Standardized visual field assessment for patients with birdshot chorioretinopathy

Purpose: To adapt a standardized technique for assessment of visual fields to the study of patients with birdshot chorioretinopathy and to describe visual field patterns and changes over time for affected individuals. Methods: A retrospective chart review was performed of patients with a diagnosis of birdshot chorioretinopathy who had undergone at least two automated visual field studies. A masked evaluation of each visual field was performed using standardized criteria. Subjective symptoms and visual acuity measurements were compared to visual field data from the same examination dates. Serial visual field studies were evaluated for changes in the findings over time. Results: Six patients met inclusion criteria. A total of 104 visual field studies ( ranging from 2 - 19 studies per eye) were evaluated. Visual field abnormalities occurred in all tested eyes and were observed even in eyes with a Snellen visual acuity of 20/15. Discordant patterns were observed in the two eyes of some individual patients. On serial testing, multiple patterns of visual field abnormality were observed in the same eye over time. Conclusions: A standardized protocol for systematic evaluation of visual field measurements can be used to characterize disturbances of vision in patients with birdshot chorioretinopathy. Abnormalities of visual fields may occur even when central visual acuity is preserved.