A new glaucoma surgery is proposed in which Er:YAG (infrared) laser energy is used to remove trabecular tissue atraumatically. Phase I results clearly demonstrated the feasibility of the technique and showed on the basis of histology the optimum values of laser pulse width that minimized associated mechanical and thermal damage. Primate studies indicated persistent lowering in intraocular pressure could be achieved. In Phase II Candela Laser will complete the development of a clinically useful laser, fiber optic delivery system and intraocular probe. The preclinical studies will be completed to refine laser and ablation parameters and a novel technique will be developed for the potential measurement of changes in outflow facility intraoperatively. This would provide the physician with an indication of efficacy at the time of surgery. A pilot clinical study will be conducted in 20 patients to establish the safety and effectiveness of this new laser treatment for the purpose of decreasing IOP and preserving the visual field. Trabecular surgery is a potentially attractive alternative to filtration surgery because of theoretically lower incidence of postoperative hypotony, flat anterior chambers, scarring in the subconjunctival space, and late endophthalmitis from infected blebs.