Anterior segment indocyanine green angiography in scleral inflammation

Purpose To assess the feasibility of using indocyanine green angiography in scleral inflammation; to define the characteristic patterns of the anterior segment vasculature for this anterior segment disease; and to correlate the findings with those of anterior segment fluorescein angiography. Methods Anterior segment fluorescein and indocyanine green digital angiography were used to evaluate scleral inflammation in 3 patients with diffuse episcleritis, 2 patients with nodular episcleritis and 5 patients with nodular scleritis. Angiograms from both techniques were assessed based on the time for complete disappearance of the dye and the type of leakage. Results Both fluorescein and indocyanine green dye appeared in vessels at approximately the same time, but, whereas fluorescein had disappeared completely from vessels by the 70th second, indocyanine green was observed within vessels for up to 23 min. Leakage of fluorescein occurred in all patients with diffuse episcleritis but staining occurred in only 1 patient with nodular scleritis. No leakage of indocyanine green, or staining, occurred in patients with diffuse episcleritis. However, leakage of indocyanine green was apparent in all nodular episcleritis and scleritis patients, staining the nodules in patchy form. Conclusion The longer transit time, as well as leakage and staining patterns due to its protein-binding properties, make indocyanine green angiography a potentially useful technique in the investigation of patients with scleral inflammation, and in distinguishing diffuse from nodular variants. Further studies are necessary to correlate staining patterns with clinical findings.