Reduced light sensitivity due to impaired retinal perfusion in branch retinal vein occlusion

To study the reduction in light sensitivity in areas where impaired retinal perfusion was established by fluorescein angiogram (FA) in eyes with branch retinal vein occlusion (BRVO) that recovered from retinal edema and hemorrhage. Retrospective observational case series. A study of the reduction in light sensitivity demonstrated by total deviation display of the Humphrey perimetry program 30-2 in 43 eyes from 42 patients with BRVO, whose perfusion status was assessed by FA images taken at least 6 months after disease onset. Each of the 15 retinal squares in the FA images, corresponding to the 15 Humphrey test points around the fixation point in the affected vertical hemisphere, was classified as either perfused, partially perfused, or non-perfused. Correlation between light sensitivity and perfusion status was investigated by three evaluators in a total of 645 squares, 15 squares from each of the 43 subject eyes. In 459 retinal squares (71.2%) with complete agreement on the perfusion status among the three evaluators, light sensitivity was significantly different among retinal squares of perfused (median: - 4.0 dB, n = 258), partially perfused (median: - 8.0 dB, n = 41), and non-perfused (median: - 16.0 dB, n = 160) (P < .000001, Kruskal-Wallis test). Light sensitivity is decreased in retinal areas exhibiting impaired perfusion, likely due to neuronal loss in the inner retinal layer in eyes with chronic BRVO.