What causes secondary glaucoma?

Key Takeaways

  • Secondary glaucoma is a type of glaucoma that is caused by a secondary factor such as injury, another illness, or medications.
  • Getting your eyes examined every year is the best way to reduce or prevent eye damage from secondary glaucoma.

The basic cause of glaucoma is a blockage to the drainage system of the eye; something gets in the way of the eye’s natural drain, and as a result, pressure builds up. This pressure damages the optic nerve and causes the nerve tissue to degenerate. This leads to irreversible vision loss such as blurred or blind spots in the vision, glare, and the inability to see in dimly lit conditions.

There are two main subtypes of glaucoma – primary glaucoma, which has no identifiable cause, and secondary glaucoma, in which the condition is caused by a secondary factor such as injury, another illness, or medications. It is important to be vigilant about your overall health and be aware of things that can increase your chances of developing glaucoma.

Trauma to the eye can occur as a result of injury such as an accident that causes the eye or surrounding structures to be hurt, or as a result of another eye surgery or laser treatment. Injuries can stretch and cause scarring to the eye’s drainage system. Sometimes blood or even a foreign body can land in the drainage system and lead to the drain slowing down to the point where the amount of fluid being formed in the eye is too much for it to handle. People who have had an eye injury should get a test called “gonioscopy” to check the drainage angle. There are certain diseases (systemic) that affect your entire body and can lead to secondary ramifications to the eye.  Autoimmune conditions lead to inflammation in the body and may also involve the eye. The inflammation clogs the drainage apparatus, and the pressure builds up. Steroid medications are a common treatment for autoimmune or inflammatory conditions, but when used for more than a few weeks, they can also cause dysfunction of the eye’s drain.  Light sensitivity can occur with inflammation in the eye, but usually there aren’t any major symptoms. Therefore, it is important to get a yearly eye exam, especially if you have a chronic illness.

Diabetes, high blood pressure, and other cardiovascular diseases do not cause glaucoma directly, but if any of these conditions is uncontrolled, abnormal blood vessels can actually grow into the eye and close the drainage system off.  In this case, eye pressure can be extremely high and can lead to loss of vision if not treated quickly.  Symptoms to look out for are reduced vision, red eye, eye pain, and headache. We recommend that if you have one of the conditions mentioned above, you should get a dilated eye exam every year.

The best way to reduce or prevent damage to the eye is simple, get your eyes checked every year!  Don’t wait for symptoms to show up.  Remember, once glaucoma starts, the damage that it causes cannot be reversed.

Source: Mona Kaleem, MD, Glaucoma Research Foundation; see source article