Eyeworld

EW NEWS & OPINION 26 May 2016 "We are hoping to look at some larger population-based studies that have sleep histories and AMD to see if the correlation holds up in larger analyses," he said. EW Reference 1. Khurana RN, et al. Increasing sleep duration is associated with geographic atrophy and age-related macular degeneration. Retina. 2016;36:255–258. Editors' note: Dr. Khurana has no financial interests related to his comments. Contact information Khurana: rnkhurana@gmail.com by Michelle Dalton EyeWorld Contributing Writer Clinical relevance While the average hours of sleep ranges between 7 and 8 hours per night, those with GA slept more than that, averaging 9 or so, Dr. Khurana said. "Sleeping more than 8 hours is associated with an increased risk of GA 7-fold," the study authors wrote. But association does not imply causation, Dr. Khurana said. "It's always challenging to differentiate between causation and correlation," he said. "AMD is correlated with depression and now with altered sleep patterns, but is the depression causing the altered sleep patterns or is the AMD causing it? Patients with GA have poor vision (since there are no treatments), which leads to depression and al- tered sleep patterns." The study authors noted de- pression and visual acuity were not analyzed, which could be potential confounders in the association be- tween increased sleep time and GA. A new study suggests longer sleep durations are associated with geographic atrophy S leep affects health—that is a well-accepted prem- ise. Too much or too little sleep has been associat- ed with total mortality, cardiovascular disease, diabetes, and hypertension. Two of those—cardio- vascular disease and hypertension— are also risk factors for age-related macular degeneration (AMD). Now, according to a group of researchers, longer sleep duration may also be a risk factor for geographic atrophy (GA). Rahul Khurana, MD, and colleagues prospectively evaluated the sleep patterns of 1,003 patients who presented in a retina practice in Mountain View, California. A masked ophthalmic exam was per- formed and graded, and the relation- ship between AMD and sleep hours was analyzed in a logistic regression model, Dr. Khurana said. "Clinicians taking care of pa- tients with AMD should be aware of these altered sleep patterns and be on the lookout for depression in this population," Dr. Khurana said. "Patients with low vision have high rates of depression, and we should be aware of these other comorbidi- ties affecting this population." Patients had been graded as no AMD, early AMD, neovascular AMD, or GA. As might be expected, patients with any form of AMD were older than those without AMD. Dr. Khurana said patients slept more with early AMD, neovascular AMD, and GA than those without AMD (averaging 8.17, 8.48, 9.00, and 7.97 hours, respectively). "The propensity of patients sleeping more than 9 hours with- out AMD, early AMD, neovascular AMD, and GA was 25%, 28%, 41%, and 51%, respectively," the study authors wrote. 1 Significantly more patients with GA slept more than 9 hours (51%) than those with any other form of AMD or those without AMD. How much sleep is too much? " We are hoping to look at some larger population-based studies that have sleep histories and AMD to see if the correlation holds up in larger analyses. " –Rahul Khurana, MD

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