TRANSSCLERAL PARS PLANA CHOROID ABLATION USING THE IRIDEX LASER SYSTEM YIELDS IMPROVEMENTS FOR SURGICAL INSERTION OF THE PORT DELIVERY IMPLANT IN A MINIPIG MODEL.

Abstract

To evaluate an alternative surgical approach for Port Delivery System with ranibizumab implant and a novel application of Iridex laser system in Gottingen minipig model. A total of 17 male minipigs (Part 1: nine animals in nonrecovery and Part 2: eight animals observed for 8 days after surgery Part 2) received Port Delivery System implant insertion into each eye. The effect of Iridex 810-nm infrared diode laser with varying energy (power or duration) on transscleral pars plana ablation surrounding ocular tissue and postsurgical vitreous hemorrhage was investigated. The most effective laser parameters for transscleral pars plana ablation in mitigating vitreous hemorrhage with no surrounding tissue damage were continuous wave mode, 1,750 mW, 1,000 ms, and 16 spots (eight overlapping spots/sweep applied over two rows) across a 4 mm segment, posterior to the limbus, delivering a total energy of 28 J. Minimal self-limiting scleral hemorrhage was observed with two of the implants, and no vitreous hemorrhage was observed. Microcomputed tomography imaging was consistent with clinical ophthalmic observations. On microscopic observations, no tissue damage was observed at these laser settings. This Göttingen minipig model demonstrated a novel application of Iridex laser for transscleral pars plana ablation that streamlines the Port Delivery System implantation surgery.