About Glaucoma Surgery
Once glaucoma is diagnosed, the primary treatment is to reduce the eye pressure, to halt the optic nerve damage.
There are other factors, like blood supply to the optic nerve, inherent( genetic) tendency towards optic nerve weakness, which cannot be altered or treated. These factors unfortunately, also play a role in Glaucoma.
However, world over, the accepted way to manage this problem, is by reducing the Intraocular pressure, the only modifiable risk factor, in this disease.
The extent to which the pressure needs to be reduced varies from person to person, and depends on the highest eye pressure pretreatment, and the extent of the damage already present in the optic nerve, and the estimated lifespan of the patient. The modalities of eye pressure reduction can vary from medical- eye drops and tablets, Laser, and surgical treatments.
Whatever the modality a doctor chooses in a patient, continued monitoring of the eye pressure, optic nerve, and visual fields is mandatory. None of the treatment modalities, either eye drops., Laser, or surgery, offer a completely permanent solution. The effects of treatment vary with time, and continued follow up remains absolutely necessary for the effective management of this problem. There is no one- shot treatment for glaucoma.
Microsurgery for glaucoma can be penetrating or nonpenetrating filtering type of surgery. Surgery is done in the operation theatre under local anesthesia.
In this filtering microsurgery, a tiny drainage hole is made in the sclera, which allows the fluid to flow out of the eye, and helps to lower the eye pressure. Anti wound healing drugs such as Mitomycin-c or 5- fluorouracil are used during surgery to slow the healing of the opening.70 to 90% of operated patients can stop all their glaucoma medications and have controlled eye pressure following the surgery. Occasionally the surgically created drainage hole begins to heal, over time and close which causes the pressure to rise again. In such situations your doctor may advise re starting of eye drops to reduce the eye pressure.
Your doctor might need to see you very frequently in the immediate post operative period. This is when a tendency for the opening to close down can be detected early and managed with appropriate injections, or medical treatment. You may also beinstructed to massage the eye following the glaucoma surgery.
Your doctor will inform you about the technique, and how to perform this finger massage to the eye. You will be required to use the post operative eye drops for a period of 6 weeks following the surgery.
Glaucoma medications, which were being used prior to the surgery, can be stopped unless otherwise instructed.
Post Operative Instructions
- On the day of surgery, rest quietly at home
- Do not rub your eye
- Wash your hands before applying any eye drops
- No heavy lifting for 2 weeks (after cataract surgery) or 1 month (after trabeculectomy)
- No swimming for 6 weeks (after glaucoma surgery, for swimming advice, consult your eye doctor, you may always need to protect your eyes while swimming)
- Do not drive after eye surgery until you feel safe to do so
- Do not use a handkerchief to wipe away any tears; use a clean disposable tissue/sterile cotton.
- No eye makeup (for 2 weeks after cataract surgery, for 2 months after glaucoma surgery)
- Please make sure that water does not enter the eye when you wash your face.
- Wipe eyes and surrounding areas with a clean wet cloth/ cotton.
- You can start reading, watching TV, etc as soon as you are comfortable. Please do not strain /persist in reading if there is discomfort.
- You can go out for walks/ drives. Please wear the protective glasses during these outings.
What To Expect After Surgery
Your eye may ache or be gritty for the first 12 hours after surgery. Regular strength painkillers should suffice. After cataract or glaucoma surgery, often there is very little
discomfort, but occasionally due to surface corneal dryness, there can be significant sharpness or a gritty feeling that may take 24 hours to improve. Generally, any discomfort should get better day by day. If you are concerned, please contact your phthalmologist directly. Your eye may water a lot after surgery. This is normal. You may also experience double vision. Again this is normal in the first few days, and any double vision should wear off after 24 hours. Due to the effect of the drops vision ma yalso be slightly blurred and you may experience difficulty reading small print. This will usually become better by two weeks time.
You may experience some excess sensitivity to light. This usually improves over 1 to 3 weeks after surgery. Sunglasses may help Your doctor may call you for frequent post operative checks if he/she suspects that you have a tendency for aggressive healing of the surgical site. Some medications or injections may beadvised to control the healing process in this period.
Further advanced techniques are also done where artificial drainage shunts, which are known as Setons or shunts used.
These are small plastic/ metal tubes, which are implanted in the eye to maintain the patency of the opening created. Few examples are: Express Glaucoma shunt, and other implants like Ahmed Glaucoma Valve.
Non Penetrating Filtration Surgery
In this type of surgery, the anterior chamber of the eye is not entered, thus reducing chances of overfiltration. Deep sclerectomy and Viscocanalostomy are the two types of procedures done
There may be some vision changes such as blurred vision for few weeks after surgery. After that time, vision will return to the same level as it was before surgery. Drop in vision ( especially in end stage glaucomas), cataract formation, and overfiltration are some of the complications noted after surgery.
Glaucoma surgery is done to maintain the existing vision in the eye. It cannot improve vision, or restore vision that has been already lost.