Everybody knows that their eye doctor is the best place to go for a vision check and a screening for diseases of the eye, like glaucoma, but it may be surprising to find that a dilated eye exam can be the window to total body health.
Most people dislike dilated eye exams and avoid them when possible. After all, we go to the eye doctor to help us see better. right? And, usually, a dilated exam isn’t necessary to tell a person how strong their glasses or contacts need to be. But as we age, the importance of regular dilated exams, every two years, grows. First and foremost, dilated eye exams are the standard way to check for diseases of the eye that come with age, like cataracts and age-related macular degeneration. Both conditions can steal a person’s sight. Cataracts, however, can be removed. Macular degeneration can only be treated and sight lost to it, is almost never regained.
Cataracts develop with age, as a result of trauma to the eye, or in some cases, because of medications prescribed for chronic conditions. Children who are born premature or with other birth defects can also sometimes be born with a form of cataracts.
Cataracts often develop slowly and people don’t notice the slow degeneration of their visual acuity. A cataract is a clouding of the natural lens of the eye, the clear fluid-filled sac behind the pupil that determines how light reaches the retina and the back of the eye.
A cataract makes that lens cloudy, or in extreme cases, to smoky to see through. Usually, cataracts develop in both eyes at the same time, though one is usually slightly worse than the other. Macular degeneration is a condition that occurs when the macula, a tiny portion of the retina, begins to fail. Some studies have shown that there is a correlation between poor nutrition and macular degeneration and there are some indications that it may run in families, but no one knows the exact cause of the disease yet.
What they do know is that the damaging effects of macular degeneration, sometimes called ARMD, cannot be reversed. At best, ophthalmologists can treat the condition and try to keep it from getting worse. Patients with macular degeneration lose their central vision, creating a confusing and sometimes frightening ability to see things “out of the corner of my eye” but not when it is directly in front of them.
In its earliest stages, the treatment for ARMD is to not smoke, take daily vitamins and monitor the condition. If it becomes an advanced case, sometimes called wet macular degeneration, because it indicates the problem has become so extreme that the tiny capillaries in the macula bleed, ophthalmologists can treat the problem with injections of various new medications and sometimes with laser therapy. However, sight lost to macular degeneration generally does not return, no matter what treatment. Treatment is offered to stop the vision loss from getting worse.
A third condition that can be monitored through a dilated exam, but diagnosed with almost any eye exam, is a glaucoma. Once a patient is diagnosed with glaucoma, it is likely his doctor will recommend yearly dilated exams so that the doctor can monitor the progress of the disease. Glaucoma is a condition that causes deterioration of the optic nerve, usually through high pressure in the eyes. A dilated exam lets the doctor look at the optic nerve and determine if damage is being done.
But in addition to these eye diseases and conditions, a dilated eye exam can help doctors determine what other systemic health problems might be plaguing the patient, sometimes before they are seen elsewhere.
The optic disk, the end of the optic nerve that is visible during a dilated exam, can clue doctors in to many health conditions including multiple sclerosis, lupus and ALS, commonly called Lou Gehrig’s disease. The optic disk also swells when there is unusual pressure on the brain or nervous system, such as when a patient has pseudotumor cerebri. Pseudotumor cerebri is a condition resulting from overproduction of spinal fluid, causing pressure on the brain. Often, the first symptoms are severe headaches and vision disturbances, meaning this condition is often diagnosed by eye doctors.
A dilated eye exam also allows doctors to look at the blood vessels in the back of the eye. Too many of them, or new growth of blood vessels, will probably result in your eye doctor sending you for follow up lab work with your general doctor for a diabetes check. Blood sugar levels that are too high for prolonged periods of time result in a condition called diabetic retinopathy, the growth of additional blood vessels in the retina. The new blood vessels are weak and brittle and often break, leading to bleeding on the retina. Bleeding can lead to vision loss.
Diabetic retinopathy is treated with lasers to destroy the extra blood vessels and lasers to seal the blood vessels that are leaking, as well as injections into the eye. Both the lasers and the injections are painful, so doctors recommend avoiding the problem. The best way to do that is to keep blood sugar levels under control.
Dilated eye exams can also help doctors to detect tiny blockages in the capillaries feeding blood to the eyes. Often, this is an early indicators that a person has excessive plaque in their veins and should be watched closely for signs of a stroke.
Visual changes can also be indicative of problems ranging from thyroid disease to brain tumors. So the next time your eye doctor suggests a dilated exam, bite the bullet, make a free hour and have the test done.
Dilation requires putting drops into the eyes to force the pupils to open up enough that doctors can see behind it. After the drops are put in, doctors will usually have you wait in a dimly-lit area for about 20 minutes for the drops to take affect.
After that, it’s simply a matter of lying back in the exam chair and letting the doctor take a look. The entire process usually takes about an hour, though your eyes may remain dilated for 6 to 24 hours after the exam, depending largely on eye color.
While your eyes are dilated, you will be a little more sensitive to light than usual and will not be able to focus on items up close. Your distance vision will likely be fine, but dialing a cell phone is a bit of a problem. If you are concerned about eye diseases, make a point to ask your doctor about the need for a dilated exam. Most doctors will happily assess your risk factors and determine if the additional exam is needed. If you do decide to have your eyes dilated, bring a driver to take you home. And, remember, an hour exam by the eye doctor can be a lot more pleasant than the needles and poking it might otherwise take to screen for various illnesses.