James L. Hobart

RF excited CO2 slab waveguide laser

A transverse radio frequency discharge excited CO2 slab laser has been operated with hybrid waveguide/confocal resonator to produce an output power of 46 W. The active volume of 2.5x27x270 mm3 consists of a single discharge section with one cable feed. A spatial structure of radiation is presented.

Initial Clinical Experience With an Erbium:YAG Laser for Vitreoretinal Surgery

PURPOSE We tested the efficacy of an erbium:YAG laser for maneuvers in patients undergoing vitreoretinal surgery. METHODS An erbium:YAG laser equipped with a flexible fiberoptic and interchangeable 20-gauge endoprobes of various tip configurations ranging from 100 to 365 microns was used for specific maneuvers in 13 patients referred for vitreoretinal surgery for diabetic traction detachment, proliferative vitreoretinopathy, retinal detachment with posterior break, and epimacular membrane. The following maneuvers were performed: (1) transection of elevated vitreous membranes, (2) incision of epiretinal membranes, (3) drainage and relaxing retinotomy, (4) transection of subretinal membranes, (5) noncontact ablation of epiretinal membranes in air-filled eyes, (6) ablation of lens remnants, (7) posterior capsulotomy, (8) iris surgery, and (9) retinal vascular coagulation. RESULTS Forty-eight defined maneuvers were performed with energy levels ranging from 0.2 to 5.0 mJ and repetition rates of 2 to 30 Hz. Transection of elevated membranes, subretinal membranes, and retinotomies were easily performed. Fourteen incisions into vascularized epiretinal membranes in diabetic traction detachment surgery demonstrated a fine margin of coagulation that permitted hemostatic incision. Retinal breaks were created during one of these incisions. Lens remnant ablation, posterior capsulotomy, and iris tissue removal were successful, with a single complication consisting of damage to the posterior surface of an intraocular lens during a pars plana posterior capsulotomy accomplished by means of a side-firing probe. Epiretinal membrane ablations in air-filled eyes were effectively performed in a gradual fashion without hemorrhage. CONCLUSIONS The erbium:YAG laser offers precise and effective tissue cutting and removal in vitreoretinal maneuvers. Further study will determine the role of this technology in vitreoretinal surgery.