What is Secondary Glaucoma?

Secondary glaucoma is glaucoma that develops from an identifiable source. Unlike primary glaucoma, secondary glaucoma occurs because of a known medical problem, meaning that it is secondary to another issue. Secondary glaucoma can range from mild to severe, and onsets are a result of a rise in intraocular pressure, also known as ocular hypertension.

Secondary glaucoma comes in two types, differentiated by the drainage angle in the eye that controls aqueous outflow. The first type is called open-angle glaucoma, which is sometimes referred to as chronic glaucoma. Its symptoms include a gradual loss of peripheral vision and possibly tunnel vision in advanced stages of the disease. The second type is called angle-closure glaucoma, which is sometimes referred to as acute glaucoma. Its symptoms include nausea and vomiting, blurred vision, severe eye pain, reddening of the eye and visual disturbances.

There are several risk factors for secondary glaucoma. A person might be at advanced risk if he or she has an eye tumor, eye inflammation, diabetes, an advanced cataract or has had a past eye surgery or an eye injury. Individuals who are nearsighted have a natural predisposition for glaucoma. Light-skinned women and persons of Scandinavian descent have a greater chance of acquiring the disorder. Anyone who has taken steroids also might develop the disease.

Secondary glaucoma also can be the result of a poor diet or nutritional deficiencies. Anyone with digestive problems from taking too many antibiotics or having a stressful lifestyle can be prone to having glaucoma. Chronic health issues such as obesity, cardiovascular disease or thyroid disease also can be extenuating factors in the disorder's development.

Treatment for secondary glaucoma depends on whether it is open-angle or angle-closure glaucoma. Open-angle glaucoma is sometimes temporary, so treatment usually is based on controlling the introcular pressure with eye drops. For angle-closure glaucoma, a very powerful type of water tablet called acetazolamide might be used. This will bring the intraocular pressure down to a low enough level that laser iridotomy or surgical iridectomy can be performed. With treatment, functional sight usually can be retained for life.

Anyone who is at higher risk of developing secondary glaucoma should have regular vision exams. This is particularly true for individuals who are middle-aged and older. Worldwide, glaucoma is the leading cause of irreversible blindness. As with any health issue, the sooner secondary glaucoma is detected, the better chance a doctor has a to treat it effectively.