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Don't wait for symptoms, the experts say: When you reach the age of 40, get a comprehensive eye exam.
“When you age, the risk factors start to increase. For instance, glaucoma in African Americans can be silent. It may not manifest itself until you've lost vision,” says William Benson, professor and chairman in the Department of Ophthalmology at the Virginia Commonwealth University School of Medicine. “Before age 40, nobody needs to go see an ophthalmologist for an eye exam unless they've been referred to us by their primary care physician for an abnormality that is unaccounted for.”
Benson says that, in the young adult, the rate of development of significant eye disease is low. “It increases steadily after the age of 40. So if you made it through your teenage years without any eye abnormalities, you're probably good to go until you’re 40.”
The American Academy of Ophthalmology recommends an exam by an ophthalmologist every two to four years for people age 40 to 54 with no risk factors, and every one to three years for those aged 55-64 who have no risk factors.
To many, seeing an eye specialist will be unfamiliar territory. But you've been getting your eyes checked since you were born — by your primary care doctor. Those checkups include the familiar visual acuity test, covering one eye and identifying letters of varying sizes with the other, which has roots in the Snellen eye chart, developed more than 150 years ago by Dutch eye doctor Hermann Snellen. “This test is sort of the vital signs for eye care. You won't ever get an eye exam without it,” says Rachel Bishop, special assistant to the clinical director of the National Eye Institute, an agency of the Department of Health and Human Services.
“The eye is a window into the soul. So we can evaluate the health of the blood vessels and blood flow and ... disease[s] like diabetes.” —William Benson, professor and chairman, Department of Ophthalmology, VCU School of Medicine
There's also the peripheral visual field test. “A person can maintain perfect 20/20 central vision but still be viewing the world as if they were looking through a tunnel,” Bishop says. That can be a symptom of glaucoma. She adds that the family doctor will also check to see that the eyes are in alignment and moving properly, and if the pupil reflexes are normal. “If any of those indicators are off, the doctor will recommend that you see an ophthalmologist.”
With an ophthalmologist's more comprehensive exam, Benson, who has given thousands of eye exams over 30 years, says that vision and pressure are thoroughly checked. “Those are our vital signs for the eyes,” he says. “They are markers for a healthy eye if normal or raise our suspicions if they're abnormal.”
If further diagnostics are needed, new screeners using light energies and various types of cameras can capture features that allow doctors to see the eye's anatomy and structure in more detail. “We are moving into a new age in eye health care where advances in imaging technology are enabling opticians to spend less time taking measurements, and more time analyzing the findings and providing patients with a tailored management plan,” reports Catharine Chisholm, former president of the British Contact Lens Association, in a recent U.K. interview.
One advance has been Optical Coherence Tomography. “It looks like an ultrasound of a baby,” says Bishop, “it can give fabulous information about the anatomy in the front and the back of the eye, and gives us a cross-sectional look at the retina.” It’s noninvasive and causes no discomfort.
Doctors today are also better able to see how blood flows in the eye. “A lot of diseases that rob patients of vision have to do with impaired blood vessel supply, such as in diabetes, or growth of abnormal blood vessels, such as macular degeneration,” she says. “So now we can see how blood is flowing without having to do the more complicated tests we used to do where we had to put dye in.”
She also mentions corneal mapping, which allows doctors to determine the exact shape of the cornea, important if you are going to employ laser reshaping, or Lasik surgery.
Through recent advances in eye care, doctors are also able to better chart a patient's overall health. “The eye is a window into the soul,” Benson says. “So we can evaluate the health of the blood vessels and blood flow and any metabolic or disseminated disease like diabetes, which is the most important diagnostic disease that we monitor through the eye.”
Eye exams can also provide clues on whether hypertension is having an impact on health, according to the American Heart Association. That can help in heading off a heart attack or stroke.
Still, Benson notes, the gold standard for eye examination remains dilating a patient’s pupils for a good look. “We do the same things now that we did 30 years ago when I started, and with the same equipment,” he says. “The only things that have advanced is the diagnostic testing available to us, that technology that goes into evaluating the retina in the back of the eye or the lens of the front of the eye, or the ocular pressure.”
“The pupils, in their normal state, keep extra light out, so it's hard to see in, to view all of the structures within the eye,” Bishop explains. “It's like looking into a room through a little keyhole, but if you dilate the pupils, you can have a good view of the complete structures within the eye, like opening the door instead of looking through the keyhole.”
In recent years, at-home vision monitoring devices — ranging in price from $39.95 to $99.95 — have appeared on the consumer market. Benson says they are “completely bogus,” and Bishop has major qualifications.
“I think, if they are set up properly, they can be very accurate,” she says. “The caveat is that there are things that we'll do in an eye exam that go beyond visual acuity. With these devices, you won't catch the most common eye diseases, like macular degeneration, or early diabetic retinopathy, or early glaucoma. Yes, these home devices can be useful, but they are not, in any way, a substitution for an eye exam.”
