Retinal architecture as a determinant of brilliant blue G phototoxicity during internal limiting membrane peeling: A case series

BACKGROUND: Chromovitrectomy using vital dyes has become integral to internal limiting membrane (ILM) peeling in macular surgery. Although brilliant blue G (BBG) is considered safer than earlier dyes, emerging clinical and experimental evidence suggests that dye-light interactions during surgery may result in retinal phototoxicity under specific conditions. AIM: To describe the retinal phototoxicity features associated with BBG dye in patients undergoing ILM peeling for macular surgeries. METHODS: This observational, comparative, retrospective case series analyzed 9 eyes of 9 patients demonstrating retinal phototoxicity after uneventful BBG-assisted ILM peeling. Surgical indications included full-thickness macular hole (MH) in 4 eyes, epiretinal membrane associated retinal traction in 4 eyes, and vitreomacular traction in 1 eye. Retinal phototoxicity was assessed during clinical examination, using optical coherence tomography, and fundus autofluorescence imaging. Parameters such as preoperative and postoperative visual acuity (VA), macular thickness, BBG exposure characteristics (single/repeated staining, exposure duration, staining medium), and follow-up outcomes were recorded. Cases were grouped based on surgical indications: Group A (MH, 4 eyes) and group B (non-MH, 5 eyes). RESULTS: In group A, all cases showed foveal phototoxic damage along with macular involvement despite successful MH closure. Two eyes experienced worsened VA, while the other two maintained baseline VA. In group B, phototoxicity involved the macular region but spared the fovea; VA improved in 3 eyes (60%) and was maintained in 2 eyes (40%). Retinal toxicity, characterized by photoreceptor and retinal pigment epithelium damage, was evident within 1-4 weeks postoperatively. CONCLUSION: BBG-related retinal phototoxicity may occur following ILM peeling, with eyes undergoing MH surgery appearing more vulnerable, possibly due to the absence of protective foveal neurosensory tissue. Awareness of this potential risk may encourage surgeons to consider minimizing illumination intensity and dye exposure, and to adopt protective intraoperative strategies aimed at preserving foveal integrity and optimizing visual outcomes.