Neodymium-YAG transscleral cyclocoagulation in rabbit eyes.

Transscleral ruby cyclocoagulation has been successfully used to lower intraocular pressure. The recent commercial availability of Nd-YAG lasers with a thermal mode provides a possible alternative by which to perform this procedure. We treated one eye of seven pigmented rabbits using the thermal mode of the Nd-YAG laser. The intraocular pressures were followed up for three months. The treated eyes had significantly lower mean intraocular pressures were followed up for three months. The treated eyes had significantly lower mean intraocular pressures than the untreated contralateral eyes (p less than 0.001). Moreover, the decrease was sustained over the three-month duration of the study. Pathological examination revealed very selective destruction of the ciliary processes, with sparing of the overlying ciliary muscle, sclera, and conjunctiva. The potential value of this mode of therapy for use in patients with glaucoma is discussed.