Effect of transscleral Nd:YAG laser cyclophotocoagulation: research for a new manner of treatment.

Twenty-six eyes of 24 patients with advanced glaucoma refractory to conventional therapy were treated with noncontact neodymium: YAG laser cyclophotocoagulation and were followed for a minimum of 6 months postoperatively. The mean baseline intraocular pressure (IOP) was 34.2 +/- 2.0 mm Hg. Nine to 10 evenly spaced pulses per quadrant were circumferentially applied 2.0-2.5 mm posterior to the limbus. Eight to 35 pulses (mean, 19 pulses) were delivered per treatment with an energy per pulse of 3.9-5.7 J (mean, 4.7 J), and the total energy per treatment was 35.6-164.9 J (mean 91.1 J). Twelve eyes of 11 patients (46%) required 2 or more treatments (mean, 1.7). The mean final IOP was 17.0 +/- 2.1 mm Hg, and the mean percent decrease in IOP was 41.7 +/- 6.5%. Statistical analyses revealed that the IOP reached its lowest point about 1 week after treatment and remained that level through 6 months of follow-up. There were significant correlations between the percent pressure decrease and preoperative IOP, the number of administered pulses and the total energy at the last procedure. Based on these results, we introduce intentional multiple treatments as a new manner of treatment to avoid phthisis bulbi. An initial treatment is performed circumferentially for 180 degrees and if sufficient pressure reduction is not obtained, an additional treatment 180 degrees should be employed 1 week after the most recent procedure, whether initial or not.