Micropulse transscleral cyclophotocoagulation in canine glaucoma: A retrospective study evaluating sweep velocity.

Objective: To report preliminary results of MP-TSCP in canine patients with glaucoma while evaluating sweep velocity, treatment efficacy, and safety utilizing standardized surgical parameters.

Animal Studied: Client-owned dogs that underwent MP-TSCP at a veterinary referral hospital.

Procedure: Medical records of 19 eyes (14 dogs) treated with MP-TSCP were reviewed. Eleven eyes were treated with a 10 s/sweep (s) velocity and 8 eyes with a 20 s/s. Laser duty cycle was set at 31.3%, mean laser energy was 2766 mW, and mean duration was 120 s per hemisphere. Minimum post-operative follow-up was 6 months. Outcomes of intraocular pressure (IOP), vision status, degree of antiglaucoma medications, and complications were evaluated.

Results: There was a significantly lower median (IQR) IOP (<25 mmHg) at each timepoint postoperatively compared to IOP pre-operatively (p < 0.05). The overall success rate for IOP control at 6 months was 84%, 100% for the 10 s/s and 62.5% for the 20 s/s. Vision was preserved in 10/11 (90%) eyes from the 10 s/s group and 4/8 (50%) eyes from the 20 s/s group at 6 months. Average number of glaucoma medications in the 10 s/s group decreased from 4.4 to 1.5 and from 3.3 to 2.5 in the 20 s/s group. Post-operative complications were mild and resolved within 1 week.

Conclusions: MP-TSCP is a non-invasive treatment alternative for canine glaucoma. Employing higher energy levels rendered long-term IOP control while retaining a high safety profile with minimal postoperative complications. There was no statistical difference between a 10 s/s and 20 s/s surgical velocity, both leading to successful surgical outcomes up to 6 months post-operatively.