Residual Indocyanine Green After Internal Limiting Membrane Peeling and its Effect on Visual Acuity

Abstract

Abstract: : Purpose: Peeling of the internal limiting membrane (ILM) is a standard procedure in macular hole surgery. Indocyanine green (ICG) is often used as an adjunctive to visualize the ILM intraoperatively. Recently, ICG fluorescence was reported to remain long term after surgery in some cases, and ICG may produce toxicity directly or indirectly on retinal pigment epithelial cells. In this study, we evaluated ICG staining postoperatively and its effect on visual acuity (VA). Methods: We examined 40 (11 males, 29 females; 41 eyes) who underwent ICG-assisted ILM peeling 11 days to 19 months postoperatively. ICG fluorescence was observed using a scanning laser ophthalmoscope (SLO, Rodenstock) and a high-resolution digital ICG angiography camera (TRC-50IX, TOPCON). Results: ICG fluorescence was detected in all eyes using the TRC-50IX and in 35 (85%) eyes using the SLO. ICG fluorescence was observed in the disc and the entire posterior retina except the area from which the ILM was peeled within 6 months postoperatively, in the area along the vascular arcade and the disc between 7 to 12 months postoperatively, and in only the optic nerve disc after 12 months postoperatively. ICG fluorescence was detected at the fovea in 27 (66%) eyes after macular hole surgery. Postoperative VA was 0.46±0.53 (mean±SD) in eyes with ICG at the fovea and 0.42±0.55 in eyes without it (p=0.704). Conclusions: ICG remains on the retina or the disc for extended periods of time, at least up to 19 months after macular hole surgery. ICG fluorescence at the fovea does not seem to affect VA.

Keywords: macular holes • drug toxicity/drug effects • vitreoretinal surgery