[Retinal ICG-accumulation after ILM-staining during macular hole surgery?]

In earlier animal studies retinal accumulation of ICG after intravitreous application with subsequent transport to the optic nerve could be observed. In order to evaluate the possible retinal accumulation of ICG after ILM staining during macular hole surgery and to examine the potential changes in optic nerve function, a prospective study was initiated.

In 20 patients with macular holes grade 3, vitrectomy with ICG staining of the ILM (0.3 ml of a 1:10 diluted ICG solution under air), consecutive ILM peeling, and finally gas tamponade were performed. Preoperatively and 2, 4, 8, 12, and 24 weeks after vitrectomy, all patients underwent normal ophthalmological examination, native ICG picture, VEP examinations, and central visual field examination.

Retinal ICG accumulation in the area of the macular hole, in the retinal axons at the temporal arcades, and around the optic disc could be observed in all 20 patients. This staining with ICG was progressively transformed towards the optic disc at the 4- and 8-week examinations. At the 12-week examination, ICG staining around the optic disc was still visible in all patients. The function of the optic nerve (VEP) demonstrated only minor changes during follow-up, and in the visual field examinations no peripheral changes could be observed.

After ILM staining with ICG during macular hole surgery even with highly diluted ICG solutions an accumulation of ICG in the retinal ganglion axons was observed. This accumulation was visible shortly after surgery at the macular hole, temporal arcades, and the optic disc. The predominant staining of ICG at the optic disc during follow-up can be interpreted as transport of the accumulated ICG in the retinal axons and optic nerve. There seem to be no functional implications for optic nerve function and visual field examinations.