Neodymium YAG and dye laser iridotomy--a comparative study.

A prospective, randomised study compared Neodymium:Yttrium Aluminium Garnet (Nd:YAG) and dye laser iridotomy in 100 eyes of 61 patients for the relief of pupil block glaucoma. Nd:YAG laser iridotomy was accompanied by less severe complications at the time of iridotomy--failure to produce full-thickness iridotomy, post-laser hypertensive response, bleeding, dissemination of pigment throughout the anterior chamber and posterior synechiae formation--than the dye laser. Nd:YAG laser iridotomy initially achieved relief of pupil block in all the eyes undergoing this procedure. However, the overall success rate of Nd:YAG iridotomies over the 3 months' follow-up period fell to 78 per cent due to inability of small iridotomies to relieve pupil block (4 eyes), and closure of iridotomies by iris pigment epithelial proliferation (3 eyes) and/or stromal healing (3 eyes). In patients with narrow angle glaucoma severe, and in cases prolonged elevations of intraocular pressure occurred following iridotomy with both lasers. Significant lens damage occurred in 5 eyes following dye laser iridotomy.