To examine the influence of irradiation methods on the long-term results of contact transscleral Nd:YAG laser cyclophotocoagulation and to evaluate the factors that affect changes in intraocular pressure (IOP) and occurrence of ocular hypotony after cyclophotocoagulation.

In this retrospective study, 36 refractory glaucomatous eyes of 36 patients were observed for at least one year after a cyclophotocoagulation procedure. Contact transscleral Nd:YAG laser cyclophotocoagulation was performed with 7 to 10 Watts of power, a duration of 0.7 seconds, with one or two rows, and ranges of either greater or less than 180 degrees. The change in IOP, the success rate of the procedure, and the occurrence rate of hypotony were analyzed with regard to the methods of cyclophotocoagulation.

In this series of patients with refractory glaucoma, the final IOP and success rate were not significantly influenced by the laser application method or by the total energy used. The eyes with ocular hypotony showed significantly decreased IOP one year after cyclophotocoagulation when compared with eyes without ocular hypotony. The IOP percent reduction in the patients with ocular hypotony tended to decrease more rapidly than did that of the patients without hypotony, beginning three months after the operation.

The application methods of cyclophotocoagulation appear to have no significant influence on success rate, IOP or ocular hypotony rate. The percent reduction in IOP was higher in the hypotony group, including during the early postoperative periods.