Glaucoma

Glaucoma may be categorised into the following four types: 

• Primary open angle glaucoma develops very slowly is the most common type. Black African and Black Caribbean populations have a higher risk of developing this condition.
• Angle closure glaucoma may develop slowly (chronic) or rapidly (acute), causing sudden, painful elevation of intraocular pressure. Asian populations have a higher risk for developing this condition than other ethnic groups. This is a rare condition.
• Secondary glaucoma occurs due to other eye conditions, such as uveitis (inflammation of the uvea, the middle layer of the eye), or eye injuries.
• Developmental (congenital) glaucoma is a serious eye abnormality that usually develops at or shortly after birth. This is also a rare.

Glaucoma develops slowly over several years, initially affecting peripheral vision. Most people do not realise that they have glaucoma until it is diagnosed during a routine ophthalmic examination.

The following symptoms may occur:

• Blurry vision
• Appearance of rainbow-coloured circles around bright objects/lights

Although both eyes are usually affected, glaucoma may be more severe in one eye. Occasionally, sudden glaucoma develops with the following symptoms:

• Redness
• Blurred vision
• Intense eye pain
• Tenderness around the eyes
• Appearance of rings around lights or bright objects
• Headache, nausea, and vomiting
   

Most cases of glaucoma are caused by increased intraocular pressure due to improper drainage of fluid within the eye, which damages the optic nerve. Although an exact cause has not yet been identified, certain factors increase the risk for developing glaucoma:

• Age (glaucoma is more common with older age)
• Ethnicity (Caribbean, African, or Asian populations are at a higher risk)
• Family history
• Other medical conditions, such as diabetes, hypertension, short-sightedness, and long-sightedness, may increase the risk for developing glaucoma.

Glaucoma is diagnosed with the following main tests:

• Optical coherence tomography (OCT) to detect structural changes and thinning or loss of the retinal nerve fibre.
• Perimetry or Humphrey Field Analyser (HFA) to assess the peripheral visual field.

Vision loss already caused by glaucoma cannot be reversed. However, specific treatment methods can stop vision from worsening.

The recommended treatment depends on the type of glaucoma and includes:

• Anti-glaucoma eyedrops to reduce the intraocular pressure.
• Laser treatments to reverse the blockage of drainage tubes or reduce fluid production within the eye.
• Trabeculectomy is a type of surgery to enhance fluid drainage from the eye and reduce the intraocular pressure.
• Microinvasive glaucoma surgery (MIGS), a minimally invasive eye surgery that lowers intraocular pressure by creating small incisions. 

Medical attention is recommended if:

• You experience sudden onset of severe eye pain, redness, or blurred vision.
• You notice rainbow-coloured circles or halos around lights.
• You have frequent headaches, nausea, or vomiting associated with vision problems.
• You are over 40 years old and have a family history of glaucoma.

Glaucoma cannot always be prevented, but these steps can help reduce the risk of vision loss:

• Attend routine eye examinations, especially if you are over 40 or have risk factors.
• Manage systemic conditions such as diabetes and hypertension effectively.
• Protect your eyes from injury by wearing protective eyewear.
• Follow treatment plans carefully, including regular use of prescribed eye drops.

Patients with suspected or confirmed glaucoma should consult an ophthalmologist, ideally one specialising in glaucoma management. Optometrists also play a key role in detection during routine eye checks and in referring patients for specialist care.