What is glaucoma?

Glaucoma is a group of eye diseases that most patients are usually unaware of, especially in the initial stage.  If left untreated, glaucoma leads to permanent damage of the optic nerve and resultant visual field loss.  The part that is damaged prior to treatment cannot be repaired.  The disease can damage vision slowly and lead to vision loss or complete blindness.  The only course of action is to slow the progression of glaucoma.

An eye examination with complete optic nerve evaluation helps detecting the glaucoma in the early stages

What causes glaucoma?

Elevated eye pressure due to a buildup of a fluid that flows throughout the eye gradually deteriorates the optic nerve.

What are the risk factors of glaucoma?

  • Age: older are more likely to develop glaucoma especially 40 years of age or older
  • Family history of glaucoma
  • High ocular pressure
  • High degree of near and far sightedness
  • Long-term steroid medications use
  • Having certain medical conditions such as, thin cornea, diabetes, cardiovascular disease, hypertension, migraines, and thyroid diseases
  • Having had an eye injury
  • African people are more susceptible to glaucoma, while Asian people are at higher risk of angle-closure glaucoma.

Types of glaucoma

  • Primary open angle glaucoma: This is the most common type of glaucoma. It occurs when the trabecular meshwork becomes clogged.  As the fluid builds up, it causes pressure to build within the eye. High pressure damages the optic nerve.
  • Normal-tension glaucoma: Some patients develop glaucoma with eye pressure below 22 mmHg.
  • Closed-angle glaucoma: It occurs when the iris bulges forward to block the drainage angle formed by the cornea and iris.  As a result, fluid is unable to circulate through the eye and pressure increases. 
    • Acute angle closure glaucoma causes severe headache, eye pain, redness, blurred vision, halos around lights, nausea and vomiting.  Due to the sudden extreme increase in eye pressure, this can lead to blindness if left untreated.
    • Sub-acute angle-closure glaucoma: Symptoms are mild and intermittent which makes it’s difficult to diagnose without an eye screening.
    • Chronic angle-closure glaucoma is asymptomatic and patient is usually unaware as it develops very slowly.
  • Congenital and developmental glaucoma develops in small children with congenital eye abnormalities.  It can be inherited. While it is rare, the symptoms require immediate treatment as it is hard to be controlled and can lead to permanent vision loss.
  • Secondary glaucoma can result from an eye disease or underlying medical condition, including an eye injury, eye inflammation, eye tumor, advanced cataract, diabetes, and the use of certain medications such as steroids.

What are the symptoms of glaucoma?

Most patients have no warning signs in early stages. The loss of sight gradually starts with peripheral vision which spreads into the central area and finally resulting in permanent vision loss.  The scope of vision or visual field will gradually decrease without recognizing it.  Patients usually recognize that they are suffering from the disease when it is quite advanced. 

Promptly go to ophthalmologist if you experience symptoms of acute angle-closure glaucoma, such as blurred vision, eye pain, severe headache and nausea and vomiting.

How is glaucoma diagnosed?

An ophthalmologist will perform a comprehensive eye exam which includes;

  • Slit-lamp Microscopy Eye Exam
  • Eye Pressure Test (Intraocular Pressure)
  • Corneal Thickness (Pachymetry)
  • Anterior Chamber Angle Exam
  • Optic Nerve Exam
  • Visual Field Test
  • Optical Coherence Tomography (OCT): a state-of-the-art equipment used for retina evaluation, optic nerve structure, and thickness of the retina, which aids diagnosis and the tracking progression of glaucoma and other optic nerve abnormalities.

How can glaucoma be treated?

The best way is prevention as the damage caused by glaucoma can’t be reversed.  Treatment and regular checkups can help slow down the damage and prevent vision loss.  The primary goal in treating glaucoma is to reduce intraocular pressure.

Treatment options are vary from medications, laser treatment and surgery, depending on the type and stage of the condition.