The following is a summary of “Microperimetric analysis of eyes after macular hole surgery with indocyanine green staining: a retrospective study,” published in the October 2023 issue of Ophthalmology by Jun et al.
Indocyanine green (ICG) improves visualization of the internal limiting membrane (ILM), but its clinical toxicity during macular surgery is poorly understood. Researchers performed a retrospective study to evaluate ICG toxicity-related functional and structural changes in retinal sensitivity and thickness in patients with macular holes undergoing ICG-assisted ILM peeling.
The study applied ICG staining to the macular region beneath an imaginary horizontal line connecting the fovea and optic disc. ILM was peeled off across the entire macular area within the vascular arcade. Visual acuity, spectral domain optical coherence tomography, and microperimetry were conducted at 4-time points, mainly baseline, 1 month, 3 months, and 6 months after the surgery. The average retinal sensitivity in these 4 macular regions was then calculated and subjected to analysis.
The study involved 11 eyes, and successful closure of macular holes was achieved in all patients. After 6 months postoperatively, retinal sensitivity showed insignificant improvements in Area 1 (ICG-/ILM-) and Area 2 (ICG-/ILM+) but a decrease in Area 4 (ICG+/ILM-). In 3 months postoperatively, there was a significant decrease in retinal sensitivity in Area 3 (ICG+/ILM+; 26.63 ± 1.80 vs. 25.52 ± 2.08 dB, P= 0.036). The statistical significance of this result was no longer present six months after the surgery (P= 0.059). The change in Gc-IPL thickness in Area 3 was significantly different compared to Area 2 at both the 3- and 6-month postoperative time points (P= 0.01, 0.05).
The study found that ICG staining during macular hole surgery reduces retinal sensitivity at 3 months, but the effect resolves by 6 months.