Long-term results of pars-plana (double-port) vitrectomy in equine recurrent uveitis

Equine recurrent uveitis (ERU) is an inflammation of all ports of the uvea. Following new investigations it is mediated by a leptospiral infection of the inner eye with an immunologically mediated reaction to the infectious agents. Pars-plana-vitrectomy is documented as a successful treatment of ERU. Fruhouf et al. (1998) conducted only single-port vitrectomies with one scleral port, while Winterberg and Gerhards (1997) describe both single-port and modified double-port vitrectomies. A total of 56 vitrectomies were performed using the double-port method on 53 horses at the Equine Clinic of the University of Veterinary Medicine Hannover, Foundation, from January, 1999, until March, 2004. Of the 50 eyes included in a long-term follow-up study, 47 (94%) had no recurrence. This result confirms that ERU can be successfully treated by vitrectomy. In our study 14% of the eyes with no recurrence developed blindness due to retinal detachment and progressive cataract. There had been obvious damage to these eyes before surgery, so its purpose was to relieve pain and prevent recurrence. As these goals were achieved, the surgery is to be considered a success.