Internal sclerostomy with the Er:YAG laser using a gradient-index (GRIN) endoscope

BACKGROUND AND OBJECTIVE: To show that sclerostomy, a glaucoma filtering surgery, can be performed using an Er:YAG laser. Scarring at the filtering site, a recurrent problem, may be reduced through proper positioning of the sclerostomy by using an intraocular endoscope. MATERIALS AND METHODS: Ab interno fullthickness sclerostomies were performed on eye bank eyes with an Er:YAG laser through a custom made optical delivery system. The intraocular laser probe consisted of a low OH silica fiber inserted in a metallic tapered sheathing. A rigid intraocular endoscope based on gradient-index lenses allowed visualization of the filtration site. RESULTS: A clear view of the anterior chamber angle was obtained through the endoscope, allowing for precise location of the sclerostomy. Full-thickness sclerostomies could then be performed at the desired location. Histologic sections showed thermal necrosis less than 50 μm thick in tissue adjacent to the sclerostomy. CONCLUSIONS: A sclerostomy performed with a combined procedure using an Er:YAG laser and intraocular endoscopy increases the speed of the procedure. The use of a high-resolution intraocular endoscope may increase the success rate of ab interno laser glaucoma surgeries.