title: Treatment of immune-mediated keratitis in horses with episcleral silicone matrix cyclosporine delivery devices.
abstract: OBJECTIVE
  To describe the use of episcleral silicone matrix cyclosporine (ESMC) drug delivery devices in horses with immune-mediated keratitis (IMMK) with evaluation of tolerability and efficacy in long-term control of inflammation.
  
  
  METHODS
  Retrospective study. ESMC implants (1.2 cm length, 30% wt/wt cyclosporine (CsA) in silicone; with approximately 2 μg/day steady-state release for at least 400 days) were used.
  
  
  RESULTS
  Nineteen horses (20 eyes) received two or more ESMC implants for superficial stromal (n = 9), midstromal (n = 3), or endothelial (n = 5) IMMK. Three additional horses received two or more ESMC implants for pigmentary keratouveitis (PK). Nine eyes of eight horses with superficial and five eyes of five horses with endothelial IMMK were well controlled after placement of ESMC implants (mean follow-up 176.8 and 207.2 days, respectively). Horses with midstromal IMMK and PK were not controlled with ESMC implants alone, but instead required frequent use of other medications or surgery to control the disease. The mean duration of disease prior to ESMC implantation of horses with midstromal IMMK was 495 ± 203.9 days, compared with 121.6 ± 92.7 days with superficial IMMK. ESMC implants were well tolerated by all horses without documented loss of the device.
  
  
  CONCLUSIONS
  Results from this preliminary retrospective study suggest that the ESMC implants were well tolerated and associated with treatment success with superficial and endothelial IMMK, especially if placed early in the disease process. Further study is needed to determine the duration of efficacy, number of implants required, and better therapies for chronic midstromal IMMK and pigmentary keratouveitis.
authors.affiliation: Department of Clinical Sciences, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Gilger
authors.forename: Riccardo
authors.initials: R
authors.lastname: Stoppini
authors.forename: David A
authors.initials: DA
authors.lastname: Wilkie
authors.forename: Alison B
authors.initials: AB
authors.lastname: Clode
authors.forename: Nelson H
authors.initials: NH
authors.lastname: Pinto
authors.forename: Julie
authors.initials: J
authors.lastname: Hempstead
authors.forename: Joseph
authors.initials: J
authors.lastname: Gerding
authors.forename: Jacklyn H
authors.initials: JH
authors.lastname: Salmon
mesh_terms: D000818:Animals; D016572:Cyclosporine / Q000008:administration & dosage* / Q000627:therapeutic use; D004343:Drug Implants / Q000008:administration & dosage*; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D007166:Immunosuppressive Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D007634:Keratitis / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D012590:Sclera; D012828:Silicones; D016896:Treatment Outcome
chemical_list: D004343:Drug Implants; D007166:Immunosuppressive Agents; D012828:Silicones; D016572:Cyclosporine
keywords: cyclosporine; horse; immune-mediated; keratitis; sustained release