Dose effect correlation of transscleral contact cyclophotocoagulation

Purpose: In recent years, transscleral contact-cyclophotocoagulation has increasingly been used for the treatment of therapy-refractive glaucomas. The dose-effect correlation varies according to different authors. In this retrospective study, we tried to determine whether there is a dose-effect correlation of transscleral contact-cyclophotocoagulation. Methods: Following diagnosis, 124 eyes of 113 patients (age range 49.9+/-26.5 yea rs) were included in the study. The laser parameters used were reviewed along with the intraocular pressure (IOP) before treatment, after treatment and during the follow-up (mean 6 months). Results: The IOP of 45.2% (56) of 124 eyes was <22 mmHg. In 25.8% (32 eyes) a retreatment was necessary. No correlation between energy and decrease of IOP was found (P-rs = 0.08 nonsignificant. Spearmann rank correlation). The IOP was reduced from 35.8+/-10.5 mmHg preoperatively to 26.3+/-10.5 mmHg at the end of follow-up (P approximate to O, Wilcoxon test). Therapy could be reduced by up to three antiglaucomatous drugs in therapy-refractive eyes. Conclusions: These data show that a decrease of about 10 mmHg of the IOP is possible using transscleral contact-cyclophotocoagulation. In therapy-refractive eyes, fewer drugs were needed to reach an IOP <22 mmHg. Regardless of the diagnosis, a dose-effect correlation between the decrease of IOP and laser energy was not found.