New Direct and Indirect Ophthalmoscopy Teaching Methodology for Veterinary Doctors.

Ophthalmic diseases can reflect the presence of systemic disease in animals. Thus, specialists in veterinary medicine must master the technique of fundus examination. To aid in the acquisition of this skill, we developed a teaching methodology using a low-cost model that students can build themselves and a device that allow for the examination of the animal's retina to teach the techniques of direct and indirect ophthalmoscopy in veterinary medicine.

Retinal structural and microvascular abnormalities in retinal dysplasia imaged by OCT and OCT angiography.

OBJECTIVE: To describe the in vivo structural characteristics of multifocal and geographic retinal dysplasia visualized with advanced retinal imaging including confocal scanning laser ophthalmoscopy (cSLO), optical coherence tomography (OCT), en face OCT, and the novel vascular imaging technique OCT angiography (OCTA). DOGS STUDIED AND PROCEDURES: Two dogs were diagnosed with unilateral multifocal or geographic retinal dysplasia and underwent advanced retinal imaging under general anesthesia at the Retinal Disease Studies Facility of the University of Pennsylvania. RESULTS: In both cases, the morphological pattern of the lesions was similar including outer retinal folds that invaginated and formed tubular retinal rosettes, surrounding a central inner retinal thickening (multifocal) or plaque (geographic). The two dogs had multiple vascular anomalies in the lesions such as increased tortuosity, abnormal change of vessel diameter including aneurysms and capillary network disruption. We also identified increased autofluorescence by AF cSLO with short wavelength light source (488 nm and barrier filter at 500 nm), and several areas of photoreceptor loss associated with the lesions. CONCLUSION: The use of OCTA allowed the identification of microvascular abnormalities associated with multifocal and geographic retinal dysplasia in two dogs. To our knowledge, this is the first report where the dye-free OCTA technique is used to study vascular lesions in canine retinas.

In vivo imaging comparison of unilateral circular retinal plaques in retriever dogs to dysplasia and detachment in the English Springer Spaniel.

PURPOSE: To compare the scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and fluorescein angiography (FA) findings in retrievers with a single unilateral circular retinal plaque to those of an English springer spaniel with bilateral retinal dysplasia. PROCEDURES: A retrospective record review identified three dogs with circular retinal plaques that underwent SLO and OCT; in two of the three dogs, FA was also completed. Morphologic changes, lesion measurements, and angiogram characteristics were documented. An English springer spaniel with bilateral retinal dysplasia that had undergone SLO, OCT, and FA was used for comparison. RESULTS: Scanning laser ophthalmoscopy of the retriever dogs revealed circular retinal plaques with a dark periphery located in the tapetal retina. OCT revealed a thickening of the nerve fiber layer corresponding to the circular pattern observed on SLO. Within the circular plaque, the retina was predominantly of normal architecture. FA revealed variable hypofluorescence of both the rim and the center of the circular lesion throughout the early angiogram phases. In the late recirculation phase, small multifocal areas of hyperfluorescence were observed. OCT of geographic retinal dysplasia in the English springer spaniel revealed disorganization of both inner and outer retinal layers, and retinal detachment. CONCLUSIONS: Circular plaques observed in the tapetal retina are predominantly formed by a thickening of inner retina, while retinal dysplasia has disorganization of both inner and outer retinal layers. Further etiologic research is needed, including pedigree mapping to determine whether retinal plaques are an acquired or inherited condition.

Multiple ocular developmental defects in four closely related alpacas.

OBJECTIVE: To describe the clinical, gross pathologic, and histopathologic findings for a visually impaired 5.8-year-old female alpaca with multiple ocular abnormalities, as well as the clinical findings for three closely related alpacas. ANIMALS STUDIED: Four alpacas. PROCEDURES: Ophthalmic examination was performed on a 16-month-old female alpaca following observation of visual impairment while hospitalized for an unrelated illness. Following acute systemic decline and death 4.5 years later, the alpaca's brain, optic nerves, and eyes were examined grossly and histologically. Ophthalmic examination of three closely related alpacas was subsequently performed. RESULTS: The 16-month-old female alpaca (Alpaca 1) had ophthalmoscopic findings suggestive of a coloboma or hypoplasia of the retinal pigment epithelium (RPE) and choroid, and suspected optic nerve hypoplasia OU. Histopathology performed 4.5 years later revealed moderate to severe choroidal, RPE, and retinal hypoplasia with multifocal retinal detachments OU. However, the optic nerves were normal in size and histologic appearance when compared to an age-matched control. Clinical evaluation of the 2-year-old son of Alpaca 1 revealed iris colobomata OU and choroidal dysplasia/hypoplasia OD in addition to nonpathologic variations in melanin density including heterochromia iridis and a subalbinotic fundus OU. Clinical evaluation of the 13-year-old mother of Alpaca 1 revealed heterochromia iridis, cataracts, and a subalbinotic fundus OU. A 2-year-old half-brother of Alpaca 1 had an RPE and choroidal coloboma OS. CONCLUSION: The developmental ocular abnormalities diagnosed in these closely related alpacas are likely hereditary.

Retinal dysplasia in the crab-eating fox (Cerdocyon thous) / Displasia retiniana em cachorro-do-mato (Cerdocyon thous)

Previously described in humans and domestic animals, retinal dysplasia has three clinical forms: focal/multifocal, geographic and total. A young orphan crab-eating fox (Cerdocyon thous) from wildlife, male, approximately 45 days old referred to the Wildlife Medicine and Ophthalmology Services of the "Governador Laudo Natel" Veterinary Hospital of the Universidade Estadual Paulista, Jaboticabal Campus, SP, Brazil, where it received primary outpatient care. The patient was in good general health condition, without hematological, biochemistry or serological alterations and no signs of visual impairment. Indirect binocular ophthalmoscopy showed retinal changes in the left eye, distributed over the tapetal area in the form of grayish folds and rosettes. In the affected areas, tapetal reflectivity was reduced. No other ophthalmic abnormalities were observed. This is the first report of retinal dysplasia in the crab-eating fox (Cerdocyon thous) from wildlife.(AU)

Descrita no homem e em animais domésticos, a displasia de retina, se apresenta nas formas focal/multifocal, geográfica e completa. Um espécime de cachorro-do-mato (Cerdocyon thous) de vida livre, macho, com 45 dias de vida foi capturado e encaminhado aos Serviços de Medicina de Animais Selvagens e de Oftalmologia do Hospital Veterinário "Governador Laudo Natel" da Universidade Estadual Paulista ­ Unesp, Câmpus Jaboticabal-SP, Brasil, onde recebeu atendimento primário ambulatorial. O paciente apresentava-se em bom estado geral, sem alterações hematológicas e sorológicas, e não havia sinais de déficit visual. A oftalmoscopia binocular indireta mostrou alterações retinianas no olho esquerdo, distribuídas na área tapetal na forma de pregas e de rosetas de coloração acinzentada. Nas áreas acometidas, a reflectividade tapetal estava reduzida. Não foram observadas outras alterações oftálmicas. Trata-se do primeiro relato de literatura sobre displasia retiniana em cachorrodo-mato (Cerdocyon thous).(AU)

Characterization of an Early-Onset, Autosomal Recessive, Progressive Retinal Degeneration in Bengal Cats.

PURPOSE: A form of retinal degeneration suspected to be hereditary was discovered in a family of Bengal cats. A breeding colony was established to characterize disease progression clinically, electrophysiologically, and morphologically, and to investigate the mode of inheritance. METHODS: Affected and related cats were donated by owners for breeding trials and pedigree analysis. Kittens from test and complementation breedings underwent ophthalmic and neuro-ophthalmic examinations and ERG, and globes were evaluated using light microscopy. RESULTS: Pedigree analysis, along with test and complementation breedings, indicated autosomal recessive inheritance and suggested that this disease is nonallelic to a retinal degeneration found in Persian cats. Mutation analysis confirmed the disease is not caused by CEP290 or CRX variants found predominantly in Abyssinian and Siamese cats. Ophthalmoscopic signs of retinal degeneration were noted at 9 weeks of age and became more noticeable over the next 4 months. Visual deficits were behaviorally evident by 1 year of age. Electroretinogram demonstrated reduced rod and cone function at 7 and 9 weeks of age, respectively. Rod responses were mostly extinguished at 14 weeks of age; cone responses were minimal by 26 weeks. Histologic degeneration was first observed at 8 weeks, evidenced by reduced photoreceptor numbers, then rapid deterioration of the photoreceptor layer and, subsequently, severe outer retinal degeneration. CONCLUSIONS: A recessively inherited primary photoreceptor degeneration was characterized in the Bengal cat. The disease is characterized by early onset, with histologic, ophthalmoscopic, and electrophysiological signs evident by 2 months of age, and rapid progression to blindness.

A case of primary choroidal malignant melanoma in a cat.

This report describes the clinical presentation, diagnosis, histological lesions, and prognosis of a primary choroidal malignant melanoma in a 15-year-old cat. The animal was presented for unilateral blindness. On ocular examination, a raised pigmented mass protruding from the posterior pole into the vitreous body was observed by diffuse transillumination and indirect ophthalmoscopy. Ocular ultrasound and computer tomography (CT) scan confirmed localization of the tumor to the posterior segment. The diagnosis of primary choroidal melanoma was confirmed by histopathology after enucleation. To our knowledge, this is the first reported case of a feline malignant melanoma with a primary choroidal localization without iris involvement.

O olho da coruja-orelhuda: observações morfológicas, biométricas e valores de referência para testes de diagnóstico oftálmico / The eye of the striped owl: morphologic observations, biometric findings and reference values for selected ophthalmic diagnostics tests

Objetivou-se relatar características morfológicas do bulbo ocular e determinar valores de referência para testes oftálmicos selecionados em corujas-orelhudas (Asio clamator). Foram estudados 32 olhos de 16 corujas (Asio clamator), adultas e jovens, machos e fêmeas, de vida livre. Sendo compilados dados referentes a observações morfológicas do crânio, bulbo ocular e anexos, além de mensuração de testes oftálmicos, incluindo, Teste Lacrimal de Schirmer (TLS), cultura da microbiota normal da conjuntiva, estesiometria, pressão intraocular (PIO), espessura de córnea central (ECC), diâmetro horizontal da rima palpebral, diâmetro horizontal da córnea e oftalmoscopia indireta. Vinte e dois tipos de bactérias foram identificados em 12 corujas havendo predominância de microrganismos Gram-positivos. A média encontrada para o TLS foi de 5,03±3,28mm/min, para o diâmetro horizontal da rima palpebral em 16 corujas foi 21,24±1,17mm, e 15,7±2,74mm para o diâmetro horizontal da córnea. O valor médio para o teste de estesiometria foi de 0,80±0,59cm, a PIO média de 13,81±5,62mmHg e ECC média de 0,28±0,03cm. O estudo contribuiu para a caracterização da morfologia ocular e para o estabelecimento de valores de referências de testes diagnósticos oftálmicos em corujas-orelhudas, sendo necessário ainda o desenvolvimento de estudos complementares sobre histologia ocular desta espécie.

The investigation aimed to describe the most relevant morphological characteristics of the eyes of the striped owl (Asio clamator) and determine normal values for selected ophthalmic diagnostic tests. A total of 32 eyes of 16 young and adult free-ranging healthy striped owls of both sexes were investigated. Data of different morphological observations of the skull, eye globe and adnexa, clinical tests and parameters were collected, including Schirmer Tear Test (STT), normal conjunctival bacterial microbiota, esthesiometry, intraocular pressure (IOP), central corneal thickness (CCT), horizontal palpebral fissure length, horizontal, corneal diameter and fundoscopy. Twenty two types of bacteria were identified in twelve owls, the most frequent bacteriae were the Gram-positive. The mean value found for the STT was 5.03±3.28mm/min; horizontal palpebral fissure lengths was 21.24±1.17mm, and 15.7±2.74mm for horizontal corneal diameter. The mean value for the esthesiometry was 0.80±0.59cm, IOP was 13.81±5.62mmHg and CCT was 0.28±0.03cm. This study contributes to establish reference values for selected ophthalmic diagnostic tests in the striped owl, as well as for morphological characterization of the eyeball of Asio clamator; but it is still necessary to characterize furthermore its histologic features.

Refração por retinoscopia com luz em faixa em cães / Refraction by streak retinoscopy in dogs

A refração ocular por retinoscopia com luz em faixa em 10 cães normais, sem raça definida, demonstrou que a maioria dos animais, independentemente do porte, apresentou tendência à hipermetropia, além de anisometropia e astigmatismo.

Ocular refraction by streak retinoscopy performed in 10 mixed breed dogs showed that most of the animals, independently of size, had a tendency to hypermetropia, anisometropia, and astigmatism.

Clinical, morphologic, and biochemical characteristics of Chediak-Higashi syndrome in fifty-six Japanese black cattle.

OBJECTIVE: To characterize Chediak-Higashi syndrome (C-HS) in Japanese Black cattle. ANIMALS: 56 of 200 cattle with a bleeding disorder and giant granules in leukocytes. PROCEDURE: Clinical observation, CBC, hemostatic screening test, platelet aggregometry, electron microscopy, platelet constituent analysis, and ophthalmoscopic examination were done. RESULTS: Affected Japanese Black cattle had increased bleeding tendency and abnormal granules in their leukocytes. Susceptibility to infection was not increased. Cutaneous albinism was evident in 6 new-born calves, but not in most affected cattle. In all affected cattle, the tapetal fundus was pale and the nontapetal fundus was almost devoid of pigment. By electron microscopy, a remarkable decrease in the number of dense granules in platelets was observed. Functionally, collagen-induced platelet aggregation was markedly reduced. CONCLUSIONS: This bleeding disorder was diagnosed as C-HS. With regard to susceptibility to infection, albinism, and mortality, clinical manifestations of C-HS in Japanese Black cattle were moderate, compared with C-HS in human beings and Hereford cattle. CLINICAL RELEVANCE: Because an autosomal recessive mode of inheritance was documented and recessive homozygotes could be easily detected, C-HS in Japanese Black cattle can be controlled.

Occurrence of cataracts in triploid Atlantic salmon (Salmo salar) on four farms in Scotland.

In September 1991 cataracts occurred in two year-classes of triploid Atlantic salmon. The fish showed varying degrees of blindness, were lethargic and became emaciated owing to their inability to feed. The lesions in the lens were mainly in the anterior and posterior cortex and perinuclear areas, the capsule and embryonic nucleus remaining unaffected. Diploid fish of the same year-class did not have cataracts. The origin of the triploid fish, the method of triploidisation, their diet and disease status were investigated, but no predisposing factors could be found to account for the high incidence of cataracts.

Evaluation of zones of iris hypoplasia in horses and ponies.

Mass-like lesions of the iris were evaluated in 15 horses or ponies of various ages and breeds. Breed or gender predilection was not found. These lesions were most often found in blue irides at the 12 o'clock region. Because the lesions transilluminated and changed shape rapidly with changes in pupillary size, they were hypothesized to be zones of iris hypoplasia. Histologic evaluation of one specimen supported this interpretation. The lesions were not associated with any other ocular or systemic abnormality.

CI-744 anesthesia for ophthalmological examination and surgery in monkeys.

CI-744 is a new agent for chemical restraint and surgical anesthesia in animals, consisting of equal parts by weight of the cataleptoid agent tiletamine-HCl and the tranquilizer zolazepam-HCl. We have used it in the intramuscular dose of five to ten milligrams per kilogram to anesthetize 110 cynomolgus and 10 vervet monkeys a total of 1,500 times for various ophthalmological procedures. At these dosages its characteristics of action were rapid onset, thirty of fifty minutes of surgical depth anesthesia during which there was excellent muscular relaxation and an absence of ocular movements, a very gradual emergence, and no adverse after effects. In these monkey species, we judge CI-744 superior to phencyclidine or methohexital as a short-acting general anesthetic for most ophthalmological procedures.