Preliminary findings in 30 dogs treated with micropulse transscleral cyclophotocoagulation for refractory glaucoma

The purpose of this study was to report the preliminary results of a novel micropulse transscleral diode laser cyclophotocoagulation (MP-TSCP) as primary therapy for glaucomatous dogs.

Client owned dogs undergoing MP-TSCP therapy at a veterinary referral center.

Retrospective study of dogs with glaucoma that were treated with MP-TSCP with a minimum of 1 month (range: 1-18 months) of follow-up. Reported outcomes were intraocular pressure (IOP), treatment parameters, reduction in medications, complications, and incidence of repeat therapy.

Thirty dogs (35 eyes) were evaluated. The mean age was 9.0 years. Mean preoperative IOP was 34.5 mm Hg. Mean postoperative IOP at 1 month (35/35 eyes) was 22 mm Hg, 2 months (26/35 eyes) was 20.5 mm Hg, 4 months (20/35 eyes) was 19 mm Hg, 6 months (10/35 eyes) was 19 mm Hg, 12 months (8/35 eyes) was 21 mm Hg. First treatment success rate was 19/35 eyes (54.3%). Repeat laser was performed in 11 eyes with 4/11 eyes responding favorably for a total IOP control of 23/35 eyes (65.7%). Mean energy levels employed were 137.5 seconds and 2351 mW at 31.3% duty cycle. Reduction in medications was from a mean of 3.6 medications preoperatively to 3.1 medications postoperatively. Complications included corneal ulcers 5/35 eyes (14.3%), uncontrolled IOP in 12/35 eyes (34.3%) and repeat treatment in 11/35 eyes (31.4%).

MP-TSCP was successful in controlling IOP in most patients as well as to reduce postoperative medications with minimal resultant intraocular inflammation and complications. The micropulse procedure also can be repeated. Future investigations to study effective treatment parameters are warranted in a larger series of patients over a longer period of evaluation.