Genetic testing can provide early detection of macular degeneration, and possibly save patients’ vision
A leading cause of blindness for those 55 and older that aff ects more than 10 millionAmericans, macular degeneration is caused by deterioration of the central portion ofthe retina, known as the macula, and characterized by loss of central vision.
By MIKE CULLITY | NEW HAMPSHIRE SUNDAY NEWS-
A FEW YEARS AGO, GaryHermsdorf learned hewas in the early stagesof age-related maculardegeneration.A leading cause of blindnessfor those 55 and older that affectsmore than 10 million Americans,macular degeneration is caused bydeterioration of the central portionof the retina, known as the macula,and characterized by loss of centralvision, according to the AmericanMacular Degeneration Foundation.The disease robbed Hermsdorf’suncle of his vision, but the 66-yearoldHooksett retiree is determinedto avoid the same fate.“Seeing that happen to my uncleand knowing I was starting downthe same road, I would and will doabsolutely anything that will helpme,” he said.Recently, Hermsdorf’s eye doctortold him about a new DNA testfor patients diagnosed with earlyforms of macular degeneration thatidentifi es those most likely to progressto more advanced forms ofvision loss. The test, called MaculaRisk, uses genetics and smokinghistory to identify a patient’s risklevel.New Hampshire Eye Associates,the Manchester practice whereHermsdorf is a patient, beganoffering the test late last year, saidAnthony Correnti, the eye surgeonand retina specialist who treatsHermsdorf. The practice is one ofonly about 500 that offer it nationwide,Correnti said.The prevalence of maculardegeneration among its patientsprompted New Hampshire EyeAssociates to introduce the test,Correnti said. “About 70 percent ofthe patients I see are dealing withsome form of it,” he said.People with early maculardegeneration have no symptomsor vision loss, according to the NationalEye Institute. The hallmarksof the condition are drusen, or fi neyellow deposits under the retina detectable only by an eye exam,Correnti said.Early macular degeneration isone of three stages of the “dry”form of the disease, which is typified by gradual vision loss.“Sometimes the changes happen so slowly that people don’t realizeit until they’ve lost almost all theirvision in one eye,” Correnti said.While 90 percent of those withmacular degeneration suffer fromthe dry form, the disease also hasa “wet” form that occurs whenabnormal blood vessels behind theretina start to grow under the macula,damaging it rapidly by leakingblood and fluid, according to the National Eye Institute.
Dry maculardegeneration always precedes thewet form, which can cause the lossof central vision quickly, accordingto the institute.“It’s like blackout almost,” Correntisaid.By identifying patients most atrisk for advanced forms of the disease,the Macula Risk test can helpphysicians intervene to prevent visionloss, Correnti said. For higherriskpatients, New Hampshire EyeAssociates typically recommendsmore frequent eye exams and canprescribe high-dose vitamins thathave been shown to slow the progressof dry macular degeneration,Correnti said.By monitoring high-risk patientsmore frequently, the Manchesterpractice also hopes to increaseearly detection of wet maculardegeneration, which can be treatedwith injections that stop bleedingand fl uid development, Correntisaid.“Hopefully that will lead to improvedoutcomes,” he said.The Macula Risk test, which consistsof two simple cheek swabs, iscovered by most insurance providersand Medicare, Correnti said.“Physicians’ offi ces don’t makemoney off this test,” he said.While offering the test to itsown patients with early forms ofmacular degeneration, New HampshireEye Associates is also happyto accommodate patients referredfor the test from other practices,Correnti said.After Correnti explained the testto Hermsdorf, the Hooksett manquickly agreed to it.“I could see absolutely no downside,” Hermsdorf said. “It was all tomy benefi t.”The test showed Hermsdorf tobe at a moderate risk for advancedmacular degeneration, he said. Asa result, he has already discussedincreasing his eye exams from onceto twice a year and plans to bemore attentive to his Amsler grid,an eye chart that can help detectchanges in his condition.Treatment plans aside, the testgave Hermsdorf peace of mind.“I’m thankful to be (at moderaterisk), frankly,” Hermsdorf said. “Itlooks like with the proper vigilance,I should be all right.”
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