Long-term results of pars plana vitrectomy in relationship to leptospiral antibody detection in vitreous humor in 118 horses with equine recurrent uveitis (ERU)In the ongoing discussion regarding aetiopathogenesis and therapeutic approach of equine recurrent uveitis (ERU) it was the aim of the present study to elucidate the relationship of leptospiral antibody detection in vitreous humor and success of pars plana vitrectomy (PPV) in horses with ERU. In a retrospective study of 118 ERU patients of different age, gender and breed undiluted vitreous humor, aseptically taken at the beginning of PPV, was examined by culture. Furthermore vitreous humor and serum were tested for specific antibodies against different serovars of Leptospira interrogans by microscopic agglutination test (MAT). Horses were treated via single port pars plana vitrectomy. The presence or absence of inflammation of the inner eye 8 to 54 months after PPV was evaluated by repeated ocular examinations, as well as by interrogation of referring veterinarians and horse owners. The absence of recurrent inflammation in terms of symptoms of classic uveitis after surgery was considered a success. A total of 55 of 118 horses (46.6 %) had serum antibodies against different serovars of Leptospira (L.) interrogans (≥ 1 : 100). Culture of vitreous humor was positive in 16/118 (13.6 %) patients with ERU. In 49 of 118 horses (41.5 %) and 52 of 134 eyes (38.8 %) leptospiral antibodies were detected in vitreous humor via MAT. L. interrogans serovar Grippotyphosa (48) and L. interrogans serovar Pomona (12) were identified most frequently. A total of 90/118 (76.3 %) horses and 104/134 eyes (77.6 %) remained relapse-free over a period of 8 to 54 months. Forty-one/49 horses (83.7 %) and 44/52 eyes (84.6 %), tested positive for antibodies against L. interrogans via MAT and 49/69 horses (71.0 %) and 60/82 eyes (73.2 %), in which no leptospiral antibodies were detected in vitreous humor, showed no further episodes of ERU (Fishers exact test: P ≥ 0.05). These findings confirm the therapeutic approach to perform a vitrectomy according to the clinical ERU diagnosis irrespective of the leptospiral antibody result.Keywords: horse, equine recurrent uveitis, vitrectomy, leptospira; ophthalmology Zitation: Dorrego Keiter E., Tóth J., Dikker L., Sielhorst J., Schusser G. F. (2017) Long-term results of pars plana vitrectomy in relationship to leptospiral antibody detection in vitreous humor in 118 horses with equine recurrent uveitis

A multitude of ocular diseases can lead to a loss of vision and permanent ocular pain in horses.The present paper addresses the topic of cosmetic and reconstructive surgery in equine ophthalmological patients based on the implantation of intrascleral silicone prostheses. Thirteen horses aged between four and twenty years with various ocular problems requiring removal of a blind and/or painful eye were placed under general anaesthesia. After evisceration of the globe, a silicone prosthesis was introduced into the sclera. Sclera and conjunctiva were sutured and the horses were treated with NSAIDs and ophthalmic ointments postoperatively. After healing of the surgical wound, a dark tinted bandage lens could be placed over the eye by the owner to further enhance the cosmetic result. The surgical wounds healed well in all horses. One horse had a deep corneal ulceration and the prosthesis had to be removed two weeks after surgery. Two horses developed eosinophilic keratitis six and eight weeks after surgery, respectively. The condition was repeatedly treated with a diode laser and ophthalmic ointments and resolved subsequently. One horse showed transient swelling in the surroundings of the eye that resolved within two days. The corneas of the eyes that underwent surgery passed through various stages of cloudiness and vascularization, as well as epithelial reconstruction, followed by pigmentation. Intrascleral silicone prostheses in combination with a dark tinted bandage lens yield a cosmetically excellent result that is well received by the owners. It serves as a cosmetically superior alternative to plain enucleation or enucleation and subsequent placement of an intraorbital prosthesis in cases where the removal of a blind and/or painful eye is inevitable.

Diagnostic value of infrared imaging in equine ophthalmologyA thorough diagnostic investigation is an essential precondition for a successful therapy in all ocular diseases. Nowadays, a multitude of diagnostic means are available to the examiner, and yet there are areas of the eye that can prove to be inaccessible to further investigation for different reasons. One of those reasons can be opacities in the anterior segment of the eye. This publication introduces the method of infrared diagnostic imaging which allows visualization and examination of the anterior segment of the eye even through opacities and cloudiness of anterior ocular structures (cornea, anterior chamber, iris, pupil, lens). The accompanying figures demonstrate how certain ocular structures appear under "regular" conditions and in infrared digital imaging and thus illustrate the diagnostic potential of this method. In the opinion of the authors, the method of infrared digital imaging is a valuable addition to regular digital photography in equine ophthalmology. The acquisition of the required equipment (suitable digital camera) is low in cost when compared to the benefit that can be achieved with it.

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