Glaucoma is the term for a diverse group of eye diseases, all of which involve progressive damage to the optic nerve. Glaucoma is usually, but not always, accompanied by high intraocular (internal) fluid pressure. Optic nerve damage produces certain characteristic defects in the individual’s peripheral (side) vision, or visual field.
There are three basic types: Primary, Secondary, and Congenital Glaucoma
Primary Glaucoma is the most common type and can be divided into open angle and closed angle Glaucoma.
Open angle Glaucoma is the type seen most frequently in the United States. It is usually detected in its early stages during routine eye examinations.
Closed angle Glaucoma, also called acute Glaucoma, usually has a sudden onset. It is characterized by eye pain and blurred vision.
Secondary Glaucoma occurs as a complication of a variety of other conditions, such as injury, inflammation, vascular disease and diabetes.
Congenital Glaucoma is due to a developmental defect in the eye’s drainage mechanism.
Early detection of open angle Glaucoma is extremely important, because there are no early symptoms. Fortunately, routine eye exams are a major factor in early detection. People with a family history of Glaucoma should be checked at intervals in their 30s to establish a baseline. Initially, detection is based often on intraocular pressure readings, but also includes observation of the optic nerve as well as evaluation of optic nerve function using visual field tests.
When medication and laser surgery fail to control progression of Glaucoma, a surgical procedure known as a filtering operation is recommended to create an artificial outlet for fluid from the eye, thus lowering intraocular pressure. Requiring use of an operating microscope and a local anesthetic, this procedure is performed in the hospital. If such a procedure is not feasible or has failed, production of aqueous fluid may be reduced by freezing (cryoprobe) or laser energy directly applied to the eyeball over the area where the fluid is produced.
The most helpful advice concerning Glaucoma is to keep in mind the importance of early detection through routine eye examination, faithful use of prescribed medications, and close monitoring by an eye doctor of the optic nerve, visual fields and pressures.
Between 89,000 and 120,000 people are blind from Glaucoma yearly. It is a leading cause of blindness, accounting for between nine and 12 percent of all cases of blindness. The rate of blindness from Glaucoma is between 93 and 126 per 100,000 population over 40.
Between one million and two million Indians age 40 and over, or about one in every 100 people in that age group have Glaucoma. This includes at least one half of all those who have Glaucoma are unaware of it.
In the vast majority of cases, especially in early stages, there are few signs or symptoms. In the later stages of the disease, symptoms can occur that include:
- loss of side vision
- an inability to adjust the eye to darkened rooms;
- difficulty focusing on close work
- rainbow colored rings or halos around lights; and
- frequent need to change eyeglass prescriptions
Not yet. Any sight that has been destroyed cannot be restored, but medical and surgical treatment can help stop the disease from progressing.
Not yet, but blindness from Glaucoma can be prevented through early detection and appropriate treatment.
A number of risk factors for the development of Glaucoma exist. The most important of these include high pressure inside the eye, advanced age, extreme near-sightedness, or a family history of Glaucoma.
Have annual eye exams. See us immediately if you notice any symptoms or any decline in your vision.