Accidental subretinal brilliant blue G migration during internal limiting membrane peeling surgery.

IMPORTANCE: This case report describes a man who developed retinal changes in his right eye associated with brilliant blue G migration into the subretinal space during 2 years of follow-up. OBSERVATION: The patient's best-corrected visual acuity in the right eye was 20/70 before surgery, and it improved to 20/25 at 1 year after surgery. Fluorescein angiography showed staining during the late phase in the central macula at all follow-up visits after surgery. Multifocal electroretinography demonstrated normal amplitude and implicit times before surgery but decreased amplitudes and increased implicit times in at least 5 contiguous hexagons after surgery on all 3 examinations performed during the 2-year follow-up period. These functional changes were not topographically correlated with the area of fluorescein staining or with the internal limiting membrane peeled area, but were matched to the area where brilliant blue G accidentally entered the subretinal space. Microperimetry demonstrated reduced retinal threshold sensitivity, particularly in areas with decreased multifocal electroretinography amplitude. CONCLUSIONS AND RELEVANCE: Despite the visual acuity improvement observed in this case, multifocal electroretinography and microperimetry indicate that subretinal brilliant blue G might cause focal macular damage with a decrease of macular function suggestive of a toxic effect.