Changes in intraocular indocyanine green concentrations during macular hole surgery.

Purpose: To report changes in intraocular indocyanine green (ICG) concentration which was used for visualization of the internal limiting membrane (ILM) during vitreous surgery on 3 eyes of 3 patients with full-thickness macular hole. Methods: During intraocular surgery with ICG-assisted ILM peeling, aliquots of intraocular fluid obtained at 1 min after ICG administration (0.5 ml of 5 mg/ml ICG solution), before and after ILM peeling, and before and after fluid/gas exchange were subjected to spectrophotometric analysis. Results: Intravitreous concentrations of ICG were dramatically reduced to approximately 0.4 mu g/ml during the surgery for macular hole in all cases. Conclusion: The present study indicates that the levels of remaining intraocular ICG concentrations after macular hole surgery are much lower than the levels that induced retinal toxicity in experimental models.