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

Abstract

ZusammenfassungBei der equinen rezidivierenden Uveitis handelt es sich nach neueren Erkenntnissen um eine durch eine Leptospireninfektion des inneren Auges sowie der daraus resultierenden T-Zell-assoziierten immunologischen Reaktionen ausgelöste Entzündung aller Uveastrukturen. Nach Werry und Gerhards (1991) Schlüsselwörter: Pferd, Auge, equine rezidivierende Uveitis, Vitrektomie, double-port Long-term results of pars-plana (double-port) vitrectomy in equine recurrent uveitisEquine recurrent uveitis (ERU) is an inflammation of all parts 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. Frühauf 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.

The role of Leptospira spp. in horses affected with recurrent uveitis in the UK

“…This is important because treatment options can vary according to the initiating cause of the intraocular inflammation. Pars plana vitrectomy (PPV), a procedure in which the ocular media, cells and inflammatory mediators are removed from the posterior segment, has been recommended for Leptospira-associated cases and has achieved good success rates [37,38]. Case selection is essential because of the potential for serious complications following PPV; the present study suggests that only a small percentage of animals in the UK would benefit from this surgical technique and aqueocentesis should be an essential part of the diagnostic work-up if PPV is under consideration.…”

Detection of intraocular leptospiral DNA, antibodies and Leptospira spp. in horses with equine recurrent uveitis in different laboratories

“…The gentamicin-concentration of flushing solution used for vitrectomy of horses varies in the literature between 80 µg/ml and 200 µg/ml as far as noted, and no toxic side effects of the gentamicin in the flushing solution were described so far. This might be due to the high volume of flushing solution (250 to 500 ml) used during vitrectomy (Frühauf 1998, von Borstel et al 2005, Wollanke et al 2000). …”

“…Complications, such as retinal bleeding, pupil constriction and choroidal haemorrhages, were described in human patients for sampling the vitreous without immediate volume replacement (Quiroz-Mercado et al 2005). Complications recorded during pars plana vitrectomy in equine patients are retinal detachment and vitreal and/or retinal haemorrhage (Frühauf 1998, von Borstel et al 2005, Werry and Gerhards 1991, Werry et al 1992. Therefore, this approach was not used on patients in the present study with respect to possible complications.…”

“…The most promising treatment of ERU is pars plana vitrectomy (Werry et al 1992), with success rates for non-recurrence of uveitis between 73.6 and 100 % (Frühauf 1998, Tömördy et al 2010, von Borstel et al 2005, Werry H. et al 1992, Winterberg 1997. Tömördy et al (Tömördy et al 2010) suggested a better outcome for horses with intraocular antibodies against leptospires which were detectable by the MAT.…”

Improving the laboratory diagnosis of leptospiral uveitis in horses by using an indirect ELISA for the detection of antibodies against Leptospira spp. in intraocular samples

“…Recurrences of equine uveitis can only be observed during a persistent leptospiral infection. A vitrectomy, however, removes not only the vitreous cloudiness that is caused by the intraocular inflammation and impairs vision, but also the leptospiral infection itself (Wollanke et al 2004a) and, therefore, successfully prevents further inflammatory episodes (Winterberg and Gerhards 1997, Wollanke 2002, Wollanke et al 2004a, von Borstel et al 2005, Tömördy et al 2010, Schinagl 2017. Consequently, in addition to the removal of vitreous opacities, the presence of an intraocular leptospiral infection is the primary indication for a therapeutic vitrectomy in affected horses (Gerhards et al 1999, Wollanke 2002, Wollanke et al 2004a, Gerhards und Wollanke 2005, von Borstel et al 2005, Gerhards und Wollanke 2006, Tömördy et al 2010, von Borstel et al 2010, Schinagl 2017).…”