Observation of the ocular fundus by an infrared-sensitive video camera after vitreoretinal surgery assisted by indocyanine green

Purpose: To investigate how long indocyanine green (ICG) dye remains in the ocular fundus and how the remaining dye interferes with ICG angiographic findings after vitreoretinal surgery assisted by ICG. Methods: Eight eyes with macular hole, three with epiretinal membrane, and one with an a intraocular foreign body were included. Those patients underwent vitrectomy facilitated by an intraocular administration of ICG. An infrared sensitive video camera was used to take fundus pictures pre- and postoperatively. In 2 of 12 cases, the authors performed ICG angiography at 2 weeks and at 3 months after the surgery. Results: At 1 month after surgery, diffuse hyperfluorescence was observed throughout the posterior pole of the ocular fundus in all cases. The area where macular hole existed before the surgeries revealed hyperfluorescence in 6 of 8 eyes with macular hole (75%). These hyperfluorescent findings became less prominent with time postoperatively, while optic disk hyperfluorescence persisted for 12 months in all cases. In the early phase of ICG angiography at 2 weeks postoperatively, the retinal and choroidal circulation could be depicted. However, in the middle phase the choroidal veins were hardly visible. The angiographic pictures of the late phase mimicked those seen without intravascular administration of ICG. Even at 3 months after surgery, the optic nerve head revealed hyperfluorescence in the middle and late phases. Conclusions: The residual ICG in the ocular fundus produced prolonged hyperfluorescence after surgery. This abnormal condition affected ICG angiographic findings in the middle and late phases.