Preclinical investigation of internal limiting membrane staining and peeling using intravitreal brilliant blue G

PURPOSE: To investigate the effects of intravitreal brilliant blue G (BBG) on the morphology and functions of the retina and its possible use for staining and peeling of the internal limiting membrane (ILM). METHODS: Rat eyes (n = 78) underwent gas compression vitrectomy. BBG solution was then injected into the vitreous cavity. The eyes were enucleated at 2 weeks and 2 months. Light as well as electron microscopy, terminal nick-end labeling staining, and electroretinography (ERG) were used to investigate retinal damage and function. To test the clinical potential of BBG, ILM staining was evaluated in primate eyes after pars plana vitrectomy followed by ILM peeling. RESULTS: In the rat eyes, no pathologic changes were observed with light microscopy. Electron microscopy revealed that high doses of BBG induced vacuolization in the inner retinal cells, but apoptosis was not detected. There was no reduction in the amplitude of the ERG waves. In the primate eyes, the ILM was clearly visualized after the intravitreous injection of BBG and was peeled off easily from the retina. CONCLUSIONS: These results demonstrate that BBG, which has low potential for toxicity, high staining ability, and ease of handling, is a good candidate dye for ILM peeling.