Remote interpretation of fundus images

Fundus images were graded by two masked retina specialists. Reading stations followed NHS quality guidelines, which recommend a screen size of at least 17 inches diagonally.[18] The retina specialists received batches containing approximately 400 randomly selected images from any three imaging modalities. Photographs from the same patient taken with different cameras were not included in the same batch to minimize bias from seeing potentially higher quality images of the same fundus. The retina specialists graded each field (macular, superotemporal, nasal) according to predefined quality criteria of excellent, acceptable, and ungradable (eFigure 1 - available online). These quality standards were based on guidelines set forth by the NHS to distinguish between adequate and inadequate images.[19] The two retinal specialists that took part in this study agreed upon additional standards to further distinguish between excellent and acceptable images for those images that were defined as adequate by NHS guidelines.