diagnostic focus

Genetic Testing for Your AMD Patients

A test identifies those most likely to progress to wet AMD and vision loss.

Tara Rosenzweig

Genetics account for more than 70% of a person's risk of getting age-related macular degeneration (AMD), and having a first-degree relative with AMD significantly increases the likelihood that a person will get the disease themselves.

Genetics also play a significant role in the progression of AMD. Macula Risk (www.macularisk.com), a test intended for patients ages 65 and older who have been diagnosed with early or intermediate AMD, tests for several genetic markers and accounts for age and smoking status to predict the patient's risk for progressing to advanced (wet or exudative) AMD.

Available only through an eyecare professional (ECP), the test consists of a simple cheek swab, taken in the ECP's office, which is sent to a lab. With the test results, the ECP can then prescribe the most effective course of treatment. In patients who are at risk to progress to wet AMD, for example, treatment may include lifestyle or dietary changes.

Saving both eyes

Gary Morgan, O.D., of Eye Tech in Peoria, Ariz., explains that 80% of wet AMD patients present with a blind eye. “In the past, the goal was to save the second eye,” he says. “With Macula Risk, we can now concentrate on trying to save the first eye.”

“[Macula Risk] has the potential to not only help the doctor formulate a treatment plan, but to help educate patients about the importance of the doctor's plan,” says Jeffry D. Gerson, O.D., of West-Glen Eyecare in Shawnee, Kan.

Optometrist David Nelson of Eye Contact in Beloit, Wis., says that the Macula Risk test results can be surprising because some patients who have significant eye disease will actually have a low risk of vision loss from wet AMD—and vice versa—according to the test.

“What I have noticed is that I'm not sure who will be at higher risk based only on what I see in the eye,” he explains.

In addition, Jerome Sherman, O.D., professor at the College of Optometry at the State University of New York in New York City, says that two patients may look clinically identical but can score at opposite ends of the Macula Risk scale. “This specific test is more powerful than knowing the genetic history,” he adds.

The best time to educate patients about genetic testing for AMD is in the exam room, says Dr. Gerson. “When I see a patient with drusen or other early AMD changes, as soon as I finish my exam, I describe the findings and the test,” he says. “I tell them the test is optional, but I recommend it to them and tell them how easy it is to take.”

Treatment protocols

According to Dr. Morgan, the suggested follow-up schedule for patients in the Macula Risk categories MR1 and MR2 (less than average or average risk of developing vision loss by age 80) is annually; MR3 (moderate risk) every six months; MR4 (high risk) every four months and MR5 (very high risk) every three months.

“At follow-up visits I perform a dilated exam of the macula and usually perform OCT,” Dr. Morgan says. “I also use preferential hyperacuity perimetry (PHP) testing to monitor patients when appropriate.”

Dr. Sherman says that for patients falling into the highest risk category, “We will do procedures such as OCT, fundus autofluorescence, possibly microperimetry, and certainly fundus photography.”

Like Dr. Morgan, Dr. Sherman says he also recommends PHP testing so that patients can monitor their condition at home for possible rapid progression to advanced AMD.

“Explanation and prescribing lifestyle changes—exercise, smoking cessation and nutrition counseling—are preventative treatment plans,” says Dr. Nelson. In addition, he says supplementation of carotenoids and high-quality fish oils are very important for patients who have a high score on the Macula Risk test, early signs of AMD or a significant family history of the disease.

Coverage and reimbursement

Macula Risk is covered by most insurance providers including Medicare, according to Dr. Morgan. However, the patient must have a diagnosis code (ICD-9) for AMD to obtain reimbursement, he says.

“Paperwork for each patient, including their insurance information, is submitted to the laboratory along with their DNA sample,” Dr. Morgan explains. The laboratory bills the patient's insurance carrier for the test. The O.D. isn't paid for the test and doesn't need to collect any money from the patient or submit any bills to insurance providers. OM