What Is Glaucoma?

Glaucoma is a progressive eye condition in which the optic nerve becomes damaged, resulting in permanent vision loss or blindness. It occurs as a result of an abnormally high pressure in the eye, which in turn is caused by a build-up of fluid called the aqueous humour.

Known as the “silent thief of sight”, glaucoma does not usually cause telling symptoms until the disease is in its advanced stages and the symptoms are irreversible. It is a primary cause of blindness among those aged 60 years and above, but it can also occur at any age.

Causes of Glaucoma

Glaucoma is generally caused by excessive eye pressure resulting from an overproduction of a fluid called aqueous humour, or the inability of the fluid to be properly drained out of the eye.

Glaucoma also has a hereditary component. Those who have immediate family members with glaucoma are at a higher risk of developing the disease. Severe eye infections, blocked blood vessels in the eye, inflammatory conditions, and a blunt or chemical injury to the eye are also said to increase the risk of developing glaucoma.

Types of Glaucoma

• Open-angle Glaucoma – This is the most common type of glaucoma where the drainage angle formed by the cornea and iris remains open, but the trabecular meshwork is partially blocked. This results in a gradual increase of pressure in the eyes that can irreversibly and progressively damage the optic nerve.
  
• Angle-closure Glaucoma – Called closed-angle glaucoma, this occurs when the drainage angle formed by the cornea and iris becomes blocked or narrow, preventing fluid from draining or circulating. This then leads to an increase in eye pressure.
  
• Normal-tension Glaucoma – This refers to a condition where despite the patient’s eye pressure staying within the normal range, the optic nerves continue to be damaged. A sensitive optic nerve or less blood supply to the optic nerve is said to be the root cause of this problem. 
  
• Pigmentary Glaucoma – Here, tiny bits of pigment granules form in the iris and block the drainage channel, slowing down or blocking the fluid exiting the eye.
  
• Secondary Glaucoma – Health conditions like diabetes can increase eye pressure, thus resulting in glaucoma.

Symptoms of Glaucoma

Indicators that an individual has glaucoma depend on the type and stage of the condition.

Open-angle glaucoma

• patchy blind spots on your side (peripheral) or central vision, frequently in both eyes
• tunnel vision (advanced stages)
• reduced vision and loss of peripheral vision
• swollen or bulging cornea
• pupil dilation to a medium size that doesn’t change with increasing or decreasing light
• eye redness
• nausea

Acute angle-closure glaucoma

• severe headache
• eye pain
• nausea and vomiting
• blurred vision
• halos around lights
• eye redness

How to Prevent Glaucoma:

It is necessary to take some preventive measures to detect glaucoma at an earlier time, slow its debilitating effect, and even prevent it from happening. These steps include: 

• Regular eye examinations – Frequent and consistent eye exams can aid to detect glaucoma in its early stage.
• Family’s eye health history – Genetics plays a major role in one’s risk of developing glaucoma. That’s why those who have a family history of glaucoma are recommended to get early and regular eye screenings.
• Wear eye protection – Serious eye injuries can lead to glaucoma, and so eye protection must be worn when engaging in activities that are high-risk for eye injuries.
• Exercise – There are certain routines and exercises that can increase pressure in one’s eyes.

Treatment for Glaucoma

Glaucoma currently has no cure, but there are treatments that can help slow down its progression and preserve vision. 

• Eye Drops – This is given to either minimise the accumulation of fluid in the eye or facilitate smoother drainage.
• Oral Medication – Aside from medications that can be applied directly to the eye, there are also those that can be taken by mouth. Some of these drugs can improve the drainage and slow the production of fluid in the eye.
• Laser Surgery – A high-energy beam of light is aimed at the part of the eye that is causing fluid to build up, thus removing the blockage and allowing the fluid to circulate and flow out properly. 
• Surgery – For severe cases, surgery may be recommended. Trabeculectomy is the most common type of surgery in which part of the eye’s drainage tubes are removed so fluid can be drained out easily.