Glaucoma

Impact of Glaucoma on Anatomy and Health

The optic nerve transmits visual information from the retina to the brain, allowing us to see. In glaucoma, the damage to the optic nerve typically begins with peripheral vision loss that can progress to central vision loss over time. This loss of visual field is often irreversible, and if left untreated, it can lead to permanent blindness.

Glaucoma impacts the eye by causing increased intraocular pressure. This increased pressure can damage the optic nerve over time.

Who is at Risk of Glaucoma? 

Glaucomas can occur at any age but are more common in middle-aged people. Some people have a higher-than-normal risk of getting Glaucoma. This includes people who:

• Age 40 or over
• Have a family history of Ocular Hypertension or have high eye pressure
• People who are short-sighted or myopic (nearsighted)
• Are of African or Hispanic heritage
• Are farsighted (Hyperopia) or nearsighted (Myopia)
• Have corneas that are thin in the centre
• Have diabetes, migraines, poor blood circulation or other general health problems that affect the eye.
• Have had an eye injury
• Long-term steroid medication use
• Pigment dispersion syndrome sufferers 
• Exfoliation syndrome sufferers
• Women

Causes of Glaucoma

The primary cause of glaucoma is an imbalance between the production and drainage of aqueous humour (the clear fluid inside the eye). This imbalance leads to increased intraocular pressure, damaging the optic nerve. 

Symptoms of Glaucoma

In the early stages of glaucoma, there are typically no noticeable symptoms. This is why it's often called the "silent thief of sight." Vision loss starts at the periphery and slowly progresses towards central vision. As the condition advances, symptoms might include:

• Peripheral Vision Loss: The most common symptom is a gradual loss of peripheral (side) vision, often unnoticed until it's advanced.
• Tunnel Vision: As peripheral vision diminishes, you might perceive your visual field as if you're looking through a tunnel.
• Halos: Some individuals may experience halos around lights, especially in low-light conditions.
• Blurred Vision: Vision might become blurred, and it can be challenging to focus on objects.
• Eye Pain or Discomfort: Acute angle-closure glaucoma can cause sudden symptoms like severe eye pain, headache, nausea, vomiting, and blurry vision.
• Red Eyes: Acute angle-closure glaucoma can also cause the eye to become red and inflamed.

What are the Types of Glaucoma?

There are several types of glaucoma, each with its characteristics and underlying causes. Some of the main types of glaucoma include:

• Primary Open-Angle Glaucoma (POAG): This is the most common type of glaucoma. It occurs when the drainage angle in the eye becomes less efficient over time, leading to gradual increases in intraocular pressure. POAG typically progresses slowly and often doesn't have noticeable symptoms until significant vision loss has occurred.
• Angle-Closure Glaucoma: This type occurs when the drainage angle suddenly becomes blocked, causing a rapid increase in intraocular pressure. It can lead to sudden and severe symptoms such as eye pain, headache, nausea, vomiting, and blurry vision. This is a medical emergency that requires immediate treatment.
• Normal-Tension Glaucoma: Also known as low-tension or normal-pressure glaucoma, this type occurs even though intraocular pressure remains within the normal range. The exact cause is poorly understood, but factors such as decreased blood flow to the optic nerve and increased optic nerve sensitivity are believed to contribute.
• Secondary Glaucoma: This type of glaucoma is caused by an underlying medical condition, injury, or medication. It can result from factors like uveitis (inflammation of the eye), diabetes, trauma, or prolonged use of corticosteroids.
• Congenital Glaucoma: This is a rare type of glaucoma present at birth due to developmental abnormalities in the eye's drainage system. It's typically diagnosed in infancy or early childhood.

How can Glaucoma be Treated?

Eye Drops

At the early stage of the disease, patients can usually be managed medically with eye drops that lower the eye pressure. 

Laser Trabeculoplasty

Laser Trabeculoplasty is often used to treat open-angle Glaucoma. 

The laser is aimed at trabecular meshwork, where fluid drains from the eye. This surgery opens the clogged areas and makes it easier for fluid to flow out of the eye.

There are two types of laser trabeculoplasty surgery:

• Argon Laser Trabeculoplasty (ALT) - During ALT, a laser creates burns in the trabecular meshwork.
• Selective Laser Trabeculoplasty (SLT) - During SLT, a laser is used at different frequencies to treat specific cells in the trabecular meshwork.

This procedure aims to lower the eye pressure by increasing fluid drainage by opening up the clogged areas in the meshwork, making it easier for the fluid to flow out of the eye.

Minimally Invasive Glaucoma Surgery (MIGS)

Recently, a new surgical treatment called Minimally Invasive Glaucoma Surgery or MIGS has been introduced. This procedure involves the insertion of microstents into the eye's drainage angle during cataract surgery. This procedure has been shown to reduce eye pressure and is very safe. 

Trabeculectomy or Tube Shunt

These procedures can be an option if the patients have been treated with maximum medical therapy and their eye pressures remain high.

This procedure diverts the fluid outside the eye so the pressure is reduced.As only controlled and precise amounts of fluid are let out, the internal pressure of the eye stands or is maintained at a healthy level. This advanced Glaucoma drainage surgery can be an option to control your pressure and any consequential damage caused by the disease.