Indocyanine green angiography of the anterior segment in patients undergoing strabismus surgery

Background-Anterior segment imaging using fluorescein angiography is only s uitable in Lightly pigmented irides as the brown pigmentation of the iris m asks fluorescein transmission. Indocyanine green (ICG) angiography has exce llent penetration of pigment epithelium and, therefore, has potential appli cation in detecting perfusion changes of dark irides after strabismus surge ry. Methods-A prospective study was conducted on patients older than 15 years u ndergoing strabismus surgery. A fundus camera was focused on the arteriolar tufts of the pupillary margin and 50 mg of ICG (concentration of 12.5 mg/m l) was given intravenously. Images were then obtained at 1 minute intervals of 5 minutes' duration. Results-45 patients with a mean age of 54.6 years and a mean follow up peri od of 8.6 weeks were studied. There were 23 patients in the primary surgery group, 11 in the secondary surgery group, and 11 in the staged group. Iris ICG angiograms were successfully performed in all patients. No persistent filling defect was detected in the primary and secondary horizontal recti s urgery groups or in the secondary or staged vertical and combined vertical rectus groups 6-8 weeks postoperatively. 57% of both primary vertical and c ombined vertical and horizontal groups showed defects in the early postoper ative phase. Only three cases demonstrated late perfusion defects in this s eries. Conclusion-ICG can detect iris perfusion changes in dark irides after strab ismus surgery. Iris reperfusion was achieved in the majority of the cases.