Retinal hazards during laser irradiation of the iris.

Transpupillary pulsed laser radiation has been extensively studied to determine both the level at which it becomes a hazard to the retina (Ham, Williams, Mueller, Guerry, Clarke, and Geeraets, I966), and its effects on that tissue when such levels are exceeded (Marshall and Mellerio, I967a,b, I968). In spite of the development of various codes of practice to protect users, several accidents have been reported (Rathkey, I965; Zweng, I967; Curtin and Boyden, I968). More recently an attempt has been made to evaluate trans- scleral hazards (Smith and Stein, I968, i969), and safe levels have now been defined for both ruby and neodymium laser beams entering the eye through this tissue.