Use of Implants to Treat Keratoconjunctivitis Sicca

Keratoconjunctivitis sicca (KCS) is a common ocular disease in dogs. Although the exact cause is unknown, underlying autoimmune disease is suspected. Topical cyclosporine A (CsA) is an effective treatment because it has immunomodulating and tear-stimulating properties. This retrospective study evaluated the effect of episcleral silicone matrix CsA implants in dogs with KCS. Eyes were divided into 2 groups: (1) good candidates (GC) with Schirmer tear test (STT) values >5 but <10 mm/min and (2) poor candidates (PC) with STT values <5 mm/min and failure to respond to topical CsA or tacrolimus. Twenty-seven eyes from 15 dogs received implants (15 GC, 12 PC). Response was evaluated using STT values and clinical scoring (ie, ocular discharge, conjunctival hyperemia, corneal neovascularization, corneal opacity). Mean follow-up was 18 ± 2 months for GC and 10.4 ± 15 months for PC. Both groups experienced statistically significant increase in STT values over baseline, with maximum STT increase at 90 days; however, there was no significant improvement from baseline at 330 and 300 days for GC and PC, respectively. Significant improvement in clinical scores was noted from 60–90 days and remained significant up to 480–540 days postimplantation. The implants were well tolerated; however, implants were lost in 2 eyes at 12-month and 1-week follow-up, respectfully.

Commentary

At this time, episcleral CsA implants are unlikely to become the recommended standard of care for most dogs with KCS because implantation requires general anesthesia, repeated implant placement is expected, there is risk for implant extrusion, there is lack of a commercially available product, and there is general absence of prospective clinical studies. However, CsA-containing implantation may represent a potential future option for appropriate cases, improving patient care when topical treatment is not feasible. Finally, if affordable, safe, accessible implant devices that deliver a longer duration of medication are developed, this treatment may become appropriate for more dogs with KCS.—Allyson Gosling, DVM

Source

Use of episcleral cyclosporine implants in dogs with keratoconjunctivitis sicca: A pilot study. Barachetti L, Rampazzo A, Mortellaro CM, et al. VET OPHTHALMOL doi: 10.1111/vop.12173.