Diode Laser Transscleral Cyclophotocoagulation as a Primary Surgical Treatment for Primary Open-angle Glaucoma

Abstract

To evaluate the feasibility of diode laser transscleral cyclophotocoagulation (TSCPC) as a primary surgical treatment for primary open-angle glaucoma and to compare 2 laser energy settings used for treatment. In a prospective clinical trial in Cape Coast and Accra, Ghana, 1 eye of each of 92 patients with primary open-angle glaucoma was treated by diode laser TSCPC as a primary surgical treatment. Eyes were randomly assigned to receive treatment by 20 applications of either 1.5 W applied for 1.5 seconds or 1.25 W applied for 2.5 seconds. Seventy-nine (86%) of 92 patients completed 3 months of follow-up; follow-up was 13.2 +/- 6.0 months (mean +/- SD). Intraocular pressure decreased in 53 (67%) of the 79 eyes. The drop in intraocular pressure was 20% or more in 37 eyes (47%) and final intraocular pressure was 22 mm Hg or less in 38 eyes (48%). An atonic pupil was a previously unreported complication that arose in 27 (28%) of 92 eyes. There were no serious complications of hypotony, phthisis bulbi, or sympathetic ophthalmia. Visual acuity decreased in 18 (23%) of 79 eyes treated by TSCPC and in 10 (23%) of 47 fellow eyes treated only with glaucoma medications. There was no difference in outcomes between the 2 laser energy settings. Diode laser TSCPC is a practical, rapid, well-tolerated procedure that may provide a modest and variable lowering of intraocular pressure. The treatment, used with conservative energy levels applied to the eye, seems to have few serious complications, although a previously unrecognized complication of atonic pupil needs further evaluation. A moderate variation in laser energy settings does not influence the results of treatment.