Central corneal dermoid in a Labrador retriever puppy.

An eight-week-old, male Labrador retriever puppy was presented with an abnormal appearance of the left cornea, observed after the eyelids opened in the second week of life. Ocular examination showed a large central dermoid of the left cornea. The dermoid was excised by superficial keratectomy, and healing was uneventful. The dermoid was classified as a Mann's second type. To the authors' knowledge, a Mann's second type corneal dermoid has not previously been reported in a dog.

Primary glaucoma in Burmese cats.

OBJECTIVE: To document the clinical signs and management of primary glaucoma in Burmese cats. DESIGN: A retrospective study of six affected Burmese cats, from 1996 to 2001. Procedure Six Burmese cats diagnosed with primary glaucoma were managed over periods varying from 3 months to 4.5 years. Clinical details were obtained from practice records. Gonioscopic examination of the drainage or iridocorneal angle in eyes of these affected cats was made. RESULTS: Six desexed female Burmese cats (ages 7.0 to 10.5 years) presented with complaints of either unilateral (n = 4) or bilateral (n = 2) red eye, dilated pupil or enlarged eye. In one of the affected cats, one eye had been enucleated prior to the commencement of the study, thus a total of 11 eyes were examined. Clinically, all affected eyes (n = 8) had injected episcleral blood vessels and elevated intraocular pressure. Gonioscopy revealed the presence of nine narrow and two closed iridocorneal angles. Medical therapy included topical 2% dorzolamide (n = 8), 0.5% timolol maleate (n = 1), 0.005% latanoprost (n = 1) and 0.5-1.0% prednisolone acetate (n = 8). Surgery was performed in six eyes using either diode laser (n = 5) and/or cryothermy (n = 2) and one eye was eviscerated, with implantation of a prosthesis. With therapy, five affected eyes maintained vision and normal intraocular pressure, one eye remained blind with normal intraocular pressure, one eye remained blind with elevated intraocular pressure and one eye was eviscerated. CONCLUSIONS: The Burmese cat may be predisposed to primary narrow-angle glaucoma. Early diagnosis and continuous antiglaucoma therapy can help control intraocular pressure and maintain vision.

Morphologic alterations in the anterior lens capsule of canine eyes with cataracts.

OBJECTIVE: To examine the morphologic changes in the anterior lens capsule and lens epithelium of canine eyes with cataracts. SAMPLE POPULATION: Anterior lens capsules from the eyes of 25 dogs with cataracts and from an additional 10 canine globes with lenses subjectively assessed to be normal. PROCEDURE: Thickness of each anterior lens capsule was measured by use of a digital microscopic camera and imaging software. All 25 capsules from eyes with cataracts were submitted for light microscopy; 4 were also submitted for electron microscopy. RESULTS: Thickness of the anterior lens capsule increased with age for the normal lenses and the lenses with cataracts; the change with age was similar for both groups. Light microscopy revealed fibrous metaplasia of lens epithelial cells in 7 of 25 anterior lens capsules with focal thickenings of the posterior aspect of the capsule. Electron microscopy revealed deposition of collagen and basement membrane-like material by fibroblast-like cells. CONCLUSIONS: Results indicate that thickness of the anterior lens capsule in dogs increases with age and that this increase in thickness is not significantly different between normal lenses and lenses with cataracts. In addition, epithelial cells from lenses with cataracts may undergo metaplasia to form plaques composed of fibrous tissue and ectopic basement membrane produced by epithelial cells.

Convergent strabismus in a white Bengal tiger.

A white Bengal tiger was noted to have a convergent strabismus with poor vision since a cub. The tiger and a littermate with normal colouring and apparently normal eyes were anaesthetised for comparative ocular examination. A fundus typical of colour-dilute cats and dogs was noted in the white tiger. Except for strabismus, no abnormalities were observed. Electroretinography showed similar retinal function in both tigers. Possible causes of strabismus considered were an adaptation to genetically determined abnormal visual pathways related to lack of pigment, abnormalities of the abducent nerves and mechanical restricting conditions of the medial rectus muscles.

Primary corneal papilloma and squamous cell carcinoma associated with pigmentary keratitis in four dogs.

Squamous cell carcinoma (SCC) and squamous papilloma are rarely reported as primary lesions of the cornea in dogs. One case of corneal papilloma and 3 cases of SCC, each arising as a primary central corneal neoplasm rather than spreading from adjacent limbal conjunctiva, were reviewed. The most common cause of SCC in animals is chronic exposure of lightly pigmented epithelium to UV light; however, all dogs in this study had a history of chronic pigmentary keratitis. Three of the 4 dogs were of brachycephalic breeds with naturally proptotic eyes and oversized palpebral fissures that may have exposed the cornea to greater excessive solar radiation. Alternatively, mechanical factors that caused chronic changes in the cornea may have been causative factors for induction of primary dysplastic or neoplastic changes. Primary corneal neoplasia should be considered in the differential diagnosis of corneal masses.

Ocular infections with dematiaceous fungi in two cats and a dog.

Pigmented fungi were identified in ocular tissues from 2 cats and 1 dog. The first cat was euthanatized because of acute anterior uveitis that was unresponsive to treatment. On histologic examination, intraocular structures had been obliterated and replaced by a gray coagulum of inflammatory infiltrates and fungal elements. The second cat was treated for unilateral glaucoma that was unresponsive to treatment. A large retrobulbar mass, discovered and removed during an enucleation procedure, contained plant-origin foreign material. Keratitis, episcleritis, and orbital cellulitis with fungal elements were found on examination of the enucleated globe. The dog, examined because of a presumed corneal scratch of 2 weeks' duration that was unresponsive to treatment, had a corneal lesion subsequently removed by lamellar keratectomy that contained fungi on histologic examination. Infections caused by dematiaceous fungi are not common in domestic animals, and, to our knowledge, such infections in the eye have not been described.