[Dose-response relationship of trans-scleral contact cyclophotocoagulation]

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.

Following diagnosis, 124 eyes of 113 patients (age range 49.9 +/- 26.5 years) 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).

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 (Prs = 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 approximately 0, Wilcoxon test). Therapy could be reduced by up to three antiglaucomatous drugs in therapy-refractive eyes.

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.