Goniotomy

A goniotomy is a surgical procedure to lower eye pressure due to accumulation of aqueous humor, the clear liquid inside the front part of the eye . The procedure involves making a tiny opening in the trabecular mesh - a network of small canals that aid in draining the aqueous humor from the eye. This opening facilitates the flow of excess fluid from the eye which in turn reduces eye pressure. The procedure utilizes a special lens called a goniolens to evaluate the eye’s drainage system and conduct the procedure; hence it is called a goniotomy.

Indications

A goniotomy is typically indicated for an eye condition called glaucoma.

Glaucoma is an eye disease that adversely affects the optic nerve – the nerve that supplies visual information from your eyes to your brain. With a glaucoma, damage to the optic nerve can occur due to an abnormally high intraocular pressure, or pressure inside the eye. This pressure is due to too much aqueous humor. When this fluid does not properly drain from your eye, it builds up and exerts pressure on the optic nerve, which can lead to nerve damage and vision problems.

Your surgeon may recommend a goniotomy when eye drops or laser treatment have not been successful in reducing eye pressure caused by glaucoma.

Who is a Good Candidate for Goniotomy Surgery?

You may be a suitable candidate for goniotomy if you have the following:

• Congenital glaucoma
• Open-angle glaucoma
• Juvenile open-angle glaucoma
• Uveitic glaucoma associated with juvenile rheumatoid arthritis
• Aniridia (a condition in which the eye is missing all or part of its iris – the colored portion of the eye) 75% of individuals with aniridia will develop glaucoma

Preparation

Your ophthalmologist will carry out an eye exam to check the overall health of your eye and review your medical history prior to surgery. Additional instructions will be given, such as:

• Instilling prescription antibiotic eye drops in the affected eye every six hours, one day prior to surgery
• Providing your physician with a list of medications and supplements you are taking
• Adjusting the dose of medications you are on, or stopping certain medications, such as blood thinners or supplements such as Vitamin E and/or Fish Oil? Omega 3 for at least a week prior to surgery
• Informing your doctor of any recent illnesses or other medical conditions you have, such as heart or kidney disease
• Refraining from eating or drinking at least 6 hours before the procedure. If you are on regular medication for conditions such as high blood pressure, diabetes, or heart disease, you may take it with a sip of water.
• Avoiding wearing any eye make-up
• Arranging for someone to take you home after the procedure

Surgical procedure

Goniotomy surgery is performed in the operating room under anesthesia. In general, the procedure will involve the following steps:

• The surgery eye is cleaned and numbed with anesthetic eye drops.
• An eyelid holder is placed over the eye to prevent the eye from blinking.
• Advanced surgical devices are used to make tiny incisions in the front of the eye, and a special lens is placed on the eye to view the eye’s natural drain.
• A segment of the wall obstructing the drain is removed.
• An open channel is created, enabling the fluid to leave the eye more easily, reducing the eye pressure and treating the glaucoma.

Postoperative care

Your surgeon will provide a series of postoperative instructions to be followed for a defined period. These include:

• The use of steroid and antibiotic eye drops to minimize the risk of infection and inflammation
• Wearing an eye shield to protect the eye and prevent rubbing it in your sleep
• Taking time off work for a few days to rest the eye and promote healing
• Avoiding sports activities or exercises that may stress the eye
• Avoiding getting soap in your eye
• Avoiding hot tubs or swimming
• Avoiding cream, lotions, or make-up around the eye
• Refraining from driving until your vision is restored
• Wearing sunglasses to protect the eye outdoors

Risks and Complications

The risks and complications of goniotomy may include:

• Bleeding
• Infection
• Cataracts
• Discomfort
• Temporary increase in intraocular pressure
• Hyphema – a collection or pooling of blood at the front of the eye

Summary

A goniotomy is an effective treatment for many types of glaucoma and can be performed on individuals of all ages. The outcomes from a successful goniotomy surgery can offer long-term relief from intraocular pressure related to glaucoma, reduce dependency on glaucoma drugs, and help prevent irreversible damage to the optic nerve.