ULTRASOUND BIOMICROSCOPIC IMAGING OF THE EFFECTS OF YAG LASER CYCLOABLATION IN POSTMORTEM EYES AND LIVING PATIENTS

Purpose: The authors performed a series of experiments designed to det ermine if early effects of YAG laser cycloablation could be detected b y ultrasound biomicroscopy in postmortem eyes and living patients. The y also designed an apparatus that allowed simultaneous ultrasound biom icroscopic imaging of YAG laser cycloablation. Methods: Treated and un treated regions of postmortem eyes treated with YAG cycloablation were imaged and compared. Treatment was placed at varying distances from t he limbus in postmortem eyes and the resulting effects imaged. Histolo gic examinations were performed after imaging. Six living patients had ultrasound biomicroscopy before and after YAG cycloablation. An appar atus combining contact YAG laser and ultrasound biomicroscopy was used in postmortem eyes. Results: Early treatment effects imaged included ciliary epithelial disruption, ciliary epithelial separation, and bubb le formation. Ultrasound biomicroscopic findings varied with the dista nce of treatment from the limbus and were maximal below the treatment site. Results of histologic examination showed close correlation to th e ultrasound biomicroscopic images. Similar findings to those found in postmortem eyes were found in living patients after treatment. The ap paratus combining contact YAG and ultrasound biomicroscopy allowed rea ltime imaging of effects of YAG laser cycloablation. Conclusions: The ability of ultrasound biomicroscopy to detect changes associated with cyclodestructive procedures potentially could provide us with a method of improving treatment precision and correlating treatment effect wit h clinical response.