Glaucoma explained

Glaucoma is one of the leading causes of blindness. It refers to a group of diseases that damage the optic nerve. It is often called the silent thief of sight because vision loss progresses slowly and is difficult to notice during the early stages.

Types and symptoms

Peripheral vision is usually lost first and slowly. As a result patients often don’t notice problems until the condition is fairly far along. There are standard tests that eye doctors can do for glaucoma. These are often performed as part of your routine eye exams.

The term glaucoma broadly refers to a group of conditions that cause damage to the optic nerve. They are associated with increased eye pressure. There are two main types: open-angle and closed-angle glaucoma.

Open-angle glaucoma progresses slowly and has no symptoms until the later stages. It can be treated with medication or surgery that tries to reduce the pressure in the eye. This is the more common type of glaucoma.

Closed-angle glaucoma presents as sudden and very serious symptoms. It involves eye pain, redness, nausea and vomiting. If these symptoms occur seek immediate medical attention.

Treatment

After vision loss occurs it is usually permanent. Glaucoma treatment seeks to prevent additional vision loss. Once it is diagnosed it is possible to slow or prevent vision loss with medication and surgery.

Risk factors

As you age the risk of glaucoma increases significantly. Those over the age of 50 are at a much higher risk than younger individuals. Diabetics are twice as likely to get glaucoma. People of East Asian, African and Inuit ancestry are more likely to develop glaucoma. Women are more at risk than men.

Prevention

The best way to prevent glaucoma is to get regular eye exams. Open-angle glaucoma rarely presents symptoms before causing damage. Your eye doctor can detect signs of glaucoma early and help stave off further damage.

Testing

The test that you are most likely to get for glaucoma is the so-called puff of air test. This is done with a tonometer, which measures the pressure of the fluid in your eye. If you have an abnormal result then your eye doctor can proceed to further diagnostic tests. While this test can be uncomfortable it is important. Additional tests include ophthalmoscopy, perimetry, gonioscopy and pachymetry.

Ophthalmoscopy is used to examine the optic nerve for damage. Pupil dilating drops are used. A device with a light and magnifying glass is used to look at the optic nerve.

Perimetry is a field of vision test. Glaucoma often affects peripheral vision. You will be asked to look straight ahead while lights flash in your side vision.

During a gonioscopy exam drops are used to numb the eye. A contact lens with a mirror is used to determine the angle between the iris and the cornea. This angle helps determine, which specific type of glaucoma is affecting the patient.

An additional test that may be performed is pachymetry, which measures the thickness of the cornea. A pachymeter is placed on the eye during the test. The thickness of the cornea can influence eye pressure. Having this information can help your eye doctor to better understand the pressure in your eye.