2. North Carolina State University, Raleigh, NC, USA.
3. Animal Health Trust, Newmarket, UK.
4. Eye Care for Animals, Reno, NV, USA.
5. Pinecrest Veterinary Hospital, Miami, Fl, USA.
Background: The purpose of this study was to describe the visual outcomes of surgical therapy for lens luxation/subluxation in the horse.
Methods: The medical records of horses that had surgical correction of lens luxation/subluxation at the University of Florida Veterinary Medical Center, Gainesville, Florida, USA; North Carolina State University, Raleigh, North Carolina, USA; Eye Care for Animals, Reno, NV, USA; Pinecrest Veterinary Hospital, Miami, Fl, USA; and the Animal Health Trust, Newmarket, UK were retrospectively reviewed. Data collected from the medical records included signalment, clinical descriptions of ocular lesions, type of surgical procedure performed, any surgical complications noted, and the visual outcomes.
Results: Phacoemulsification under general anesthesia was performed in ten horses (two Quarter Horse mares (14 years; 16 years), one Thoroughbred gelding (10 years), three Thoroughbred fillies (4 months; 1 year; 4 years), two Quarter Horse geldings (9 years, 11 years), one Arabian stallion (6 years), and one Arabian mare (12 years)) with lens luxation/subluxation in one eye. Intracapsular lens extraction (ICLE) was performed under general anesthesia in five horses (one Standardbred filly (6 months), one Icelandic pony mare (8 years), one Westphalian gelding (10 years), one Appaloosa gelding (11 years) and one Arabian gelding (28 years)) with lens luxation/subluxation in one eye. Surgical complications included incision dehiscence, stromal abscesses, corneal ulceration, ulcerative keratitis with keratomalacia, hyphema, iridocyclitis, glaucoma, displaced lens fragments, expulsive choroidal hemorrhage, bullous keratopathy, retinal detachment, and infectious endophthalmitis. Five eyes were quickly enucleated postoperatively (33.3%), four eyes became rapidly phthisical (26.7%), two eyes became acutely glaucomatous, one eye developed retinal detachment, one eye had compromised vision (menace response positive but marked progressive corneal opacification) at 3 years, one eye was visual at eight months postoperatively, and one eye had light perception despite severe posterior capsular fibrosis ten years postoperatively. Only the latter three cases (20.0%) had any evidence of visual capability in the operated eye.
Conclusions: Surgical removal of a very unstable subluxated or completely luxated lens in a horse is a difficult endeavor with a high rate of severe intraoperative and postoperative complications, and generally poor visual outcomes.
Keywords: Equine, lens luxation, subluxation, surgical