Ophthalmologist Dr. William Bray of Rockwood Clinic explains how glaucoma rarely shows signs and symptoms before it's too late. Early diagnosis is key, so keep up with those eye exams.
Q: Give us a definition of glaucoma and its symptoms.
A: Glaucoma is a kind of optic neuropathy with characteristic visual field changes, often but not always associated with elevated intra-ocular pressure (IOP). Let me put that in understandable language: Optic neuropathy means there has been damage to the optic nerve, the nerve of sight, that goes from the eye to the brain. Too much damage to the optic nerve and a person cannot see well. The visual field changes mean that there is loss of vision, first in the peripheral vision and only late in the central vision. Most, but by no means all, patients with glaucoma have elevated IOP. There is a category (some say as much as 30%) that have normal IOP's but still have the characteristic optic neuropathy.
As far as symptoms, most people do not have symptoms until late in the disease. The defects in vision are often "holes" in the peripheral vision that are not noticeable until they get very large. There are some people that have a form of glaucoma known as "angle closure glaucoma" that can have symptoms of visual blurring, pain, redness, and halos around lights. This is because those people can have acute elevated IOP to very high levels with angle closure. If the pressure goes up slowly, usually there are no symptoms until the visual loss is very far advanced. And with glaucoma visual loss, once it is gone, it cannot be recovered.
Q: What can you do to prevent glaucoma?
The main risk factor for glaucoma is elevated IOP. Another big risk factor is genetics. Age also plays a role (the older you are, the higher the IOP gets). Race is also a risk factor, with glaucoma being more prevalent in African-Americans. High myopia (nearsightedness) is also a risk factor, as is diabetes in some studies.
As you can see from the risk factors, there is not a lot a person can do to prevent glaucoma. We can't pick our age, or race, or genetics. What can be prevented the vast majority of the time is the damage done to the optic nerve by glaucoma. That means getting the eyes checked regularly. And not just getting a pressure check for IOP, but having the optic nerve looked at by a knowledgeable eye care practitioner.
Q: Who is at most at risk of glaucoma?
See the above descriptions for risk factors: family history, age, African-American, highly nearsighted. People with any of those characteristics should have their eyes checked regularly. Diabetics are also at increased risk, and hopefully they are getting their eyes checked regularly for the diabetes.
Q: How important are regular eye exams in determining the risk of glaucoma for patients? As said in number 3 above people with risk factors should get eye exams yearly, especially after age 40. Only about 25% of people have obvious risk factors though, so people in general should get their eyes checked every couple years after age 40. The recommendations of the American Academy of Ophthalmology are for people to get yearly eye exams after that age. If people without risk factors get checked regularly, they can probably get by a little less often than yearly.
Q: Anything else you would like to add?
Glaucoma is one of the leading causes of blindness, both here in the US and worldwide. If detected early enough, and treated appropriately, visual loss from glaucoma can often be prevented, or at least slowed down. But early diagnosis is the key, so the need for regular eye check-ups becomes paramount. Most people with chronic glaucoma are treated with eye drop medications, although as many as 25% may go on to need either laser or incisional surgery to prevent visual loss.