Glaucoma is a leading cause of vision loss and blindness. In the early stages, there are no symptoms. While glaucoma can strike anyone, the risk is much greater for certain groups of people. High-risk glaucoma groups include people with diabetes and people with a family history of glaucoma. The risk is much greater for people over 60.
Glaucoma is included in a group of diseases that can damage the eye’s optic nerve, resulting in loss of vision and blindness. There are several different types of glaucoma. Most of these involve the drainage system within the eye. At the front of the eye, there is a small space called the anterior chamber. A clear fluid flows through this chamber and bathes and nourishes the nearby tissues.
For unknown reasons, in glaucoma, the fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye rises. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye, resulting in loss of vision.
The most common type of glaucoma is called open-angle glaucoma. In the normal eye, the clear fluid leaves the anterior chamber at the open angle where the cornea and iris meet. When fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
There is no cure for glaucoma. Vision that is lost due to this disease cannot be restored. There are, however, treatments that may save remaining vision. That is why an early diagnosis is important.
Causes and risk factors
In addition to age, eye pressure is a risk factor. Whether or not one develops glaucoma depends on the level of pressure one’s optic nerve can tolerate without becoming damaged. This level is different for each person. That is why a comprehensive dilated eye exam is very important. It can help the eye care professional determine what level of eye pressure is normal for that particular individual.
Another risk factor for optic nerve damage relates to blood pressure. Thus, it is important to also make sure that your blood pressure is controlled by your doctor at a correct level.
Symptoms and tests
Glaucoma can develop in one or both eyes. The most common type of glaucoma, open-angle glaucoma, has no symptoms at first. It causes no pain and vision seems normal.
Without treatment, people with glaucoma will slowly lose their peripheral, or side vision. They seem to be looking through a tunnel. Over time, straight-ahead vision may decrease until no vision remains.
Glaucoma is detected through a comprehensive eye exam that includes a visual acuity test, visual field test, dilated eye exam, tonometry, and pachymetry.
Although open-angle glaucoma cannot be cured, it can usually be controlled. While treatments may save remaining vision, they will not improve sight already lost due to glaucoma.
The most common treatments for glaucoma are medication and surgery.
Medication for glaucoma may either be in the form of eye drops or pills. Some drugs reduce pressure by slowing down the flow of fluid into the eye. Others help to improve fluid drainage.
Laser surgery is another treatment for glaucoma. During laser surgery, a strong beam of light is focused on the anterior chamber where the fluid leaves the eye. This results in a series of small changes that makes it easier for fluid to exit the eye.
Protecting your vision if you are “high-risk”
Data from population-based surveys indicate that one in 40 adults over the age of 40 suffer from glaucoma with loss of visual function, which equates to 60 million people worldwide being affected and 8.4 million being bilaterally blind. Even in developed countries, half of the cases of glaucoma are undiagnosed. Glaucoma is mostly asymptomatic until late in the disease when vision problems arise.
So, if you fall into one of the higher risk groups for glaucoma disease, make sure to have a comprehensive dilated eye exam, at least once every two years, by an ophthalmologist.
This article has been submitted by the Department of Ophthalmology at the HPA Health Group.