Effect of squalamine on iris neovascularization in monkeys.

PURPOSE: To investigate the effect of squalamine, an antiangiogenic aminosterol, in an experimental model of iris neovascularization.

METHODS

Iris neovascularization was created in cynomolgus monkeys by occluding retinal veins with an argon laser and inducing persistent hypotony with a central corneal suture. Twenty-four eyes were treated in three groups. In Group 1, four eyes were injected intravitreally with 3 microg/0.1 mL squalamine and four eyes with balanced saline solution (controls) immediately after vein occlusion (day 1); injections were repeated every 3 days for 3 weeks. In Group 2, 1 mg/kg squalamine was administered with intravenous infusion in dextrose 5% in four animals; four control animals received only dextrose. Infusions began on day 1 and were repeated every 3 days for 3 weeks. In Group 3, after development of iris neovascularization on day 7, 1 mg/kg squalamine was injected systemically in four animals; four control animals received dextrose 5%. Monkeys were examined by slit-lamp biomicroscopy and underwent color photography and fluorescein angiography.

RESULTS

Group 1: All eyes, treated and control, developed intense and persistent rubeosis iridis. Group 2: Two of the four treated eyes in this group developed minimal iris neovascularization; the other two had no iris neovascularization. All four control eyes developed intense, persistent iris neovascularization. Group 3: All eyes developed extensive rubeosis iridis; iris neovascularization regressed in all four treated eyes after squalamine injections. Two of four treated eyes retained minimal iris neovascularization; two showed complete regression of rubeosis iridis. Rubeosis iridis completely regressed in two of the four control eyes; the remaining two control eyes had intense, persistent iris neovascularization.

CONCLUSIONS

Intravitreally injected squalamine did not affect the development of iris neovascularization; however, systemic squalamine injection inhibited the development of iris neovascularization and caused partial regression of new vessels in a primate model.