Genetic AMD Test Helps Predict Risk
BY Samantha Stahl, ASSISTANT EDITOR
Genetic risk assessment has gotten more spotlight as various tests aim to give physicians insight about patients’ futures.
RetnaGene AMD, from Sequenom Center for Molecular Medicine, is a laboratory-developed test that assesses risk of developing wet AMD. Proponents believe results may aid disease management before a patient experiences advanced vision loss.
While looking at patients’ family and smoking history, BMI and socioeconomic status can give an overview of AMD risk, these variables also provide opportunity for inaccuracies that could influence disease management incorrectly. Rather than relying on patient-reported factors, the RetnaGene test uses genetic markers that remain static throughout life.
Nancy Holekamp, MD, Director of Retina Services at the Pepose Vision Institute and Professor of Clinical Ophthalmology at Washington University School of Medicine in Saint Louis, uses the test almost daily for people who have drusen. She finds the test particularly useful for younger patients who wish to have some window into their medical future, and for those with macular pigmentary changes that may be drusen, but could also represent other diseases. “If the test score is low, then it’s likely these patients don’t have AMD, and it can be quite a big relief to them,” she says.
RetnaGene is simple to administer, according to Dr. Holekamp, who says her technicians are very adept at getting cheek swab samples that are then mailed to the Sequenom lab. Results come back within two weeks.
PUTTING RISK SCORE TO USE
Dr. Holekamp encountered a 61-year-old female patient whose mother had gone blind from advanced AMD. The woman had soft drusen in both eyes and was concerned about her risk for AMD. When the RetnaGene test reported a 92% chance of developing the disease, Dr. Holekamp recommended that the patient use an at-home AMD monitoring device. Within a few months, the patient got an alert from the device. Examination confirmed she had exudative AMD.
A spectra result of multiple AMD target mutations used in the RetnaGene test.
Fortunately, says Dr. Holekamp, “we caught it early, before any loss of vision, and she’s getting injections.”
Understanding risk score is only half the battle, considering there are few preventative measures a patient can take to halt disease development. Young people with drusen and high risk, she says, deserve education about what they can modify in their daily lives, as well as frequent monitoring.
Finding a low score can also have other clinical payoffs. A 67-year-old man diagnosed with AMD was placed in the CATT trial and received 24 anti-VEGF injections over the course of two years. His subretinal fluid never changed, so after exiting the study he came to see Dr. Holekamp for a second opinion. She found his changes more in line with old central serous retinopathy, so she performed the RetnaGene test and found that his risk score was extremely low — only 10%. She treated him with focal laser for central serous retinopathy; a month later, his fluid was less. In this case, the test helped to rule out AMD and support the best course of action.
“RetnaGene helps me explain why certain patients are refractory and need multiple injections,” she says. For example, a patient needed 18 injections in her left eye and 23 in her right eye before the disease was rendered inactive. “She took the RetnaGene test and had a 98% risk score — now her need for multiple injections makes sense to me. She did well and her vision is now 20/25.” RP
For more information, visit www.SequenomCMM.com.