Visual Loss After Transscleral Diode Laser Cyclophotocoagulation for Primary Open-Angle and Neovascular Glaucoma

Abstract

Varying incidences of visual loss after transscleral diode laser cyclophotocoagulation for uncontrolled intraocular pressure (IOP) have been reported. This study compared the treatment response in primary open-angle (POAG) and neovascular (NVG) glaucoma, particularly regarding vision loss. Case notes of consecutive patients who underwent transscleral diode laser cyclophotocoagulation between March 2001 and September 2005 were retrospectively reviewed. A diagnosis of POAG or NVG and at least 6 months of follow-up were required for inclusion. Conservative laser parameters were used. The treatment response of the POAG and NVG groups was compared. Twenty-five eyes of23 patients with POAG and 14 eyes of 14 patients with NVG were studied. Mean follow-up was 22.4 and 12.9 months in the POAG and NVG groups, respectively. Post-treatment, both groups had significant reduction in mean IOP of 7.3 (29.2%) and 13.2 (36.6%) mm Hg, respectively (between group P = .18). One eye in each group had mild hypotony of 4 mm Hg, and no eyes became phthisical. Oral acetazolamide treatment was significantly reduced in both groups. Visual acuity post-treatment decreased in both groups; the POAG eyes had better initial visual acuity and lost more visual acuity. Nine of 25 (36%) POAG and 4 of 8 (50%) NVG eyes lost 2 or more LogMAR lines. Transscleral diode laser cyclophotocoagulation reduced IOP and medication requirements in POAG and NVG. Patients should be warned that visual loss may occur, especially in endstage glaucoma.