still successful. Just under two thirds of these required no glaucoma medication to control the intraocular pressure.
ARE THERE ANY RISKS OR COMPLICATIONS?
As with any surgery, problems can arise and there is the potential for complications. Complications can occur during surgery, shortly after surgery, or many months to years following surgery. Severe complications are uncommon. The following complications are listed to inform you and not alarm you. There are other complications which are not listed. Although most complications resolve following additional management, and with time, some complications can affect vision, sometimes permanently. • Intraocular Pressure: After the operation the intraocular pressure can be too high or too low. This may require additional treatment in the outpatient clinic or sometimes further surgery is required. Very low intraocular pressure is the biggest risk in the early post-operative period. Although it is often painless, it may be associated with a dull aching feeling or a throbbing sensation within the operated eye. About 5 per cent of trabeculectomy patients will require a return to the operating theatre in the first month after surgery, for adjustment, either because the intraocular pressure is too high or too low. • Bleeding/Infection: The risk of serious bleeding or infection in the eye is rare (approximately one in 250). This can cause a loss of vision or even blindness. Very low pressure or a precipitous drop in eye pressure can result in bleeding in the back of the eye (choroidal haemorrhage). • Inflammation: Inflammation inside the operated eye can occur and can be treated with eye drops. Rarely, inflammation of the unoperated eye which is called sympathetic ophthalmia, can occur and be associated with
11
Trabeculectomy
total or partial loss of vision, in the unoperated eye. • Ptosis: There can be a slight drooping of the eyelid (ptosis), which usually settles down.
LONGER TERM COMPLICATIONS
The longer-term complications of trabeculectomy surgery include ongoing risk of infection, discomfort, cataract and a change in glasses prescription. • Hypotony: Low intraocular pressure occasionally develops in the longer term, but generally the risk of low pressure is highest in the early post-operative period, rather than later. • Infection: Whilst risk of infection after surgery is rare, there is a small on-going life-time risk that the drainage bleb may become infected. After trabeculectomy surgery, if you develop a red, sticky or painful eye, it is important to have your eye examined immediately by an ophthalmologist, as this may be a sign of infection. The earlier an infection is treated, the better the outcome for the eye. • Discomfort: Some patient’s are aware of the elevated drainage bleb under their eyelid. Sometimes the drainage bleb may become large and affect the tear film on the eye surface, which can create a feeling of discomfort or dryness of the eye. This occurs in about 10 per cent of patients and is usually treatable with lubricants. Occasionally, the discomfort is more severe and requires surgery to make the drainage bleb smaller. • Cataract: In patients who have not had cataract surgery, there is a risk that trabeculectomy surgery can cause a cataract to develop earlier. Raised intraocular pressure and glaucoma medications have also been shown in research to cause cataract. • Astigmatism/change in glasses prescription: Most patients will require a small change in their spectacles after trabeculectomy surgery to obtain their best vision. Patients should refrain from changing their spectacles until at least 3 months after surgery, and only once the intraocular pressure has stabilised. It is advisable to check with me before changing your spectacles. Sometimes, a patient who does not require spectacles before surgery, develops a need for them after surgery.
12
Trabeculectomy
REMEMBER
The information in this leaflet is intended as a guide only, as each patient’s experience will be different. Do not wait until your next appointment, but contact me immediately, if you have: • • • • •
Redness Vision disturbance such as double vision Fluctuating or loss of vision Increasing Pain Concerned
WHERE CAN I GET FURTHER INFORMATION ON TRABECULECTOMY SURGERY? 1. From your ophthalmologist (eye specialist) - Ask me! 2. Glaucoma Australia 3. Glaucoma UK 4. American Academy of Ophthalmology
GLOSSARY • Glaucoma the name given to a group of eye disease processes which damages the optic nerve and can lead to vision loss and blindness. • Intraocular pressure is the pressure inside your eyeball. • Trabecular meshwork is the natural drain of your eye where the aqueous humour flows through to leave the eye. • Aqueous humour is the natural fluid produced by the eye. • Sclera is the protective outer white layer of the eye under the conjunctiva. • Conjunctiva is the vascular tissue which covers the sclera and lines the inside of the eyelids. • Trabeculectomy surgery will create an alternative drainage channel to help aqueous fluid drain from your eye and lower your intraocular pressure. • Scleral flap or the “flap” is the thin trap door in the sclera where the aqueous humour drains through. • Drainage bleb or the “bleb” is a reservoir of aqueous humour under the upper eyelid which can be manipulated after trabeculectomy surgery to obtain your target intraocular pressure. 1. Landers J, Martin K, Sarkies N Bourne R, Watson P. A Twenty-year follow-up study of trabeculectomy: risk factors and outcomes. Ophthalmology 2012 Apr; 119(4): 694-702.
13