Purpose: To describe the impact of indocyanine green (ICG) staining of the internal limiting membrane (ILM) on the functional outcome of anatomically successful macular hole surgery by comparing consecutive patient series with and without ILM staining.
Methods: Eighteen consecutive patients who had undergone ICG-assisted vitrectomy (0.05%) for idiopathic macular hole were retrospectively analysed (visual acuity, gain in lines, Goldmann perimetry) and compared with two consecutive series of patients who had undergone macular hole surgery without the use of ICG immediately before (n=22) and after (n=17) the introduction of ICG in our institution. The osmolarity of the ICG solution applied was 275 mosmol, pH was 7.5.
Results: Although there was no statistically significant difference in duration of preoperative symptoms (P>0.3) and preoperative visual acuity (P>0.5), the functional outcome in patients after ICG-assisted vitrectomy was significantly lower (P<0.001 for visual acuity). The incidence of visual field defects was 50% (9/18) in patients after ICG application.
Conclusion: Our findings suggest potential damage to the neurosensory retina in association with the intraoperative administration of the ICG solution. Whether this is caused by toxic effects of the dye itself, mechanical trauma to the retina or other mechanisms remains unknown.