Transscleral Diode Laser Cyclophotocoagulation: A Comparison of Slow Coagulation and Standard Coagulation Techniques

Purpose: To compare the outcomes of standard pop-titrated transscleral cyclophotocoagulation (TSCPC) and slow-coagulation TSCPC in the treatment of glaucoma.

Design: Retrospective case series.

Subjects: This study included 78 eyes with glaucoma of any type or stage that underwent TSCPC as part of their treatment course.

Methods: This study compared 52 eyes treated with slow coagulation TSCPC to 26 eyes treated with standard pop-titrated TSCPC. Patient demographics, treatment course, surgical techniques, settings and outcomes were assessed.

Main Outcome Measures: The main outcome measures were visual acuity (VA), intraocular pressure (IOP) and post-surgical complications.

Results: The initial LogMAR VA was 1.94 (0.73) [mean (SD)] in the slow coagulation TSCPC group and 1.71 (0.90) in the standard TSCPC group (p=0.507). Initial IOP was 37 (13) mm Hg in the slow coagulation group and 39 (13) mm Hg in the standard group (p=0.297). The follow-up periods were 16.36 months and 24.68 months for the slow coagulation and standard groups (p=0.124). VA remained better than light-perception in 71.1% of slow coagulation treated patients and 65.0% of standard TSCPC treated patients (p=0.599). IOP remained below 20 mm Hg in 46% of slow coagulation treated patients and 44% of standard TSCPC treated patients (p=0.870). The mean number of complications was higher in the standard group [1.46 (1.24)] versus the slow coagulation group [0.62 (0.75)] (p=0.002). The incidence of the need for a second procedure (slow coagulation- 28.8%, standard- 23.1%, p=0.588) and maximum number of medications needed to control IOP postoperatively (p=0.771) were similar between the two groups.

Conclusions: In this case series, slow coagulation TSCPC and standard pop-titrated TSCPC resulted in similar VA and IOP outcomes in the treatment of glaucomatous eyes. The complication profiles of the techniques were also comparable, although standard TSCPC had a higher incidence of prolonged inflammation postoperatively. This study suggests that slow coagulation TSCPC may achieve equivalent control of IOP while reducing the incidence of prolonged post-operative inflammation-a feared complication of TSCPC-when compared to standard "pop-titrated" TSCPC.