MicroPulse^™ transscleral cyclophotocoagulation in the treatment of canine glaucoma: Preliminary results (12 dogs)

Objective: To describe the clinical application and effect of MicroPulse™ transscleral cyclophotocoagulation (MP-TSCPC) in dogs with glaucoma. Animals studied: Twelve dogs with primary (n = 8) or secondary (n = 4) glaucoma, aged 2-13 years (mean ± SD, 7.2 ± 3.8 years). Procedures: MP-TSCPC was performed under sedation or general anesthesia. Laser duty cycle was 31.3%, laser power varied from 2000-2800 mW, and each hemisphere was treated for 90-180 seconds. The probe was applied to each quadrant in a “sweeping motion,” sparing the 3 and 9 o'clock positions. Results: The number of MP-TSCPC procedures per eye varied from 1 to 3 (1.4 ± 0.7). Intraocular pressure (IOP) was controlled (<25 mm Hg) in 11/12 dogs (92%) within 1-15 days post-operatively. The IOP control at 1 month and the duration between repeated procedures were significantly greater in eyes treated with high energy laser (2800 mW) compared to 2000-2500 mW. Long-term follow-up (315.3 ± 100.7 days) showed controlled IOP in 5/12 (42%) and vision retention in 4/8 (50%) dogs. In unsuccessful cases, loss of IOP control or vision loss occurred within 3-245 days (109.1 ± 93.7 days) and 28-261 days (114 ± 101.6 days), respectively, resulting in a salvage procedure in 6 dogs. Complications were as follows: corneal hypoesthesia (92%), anterior uveitis (67%), post-operative ocular hypertension (50%), neurotrophic corneal ulcer (25%), keratoconjunctivitis sicca (8%), and rubeosis iridis (8%). Conclusions: MP-TSCPC is a viable tool for managing canine glaucoma, although further studies are required to improve the long-term effect and reduce the complication rate.