Amniotic membrane transplantation for ligneous conjunctivitis in a doberman.

An approximately 2-year-old female Doberman Pinscher was referred for the evaluation of bilateral, chronic proliferative conjunctivitis. Ophthalmic examination revealed bilateral thick, opaque pseudomembranes originating from the conjunctivae that prevented visualization of the cornea and interior structures of the eye. Histopathological findings of biopsies of the pseudomembranes were consistent with ligneous conjunctivitis. Serum plasminogen activity levels were within the normal range. Treatment with topical and systemic anti-inflammatory and immunosuppressive drugs did not improve the conjunctival lesions. The pseudomembranes were surgically excised, and the conjunctival surfaces were reconstructed with amniotic membrane. At final re-examination two years postsurgery, there was no evidence of recurrence of the pseudomembranes. To the authors' knowledge, this is the first reported case of the successful treatment of canine ligneous conjunctivitis with amniotic membrane transplantation.

An ex vivo model for suture-less amniotic membrane transplantation with a chemically defined bioadhesive.

PURPOSE: Chemically defined bioadhesives (CDB) are "two-component reactive adhesives" made from antibiotic food additives. They contain no animal-derived ingredients and are characterized by a high level of self-degradability, low toxicity, and strong bonding properties. Amniotic membrane (AM) transplantation is used to repair severe ocular surface disease in humans and horses. AM requires meticulous suturing to the injured cornea. The purpose of this study is to determine whether CDB can facilitate the suture-less placement and adherence of equine AM to porcine cadaver cornea. DESIGN: Prospective study. MATERIALS AND METHODS: To determine whether there are differences in ex vivo adhesion force between equine AM bonded with CDB to porcine cadaver cornea and equine AM sutured to porcine cadaver cornea. The following groups were tested (n = 5 per group): (1) CDB group: trephined (8 mm in diameter) cornea was bonded with CDB to 8-mm-sized discs of AM. (2) Suture group: the 8-mm trephined cornea was sutured with 8-0 absorbable suture to the AM. (3) Control group 1: two sheets of nitrocellulose paper were bonded with CDB. (4) Control group 2: two sheets of nitrocellulose paper were attached with suture and tested. Each sample was anchored to a tensiometer materials testing machine, and the strength of adhesion measured and expressed in units of kilogram-force (kgf). RESULTS: Mean ± SD strength of adhesion force found no statistically significant difference between CDB group (0.091 ± 0.054 kgf; 15 min of CDB adhesion time) and suture groups (0.095 ± 0.037 kgf), whereas there was significant difference (P < 0.05) between control group 1 (0.679 ± 0.048 kgf) and control group 2 (0.585 ± 0.092 kgf). These results revealed that the 15 min of CDB adhesive time had adhesive properties as strong as suture group. CONCLUSIONS AND CLINICAL RELEVANCE: CDB provides a satisfactory level of adherence to ex vivo suture-less attachment of equine amniotic membrane transplantation to the porcine cornea.

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.

Ocular parameters in a captive colony of fruit bats.

OBJECTIVES: To establish normal reference ranges of ocular parameters including phenol read thread, palpebral fissure length, horizontal and vertical corneal diameter, upright and hanging intraocular pressure (IOP) and to report ophthalmic examination findings of the anterior segment and lens, in a population of captive fruit bats. ANIMALS STUDIED: Eyes of 30 bats of three species were included in this study: 10 (5 males, 5 females) Malayan Flying Foxes (Pteropus vampyrus), 10 (5 males, 5 females) Little Golden-mantled Flying Foxes (Pteropus pumilus), and 10 (4 males, 6 females) Island Flying Foxes (Pteropus hypomelanus). RESULTS: The most common ophthalmic examination findings included iris-iris persistent pupillary membranes (83%), nuclear sclerosis (56.7%), prominent arterial circle (40%), iridal hyperpigmented foci (30%), pupillary margin cysts (27%), and third eyelid defects (20%). The mean, among all species for: phenol red thread was 20.23 ± 1.28 mm/15 s both eyes (OU); palpebral fissure length was 13.34 ± 0.33 mm for OU; for horizontal corneal diameter was 10.72 ± 0.32 mm for OU; for vertical corneal diameter was 9.90 ± 0.30 mm for OU; for the hanging intraocular pressures was 19.38 ± 0.77 mmHg for OU; for upright IOP was 13.95 ± 0.60 mmHg for OU. Measurements for the individual species groups and eyes were also calculated. CONCLUSIONS: Results revealed the IOP of bats in a hanging position were significantly higher than the IOP of bats in an upright position. The size of the bat, between the species, affected palpebral fissure length, horizontal corneal diameter, and vertical corneal diameter. Information about the ocular structures and normal ophthalmic parameters for the Pteropus species is crucial for species protection because of dependence on vision for survival.

Curvularia keratomycosis in a dog.

A 10-year-old, spayed female Bichon Frise was referred to the Veterinary Medical Center of the University of Florida with a 6-week history of blepharospasm and a nonhealing ulcer of the left eye. Ophthalmic examination revealed a 3-4 mm diameter corneal ulcer with faint edema at the lesion edge, and a raised grayish area on the paraxial cornea near the 2 o'clock position. Cytological testing revealed fungal hyphae and extracellular cocci. Culture of the lesion found heavy growth of Enterococcus faecalis and Curvularia spp. Treatment with a combination of topical antibiotics (polymyxin B, sulfate/trimetoprim, and 10% sulfacetamide sodium), 1% miconazole, autologous serum, and 5% hypertonic saline was instituted. After 8 days of medical therapy, an improvement of clinical signs was noted, and 15 days after initiation of treatment, the ulcer was healed with minimal corneal scarring.

The use of amniotic membrane transplantation for ocular surface reconstruction: a review and series of 58 equine clinical cases (2002-2008).

Amniotic membrane transplantation (AMT) is an effective clinical therapy for reconstruction of the ocular surface in human and veterinary patients. Amnion is avascular and strong, contains antiangiogenic and antiinflammatory properties and growth factors, and has properties that prevent or decrease fibrosis in healing tissue. Indications for its use are steadily growing and include grafting to replace diseased, missing or excised tissue, patching to support diseased tissue during the healing process and as a substrate for the expansion of epithelial cells for transplantation to the cornea. AMT through a combination of mechanical and biologic factors can preserve the integrity of the globe, optimize the visual outcome, and minimize scarring in severely diseased corneas.

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.

Surgical management of a progressive iris melanocytoma in a Mustang.

CASE DESCRIPTION: A 7-year-old gray Mustang gelding weighing 454 kg was presented for evaluation of a brown mass within the left eye (OS) of 1 year's duration with recent enlargement. CLINICAL FINDINGS: A nonpainful, 8 mm diameter, brown, vascularized mass was identified in the anterior chamber of the OS. Ocular B-scan ultrasound confirmed iris involvement and corneal endothelial contact. Histopathology confirmed the presumptive diagnosis of a uveal melanocytic neoplasm, and revealed 1-3 mitotic figures per high power (400x) field. TREATMENT AND OUTCOME: The mass was removed via sector iridectomy without complications, but without complete margins. Three cutaneous melanocytomas noted 1.5 months postoperatively were completely excised. No tumor regrowth was noted 15 months postoperatively, supporting a diagnosis of melanocytoma for the iridal mass. CLINICAL RELEVANCE: Sector iridectomy is a reasonable treatment option for uncomplicated iridal melanocytomas in horses. Mitotic index and presence of cutaneous melanocytic neoplasms may be irrelevant to the prognosis of equine iridal melanocytic neoplasms.

Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus).

A 47-yr-old female Asian elephant (Elephas maximus) developed a corneal stromal abscess in her right eye. The elephant was trained to open her eye for topical ophthalmic therapy, and was treated six times daily with antibiotics and an antifungal solution for almost 2 mo. Nonsteroidal anti-inflammatory drugs were used to control pain, and atropine was applied topically to dilate the pupil and provide additional comfort. Vascularization of the abscess began shortly after initiating therapy, and complete resolution was obtained by 7 wk.