GLAUCOMA

Glaucoma refers to a spectrum of conditions, usually characterised by an increase in eye pressure. Glaucoma is an ocular condition that damages the optic nerve, a nerve responsible for transferring visual data from the retina to the brain. Raised intraocular pressure can damage the optic nerve, which in turn can lead to irreversible blindness.

Symptoms

Signs of acute-closure glaucoma are:

• Eye pain
• Blurry vision
• Halos
• Wide pupils
• Nausea
• Migraine near the affected eye
• Red eyes

Symptoms of open-angle glaucoma include:

• Blind spots in the periphery vision (sides)
• Advanced tunnel vision

Causes

Glaucoma is genetic and most likely to be passed down from a relative. Issues with the optic nerve or high intraocular pressure are common genetic issues linked to glaucoma. Also considered an age-related condition, glaucoma causes blindness in people over sixty.

The build-up of clear fluid, called aqueous humour that moves throughout the eye raises intraocular pressure and contributes to the formation of glaucoma. Usually, aqueous humour drains through tissue known as the trabecular meshwork, a point where the iris and cornea converge. When there is an excess of this liquid or a problem with the drainage network, there are no exit points for the liquid to leave.

There are different forms of glaucoma:

• Open-angle glaucoma
  is the most prevalent form of the condition that occurs when the trabecular meshwork becomes partially obstructed, yet the channel between the cornea and iris remain open. Intraocular pressure builds up slowly, and in the process, damages the optic nerve.
• Angle-closure glaucoma
  or closed-angle glaucoma happens when the iris protrudes from its usual position and obstructs the drainage channel that the cornea and iris forms. As a result, the aqueous humour cannot circulate throughout the eye as it should and raises eye pressure.
• Pigment glaucoma
  can affect any person and result from pigment granules building up in the iris and blocking drainage channels. Running or jogging can cause these granules to block parts of the trabecular network, affecting its drainage system.

Treatment

Glaucoma treatment aims to lower intraocular pressure. Treatment options include eye drops, laser (selective laser trabeculoplasty or SLT) and surgery, including minimally invasive glaucoma surgery (MIGS).