Silicone Matrix Episcleral Cyclosporine Implant for Treatment of Corneal Disease in Malayan Tapir (Tapirus indicus)
Corneal disease and photokeratitis have been seen in certain species exposed to significant amounts of ultraviolet (UV) light.1 For pinnipeds, inadequate shade was found to increase the likelihood of ocular disease by ten-fold.2 Episcleral cyclosporine subconjunctival implants have had positive clinical outcomes for treatment of otariid keratopathy for months to years (Colitz, unpubl. data). With their predominantly nocturnal and forest dwelling lifestyle, Malayan tapirs do not naturally have significant direct UV light exposure. In captivity, diurnal husbandry protocols, less dense forest canopy, and tropical UV light exposure have lead to corneal thickening, edema, and keratitis in two Malayan tapirs (Tapirus indicus) housed at Zoo Miami. The corneas exhibited waxing and waning stromal abscesses and keratitis, which were treated with multiple topical antimicrobial therapies. To limit the inflammatory process, a silicone matrix cyclosporine implant was used (North Carolina State University Veterinary Hospital pharmacy). Under general anesthesia, a surgical approach was made to the dorsal subconjunctival space and the implant was placed in the prepared tunnel and sutured in place. Comparative images 13 wk postoperatively showed decreased inflammation, neovascularization, and corneal edema. The manufacturer suggests that clinical effects can be seen for up to 8 mo; however, clinical results have been seen for longer in marine mammal species (Karpinski, personal communication). This case report describes the use of an immunomodulatory medication (cyclosporine) in a silicone matrix placed subconjunctivally for prolonged treatment of photokeratitis in Malayan tapir.
The authors would like to thank the keepers and staff at Zoo Miami for their assistance with this case, and to Ron Magill for photo documentation.
1. Colitz CMH, Walsh MT, and McCulloch SD. Characterization of anterior segment ophthalmologic lesions identified in free-ranging dolphins and those under human care. J Zoo Wildl Med. 2016;47:56–75.
2. Miller S, Colitz CMH, St. Leger J, Dubielzig R. A retrospective survey of the ocular histopathology of the pinniped eye with emphasis on corneal disease. Vet Ophthalmol. 2013;16:119–129.