Glaucoma: An expert insight

Glaucoma is a prevalent eye condition characterised by a lack of noticeable symptoms in the early stages.

Here, Ms Asifa Shaikh, renowned consultant ophthalmic surgeon, delves into the intricacies of glaucoma, including its types, diagnosis, and treatment options.

What is glaucoma, and what are its causes?

Glaucoma is a progressive eye condition characterised by damage to the optic nerve, which connects the eye to the brain. This damage is often caused by elevated intraocular pressure (IOP), which is the pressure inside the eye, leading to gradual vision loss. Glaucoma typically progresses slowly and without noticeable symptoms until significant vision loss occurs.

The exact cause of glaucoma isn’t fully understood. Not all people with elevated IOP develop glaucoma, and some people with normal IOP can still develop the condition. Other risk factors for glaucoma can include age, family history, certain medical conditions (such as diabetes), and ethnic background.

Are there different types of glaucoma?

The main types of glaucoma include:

• Primary open-angle glaucoma: Primary open-angle glaucoma is the most common type of glaucoma, characterised by a gradual increase in IOP due to the eye's inability to drain fluid properly.
• Angle-closure glaucoma: Angle-closure glaucoma occurs when the iris blocks the drainage angle of the eye, leading to a sudden increase in IOP.
• Normal-tension glaucoma: In normal-tension glaucoma, optic nerve damage occurs despite normal IOP levels.
• Secondary glaucoma: Secondary glaucoma is caused by other eye conditions or factors such as trauma, eye surgery, or medication use.

How is glaucoma detected and diagnosed?

Glaucoma detection and diagnosis typically involves a comprehensive eye examination, which may include the following:

• Tonometry: This test measures IOP. Elevated IOP is a significant risk factor for glaucoma.
• Ophthalmoscopy: During this examination, the ophthalmologist uses a special instrument called an ophthalmoscope to examine the optic nerve at the back of the eye for signs of damage.
• Visual field testing: This test evaluates the peripheral vision, which is often affected in glaucoma. Visual field defects, such as blind spots or reduced sensitivity, may suggest glaucoma damage.
• Gonioscopy: This examination allows the ophthalmologist to visualise the structures of the drainage angle of the eye and determine if there is any obstruction.

Detecting glaucoma in its early stages is vital to prevent the loss of vision. Regular eye examinations, especially for people at higher risk for glaucoma, are essential for early diagnosis and timely intervention.

What are the treatment options for glaucoma?

Treatment for glaucoma aims to lower IOP to prevent further damage to the optic nerve and preserve vision.

The main treatment options for glaucoma include:

• Medication: Eye drops are the most common form of medication used to lower IOP. These eye drops work by either reducing the production of aqueous humour (the fluid within the eye) or increasing its outflow. Oral medications may also be prescribed in certain cases to lower IOP.
• Laser therapy: Laser procedures, such as laser trabeculoplasty, may be used to improve the drainage of fluid from the eye, thereby lowering IOP.
• Surgery: In cases where medication and laser therapy are insufficient to control IOP, surgical intervention may be necessary to create a new drainage channel or reduce the production of aqueous humour.

What does glaucoma surgery consist of?

Glaucoma surgery aims to improve the drainage of fluid from the eye or reduce its production, thereby lowering IOP to prevent further damage to the optic nerve.

The two main types of glaucoma surgery are:

• Trabeculectomy: Trabeculectomy is one of the most common types of glaucoma surgery. During the procedure, the ophthalmic surgeon creates a small flap in the sclera (the white part of the eye) to create a new drainage channel for the aqueous humour to exit the eye, thereby lowering IOP.
• Minimally invasive glaucoma surgery (MIGS): MIGS procedures are newer, less invasive surgical techniques that involve the use of small devices to improve the eye's natural drainage system or reduce fluid production. Examples of MIGS procedures include trabecular bypass stents, canaloplasty, and iStent.

How successful is glaucoma surgery in slowing down the progression of glaucoma?

The success of glaucoma surgery varies depending on factors such as the type and severity of glaucoma, as well as the patient's overall health. In general, however, glaucoma surgery is effective in lowering IOP and preserving vision.

If you require expert treatment and management for glaucoma, schedule an appointment with Ms Asifa Shaikh via her Top Doctors profile today.