Diagnosing and Treating Glaucoma Dr. Michael Dollin, MD, FRCSC, Vitreoretinal Surgeon

Duration: 3 minute, 7 seconds

Glaucoma is a condition where the intraocular pressure is elevated beyond a safe level, such that it begins to damage the optic nerve at the back of the eye. There are several causes of glaucoma. Intraocular pressure can elevate due to the drainage of fluid being blocked. In many patients, we don't have an obvious cause for why the pressure is elevated and we refer to that as primary open angle glaucoma. There is a rare subset of patients with glaucoma, who seem to develop the disease without obvious elevated pressure and we refer to them as normal tension glaucoma patients.

Unfortunately, glaucoma will not produce symptoms until it is quite advanced. Once a patient begins to get vision loss, it is already too late to reverse the damage, which is why it's important to screen for the condition. The condition is typically painless and creates a slow deterioration of vision that's not noticed by the patient. In advanced stages, your peripheral vision tends to be lost first, until a tunnel vision situation develops. And finally, the central vision can also be lost. In the final stages, patients can lose their sight completely, which again is irreversible.

In glaucoma, damage to the eye stems from nerve damage at the back of the eye involving the retinal fibers or ‘optic nerve’. The optic nerve is what transmits signals from the back of the eye to the brain allowing us to see. If pressure on the nerves is elevated and the fibers are squeezed, they begin to die off. Once they are damaged like this, they are lost and cannot be fixed. This is why if left untreated, patients can permanently lose their vision.

People who are most likely to develop glaucoma have a family history of the disease, are patients with a short eye with a narrow anterior chamber, patients with some genetic conditions, such as pseudoexfoliation syndrome or pigment dispersion syndrome, and are at an increased risk.

Prevention is crucial in glaucoma and there are treatment options for glaucoma, all of which involve lowering the intraocular pressure. This can begin as medical therapy to reduce fluid production in the eye. There are multiple effective medical agents that can be prescribed by an ophthalmologist. In more advanced cases, or even moderate disease, some glaucoma surgeons may elect to use laser therapy to promote drainage from the trabecular meshwork when the IV laser or medical therapy are not working. Surgical options also exist which all promote the creation of alternative fluid drainage avenues from the eye, either with a fistula or a tube device.

For screening and detection of glaucoma, it is recommended that people see their local optometrist on a regular basis, particularly if you have a family history of the disease. Please don’t hesitate to reach out to your local optometrist or family doctor if you have more questions or concerns about this condition.

Presenter: Dr. Michael Dollin, Ophthalmologist, Ottawa, ON

Local Practitioners: Ophthalmologist