Glaucoma: symptoms and causes

03 March 2022

Glaucoma is a group of eye diseases that damage the optic nerve, the health of which is critical for good vision. This damage is usually caused by higher than normal pressure in the eye.

Glaucoma is one of the leading causes of blindness in people over the age of 60. It can occur at any age, but is most common in older adults.

Many forms of glaucoma have no warning signs. The effects are so gradual that you may not notice changes in vision until the disease is advanced.

Vision loss due to glaucoma cannot be recovered, it is important to have regular eye exams, including intraocular pressure measurements, for early diagnosis and proper treatment. If glaucoma is detected at an early stage, vision loss can be slowed or prevented. If you have the condition, treatment will usually be needed for the rest of your life.

Symptoms

The signs and symptoms of glaucoma depend on the type and stage of the condition. For example:

Open-angle glaucoma

Open-angle glaucoma is the most common form of this pathology. The drainage angle created by the cornea and iris remains open, but the trabecular meshwork is partially blocked. This results in a gradual increase in intraocular pressure. This pressure can damage the optic nerve. It happens so slowly that vision is lost before the person realizes there is a problem.

• Irregular blind spots in side (peripheral) or central vision, often in both eyes.
• Advanced stage tunnel vision

Acute angle-closure glaucoma

Angle-closure glaucoma occurs when the fluid leaving the eye is suddenly blocked. This causes the pressure inside the eye to rise rapidly and violently.

• Severe headache
• Eye pain
• Nausea and vomiting
• Blurred vision
• Red eyes

Causes

Glaucoma results from damage to the optic nerve. As this nerve gradually degenerates, blind spots appear in the visual field. The increase in intraocular pressure is caused by the accumulation of fluid (aqueous humor) that circulates in the eye. Normally, this internal fluid drains through a tissue called trabecular meshwork at the angle where the iris and cornea meet. When too much fluid is produced or the drainage system does not work properly, the fluid does not drain out at the normal rate and intraocular pressure increases.

Glaucoma often runs in families. Scientists have identified genes related to high eye pressure and optic nerve damage in some people.