Long-term outcome of trans-scleral diode laser cyclophotocoagulation in refractory glaucoma

Background: Long-term outcome and complications of diode laser cyclophotocoagulation (DCPC) may be important, since eyes, once treated with DCPC, are less likely to be subjected to other types of interventions in the further follow-up. Methods: Retrospective review of 131 eyes of 127 patients treated from 2000 through 2004. Success was defined as intraocular pressure (IOP) at last visit 6-21 mm Hg; hypotony: IOP <= 5 mm Hg. Results: Mean follow-up (FU) was 30.1 (SD 16.7) months. Mean number of treatment sessions per eye was 1.54, 89% of the eyes having 1 or 2 sessions; overall re-treatment rate: 38.9%. Mean total laser energy delivered per eye: 133.9 (73.7) J; mean energy per treatment episode: 86.8 (22.0) J. Eyes with 3 or more treatments (11%) had a significantly larger proportion of post-traumatic glaucoma, and patients were significantly younger. All eyes had refractory glaucomas on maximal medication, neovascular glaucoma (NVG) representing the largest subgroup (61%). IOP decreased from 36.9 (10.7) mm Hg pretreatment to 15.3 (10.4) mm Hg at the end of FU. Success was noted in 69.5% ( 91 eyes), failure (non-response) in 13%. Hypotony occurred in 17.6% eyes, of which 74% had NVG. Hypotony developed after mean 19.3 (11.0) months, range 6 to 36; with 96% of these eyes having received only 1 or 2 treatments; delivered energy did not differ from that in the successful eyes. Conclusions: DCPC is an efficient treatment for refractory glaucoma. Hypotony, the most common complication, may develop as late as 36 months post-treatment. Diagnostic category and age seem to influence the outcome stronger than laser protocol and delivered energy.