Glaucoma is a serious eye condition that can lead to blindness or vision loss of varying degrees, and is one of the most common, preventable causes of blindness in Canadians. In fact, glaucoma is the second leading cause of blindness worldwide, following only behind cataracts. It occurs when fluid inside the eye builds up – via either drainage ducts being blocked (open angle) or some form of eye infection or condition (closed angle) – pressure inside the eye increases, pressing against the retina and optic nerve. Should the pressure be enough, and applied for long enough to the retina and optic nerve, nerve damage may occur, which is irreversible with current medical technology.
Symptoms of Glaucoma
There are two main types of glaucoma:
- Open Angle Glaucoma: By far the more dangerous and prevalent of the two glaucoma types, as it is usually painless, will develop very slowly over many years (from 20 to 70 years), and often presents absolutely no symptoms until damage has already begun to the optic nerve.When it does present, it is usually not with pain, but blurred vision, acute vision loss, and the feeling of “tightness” inside the eye, as if it was being squeezed.
- Closed Angle Glaucoma: Usually an acute, or sudden, condition, closed angle glaucoma is often extremely painful, with sudden eye pain described as being “stabbed” in the eye, redness of the eye, nausea/vomiting, and the feeling of burning or scratching at the back of the eye, all developing within minutes to hours of each other.There are also associated risk factors that are related to both open and closed angle glaucoma, including hypertension, high blood pressure, diabetes, and family history or genetics. Ethnicity has also been shown to be of some relation, with those of East Asian descent more prone to closed angle glaucoma, and those of Caucasian descent more prone to open angle glaucoma.
Treatment of Glaucoma
The most effective treatment of glaucoma happens if it is detected early, such as during a regular comprehensive eye exam. More often than not, when detected very early, medication may be the only necessary treatment, with prescriptions that will relieve the pressure inside the eye applied via eye drops or, less commonly, as oral medication.
If the medication is not effective, or the glaucoma has advanced to a significant enough stage, microsurgery may be necessary, especially in open angle glaucoma. The most common surgery is known as a trabeculectomy, where a small flap is opened in the eye, part of the ducting inside of the eye (known as the trabecular meshwork) is opened or removed, and the flap loosely sewn shut, so that fluid can flow out of the miniscule gaps left between the sutures. The risks associated with this type of surgery are that the flap may scar over and close, causing a fluid bubble on the surface of the eye, or that infection may enter the eye via the sutures, if antibiotic eye drops are not applied judiciously.
Less commonly, and mostly for cases of closed angle glaucoma, laser surgery to open blocked drainage ducts, or a specialized procedure known as a canaloplasty to insert a micro-catheter into the eye to create a new drainage duct altogether, can be performed. Both are considered emergency surgeries, but can also be recommended as a treatment for open angle glaucoma should they be determined as the best course of treatment.
