NEW SEMICONDUCTOR-LASER FOR VITREORETINAL SURGERY

Background and Objective: We investigated the potential application in vitreoretinal surgery of a CW diode laser with cutting capabilities. Study Design/Materials and Methods: A semiconductor CW laser emitting 300 mW optical power at 1.94 mu m wavelength was used to perform retin otomies and membrane cutting on rabbit eyes. The device was integrated into a dedicated controller. The laser radiation was delivered throug h a low attenuation fused silica optical fiber of 200 mu m core size, terminating into a 20-gauge endo-ocular handpiece. Histological aspect s of threshold lesions obtained on the rabbits' chorioretina were eval uated by light microscopy. Results: We obtained circular and linear fu ll-thickness retinotomies with contact and noncontact procedures using energy of 120 mJ (240 mW x 0.5 s). Using a non-contact procedure, a l arger peripheral coagulation halo around the retinotomies was observed , as compared to the contact method. The adjacent zone of thermal dama ge ranged from 50 to 200 mu m. Lower efficacy was obtained on experime ntally induced epiretinal membranes, where only superficial ablation w as achieved. Conclusion: The CW 2 mu m diode laser will have a promisi ng future in vitreoretinal surgery when a higher output irradiance is available. (C) 1996 Wiley-Liss, Inc.