What is a glaucoma drainage implant?
A glaucoma drainage implant is a device that helps to lower intraocular pressure and prevent further damage to the optic nerve. Glaucoma drainage implant surgery is an alternative to trabeculectomy. For patients with certain types of glaucoma (aphakic glaucoma, neovascular glaucoma, and uveitic glaucoma), as well as for patients who have had other types of eye surgery, a glaucoma drainage implant is often more effective than a trabeculectomy procedure.
Types of glaucoma drainage implants
There are two main types of drainage implants:
- Valved drainage implants - Valved drainage implants include the Ahmed glaucoma valve implant. These implants can prevent a low intraocular pressure in the early postoperative period;
- Non-valved drainage implants - these include the Baerveldt glaucoma implant and the Molteno glaucoma implant.
Which type will be used in a particular patient is determined on an individual basis, based on the patient's condition.
How does a glaucoma drainage implant work?
All glaucoma drainage implants, despite their various sizes and shapes, have a soft, flexible tube connected to a small plate. A silicone tube is placed in the upper part of the eye, in the front chamber, between the cornea and iris. The tube allows aqueous humor to drain from inside the eye onto the plate, after which it is reabsorbed. The implant plate is usually invisible. It may take 3 months or more after surgery for intraocular pressure to stabilize.
How effective is the procedure?
Glaucoma drainage implants are used primarily in patients with advanced, refractory glaucoma. In about 5-10% of cases, repeat tube implantation is required to control intraocular pressure. The goal of glaucoma implant surgery is to lower intraocular pressure and preserve vision. It does not restore vision that has already been lost.
How is the procedure performed and what is the post-operative period?
The procedure is performed on an outpatient basis, under general or local anesthesia, and lasts about an hour.
After the operation, the eye is closed and protected with a special bandage overnight. The next day, the ophthalmologist will remove the bandage and check the condition. Eye drops are prescribed as needed to prevent infection and reduce inflammation.
Typically, it may take several weeks for the implant to heal and function normally. During this time, your ophthalmologist will monitor your condition. To minimize postoperative risks, it is important to follow the specialist's recommendations.
