PREVALENCE AND ASSOCIATIONS OF EPIRETINAL MEMBRANES - THE BLUE MOUNTAINS EYE STUDY, AUSTRALIA

Purpose: The purpose of the study is to determine the prevalence and a ssociations of epiretinal membranes in a defined older Australian popu lation and to assess their influence on visual acuity. Methods: Three thousand six hundred fifty-four persons 49 years of age or older, repr esenting 88% of permanent residents from an area west of Sydney, under went a detailed eye examination, including stereo retinal photography, Epiretinal membranes were diagnosed clinically and from photographic grading. Results: Signs of epiretinal membranes were found in 243 part icipants (7%; 95% confidence interval [CI], 6.1, 7.6), bilateral in 31 %. The prevalence was 1.9% in persons younger than 60 years of age, 7. 2% in persons 60 to 69 years of age, 11.6% in persons 70 to 79 years o f age, and 9.3% in persons 80 years of age and older, with slightly hi gher rates in women. Two stages were identified: an early form without retinal folds, termed ''cellophane macular reflex'' present in 4.8%, and a later stage with retinal folds, termed ''preretinal macular fibr osis'' (PMF), found in 2.2% of the population. Preretinal macular fibr osis, but not cellophane macular reflex, had a small, significant effe ct on visual acuity. Preretinal macular fibrosis was significantly ass ociated with diabetes, after age-gender adjustment, in subjects withou t signs of diabetic retinopathy (odds ratio, 3.2; 95% Cl, 1.4, 7.2). P reretinal macular fibrosis also was associated with increased fasting plasma glucose (odds ratio, 1.2, 95% CI, 1.1, 1.3). Epiretinal membran es were found in 16.8% of persons who had undergone cataract surgery i n one or both eyes (including PMF in 3.7%), in 16.1% of retinal vein o cclusion cases (PMF in 12.5%), both significantly higher rates than in subjects without these conditions (P < 0.0001), and in 11% of persons with diabetic retinopathy (PMF in 3.6%), not significantly higher (P = 0.17). Conclusions: This study hss documented the frequency and mild effect on vision of epiretinal membranes in an older population. Diab etes was associated significantly with idiopathic cases, whereas well- known associations with past cataract surgery and retinal disease were confirmed.