A Simultaneous Iris Angiography Technique in Pigmented Rabbits

Abstract

Purpose: To report a simultaneous iris angiography (IA) technique combined with the use of indocyanine green (ICG) and fluorescein sodium (FS) in pigmented rabbits. Methods: 15 rabbits were randomly divided into 3 groups according to the dye doses: the dose of the lower-volume group was 2 mg FS and 2 mg ICG; the dose of the moderate-volume group was 5 mg FS and 5 mg ICG, and the dose of the higher-volume group was 8 mg FS and 8 mg ICG. Fifteen IAs were performed by a confocal scanning laser ophthalmoscope and a rapid localization technique giving a flat-on image. Results: Simultaneous digital angiography provided two kinds of a fully dynamic video of iris vessels fluorescein in all pigmented rabbits, which is the same in pigmented and albino rabbits and no vascular pattern was hidden by the iris stromal pigment. Furthermore, dye doses influenced the IA effect in rabbits. The lower-volume dye can demonstrate iris vessels, without obvious leakage, which, however, extinguish rapidly after 10–15 s. In the higher-volume group, vascular imaging lasted longer, but subsequently significant FS and ICG leakage appeared as streams on the surface of the iris until the dye disappeared from the iris vessels; the diffuse and intense aqueous fluid lasted 1 day. The moderate-volume dye displayed vessels clearly by ICG for 300 s, without leakage; FS clear vessels were maintained for about 15–20 s and the structure of the iris became fuzzy due to quick leakage. Conclusions: Simultaneous IA with a rapid localization technique allows high-quality imaging of the pigmented rabbits and the moderate dosage of 5 mg FS and 5 mg ICG is preferred for best visualization.