Vol. 29 No. 4 Original Article PDF

Single-setting treatment protocol for diode-laser transscleral cyclophotocoagulation

John Patrick M. Lirio, MD, Jose Ma. Martinez, MD, Jesus Altuna, MD, Jay League, MD, Rigo Daniel Reyes, MD

Objective
To determine the efficacy of diode-laser transcleral cyclophotocoagulation (TSCPC) using a standard treatment protocol in the treatment of Asian patients with refractory glaucoma.

Methods
This is a prospective, noncomparative, interventional case series involving 35 eyes of 35 patients with refractory glaucoma and no previous cycloablation. After clinical examination and intraocular-pressure (IOP) measurements, diode laser TSCPC was performed using a standard protocol (30 shots over 270 o at 1500 mW x 1500 msec). Patients were followed up at one day postoperatively, weekly for the first month, then every four weeks for 48 weeks. Complete success was defined as IOP less than 22mm Hg or an IOP reduction of at least 30% from pretreatment level. The pre- and posttreatment IOPs were analyzed by paired student t-test and the probability of success at different follow-up periods was determined by Kaplan-Meier survival analysis.

Results
Mean pretreatment IOP was 50.9 ± 12.8 mm Hg. Mean posttreatment IOP was 26.9 ± 10.7 mm Hg (45% reduction) at 24 weeks and 27.8 ± 10.9 mm Hg (40% reduction) at 48 weeks. The cumulative success rate was 80% at 24 weeks and 77% at 48 weeks. Twelve eyes (34 %) were retreated. Medications were reduced from a mean of 1.8 pretreatment to 0.4 at the end of the study period. Among the 28 patients who completed the 48-week follow-up period, visualacuity score remained stable in 18 (64%) and deteriorated in 9 (32%). One patient experienced a 1-Snellen line improvement. Treatment complications included hyphema, tilting of an intraocular lens, severe inflammation, and conjunctival chemosis. No cases of phthisis, hypotony, or sympathetic ophthalmia were encountered.

Conclusion The diode-laser treatment protocol using fixed settings (30 shots over 270 o at 1500 mW x 1500 msec) was effective in controlling IOP in patients with refractory glaucoma. There was minimal risk of hypotony

Keywords: Glaucoma, Diode laser, Transscleral cyclophotocoagulation, Intraocular pressure