What is glaucoma?
Glaucoma is an irreversible damage to the optic nerve and high pressure in the eyes is a strong risk factor. Rarely, glaucoma can also occur with normal eye pressure. Damage to the optic nerve leads to loss of the peripheral field of vision and, in severe cases, can lead to loss of central vision as well.
Glaucoma cannot be cured, but if detected early enough, it can be stabilized to preserve sight.
Why and how are filtering glaucoma surgeries performed?
The goal of a glaucoma surgery is to decrease and/or stabilize pressure in the eye and prevent vision loss. It does not restore vision that was already damaged and no glaucoma surgery can cure the disease. Glaucoma filtering surgeries include micro-stents such as Xen gel stent as well as traditional glaucoma surgeries. Novel filtering surgeries such as the Xen micro-stent offer the advantage of being more effective than other MIGS while being safer than traditional surgeries. Filtering surgeries can be combined with cataract surgery. It creates a “bleb”, which is a reservoir of liquid around the eye under the conjunctiva (transparent skin above the white part of the eye), to completely bypass the natural drainage system. This allows the excess fluid to be rerouted to the outside of the eye. The bleb is often hidden by the upper eyelid. There is a variety of glaucoma filtering surgeries and your ophthalmologist will choose the one that suits you best.
What to expect before the surgery?
Your ophthalmologist will assess the level of glaucoma damage and then determine the type of glaucoma filtering surgery best suited for your eye.
What to expect during and after the surgery?
The surgery is done as an outpatient day surgery (you are not hospitalized) and lasts less than an hour. It is done under local anesthesia (drops to anesthetize the eye) with slight sedation if necessary. A eyelid speculum is used to keep the eyelids open and prevent the eye from blinking during the procedure. Initially, the vision will be blurred after the procedure but it improves during the first days/ weeks. The eye may be red and irritated for a few weeks after surgery as sutures are often used. Your ophthalmologist will see you the day after surgery and then after 1 week. You will have to take healing drops for about 3 months after surgery. You may need to update your glasses prescription after surgery at your optometrist’s – consult your ophthalmologist to find out when it is best to update the prescription. After surgery, it is possible that you may have to undergo other procedures in the clinic, restart glaucoma drops or receive other surgeries for your glaucoma.
What are the risks?
Complications after cataract surgery are rare and most of them can be treated successfully:
⦁ Loss of central vision
⦁ Eye pressure that is too high or too low requiring additional eyedrops or procedures
⦁ Dry eyes
⦁ Drooping eyelid
The goal of the surgery is to maintain the current vision, not to improve it.
What are the different types of traditional filtering surgeries?