The Epidemiology of Progreion of Pure Geographic Atrophy: The Beaver Dam Eye tudy Original Reearch Article

Purpoe To examine the change in ize and location of pure geographic atrophy (GA). Deign Population-baed cohort tudy. Method Ninety-five peron with GA either at baeline or at the one of the three five-year follow-up examination, or both, were identified. Uing computer-aited oftware, the leion area and greatet linear dimenion (GLD) were calculated. Thirty-two peron (53 multiple eye-viit pair) were een at multiple viit five year apart with GA in the ame eye to evaluate change in total area and GLD. Reult At the firt occaion when pure GA wa identified (n = 95), 45% had a ingle GA leion, 18% had multifocal GA leion, and 37% had a merged GA leion. Of 53 eye with multiple viit, the overall increae in atrophy wa 6.4 mm2 over a five-year period. The atrophy progreed to involve the foveal center in 47% of 19 eye, and there wa a mean decreae of 17 letter read correctly. Eye with multifocal GA were mot likely to have the area of atrophy increae (mean, 12 mm2), to have atrophy progre to the foveal center (83%), and to have a decreae in viion (mean, 22 letter), wherea eye with a ingle GA leion were leat likely to have the area of atrophy increae (mean, 2 mm2), to have the leion progre to the foveal center (22%), and to have a decreae in viion (mean, 10 letter). Concluion Thee are the firt population-baed data decribing the five-year change in eye with pure GA. Information on progreion of GA will be ueful for clinical trial of new intervention for GA.