Unilateral invasive intraocular melanoma with choroidal and optic nerve involvement resulting in bilateral vision loss in a Labrador Retriever.

A 10-year-old male castrated Labrador Retriever cross was referred for evaluation of acute vision loss. Ophthalmic examination revealed mild left sided exophthalmos, bilateral resting mydriasis, an absent direct and reduced consensual PLR in the left eye and reduced direct and absent consensual PLR in the right eye. Examination of the cornea and anterior segment with slit lamp biomicroscopy was unremarkable. Indirect fundoscopy revealed a left optic nerve head obscured by a darkly pigmented lesion. Fundic examination in the right eye was unremarkable. Magnetic resonance imaging revealed a smoothly marginated, lobulated cone to irregularly shaped, strongly T1 hyperintense, T2 and T2 fluid-attenuated inversion recovery hypointense, strongly contrast enhancing mass closely associated with the entire left optic nerve, extending across the optic chiasm and into the right optic nerve ventrally. Full clinical staging revealed no evidence of metastasis. Exenteration of the left eye was performed. Histopathology revealed an unencapsulated, poorly demarcated, multilobulated and infiltrative pigmented mass that was effacing the posterior choroid and optic nerve. The mass was composed of a moderately pleomorphic population of heavily pigmented polygonal cells arranged in sheets and clusters, displaying moderate anisocytosis and anisokaryosis. The population of cells contained moderate amounts of abundant brown-black granular pigment consistent with melanin within the cytoplasm. Mitotic figures averaged approximately three per ten 400× fields (2.37 mm2 ). This is the first report of a melanocytic tumor invading along the optic nerve and tract to result in contralateral vision loss.

Diagnosing Corneal Pigmentation in Small Animals.

The transparency of the cornea is critical to its role in transmitting light. Loss of corneal transparency results in visual impairment. Corneal pigmentation results from melanin accumulation in the epithelial cells of the cornea. Differential diagnosis for corneal pigmentation include corneal sequestrum, corneal foreign body, limbal melanocytoma, iris prolapse, and dermoid. These conditions must be excluded to reach a diagnosis of corneal pigmentation. A myriad of ocular surface conditions are associated with corneal pigmentation, including qualitative and quantitative tear film deficiency, adnexal disease, corneal ulceration, and breed-related corneal pigmentation syndromes. Accurate etiologic diagnosis is critical to determining effective treatment.

Genetics of Equine Ocular Disease.

Horses perform in a variety of disciplines that are visually demanding, and any disease impacting the eye has the potential to threaten vision and thus the utility of the horse. Advances in equine genetics have enabled the understanding of some inherited ocular disorders and ocular manifestations and are enabling cross-species comparisons. Genetic testing for multiple congenital ocular anomalies, congenital stationary night blindness, equine recurrent uveitis, and squamous cell carcinoma can identify horses with or at risk for disease and thus can assist in clinical management and breeding decisions. This article describes the current knowledge of inherited ocular disorders.

Development of a vision impairment score for the assessment of functional vision in dogs: Initial evidence of validity, reliability, and responsiveness.

AIM: To describe the development and initial validation of a questionnaire measuring functional vision in dogs. METHODS: A 17-item survey was designed to quantify functional vision in dogs. The Vision Impairment Score (VIS) was determined by summing responses to each question. Questions were assigned to one of five subcategories: overall vision, daily activities, peripheral vision, near vision, and distance vision. Content validity was established during development phases, and construct validity via comparing results of known groups (blind vs sighted; normal vs impaired vision; surgery to improve vision vs nonrestorative surgery), and through factor analysis. Concurrent criterion validity was determined with use of a validated health-related quality-of-life (HRQL) assessment tool. Reliability and responsiveness assessments were investigated using intraclass correlation coefficient (ICC) and effect size (ES), respectively. RESULTS: Responses (221) from 201 dog owners were included. Compared to sighted dogs (n = 153), blind dogs (n = 48) had a higher VIS and greater impairment in all subcategories. Among sighted dogs, a higher VIS was obtained in dogs with low vision compared to those with normal vision (P < 0.001). A higher VIS was associated with poorer HRQL (P < 0.001). Perfect reliability was obtained for 6/17 questions, and excellent reliability for 11/17 questions (intraclass correlation 1.0 and >0.9, respectively), and the VIS was highly responsive to therapeutic intervention (effect size 1.46). CONCLUSION: Results suggest the VIS may be clinically useful in assessing and obtaining a quantifiable measure of functional vision in dogs. Ongoing validation of the tool for clinical use is needed.

Magnetic resonance imaging findings in dogs with orbital inflammation.

OBJECTIVES: To describe MRI features of canine retrobulbar inflammation, their association with clinical findings and outcome and to assess the value of MRI in detecting orbital foreign bodies. MATERIALS AND METHODS: Clinical records of dogs with confirmed (23 of 31) and suspected (eight of 31) retrobulbar inflammation that underwent low field MRI studies were analysed retrospectively. RESULTS: Of the 31 dogs included in the study there was abscessation in 19. Extraocular myositis (27 of 31) was concurrent with strabismus in three cases. Of 25 patients with exophthalmos, 14 had concurrent optic nerve swelling and, of these, five had permanent loss of vision. There was no vision loss in patients without nerve swelling. One case of suspected retinal detachment on MRI was confirmed clinically. Extensive abnormal contrast enhancement in the temporalis, masseter and pterygoideus muscles was associated with facial (n=3) and trigeminal nerve deficits (n=1). Three patients with inflammation extending into the nasal cavity and frontal sinus (one of 31) or meningeal contrast enhancement (two of 31), showed optic and oculomotor nerve deficits. On MRI a foreign body was not visible in 20 of 31 case or "appeared likely" in 11 of 31 dogs. A foreign body was found at surgery in one case. CLINICAL SIGNIFICANCE: MRI outlines the extent of retrobulbar inflammation. Clinical findings were associated with imaging findings. MRI overestimated the presence of foreign bodies.

Technique, postoperative complications, and visual outcomes of phacoemulsification cataract surgery in 21 penguins (27 eyes): 2011-2015.

OBJECTIVE: To describe surgical technique, postoperative complications, and visual outcome in penguins after phacoemulsification lens extraction surgery. ANIMALS STUDIED: Twenty-one penguins (27 eyes) that had phacoemulsification from 2011 to 2015 at Animal Eye Associates. Species included are as follows: 14 southern Rockhopper (18 eyes, 66.6%), 4 Gentoo (4 eyes, 19%), 2 King (3 eyes, 9.5%), and 1 Chinstrap penguin (2 eyes, 4.8%). Eleven of the penguins were females, and 10 were males with average age at the time of surgery being 27.5 years (range of 22-31 years). PROCEDURE: This is a retrospective study of phacoemulsification cataract surgery patients from 2011 to 2015. Visual outcome was evaluated by veterinary ophthalmologists at postoperative recheck examinations and subjectively by penguin keepers using individual bird surveys and paired t tests for statistical analysis. RESULTS: All eyes were functionally visual after surgery and at the time of last follow-up. Based on keeper surveys, 81% (17/21) of penguins showed immediate improvements in overall quality of life and 90% (19/21) of penguins exhibited improvement in mobility and behavior within their exhibit following cataract removal. Of the 14 penguins that received 1:5 intracameral atracurium during surgery, 10 (71.4%) had moderate mydriasis, 1 (7.1%) had minimal mydriasis, and 3 (21.4%) showed no effect to the pupil. Seventy percent of the cases had phacoemulsification times less than 60 seconds/eye; the mean time was 72 seconds. Sixteen eyes (59.3%) underwent anterior capsulotomy only, planned anterior and posterior capsulotomies were performed in 3 eyes (11.1%), and the entire lens capsule was removed due to capsular fibrosis and wrinkling in 8 eyes (29.6%). The most common short-term postoperative complication was temporary mild blepharospasm and/or epiphora, reported in 8 eyes (29.6%) from 7 penguins (33.3%). Long-term complications, 2-6 years postoperatively, included posterior synechiation resulting in dyscoria (10 of 24 eyes, 41.7%) and capsular fibrosis in all penguins with residual lens capsule (19/19, 100%). CONCLUSION: The prognosis for vision and behavioral improvement after phacoemulsification surgery in penguins is good, with low incidence of vision-threatening complications.

Restored vision in a young dog following corticosteroid treatment of presumptive hypophysitis.

BACKGROUND: Hypophysitis is an umbrella term for a group of disorders involving inflammation of the pituitary gland. A rare occurrence in humans, hypophysitis can produce a range of clinical signs including (but not limited to) visual deficits and diabetes insipidus. Only five cases of canine hypophysitis exist in the literature, all presenting in mature dogs with no visual deficits and a grave outcome. This case report describes the clinical and advanced imaging features of blindness-inducing presumptive hypophysitis in a dog, which rapidly resolved with medical management. CASE PRESENTATION: A 1-year-and-seven-month-old neutered male Standard Poodle presented with subacute blindness, ataxia, and polyuria/polydipsia (PUPD). Magnetic resonance imaging (MRI) detected a contrast-enhancing pituitary mass with perilesional oedema compromising the optic chiasm. Suspecting neoplasia, anti-inflammatory corticosteroid was commenced prior to radiation therapy planning. Complete resolution of neurological and visual deficits occurred within 12 days of starting steroid treatment. Repeated advanced imaging indicated macroscopic resolution of the lesion. An extended thyroid panel with insulin-like growth factor-1 analysis supported a diagnosis of hypophysitis. Resolution of PUPD was achieved with tapering courses of prednisolone and desmopressin; the dog has since been clinically normal for 14 months and treatment-free for 11 months. CONCLUSIONS: To the authors' knowledge, this is the first instance in which a canine pituitary mass has demonstrated long-term resolution with palliative medical treatment alone, alongside reversal of associated blindness and presumptive diabetes insipidus. We suspect this lesion to be a form of hypophysitis, which should be included among differential diagnoses for pituitary masses, and for subacute blindness in dogs. Where possible, we advocate biopsy-confirmation of hypophysitis prior to timely intervention with anti-inflammatory treatment.

Retrospective evaluation of phacoemulsification and aspiration in 41 horses (46 eyes): visual outcomes vs. age, intraocular lens, and uveitis status.

OBJECTIVE: To determine the effect of age at the time of surgery, intraocular lens (IOL) placement, and presence of chronic uveitis on visual outcome after phacoemulsification and aspiration (PA) of cataracts in horses. ANIMALS STUDIED: Records of 41 horses (46 eyes) receiving unilateral or bilateral PA. METHODS: Retrospective analysis of horses receiving unilateral or bilateral PA at the NCSU-VTH (35 horses, 39 eyes) and in Northern Italy (six horses, seven eyes) was performed. Visual status at last follow-up was compared to age at the time of surgery, IOL status, and presence of chronic uveitis preoperatively. Seven horses with chronic uveitis also underwent placement of a suprachoroidal cyclosporine implant. Clinical ophthalmic examinations and owner questionnaires were used to evaluate visual status. RESULTS: Twenty-one of 46 eyes (46%) received an IOL and 12 of 46 eyes (26%) had chronic uveitis. Overall, 25 of 46 eyes (54%) were visual at last follow-up (mean 35.1 ± 34.8 months). Age (mean 8.6 ± 7.7 years) was not significantly associated with visual outcome. Fourteen of 21 (67%) pseudophakic eyes and 11 of 25 (44%) aphakic eyes were visual at last follow-up (P = 0.342). Eyes with preoperative chronic uveitis were significantly less likely to be visual (3 of 12 eyes [25%]) than horses without preoperative chronic uveitis (22 of 34 eyes [65%]) (P = 0.023). CONCLUSIONS: Horses with chronic uveitis had significantly less favorable visual outcome after PA. Older age at surgery and IOL use were not associated with poor visual outcome.

Visual outcomes of phacoemulsification cataract surgery in horses: 1990-2013.

OBJECTIVE: To evaluate the long-term visual outcome of phacoemulsification lens extraction surgery in foals and horses and identify any unique postoperative complications that affect the visual outcome. PROCEDURE: This is a retrospective medical records study of phacoemulsification cataract surgery in 95 foals and horses from 1990 to 2013. RESULTS: Cataracts were removed by phacoemulsification from 111 eyes of 95 horses ranging in age from 22 days to 26 years (average 8.0 ± 5.7 years). Forty-four of the 95 animals were foals (46.3%). Sixteen horses or foals had surgery bilaterally. One hundred and two eyes were blind preoperatively with 97 eyes (95.1%) having evidence of vision immediately postoperatively. Ninety of the 95 horses (94.7%) regained vision in the immediate postoperative period. Five horses did not recover vision postoperatively. Twenty-four horses had cataracts associated with equine recurrent uveitis (ERU). Trauma was noted as the cause of cataract in 10 horses, and no specific cause for the cataract identified in 61 horses. The combined visual outcome data from horses with all types of cataracts (n = 95) found 83 (87.3%) horses to be visual ≤1 month postoperatively, 47 (49.4%) horses visual for >1-6 months postoperatively, 33 (34.7%) horses visual from >6 to 12 months postoperatively, and 25 horses (26.3%) visual >24 months postoperatively. CONCLUSION: The results of phacoemulsification cataract surgery in horses indicate at least 26.3% of horses are still visual and able to continue their natural activity for 2 years or more postoperatively.

Symblepharon secondary to ophthalmomyiasis externa in a dog.

A 4-month-old crossbred female dog presented with complaints of poor vision and odd appearance of the eyes. At the age of a month, the animal was found lying in a railway road in a very bad condition and was rescued from death. At that time, the patient was presented with severe bilateral ocular discharge, and from both eyes, dipterous fly larvae were extracted. The dog was given symptomatic treatment (deworming, topical and systemic antibiotics, nutritional support) but never regained a normal eye appearance. At the time of the initial presentation, it had severe vision impairment because of bilateral cicatricial symblepharon, total in the left eye and occupying 3/4 of the cornea in the right eye. Surgery was proposed to attempt a resolution. Superficial keratectomy was performed in both eyes. After a midline incision in the cornea, the conjunctiva was dissected away. The conjunctiva was apposed to and sutured to the limbus and secured in the upper and lower conjunctival fornix. Additionally, in the left eye, a lateral canthotomy and canthoplasty were performed to enlarge the size of the eyelid opening. The corneal epithelium healed without complications, the patient regained vision, and after 36 months of follow-up, no recurrences were observed. To the authors' knowledge, this is the first report of symblepharon secondary to ophthalmomyiasis externa in a dog.

Intracranial meningioma in a baboon (Papio spp.).

Meningioma is the most common intracranial non-glial tumour of cats, dogs and man. Few spontaneously arising brain tumours have been reported in non-human primates. This report describes a meningioma in a captive baboon. Clinical signs exhibited by the animal included head pressing, visual impairment and vestibular disease. The tumour arose from the ventral aspect of the cranial cavity and compressed the overlying left side of the cerebellum and brainstem. Microscopically, the mass was characterized by pleomorphic spindle-shaped to polygonal cells arranged in sheaths, vague whorls and occasional papillary structures on vascular cores. Nuclear cytoplasmic invagination, syncytial-like cells and areas of mineralization were also evident. Immunohistochemically, the neoplastic cells expressed vimentin and S-100 protein, but not pancytokeratin, glial fibrillary acidic protein or epithelial membrane antigen. The features of this tumour are similar to those of meningiomas in other species.

Cerebellar abscess in a cynomolgus macaque (Macaca fascicularis).

BACKGROUND: A cynomolgus macaque (Macaca fascicularis) presented with decreased appetite, lethargy, ataxia, disorientation and visual impairment. It was used in a hepatitis B (HBV) study involving injections of HBV plasmid construct (450 microg) and aflatoxin B1 (25 microg/kg) in an effort to develop a model of liver cirrhosis and hepatocellular carcinoma. METHODS: The case work-up included physical examination, including assessment of hydration, thoracic and abdominal radiographs and abdominal ultrasound. Clinical pathology included complete blood counts and tests for levels of plasma ammonia (NH(3)) and serum electrolytes, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, total bilirubin, and gamma-glutamyl transferase. Serum samples had also been serially tested for the presence of HBsAg, anti-HBc antibodies, HBV e-antigen, and HBV DNA. With a tentative diagnosis of hepatic encephalopathy, treatment with lactulose, antibiotics, and fluid therapy was initiated. RESULTS: Clinical pathology and diagnostic imaging performed on the animal revealed no abnormalities except for the hyperammoniemia. Absence of HBV markers in the serum indicated unsuccessful inoculation. Not fully responding to therapeutic intervention, the animal was euthanized. Necropsy revealed fibrous peritoneal adhesions and an abscess in the cerebellopontine angle. Exudate culture indicated the presence of alpha-hemolytic streptococcus, Eubacterium lentum, and Bacteroides stercoris. CONCLUSIONS: Brain abscesses are uncommon in non-human primates. This case of cerebellar abscess is characterized by important features similar to that found in humans, including the presenting signs and the presence of the above-cultured bacteria.

Neodymium:yttrium-aluminum-garnet laser treatment of cystic granula iridica in horses: eight cases (1988-1996).

OBJECTIVE: To determine clinical features of cystic granula iridica in horses and outcome of horses treated with an ophthalmic neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. DESIGN: Retrospective study. ANIMALS: 8 horses. PROCEDURE: An ophthalmic Nd:YAG laser was used to deflate cysts in all horses. RESULTS: Horses were examined because of visual impairment (n = 5), decreased jumping performance (2), or head shaking (1). Clinical signs associated with cysts resolved in all horses after treatment. Short- and long-term complications did not develop, and cysts did not recur. CLINICAL IMPLICATIONS: Cystic granula iridica may cause vision impairment in horses. Treatment with an ophthalmic Nd:YAG laser appears to be safe and effective.

Visual outcome and ocular survival following iris prolapse in the horse: a review of 32 cases.

The medical records of 32 horses treated for iris prolapse (IP) during an 8 year period, at the University of Florida Veterinary Medical Teaching Hospital, were reviewed. Iris prolapse was associated with perforated corneal ulcers in 15 horses (47%), ruptured stromal abscesses in 2 horses (6%), and full thickness corneal lacerations in 15 horses (47%). Initial ophthalmic examinations revealed IP with severe iridocyclitis in all eyes and keratomalacia in 8 eyes with corneal ulcers, one with a stromal abscess and 1 with a corneal laceration. Hyphema was present in 7 eyes with corneal lacerations. Thirty horses were managed with combined medical and surgical therapy. Two horses were only treated medically with topically administered antibiotics. Of the 24 perforations surgically repaired, 21 were closed primarily and 13 were then covered with a conjunctival graft. After combined therapy and a minimum of 4 months of follow-up, vision was retained in 6 of the horses (40%) with perforating corneal disease and 5 of the horses (33%) with perforating corneal lacerations. Post operatively, of the 11 (37%) horses blind at discharge, 6 (55%) subsequently developed phthisis bulbi. Enucleations were performed in 4 cases with extensive keratomalacia and/or endophthalmitis, 2 cases with limbal rupture and total hyphema, and one case with a chronic IP. One horse was subjected to euthanasia after 3 surgical treatments failed to stabilise stromal melting. Horses presented with ulcerative keratitis of fewer than 15 days duration, or horses with corneal lacerations less than 15 mm in length, tended to have a favourable visual outcome. Keratomalacia, hyphema, corneal lacerations longer than 15 mm and lacerations extending to, along, or beyond the limbus, adversely influenced visual outcome. Iridectomy did not appear clinically to exacerbate anterior uveitis or adversely affect visual outcome. Ocular survival following combined therapy was 80% (12/15) in horses with corneal lacerations and 67% (10/15) in horses with ulcerative keratitis.

Traumatic ocular proptoses in dogs and cats: 84 cases (1980-1993).

Eighteen eyes of 66 dogs were visual on reevaluation of traumatic proptosis. Twenty-one eyes were enucleated, and 4 dogs were euthanatized. In 18 cats, no eyes regained vision after traumatic proptosis: 12 cats had the affected eye enucleated, 2 had an eye that was considered blind, and 4 cats were euthanatized. Affected eyes of 45 dogs and 2 cats underwent surgical replacement and temporary tarsorrhaphy. Favorable prognostic indicators for eyes undergoing surgical replacement included proptosis in a brachycephalic dog, positive direct or consensual pupillary light response, normal findings on posterior segment examination, and a proptosed eye that had vision on initial examination. Unfavorable prognostic indicators included proptosis in a nonbrachycephalic dog, proptosis in cats, hyphema, no visible pupil, facial fractures, optic nerve damage, and avulsion of 3 or more extraocular muscles.

[Retinal dysplasia in dogs--a review]. / Retinadysplasi hos hunde--en oversigt.

Retinal dysplasia is a developmental aberration of the neuroretina characterized by formation of retinal tubules, malformation rosettes and folding of the retina. Retinal dysplasia has been reported in Bedlington Terrier, Sealyham Terrier, Beagle, Labrador Retriever, English Cocker Spaniel, American Cocker Spaniel, English Springer Spaniel, Yorkshire Terrier and Rottweiler. A hereditary basis for retinal dysplasia has been proved or suggested for all breeds exhibiting retinal dysplasia except Beagle and Rottweiler. Ophthalmoscopically retinal dysplasia is characterized by vermiform streaks often radiating from the optic disc. The reflectivity of the tapetum is often altered in these areas. Accompanying retinal detachment or cataractous changes in the lens may be seen. Extensive retinal dysplasia and retinal detachment or cataract may result in visual impairment or blindness. Eyes exhibiting retinal dysplasia may be classified according to the number of layers from the retinal structure that are represented in the rosettes. Three-layer rosette. Two-layer rosette. Single-layer rosette. Primitive unilayer rosette. The etiology of retinal dysplasia includes viral disorders, irradiation, X-radiation, intrauterine trauma and heritable factors.

Meningiomas in cats: a retrospective clinical study of 36 cases.

Thirty-six cases of meningiomas in cats were reviewed as to the clinical signs and anatomic location. Age, breed, and sex also were noted. It was found that, in general, meningiomas affected older cats, with two thirds of them being greater than or equal to 10 years old. There was no breed predilection, although there was a majority of male cats. In most cases, the anatomic location was supratentorial, with only one case being infratentorial, and no tumors were below the foramen magnum. A number of cats had multiple maningiomas, and this often complicated the anatomic localization by neurologic examination. Tentorial herniation (6 cases) was associated with positional nystagmus or tetraparesis, or both, in addition to the deficits caused by the tumor.