Some causes are known, others are not. Causes differ depending on the type of glaucoma. An injury, infection or tumor in or around the eye can also cause internal eye pressure to rise either by blocking drainage or displacing tissues and liquid within the eye. Below are common types of glaucoma
PRIMARY ANGLE GLAUCOMA
The exact cause of open-angle glaucoma, where the drainage channels for the aqueous appear to be open and clear, is not known. By far the most common type, primary open-angle glaucoma develops gradually and painlessly. Since there are no early warning signs, it can slowly destroy your vision without your knowing it. The first indication may only occur after some considerable vision loss.
ACUTE ANGLE CLOSURE GLAUCOMA
Closed-angle glaucoma can occur when the pupil dilates or gets bigger and bunches the iris up around its edge, blocking the drainage channel. It causes a rapid build-up of pressure inside your eye accompanied by blurred vision, the appearance of colored rings around lights and sometimes extreme pain or redness in the eyes.
Some patients may develop glaucoma due to other underlying issues or use of medications. One may develop glaucoma after a trauma to the eye that impedes the aqueous flow. Others may develop a temporary glaucoma from the use of steroids either in the oral, injected, or eyedrop form. A mature cataract also can push the iris forward to block the drainage ‘angle’ between the iris and the cornea. Glaucoma can occur secondarily to a number of other conditions, such as diabetes, central retinal vein occlusions, and uveitis.
Glaucoma most frequently occurs after age 40, but can occur at any age. If you’re of African heritage, you are more likely to develop open-angle glaucoma — and at an earlier age — than if you’re Caucasian. Asians are more likely to develop narrow-angle glaucoma.
You have a higher risk of developing glaucoma if a close family member has it or if you have high blood pressure or high blood sugar (diabetes). There is also a greater tendency for glaucoma to develop in individuals who are nearsighted. Those at heightened risk for glaucoma should have their eyes checked at least once a year.
The optic nerve, located at the back of the eye, carries visual information to the brain. As the fibers that make up the optic nerve are damaged by glaucoma, the amount and quality of information sent to the brain decreases and a loss of vision occurs.
If diagnosed at an early stage, glaucoma can be controlled and little or no further vision loss should occur. If left untreated, peripheral vision and central vision will be destroyed and blindness may occur.
Tests for glaucoma are part of a comprehensive eye examination. A simple and painless procedure called tonometry measures the internal pressure of your eye. Ophthalmoscopy examines the back of the eye to observe the health of the optic nerve. A visual field test, a very sensitive test that checks for the development of abnormal blind spots, may also be completed. In addition to the visual field test Dr. Velasco can perform a scan of the eye called OCT (optical coherence tomography) which can detect glaucoma in its early stages.
Glaucoma is usually treated with prescription eye drops. In some cases, surgery may be required to improve drainage. The goal of the treatment is to prevent loss of vision by lowering the pressure in the eye. If you are being treated for glaucoma, it is important that you are compliant with your prescribed treatments and to adhere to the recommended follow-up schedule by you eye care provider. You will be monitored closely every one to six months where you eye pressure will be measured and various tests will be performed to make sure that your treatment regimen is keeping your glaucoma controlled.
Unfortunately, any vision loss as a result of glaucoma is permanent and cannot be restored. This is why regular eye examinations are important.
Glaucoma cannot be prevented, but early detection and treatment can control glaucoma and reduce the chances of damage to the eye and a loss of sight.