Gil Ben-Shlomo

Corneal transplantation for inflammatory keratopathies in the horse: visual outcome in 206 cases (1993-2007).

OBJECTIVE To evaluate the visual outcome of three techniques of corneal transplantation surgery in treating severe inflammatory keratopathies in the horse. DESIGN Retrospective medical records study. ANIMALS STUDIED Medical records of 206 horses that received corneal transplantation surgery at the University of Florida Veterinary Medical Center from 1993 to 2007 were reviewed. PROCEDURE Data collected from the medical records included signalment, types of ocular lesions, type of transplant surgery performed, length of follow-up, complications, and visual outcomes. RESULTS Full thickness penetrating keratoplasty (PK) was performed in 86 horses for melting ulcers, iris prolapse/descemetoceles, and medically nonresponsive full thickness stromal abscesses (SA). Posterior lamellar keratoplasty (PLK) and deep lamellar endothelial keratoplasty (DLEK) are split thickness penetrating keratoplasties that were utilized for medically nonresponsive deep stromal abscesses (DSA) in 54 and 66 eyes, respectively. The most common postoperative surgical complication was graft rejection and varying degrees of graft opacification. Wound dehiscence and aqueous humor leakage was also a common postoperative problem. A positive visual outcome was achieved for PK, PLK, and DLEK in 77.9%, 98.1%, and 89.4%, respectively. CONCLUSIONS Corneal transplantation is a tectonically viable surgery in the horse with an overall success rate of 88.5% in maintaining vision when treating vascularized and infected corneal disease in the horse.

Fungal Keratitis in a Gopher Tortoise (Gopherus polyphemus)

Abstract A free-ranging gopher tortoise (Gopherus polyphemus) presented for trauma and blindness. Fibrinous exudate obscured visualization of the globes. This exudative crust extended from the conjunctival fornices through the palpebral fissure and was manually removed. Ophthalmic examination revealed bilateral corneal ulcerations and scarring and phthisis bulbi of the left globe. Histology of the crust revealed a necrotic conjunctivitis with intralesional fungal hyphae. Culture of the corneal ulcer of the left eye isolated moderate growth of a mixed fungal flora consisting of Curvularia sp. and Aspergillus sp. Miconazole ophthalmic solution was administered and the ulcers in both eyes healed, but corneal edema continued. After 2 mo of treatment with miconazole, tramadol, acetylcysteine, hypertonic saline ointment, artificial tears, and hypertonic saline flushes, the right eye was normal with only a small scar. The left eye remained phthisical. This is the first report of fungal keratitis in a wild reptile and a gopher tortoise.

Equine subepithelial keratomycosis

OBJECTIVE To describe clinical findings in equine subepithelial keratomycosis (SEK). DESIGN Retrospective medical records study. ANIMALS STUDIED Medical records of horses that had subepithelial keratomycosis (SEK) at the University of Florida Veterinary Medical Center from 2007 to 2011 were reviewed. PROCEDURES Data collected from the medical records included signalment, clinical descriptions of ocular lesions, diagnostic techniques, and therapeutic outcomes. RESULTS Twenty-one horses, consisting of three Quarter horse geldings, two Morgan geldings, one Morgan mare, two Arabian mares, three Arabian geldings, two warm blood mares, two warm blood geldings, two Thoroughbred geldings, one Thoroughbred mare, one Appaloosa mare, one Holsteiner gelding, and one Holsteiner mare with SEK were identified. Multifocal punctate and/or geographic patterns of subepithelial opacification were present in all eyes. Intermittent phases of weak fluorescein and/or rose Bengal dye were found in 16 eyes. Clinical signs of iridocyclitis were absent in all eyes. Cytologic confirmation of fungi was found in ten cases, Candida was cultured from one eye, and Aspergillus cultured in three eyes. Nineteen of 21 eyes with SEK resolved when topical antifungal therapy was initiated. Two of the 19 responding eyes recurred and required additional therapy, and two other eyes progressed to ulcerative keratomycosis. CONCLUSIONS This is the first clinical report of a subtle form of keratomycosis in the horse. Subepithelial keratomycosis may be a distinct clinical entity or represent a continuum in the described forms of equine keratomycosis.

Characterization of the normal dark adaptation curve of the horse.

OBJECTIVE   The goal of this work is to study the dark adaptation curve of the normal horse electroretinogram (ERG). PROCEDURES   The electroretinographic responses were recorded from six healthy female ponies using a contact lens electrode and a mini-Ganzfeld electroretinographic unit. The horses were sedated intravenously with detomidine, an auriculopalpebral nerve block was then performed, and the pupil was fully dilated. The ERG was recorded in response to a low intensity light stimulus (30 mcd.s/m(2) ) that was given at times (T) T = 5, 10, 15, 20, 25, 30, 40, 50, and 60 min of dark adaptation. Off-line analysis of the ERG was then performed. RESULTS   Mean b-wave amplitude of the full-field ERG increased continuously from 5 to 25 min of dark adaptation. The b-wave amplitude peaked at T = 25, however, there was no statistical significance between T = 20 and T = 25. The b-wave amplitude then remained elevated with no significant changes until the end of the study at T = 60 (P > 0.49). The b-wave implicit time increased continuously between T = 5 and T = 20, then gradually decreased until T = 60. No distinct a-wave was observed during the testing time. CONCLUSIONS   Evaluation of horse rod function or combined rod/cone function by means of full-field ERG should be performed after a minimum 20 min of dark adaptation.

Uveodermatologic Syndrome in a Rat Terrier

A 4 yr old intact male rat terrier presented with severe bilateral nonresponsive panuveitis. Bilateral uveitis, blepharospasm, conjunctival hyperemia, diffuse corneal edema, peripheral bullous retinal detachment, and secondary ocular hypertension were noted. Ocular lesions progressed despite aggressive medical treatment and were followed by cutaneous depigmentation and crusting along the nasal planum. Intensive oral and topical anti-inflammatory and topical antiglaucoma medications were administered, but the ocular disease progressed. A bilateral enucleation was performed. Uveodermatologic syndrome was diagnosed from histopathologic examination of a skin biopsy as well as histopathology of both globes after bilateral enucleation. To maintain control of the dermatologic lesions, oral azathioprine was initiated, but it was not well tolerated by this patient. Immunosuppressive doses of oral cyclosporine and anti-inflammatory doses of oral prednisone were used to control the depigmentation and crusting skin lesions.

Iris abscesses with and without intralenticular fungal invasion in the horse.

OBJECTIVE To describe clinical and histologic findings in horses with iris abscesses. Design Retrospective medical records study. ANIMALS STUDIED Medical records of horses that had iris abscesses at the University of Florida Veterinary Medical Center, Peterson & Smith Equine Hospital, and Veterinary Eye Specialists of London, Ontario, from 2005 to 2008 were reviewed. PROCEDURE Data collected from the medical records included signalment, clinical and histologic descriptions of ocular lesions, therapy, complications, and visual outcomes. RESULTS The medical records of two Quarterhorses, one pony, one warmblood, one Westphalian, and one Arab horse with unilateral iris abscesses were identified. Mild-to-severe clinical signs of iridocyclitis were present in all six eyes with iris abscesses. The eyes of two horses with iris abscesses were also associated with deep stromal abscesses and responded to medical therapy alone in one case, and medical therapy and corneal transplantation in the other. Iris abscesses in two horses were also associated with intralenticular invasion due to a Cladosporium and a Fusarium-type fungus respectively, and resulted in enucleations. Two horses with iris abscesses and no apparent lens involvement resolved with medical therapy in one case and surgical removal of the iris abscess and medical therapy in the other. CONCLUSIONS This is the first clinical report of iris abscesses in the horse, and the first histologic report of fungal invasion of the horse lens.

Schirmer tear test I and rebound tonometry findings in healthy calves

OBJECTIVE To describe Schirmer tear test I and rebound tonometry findings in healthy bovine calves. ANIMALS STUDIED Thirty-three clinically normal dairy breed calves of mean (SD) 11 (1.1) weeks (range, 9.3-13.3 weeks) of age were evaluated. PROCEDURES A Schirmer tear test I was performed on each eye followed by tonometry, using a TonoVet(®) without topical anesthesia. We report means (SD) and statistical analysis of data for each assay. RESULTS For both Schirmer tear test (STT) I and tonometry, significant differences were not found between fellow eyes (P = 0.1536 and P = 0.83, respectively). The mean (SD) STT I value of all eyes was 20.4 (5.0) mm/min (range, 9-34 mm/min) while the mean (SD) intraocular pressure (IOP) value of all eyes was 15.2 (5.2) mmHg (range, 7-25 mmHg). CONCLUSIONS This study reports normal data for the STT I and rebound tonometry in calves. This data may be useful in complete ophthalmic examinations of cattle, guiding diagnosis of glaucoma, uveitis, and keratoconjunctivitis sicca. However, results of these diagnostic modalities must be interpreted in light of clinical signs, given the wide range of normal values obtained in this study.

Electroretinogram evaluation of equine eyes with extensive ‘bullet-hole’ fundic lesions

OBJECTIVE To evaluate the impact of extensive bullet-hole nontapetal fundic lesions in horses on retinal function as measured by full-field electroretinography (ERG). MATERIALS AND METHODS Full-field ERG was performed on two horses with numerous bullet-hole lesions in the nontapetal fundus of both eyes. The ERG was first recorded from the eye with the more extensive lesions in response to a low-intensity light stimulus (0.03 cd s/m(2) ) that was given at times (T) T = 5, 10, 15, 20 min of dark adaptation. Consecutively, combined rod-cone response was evaluated bilaterally in response to high-intensity light stimulus (3 cd s/m(2) ), followed by cone function evaluation by flicker stimulus (3 cd s/m(2) at 30 Hz). Off-line analysis of the ERG recordings was then performed. RESULTS Despite extensive bullet-hole lesions in the nontapetal fundus bilaterally in both horses, retinal function as measured by ERG did not show any observable deficits. The b-wave amplitude of the full-field ERG increased continuously from 5 to 20 min of dark adaptation peaking at 446 μv and 377 μv for horse number 1 and 2, respectively. The b-wave amplitudes of the combined rod-cone response were OS- 459 μv and OD- 392 μv for horse number 1 and OS- 491 μv and OD- 608 μv for horse number 2. The amplitude of the flicker ERG for horse number 1 was OS- 86 μv and OD- 110 μv and for horse number 2, OS- 80 μv and OD- 74 μv. CONCLUSIONS Extensive bullet-hole chorioretinal lesions do not appear to compromise outer retinal function in these horses.

Effect of topical ophthalmic dorzolamide(2%)–timolol(0.5%) solution and ointment on intraocular pressure in normal horses

OBJECTIVE To compare the effect of commercially available solution and compounded ointment formulations of dorzolamide(2%)-timolol(0.5%) on intraocular pressure (IOP) of normal horses. ANIMALS Eighteen clinically normal horses. PROCEDURES A randomized, masked prospective design was used with horses divided into two equal groups. One eye of each horse was selected for topical ophthalmic treatment with either 0.2 mL of dorzolamide(2%)-timolol(0.5%) solution or 0.2 g of dorzolamide(2%)-timolol(0.5%) ointment every 12 h for 5 days. The contralateral eye of horses in both groups was untreated. Rebound tonometry was performed every 6 h starting 2 days prior to and ending 2 days after the treatment period. RESULTS The mean IOP reduction in eyes treated with the solution or ointment formulations was 13%. Untreated eyes in both groups experienced a lesser but still statistically significant reduction in IOP. The IOP values did not return to baseline within 48 h of the last treatment. CONCLUSIONS AND CLINICAL RELEVANCE The commercially available solution and compounded ointment formulations of ophthalmic dorzolamide(2%)-timolol(0.5%) had similar effects on IOP in normal horses. Persistent IOP reduction following cessation of treatment may indicate prolonged drug effect or acclimation of horses to tonometry.

Episodic blindness and ataxia in a horse with cholesterinic granulomas.

An 11-year-old Oldenburg mare presented following three episodes of acute, transient blindness, ataxia, and disorientation within the preceding 7 months. Clinical improvement, including return of vision, occurred within 1 week of initiating corticosteroid therapy for each of the three episodes. However, mild right-sided miosis was a consistent finding on ophthalmic examinations. Routine clinicopathologic testing revealed no significant abnormalities, and testing of cerebral spinal fluid for selected infectious diseases was unrewarding. Computed tomography of the brain demonstrated a hyperattenuating mass with peripheral mineralization in the rostroventral aspect of each lateral ventricle. The mare was euthanized due to a guarded to poor prognosis. On histopathology, the masses consisted of clusters of cholesterol clefts admixed with leukocytes, mineral deposits, and connective tissue. Cholesterinic granulomas of the lateral ventricles and hydrocephaly were diagnosed. Cholesterinic granulomas should be considered a differential diagnosis in horses presenting for intermittent blindness.