Glaucoma is a condition that affects the optic nerve and if not treated leads to a loss of vision. It is important to be checked for this on a regular basis because, like high blood pressure, it is a silent disease that patients do not know they have until the damage is done.
Open-angle Glaucoma: Open-angle glaucoma is the most prevalent form. In this condition, the pressure in the eye becomes elevated because of decreased outflow of fluid inside the eye called aqueous humor. The exact mechanism of the blockage is unknown. There are also variants where the intraocular pressure is normal or even low (normal tension and low tension glaucoma). Visual loss is usually slow but progressive and can result in blindness if the disease is not controlled. Treatment is directed at lowering the eye pressure with eye drops, laser treatment or even surgery in advanced cases. Two important factors in protecting vision are compliance with the medications and regular physician follow-ups. If these are adhered to, the risk of vision loss and blindness is low.
Narrow-Angle Glaucoma: A second less common type of glaucoma is narrow-angle glaucoma. This is a condition where the colored part of the eye called the iris leans up against the drainage channel preventing aqueous fluid from leaving the eye. In some cases, it is possible to develop an acute attack of increased intraocular pressure. This may be induced by certain medications or even prolonged exposure to darkness. The symptoms of an acute angle closure glaucoma attack are ocular pain, redness, decrease or loss of vision, nausea, and vomiting. This is an emergency and an ophthalmologist should be consulted immediately. Treatment of an acute attack consists of medications in the form of drops, pills or solutions that help lower the intraocular pressure. Once the pressure is controlled, then the doctor will perform a peripheral iridotomy with a laser. This will cure the problem and prevent any recurrences. It is most helpful to diagnose the condition before an acute attack of glaucoma occurs. In this case, the doctor will recommend a prophylactic peripheral iridotomy to prevent a future attack.
In some cases, a patient can have both open and narrow or closed angle glaucoma. This is called combined mechanism glaucoma and requires treatment with a laser and eye drops. With proper care and follow up, vision loss can be prevented.