Comparison of diode laser trans‐scleral cyclophotocoagulation versus implantation of a 350‐mm²Baerveldt glaucoma drainage device for the treatment of glaucoma in dogs (a retrospective study: 2010‐2016)

Abstract

In this study, eyes treated with Baerveldt GDD implantation were more likely to maintain IOP control and retain vision compared to eyes treated with TSCP and placement of an anterior chamber suture shunt. Lack of formal randomization, inconsistencies in surgical techniques and TSCP protocols, and potential unmeasured confounders must be considered when extrapolating from this retrospective study.

The future of canine glaucoma therapy

“…This has been recognized as a high priority during our discussions. The most common complications which can result in vision loss and which should be addressed in future research projects include ocular hypertension, intracameral fibrin formation, ocular hypotony and phthisis bulbi, cataract formation, and corneal ulceration . The confounding effect of inflammation in canine eyes with PACG has to be considered in the development and improvement of surgical therapies …”

“…Improvements in implant design, surgical technique, modulation of wound healing, patient selection, and postoperative management, including IOP home monitoring to detect early implant failure, have resulted in improved success rates using the Ahmed valved device as a single surgical treatment option . Other drainage implants that are being used in dogs include Molteno and Baerveldt devices, as well as frontal sinus shunts . Scar formation over the subconjunctival bleb is one of the main reasons for implant failure in both human and canine patients.…”

“…For reasons that remain to be determined, bleb fibrosis appears much more exaggerated in dogs than humans. Currently, the main approach to inhibit scar formation continues to be the intraoperative treatment of the bleb site with antimitotic compounds, such as mitomycin‐C (MMC) or 5‐fluorouracil (5‐FU) . These reagents have to be handled with great care because of their potential toxic effect and possible conjunctival necrosis .…”

“…Based on these factors, long-term success rates for IOP control and preservation of sight vary considerably, but tend to improve with more advanced technologies and modifications of surgical techniques. The most recently published 1-year success rates of canine glaucoma surgery for both IOP control and sight preservation are ~90% for Ahmed valved drainage implants, 21,60 65%-75% for Baerveldt nonvalved glaucoma drainage device, 61,62 41%-92% for transscleral cyclophotocoagulation (TSCP) alone or in combination with the placement of Ahmed valved drainage implants, [62][63][64][65][66][67] and 72%-74% for endolaser cyclophotocoagulation (ECP). 58 Even though we have to be careful when comparing human and canine studies because of different study designs, inclusion/exclusion criteria, and specific outcome measures, these canine success rates are comparable to published results in human patients for Ahmed and Baerveldt drainage devices (ClinicalTrials.…”

Safety and efficacy of topically applied 0.5% and 1% pirfenidone in a canine model of subconjunctival fibrosis

“…Aqueous humor shunts represent an important technique in the surgical treatment of glaucoma [1][2][3][4][5][6][7][8] and correct glaucoma's underlying pathology of decreased outflow. The limitation of aqueous humor shunts lies in the formation of scar tissue around the implant footplate, which results in decreased flow through the shunt, and a return of elevated intraocular pressure.…”