Retina assessment by optical coherence tomography of diabetic dogs / Avaliação da retina de cães diabéticos pela tomografia de coerência óptica

Diabetes mellitus is one of the most common endocrine disorders characterized by relative or absolute lack of insulin; this can lead to several ocular manifestations, among them diabetic retinopathy and cataracts. Diabetic retinopathy (DR) is a microangiopathy that involves retinal precapillary arterioles, postcapillary venules, and large vessels, causing them to be functionally and anatomically incompetent. Hyperglycemia seems to be the most probable cause of damage to the retina due to interference in cellular metabolism and transduction processes. The aim of this study was to evaluate retinal thickness in eight diabetic dogs, four females and four males of different breeds and ages ranging from 6 to 15 years, by optical coherence tomography (OCT) and to compare them with non-diabetic dogs. Assessment provided by OCT in diabetic dogs showed retinal layers thinning and loss of stratification when compared to non-diabetic dogs (198μm versus 219μm respectively), with statistical significance (p=0.008). OCT images may suggest that diabetes mellitus causes retinal neuropathy in dogs, as also seen in diabetic humans.(AU)

Diabete melito é umas das principais endocrinopatias, caracterizada pela deficiência relativa ou absoluta de insulina, que pode resultar em diversas manifestações oculares, sendo as mais frequentes a retinopatia diabética e a catarata. Retinopatia diabética (RD) é uma microangiopatia que afeta primeiramente as arteríolas pré-capilares, capilares, vênulas pós-capilares e vasos de maior calibre, causando incompetência funcional e anatômica dos vasos retinianos. A hiperglicemia parece ser a causa mais provável da lesão retiniana, interferindo nas vias de metabolismo celular e no processo de transdução. Objetivou-se neste estudo avaliar e comparar a espessura retiniana total em oito cães diabéticos, quatro fêmeas e quatro machos, de diversas raças, com idade variando de seis a 15 anos, com auxílio de tomografia de coerência óptica (OCT) e comparar com a de cães não diabéticos. A espessura e arquitetura retiniana realizada pela OCT nos cães diabéticos, demonstrou afinamento das camadas da retina e perda da estratificação em comparação com os cães não diabéticos (198μm versus 219μm, respectivamente), sendo esta redução estatisticamente significante (p=0,008). Baseado nas imagens da OCT pode-se sugerir que a diabete melito, no cão, cause neuropatia retiniana como descrito em humanos diabéticos.(AU)

Avaliação da composição molecular da cápsula anterior da lente de cães idosos com catarata de alto risco / Molecular evaluation of the anterior lens capsule of older dogs suffering from high risk cataracts

Atualmente, a cápsula anterior e o epitélio da lente tem sido cada vez mais estudados, com o intuito de reduzir as possíveis complicações do pós-operatório da remoção da catarata, tal como a opacidade da cápsula posterior, alteração ocasionada principalmente pela diferenciação e migração das células do epitélio lenticular para a cápsula posterior da lente. O objetivo deste estudo foi analisar a composição molecular da cápsula anterior da lente pela técnica histoquímica de PAS (avaliação de proteoglicanos) e picrosirius red (avaliação de colágeno IV), em cães idosos com catarata diabética e não diabética do tipo hipermadura, submetidos ao uso ou não de azul de tripano a 0,1 % durante a facoemulsificação. Vinte e sete cães foram estudados, incluindo 21 fêmeas e 6 machos, de 8 a 12 anos de idade (média = 9,6 anos), de diversas raças e divididos em 2 grupos: GC (catarata hipermadura) e GCD (catarata diabética). Os resultados das análises realizadas mostraram que ambas as amostras, tanto as provenientes das cataratas hipermaduras, quanto das diabéticas, apresentam semelhante composição molecular de proteoglicanos e colágeno IV e isto independente da utilização de azul de tripano a 0,1 %. Conclui-se, portanto, que se os resultados obtidos forem decorrentes de alterações provocadas pelo rápido metabolismo da catarata diabética e pela cronicidade da catarata hipermadura sugere-se que o comprometimento da estrutura capsular seja de intensidade equivalente e, por consequência, que isto também possa prejudicar o metabolismo das células do epitélio anterior da lente, diminuindo assim a incidência da opacidade da cápsula posterior de cães com catarata diabética e hipermadura submetidos à facoemulsificação.

Nowadays, the anterior lens capsule and its epithelium have been being frequently studied aiming to reduce the incidence of posterior lens capsule opacity, a complication that frequently occurs after surgical removal of cataracts, due to epithelium cells differentiation and migration to the posterior pole. The objective of this study was to evaluate by histochemistry (PAS and picrosirius red) analysis two important molecular components of the anterior lens capsule (proteoglycans and type IV collagen) in older diabetic and non-diabetic dogs, with diabetic and hypermature cataracts, after phacoemulsification surgery utilizing 0.1% trypan blue or not. Twenty seven dogs, including 21 female and 6 male dogs, with ages varying from 8 to 12 years old (mean = 9.6 yo) of different breeds were studied. The animals were divided into 2 groups: GC (hypermature cataracts) and GCD (diabetic cataracts). Results showed that, besides their different pathophysiologies, both types of capsules studied (diabetic and hypermature ones) presented the same molecular composition of proteoglycans and type IV collagen, since no statistical significant differences were observed. In addition, 0.1% trypan blue was not capable to induce any other evident alteration for the samples. In conclusion, our findings suggest that, if the results consist in alteration induced by the aggressive metabolism of the diabetic cataract or the chronicity of the hypermature one, it is of the same intensity and independent of the use of 0.1% trypan blue. It is also possible to suggest that this alteration must be capable to compromise lens epithelium cell metabolism, which should probably favour future lens posterior capsule studies.

Avaliação da composição molecular da cápsula anterior da lente de cães idosos com catarata de alto risco / Molecular evaluation of the anterior lens capsule of older dogs suffering from high risk cataracts

Atualmente, a cápsula anterior e o epitélio da lente tem sido cada vez mais estudados, com o intuito de reduzir as possíveis complicações do pós-operatório da remoção da catarata, tal como a opacidade da cápsula posterior, alteração ocasionada principalmente pela diferenciação e migração das células do epitélio lenticular para a cápsula posterior da lente. O objetivo deste estudo foi analisar a composição molecular da cápsula anterior da lente pela técnica histoquímica de PAS (avaliação de proteoglicanos) e picrosirius red (avaliação de colágeno IV), em cães idosos com catarata diabética e não diabética do tipo hipermadura, submetidos ao uso ou não de azul de tripano a 0,1 % durante a facoemulsificação. Vinte e sete cães foram estudados, incluindo 21 fêmeas e 6 machos, de 8 a 12 anos de idade (média = 9,6 anos), de diversas raças e divididos em 2 grupos: GC (catarata hipermadura) e GCD (catarata diabética). Os resultados das análises realizadas mostraram que ambas as amostras, tanto as provenientes das cataratas hipermaduras, quanto das diabéticas, apresentam semelhante composição molecular de proteoglicanos e colágeno IV e isto independente da utilização de azul de tripano a 0,1 %. Conclui-se, portanto, que se os resultados obtidos forem decorrentes de alterações provocadas pelo rápido metabolismo da catarata diabética e pela cronicidade da catarata hipermadura sugere-se que o comprometimento da estrutura capsular seja de intensidade equivalente e, por consequência, que isto também possa prejudicar o metabolismo das células do epitélio anterior da lente, diminuindo assim a incidência da opacidade da cápsula posterior de cães com catarata diabética e hipermadura submetidos à facoemulsificação.(AU)

Nowadays, the anterior lens capsule and its epithelium have been being frequently studied aiming to reduce the incidence of posterior lens capsule opacity, a complication that frequently occurs after surgical removal of cataracts, due to epithelium cells differentiation and migration to the posterior pole. The objective of this study was to evaluate by histochemistry (PAS and picrosirius red) analysis two important molecular components of the anterior lens capsule (proteoglycans and type IV collagen) in older diabetic and non-diabetic dogs, with diabetic and hypermature cataracts, after phacoemulsification surgery utilizing 0.1% trypan blue or not. Twenty seven dogs, including 21 female and 6 male dogs, with ages varying from 8 to 12 years old (mean = 9.6 yo) of different breeds were studied. The animals were divided into 2 groups: GC (hypermature cataracts) and GCD (diabetic cataracts). Results showed that, besides their different pathophysiologies, both types of capsules studied (diabetic and hypermature ones) presented the same molecular composition of proteoglycans and type IV collagen, since no statistical significant differences were observed. In addition, 0.1% trypan blue was not capable to induce any other evident alteration for the samples. In conclusion, our findings suggest that, if the results consist in alteration induced by the aggressive metabolism of the diabetic cataract or the chronicity of the hypermature one, it is of the same intensity and independent of the use of 0.1% trypan blue. It is also possible to suggest that this alteration must be capable to compromise lens epithelium cell metabolism, which should probably favour future lens posterior capsule studies.(AU)

Lamellar keratoplasty in rabbits using human and rabbit amniotic membrane grafts: a comparative study.

OBJECTIVE: To compare the behavior of human and rabbit amniotic membrane (AM) grafts in surgically induced corneal thinning in rabbits. ANIMALS STUDIED: Thirty two NZWR were randomly assigned to two groups of 16 animals each according to AM type (Human AM: group HAM and Rabbit AM: group RAM). PROCEDURE: All animals were submitted to right keratectomy at a depth of 0.1 mm using a 5 mm trephine. Animals from HAM group had a button of 5 mm of human AM sutured into the corneal bed with a continuous pattern and 10.0 nylon monofilament suture, while animals from the RAM group had a button of 6 mm diameter of rabbit AM. Four animals in each group were euthanized 2, 7, 15, and 30 days postoperatively. Their corneas were harvested, fixed in 2% glutaraldehyde solution, and stained with haematoxylin-eosin, picrosirius red, and alcian blue for evaluation under light optical microscopy. Microscope images were digitalized and inflammatory cells and stromal blood vessels were counted. RESULTS: There were no clinically significant differences between groups, and complete corneal epithelialization was observed in all animals in 30 days. Light optical microscopy revealed AM incorporation and resorption in both groups. However, the number of inflammatory cells and blood vessels was significantly higher in group HAM than in group RAM (P < 0.05, Mann-Whitney test). Clinical responses to human or rabbit AM were similar; however, human AM induced greater inflammatory reaction and stromal neovascularization in the rabbit cornea than in rabbit AM. CONCLUSION: These differences may reflect a potential reaction to the xenograft. More studies are needed to further characterize these findings.

Aspectos da tomografia de coerência óptica em cães com retinopatia / Aspects of optical coherence tomography in retinopathy in dogs

A tomografia de coerência óptica (OCT) é um exame não invasivo e de não contato que permite avaliar a retina e o nervo óptico. As imagens da OCT fornecem informações da constituição da retina e sua integridade estrutural in vivo, gerando imagens de alta resolução, que se assemelham à microscopia óptica. Objetivou-se descrever a técnica de tomografia de coerência óptica (OCT) e sua utilização em cães. Foi possível diferenciar claramente as camadas retinianas de cães hígidos e compará-las com as de cães portadores de atrofia progressiva de retina, que apresentaram perda da estratificação e diminuição significativa das camadas. No descolamento de retina (DR) foi possível observar a separação entre a retina neurossensorial e o epitélio pigmentário da retina (EPR), além da presença de exsudatos intrarretinianos. Assim, a OCT mostrou-se eficaz no diagnóstico de retinopatias.

The OCT is a noninvasive and noncontact exam capable to evaluate the retina and optic nerve. The OCT images provide information of the constitution of the retina and its structural integrity in vivo, providing high-resolution images that resemble optical microscopy. The objective of this paper was to describe and document the use of the optical coherence tomography (OCT) in dogs. It was possible differentiate the retinal layers of healthy dogs and compare them with dogs with progressive retinal atrophy which showed altered stratification and significant reduce of the layers. In cases of retinal detachment was observed separation of neurosensory retina from the retinal pigment epithelium, and the presence of intrarretinal exudates. Thus, the OCT was effective in the diagnosis of retinopathy.

Estudo comparativo das estruturas do segmento anterior de olhos de cães normais e com catarata, portadores ou não de Diabetes mellitus, avaliados por biomicroscopia ultrassônica / Comparison of anterior ocular segment structures in healthy dogs, with diabetic or no diabetic cataract, by ultrasound biomicroscopy

A catarata representa uma das principais causas de cegueira em cães, sendo que as alterações metabólicas provocadas pelo Diabetes mellitus (DM), constituem a segunda causa mais comum de catarata nesta espécie. A biomicroscopia ultrassônica (UBM) é um método ultrassonográfico de alta frequência (50 MHz) que permite a obtenção de imagens do modo B de qualidade microscópica. Este estudo objetivou, por meio do uso da UBM, comparar as estruturas do segmento anterior de olhos de cães com catarata, diabética e não-diabética, às de cães normais, para verificar possíveis alterações decorrentes do DM. Os parâmetros avaliados foram espessura da córnea, profundidade da câmara anterior, aumento de celularidade no interior da câmara anterior e medida do ângulo iridocorneal. Foram realizados exames de 87 olhos de 47 animais da espécie canina, divididos em 3 grupos: grupo controle (GCO), grupo de portadores de catarata não-diabéticos (GCAT) e o grupo dos diabéticos (GDM). Os resultados revelam que o grupo dos diabéticos apresentou maiores espessuras de córnea que os demais grupos enquanto o grupo controle apresentou maiores câmaras anteriores. Encontrou-se aumento de celularidade em câmara anterior apenas nos grupos com catarata. Quando analisadas as medidas do ângulo iridocorneal, não houve diferença entre os 3 grupos. Com base no que foi aferido, permite-se concluir que olhos de cães diabéticos com catarata apresentam maior espessura de córnea central que olhos de cães com catarata de outras etiologias e de cães normais, que há diminuição da câmara anterior, com aumento de celularidade, em olhos de cães com catarata, quando comparados a cães normais e que não há diferença na medida do ângulo iridocorneal em olhos de cães com catarata, diabética ou não, e de cães normais.

Cataracts represent the leading cause of blindness in dogs. The second most common cause of cataract in dogs is a result of metabolic alterations caused by Diabetes mellitus (DM). Ultrasound biomicroscopy (UBM) is a high-frequency (50 MHz) ultrasonographic method that produces B mode images of microscopic quality. The objective of this study was, by means of UBM use, to compare the anterior segment structures of the canine eyes, both with diabetic and non-diabetic cataract, in order to detect changes caused by DM. The parameters evaluated were: cornea thickness, anterior chamber's depth, increased cellularity inside the anterior chamber, and iridocorneal angle measurement. Eighty-seven eyes of 47 dogs were examined, divided into three groups: control (GCO), non-diabetic cataract (GCAT) and diabetic cataract (GDM). The results showed that the diabetic group presented a higher cornea thickness than the other groups. The control group showed deeper anterior chambers without increased cellularity. When the iridocorneal angle measurements were analyzed, it was found that there were no statistically significant differences between the three groups. Based on these results, we can conclude that: the eyes of diabetic dogs with cataract showed a central cornea higher thickness compared to the eyes of dogs with cataract of different etiologies, and to dogs with normal eyes; there is a decrease of the anterior chamber depth and a increase of cellularity in the eyes of dogs with cataract compared to normal eyes, there is no significant difference between the iridocorneal angle measurement in the eyes of dogs with cataract, diabetic or not, and normal dogs.

Estudo retrospectivo do tratamento clínico da úlcera indolente em cães da raça Boxer / Retrospective study on clinical management of indolent ulcers in Boxer dogs

Indolent ulcers are superficial corneal ulcers secondary to several changes on the corneal surface. They are frequently observed in middle-aged Boxer dogs, cause pain of acute onset and requires appropriate treatment. Aiming to evaluate the efficacy of clinical managements on the rate of healing of indolent ulcers, a retrospective study was conducted (1997-2008). Results demonstrated that proteinase inhibitors were the most often prescribed medication, and its administration did not interfere on the healing rate, as well as observed in dogs that received 1 percent atropine, antibiotics and anti-inflammatory drugs. Healing was delayed in dogs administered orally with vitamin C, but the healing process was faster on those dogs that went through corneal debridement/cauterization. In conclusion, to know the various types of treatments seems to be fundamental for the rapid resolution of the disease. It is suggested that debridement/cauterization, administration of proteinase inhibitor eye drops, prophylactic topical antibiotics and oral vitamin C, should be considered as an effective clinical management for indolent ulcers in Boxer dogs.

Úlceras indolentes são úlceras corneais superficiais e espontâneas, que apresentam curso prolongado e que tendem a recidivar. Comumente observadas em cães de meia idade da raça Boxer, provoca dor de início agudo e necessita de tratamento específico, já que este, quando não realizado corretamente, pode prolongar o curso da lesão por semanas a meses. Com o objetivo de avaliar a eficácia dos tratamentos clínicos quanto à rapidez na resolução do quadro, realizou-se estudo retrospectivo (1997 a 2008). Observou-se que os inibidores das proteinases foram as medicações mais frequentemente prescritas e que sua administração não interferiu no tempo de cicatrização corneal, o que também foi observado nos casos em que se administrou antibióticos e antinflamatórios tópicos e sistêmicos e/ou atropina 1 por cento. A administração de vitamina C retardou, de maneira estatisticamente significante, o tempo de cicatrização. Por outro lado, a realização do debridamento/cauterização corneal acelerou, significativamente, o processo. Conhecer os diversos tipos de tratamentos parece ser fundamental no sucesso e rapidez da resolução da doença. Os autores sugerem que a realização do debridamento/cauterização corneal, administração de inibidores das proteinases e antibióticos tópicos, associados à vitamina C por via oral, seja considerado um tratamento clínico efetivo na rápida resolução da doença.

Comparison of full-field electroretinogram in diabetic and non diabetic dogs with cataracts / Estudo comparativo do eletrorretinograma de campo total em cães diabéticos e não diabéticos com catarata

Being the commonest ocular disorder, dense cataracts disable fundoscopic examination and the diagnosis of retinal disorders, which dogs may be predisposed. The aim of this study was to compare the electroretinographic responses recorded according to the International Society for Clinical Electrophysiology of Vision human protocol to evaluate retinal function of diabetic and non diabetic dogs, both presenting mature or hypermature cataracts. Full-field electroretinogram was recorded from 66 dogs, with ages varying from 6 to 15 years old allocated into two groups: (1) CG, non diabetic cataractous dogs, and (2) DG, diabetic cataractous dogs. Mean peak-to-peak amplitude (microvolts) and b-wave implicit time (milliseconds) were determined for each of the five standard full-field ERG responses (rod response, maximal response, oscillatory potentials, single-flash cone response and 30 Hz flicker). Comparing CG to DG, ERGs recorded from diabetic dogs presented lower amplitude and prolonged b-wave implicit time in all ERG responses. Prolonged b-wave implicit time was statistically significant (p< 0.05) at 30 Hz flicker (24.0 ms versus 22.4 ms). These data suggests full-field ERG is capable to record sensible alterations, such as flicker's implicit time, being useful to investigate retinal dysfunction in diabetic dogs.

Catarata madura e hipermadura, alteração frequentemente observada em cães, impossibilita a visibilização do fundo do olho e provável diagnóstico de degenerações retinianas. Objetivou-se comparar as respostas retiniana de cães diabéticos e não diabéticos, ambos portadores de catarata madura ou hipermadura, com auxílio do eletrorretinograma de campo total, utilizando o protocolo da International Society for Clinical Electrophysiology of Vision. Sessenta e seis cães, com idades variando entre 6 a 15 anos de idade foram divididos em dois grupos: (1) CG, cães não diabéticos com catarata madura ou hipermadura e (2) DG, cães diabéticos com catarata madura ou hipermadura. Mensurou-se amplitude pico a pico (microvolts) e tempo de culminação da onda-b (milisegundos) para as cinco respostas do ERG (resposta de bastonetes, máxima resposta, potencial oscilatório, resposta de cones e flicker a 30Hz). Avaliando-se as respostas obtidas com o exame, o grupo de cães diabéticos apresentou menor amplitude e maior tempo de culminação da onda-b em todas as respostas. O aumento do tempo de culminação da onda-b em DG foi estatisticamente significante (p<0.05) no flicker a 30 Hz (24.0ms versus 22.4ms). ERG de campo total é capaz de registrar alterações em respostas sensíveis como o tempo de culminação da onda-b do flicker, podendo ser útil para investigar retinopatias em cães diabéticos.

Padronização do eletrorretinograma de campo total em cães / Full field electrorretinogram standartization in dogs

Eletrorretinograma (ERG) é o meio diagnóstico objetivo e não-invasivo para avaliar a função retiniana e detectar precocemente, em várias espécies, lesões nas suas camadas mais externas. As indicações mais comuns para ERG em cães são: avaliação pré-cirúrgica de pacientes com catarata, caracterização de distúrbios que causam cegueira, além de servir como importante modelo para o estudo da distrofia retiniana que acomete o homem. Vários são os fatores que podem alterar o ERG tais como: eletrorretinógrafo, fonte de estimulação luminosa, tipo do eletrodo, tempo de adaptação ao escuro, tamanho pupilar, opacidade de meios e protocolo de sedação ou anestesia; além da espécie, raça e idade. Objetivou-se com este estudo padronizar o ERG para cães submetidos à sedação, seguindo o protocolo da International Society for Clinical Electrophysiology of Vision (ISCEV), utilizando Ganzfeld e eletrodos Burian Allen. Foram realizados 233 eletrorretinogramas em cães, 147 fêmeas e 86 machos, com idades entre um e 14 anos. Dos 233 cães examinados, 100 apresentavam catarata em diferentes estágios de maturação, 72 eram diabéticos e apresentavam catarata madura ou hipermadura, 26 apresentaram eletrorretinograma compatível com degeneração retiniana progressiva, três apresentaram eletrorretinograma compatível com síndrome da degeneração retiniana adquirida subitamente e 32 não apresentaram lesão retiniana capaz de atenuar as respostas do ERG, sendo considerados normais quanto à função retiniana. A sedação foi capaz de produzir boa imobilização do paciente sem rotacionar o bulbo ocular, permitindo adequada estimulação retiniana bilateralmente, com auxílio do Ganzfeld. O sistema eletrodiagnóstico Veris registrou com sucesso e simultaneamente de ambos os olhos, as cinco respostas preconizadas pela ISCEV. Como o ERG de campo total tornou-se exame fundamental na rotina oftalmológica, sua padronização é indispensável quando se objetiva comparar resultados de laboratórios distintos...

Electroretinogram (ERG) is an objective non invasive diagnostic method to evaluate retinal function which permits the early detection of lesions at retinal external layers, even before the appearance of clinical signs. In dogs, ERG is mostly utilized for preoperative evaluation in patients presenting cataracts; characterization of disturbances causing blindness, among the utilization of dogs as animal models in scientific research. Several factors interfere in ERG responses, such as the ERG machine, light stimulation, electrode, time spent on dark adaptation, pupil size, means opacity, sedation or anesthetization, species, breed and age. The purpose of this study was to standardize the full field ERG in sedated dogs, according to the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol, using Ganzfeld and bipolar electrodes. Two hundred thirty threes ERGs were performed in 147 female and 86 male with ages from 1 to 14 years old. Among those 233 dogs, 100 presented cataracts in different stages of maturation, 72 were diabetic and presented mature or hypermature cataracts, 26 presented ERG compatible to progressive retinal degeneration, 3 presented ERG compatible to sudden acquired retinal degeneration syndrome; for 32 dogs no abnormal ERG was registered and they were considered as having normal retinal function. Sedation was capable to induce a good immobilization with no bulb rotation, resulting uniform retinal stimulation, using Ganzfeld. Veris system successfully registered all 5 ISCEV responses, simultaneously from both eyes, at the same time. Full field ERG became a fundamental ophthalmic exam, then, its standardization is mandatory to allow comparison between ERGs from different laboratories. The reliability and reproducibility of this protocol has shown very good responses, using ISCEV protocol, Veris system, Ganzfeld and Burian Allen electrodes in sedated dogs.

Retrospective study of ocular disorders in Amazon parrots / Estudo retrospectivo das alterações oculares observadas em papagaios

A retrospective study was conducted to identify the occurrence and types of ocular disorders in 57 Amazon parrots admitted to the Ophthalmology Service, Veterinary Teaching Hospital, School of Veterinary Medicine, University of São Paulo, Brazil from 1997 to 2006. The most frequent observed disorder was cataracts, present in 24 of the 114 examined eyes (57 parrots). Uveitis, ulcerative keratitis and keratoconjunctivitis were frequently diagnosed as well. The cornea was the most affected ocular structure, with 28 reported disorders. Uveal disorders also were commonly observed. Conjunctiva and eyelid disorders were diagnosed in lower frequency. Results suggest that cataracts are common and that cornea, lens and uvea are the most affected ocular structures in Amazon parrots.

Realizou-se estudo retrospectivo para identificar a ocorrência e os tipos de alterações oculares observadas em 57 papagaios atendidos no Serviço de Oftalmologia do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (USP), de 1997-2006. Catarata em diferentes estágios de evolução foi a alteração ocular mais frequentemente diagnosticada, sendo observada em 24 dos 114 olhos examinados. Uveíte, ceratite ulcerativa e ceratoconjuntivite foram também diagnosticadas. A córnea foi a estrutura ocular mais acometida (28 registros). Alterações uveais foram frequentemente observadas. Alterações das pálpebras e conjuntiva foram observadas em menor freqüência. Concluí-se que catarata foi a alteração mais frequentemente observada e que a córnea, lente e úvea são as estruturas oculares mais susceptíveis a alterações em papagaios.

Extramedullary plasmacytoma of the third eyelid gland in a dog.

A case of extramedullary plasmacytoma of the third eyelid gland in a 7-year-old American Cocker Spaniel is reported. An enlargement of the third eyelid gland, abundant mucopurulent discharge, mild hyperemia and corneal pigmentation in the OD was present. Excisional biopsy of the mass revealed the gland was infiltrated and partially destroyed by a uniform population of neoplastic plasma cells. The neoplastic cells were positive for CD138, Ki-67 and lambda light chain. CD20, CD3, kappa light chain and cytokeratin were negative. Twelve months following surgery, no recurrence was observed. To the authors' knowledge, this is the first extramedullary plasmacytoma of the third eyelid gland reported in dogs.

Morphological analysis of the corneal endothelium in eyes of dogs using specular microscopy / Análise morfológica com microscopia especular do endotélio corneal em olhos de cães

Both healthy eyes of 10 six-year-old male and female mongrel dogs were studied. With a contact specular microscope the corneal endothelium was examined. Endothelial cells were analyzed in the central and peripheral cornea. Morphological analysis with regard to polymegathism and pleomorphism was performed. Three images of each region with at least 100 cells were obtained. The analysis showed that polygonal cells formed a mosaic-like pattern uniform in size and shape. The predominant number of cells was hexagonal. The polymegathism index was 0.22. The study demonstrates that the morphology of the normal corneal endothelial cells of dogs is similar to that found in the human cornea.

Foram estudados 20 olhos de 10 cães sem raça definida, machos e fêmeas com 6 anos de idade. A morfologia das células do endotélio da córnea foi analisada utilizando-se microscópio especular de contato. Foram estudadas as regiões central e periférica da córnea. De cada região da córnea foram realizadas três micrografias. De cada micrografia foram analisadas no mínimo 100 células endoteliais. Foram obtidos os valores do polimegatismo e pleomorfismo. O endotélio corneano de cães caracterizou-se por uma monocamada de células poligonais uniformes em tamanho e forma. A forma predominante das células endoteliais foi hexagonal. O índice de polimegatismo foi 0.22. Este estudo demonstrou que a morfologia das células do endotélio da córnea de cães é semelhante à observada em humanos.

Effects of topical 0.2 percent Cyclosporine A on corneal neovascularization induced by xenologous amniotic membrane implantation into a corneal stroma micropocket of rats / Efeitos do uso tópico da Ciclosporina A (CsA) 0,2 por cento na neovascularização corneal induzida pelo implante de membrana amniótica xenógena em microbolsa no estroma da córnea de ratos

The objective of the study was to evaluate the topical effects of 0.2 percent Cyclosporine A (CsA) on corneal neovascularization of rats following surgical implantation of equine amniotic membrane into a corneal stroma micropocket. The implantation of xenologous amniotic membrane was performed bilaterally in 90 rats. In the same day of the surgery each right eye started receiving topical CsA twice a day. The left eye received no medication and served as a control. The evaluation of corneal neovascularization was performed by computerized image analysis and histopathological evaluation at 1, 3, 7, 15, 30 and 60 days postoperatively. For the image analysis 10 animals were used per time period, and for the histopathological examination, five animals were used per time period. Image analysis found that corneal neovascularization began on the 3rd postoperative day, reached its peak on the 7th day, and then progressively and rapidly decreased. Statistic analysis indicated that neovascularization of the CsA treated eye on the 7th day was significantly higher than that observed in untreated eyes. On the 30th day, however, this pattern was reversed with the neovascularization observed in the CsA treated eyes declining to the low levels observed on the 3rd day. The degree of neovascularization in the untreated eyes on the 30th day declined to the baseline levels found on day 3 at the 60th day. Histopathological analysis indicated that deposition of collagen in the implanted tissue was completed by the 15th day. Therefore, we concluded that (1) equine amniotic membrane in rat corneal stroma produced an intense neovascularization until the 15th day postoperatively and then regressed, (2) deposition of collagen of the implanted tissue was completed on the 15th day postoperatively, and (3) use of CsA was associated with increase in the corneal neovascularization initially, followed by a quick and intense regression.

Este estudo teve como objetivo a avaliação dos efeitos tópicos da Ciclosporina a 0,2 por cento (CsA) sobre a neovascularização corneana de ratos após implante cirúrgico de membrana amniótica eqüina em microbolsa do estroma corneana. O implante da membrana foi feito bilateralmente em 90 ratos. O tratamento com CsA iniciou-se no mesmo dia da cirurgia, nos olhos direitos dos animais, duas vezes ao dia. Os olhos esquerdos não receberam nenhum tratamento e serviram de controle. A avaliação da neovascularização corneana foi feita por análise de imagem computadorizada e por exame histopatológico aos dias 1, 3, 7, 15, 30 e 60 de pós-cirúrgico. Para a análise de imagem foram utilizados 10 animais por período, e para o exame histopatológico, 5 por período. A análise de imagem demonstrou que a neovascularização iniciou-se no 3º dia pós-cirúrgico, alcançou seu pico no 7º dia e então regrediu rápida e progressivamente até o 60º dia. A análise estatística indicou que a neovascularização no 7º dia nos olhos tratados com CsA foi significantemente mais acentuada do que aquela observada nos olhos não tratados. Entretanto, no 30º dia este fato se reverteu, e a neovascularização observada nos olhos tratados com CsA diminuíra a níveis baixos comparáveis àquela do 3º dia. Já nos olhos não tratados, o grau de neovascularização somente pôde ser comparado àquele nível básico encontrado no 3º dia aos 60 dias de pós-operatório. A análise histopatológica demonstrou que a deposição de colágeno no tecido implantado se completou no 15º dia. Desta maneira, foi possível concluir que (1) a membrana amniótica em estroma corneano de ratos produz intensa neovascularização até o 15º dia de pós-operatório com posterior regressão, (2) a deposição de colágeno do tecido implantado foi completa ao 15º dia de pós-operatório, e que (3) o uso de CsA esteve associado com aumento inicial da neovascularização corneana, seguido de rápida e intensa regressão.

X-ray imaging in advanced studies of ophthalmic diseases.

Microscopic characterization of pathological tissues has one major intrinsic limitation, the small sampling areas with respect to the extension of the tissues. Mapping possible changes on vast tissues and correlating them with large ensembles of clinical cases is not a feasible procedure for studying most diseases, as for instance vision loss related diseases and, in particular, the cataract. Although intraocular lens implants are successful treatments, cataract still is a leading public-health issue that grows in importance as the population increases and life expectancy is extended worldwide. In this work we have exploited the radiation-tissue interaction properties of hard x-rays--very low absorption and scattering--to map distinct lesions on entire eye lenses. At the used synchrotron x-ray photon energy of 20 keV (wavelength lambda=0.062 nm), scattering and refraction are angular resolved effects. It allows the employed x-ray image technique to efficiently characterize two types of lesions in eye lenses under cataractogenesis: distributions of tiny scattering centers and extended areas of fiber cell compaction. The data collection procedure is relatively fast; allowing dozens of samples to be totally imaged (scattering, refraction, and mass absorption images) in a single day of synchrotron beam time. More than 60 cases of canine cataract, not correlated to specific causes, were investigated in this first application of x-rays to image entire lenses. Cortical opacity cases, or partial opacity, could be related to the presence of calcificated tissues at the cortical areas, clearly visible in the images, whose elemental contents were verified by micro x-ray fluorescence as very rich in calcium. Calcificated tissues were also observed at nuclear areas in some cases of hypermature cataract. Total opacity cases without distinguishable amount of scattering centers consist in 70% of the analyzed cases, where remarkable fissure marks owing to extended areas of fiber cell compaction are diagnosed.

Ascorbic acid levels of aqueous humor of dogs after experimental phacoemulsification.

Phacoemulsification has been successfully employed in humans and animals for lens extraction. This ultrasonic extracapsular surgical technique induces hydroxyl radical formation in the anterior chamber, which accumulates despite irrigation and aspiration. In this paper we determined the total antioxidant status of aqueous humor after phacoemulsification by measuring aqueous humor ascorbic acid levels. Mixed-breed dogs (n = 11; weighing about 10 kg) with normal eyes as determined by slit-lamp biomicroscopy, applanation tonometry, and indirect ophthalmoscopy had phacoemulsification performed in one eye with the other eye used as a control. Samples of aqueous humor were obtained by anterior chamber paracentesis before surgery and at days 1, 2, 3, 7, and 15 after surgery. Total aqueous humor antioxidant status was inferred from the capacity of aqueous humor to inhibit free radical generation by 2,2-azobis (2-amidopropane) chlorine. Ascorbic acid concentrations were measured by high-pressure liquid chromatography with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by anova followed by the paired t-test. Total antioxidant capacity was reduced from 48 to 27 min during the first 24 h with a gradual increase thereafter, remaining statistically lower than the control eye until 7 days postoperatively. Reduced levels of ascorbic acid followed this reduction in antioxidant capacity (from 211 to 99 microm after 24 h), remaining lower than the control eye until 15 days postoperatively. Protein concentration in aqueous humor increased from 0.62 mg/mL to 30.8 mg/mL 24 h after surgery, remaining statistically lower than the control eye until 15 days postoperatively. Paracentesis alone did not significantly alter the parameters measured. These results indicate that after phacoemulsification, the aqueous humor ascorbic acid levels and antioxidant defenses in aqueous humor are reduced, indirectly corroborating free radical production in the anterior chamber as a result of phacoemulsification. The inflammatory process consequent to the surgical procedure demonstrated by increased protein content in aqueous humor can also contribute to free radical production and ascorbic acid consumption.

Effects of travoprost 0.004% compared with latanoprost 0.005% on the intraocular pressure of normal dogs.

PURPOSE: To compare the effects of travoprost 0.004% and latanoprost 0.005% on the intraocular pressure (IOP) of normal dogs. METHODS: Twenty mixed breed dogs were randomized to two groups: latanoprost was used in group A and travoprost in group B. The drugs were instilled in the right eye of the dogs, whereas the left eye received placebo. Both drugs were instilled once a day at 8 am during 5 days. IOP measurements were made at 8 am, 10 am, 2 pm and 8 pm during the 5 days of treatment, the 3 days that preceded treatment, and 3 days following treatment. Presence of blepharospasm, miosis, anterior chamber flare, and conjunctival hyperemia were evaluated during the study. RESULTS: Mean IOP was significantly reduced in the eyes treated with both latanoprost and travoprost, when compared with the eyes treated with placebo (P<0.05). There was no statistically significant difference between the mean IOPs of eyes treated with latanoprost and travoprost at all time intervals during baseline, treatment, and recovery (P>0.05). On the fifth day of treatment and on the first day of the recovery period, a severe ocular hypotension was noted with both drugs, resulting in imprecise readings with the tonometer. Miosis and conjunctival hyperemia were observed in the treated eyes of both groups, whereas flare was noticed in one latanoprost-treated eye. CONCLUSION: Travoprost 0.004% significantly reduces the IOP in normal dogs. The hypotensive effect obtained with travoprost 0.004% is comparable to that obtained with latanoprost 0.005%.

Amniotic membrane transplantation for the reconstruction of the ocular surface in three cases.

This paper describes the use of amniotic membrane in the reconstructive surgical repair of generalized keratomalacia, ankyloblepharon, and after fibrous histiocytoma removal in two dogs and a cat. Case 1 was an 11-year-old female Yorkshire terrier with severe bullous keratomalacia in the left eye (OS). A frozen canine amniotic membrane graft and a third eyelid flap were applied. At day 80 postoperatively, only a mild scar and corneal vascularization were present. Case 2 was a 4-year-old female Siamese cat with symblepharon of both eyes after rhinotracheitis. Resection of the conjunctiva and frozen canine amniotic membrane transplant were performed. One month later, there was a little corneal scarring and corneal vascularization. Case 3 was a 6-year-old female terrier with a scleral and corneal mass at the 11-12 o'clock position (OS). Resection of the mass and amniotic membrane transplantation were performed. The mass was a fibrous histiocytoma localized to the sclera and cornea. This eye healed with mild conjunctivalization and no pigmentation. Amniotic membrane transplantation can be used as a method of reconstruction of the ocular surface with good repair of the cornea and minimal scarring in small animals.

Corneal endothelium of the Magellanic penguin (Spheniscus magellanicus) by scanning electron microscopy.

The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates.

Morphometric analysis of the corneal endothelium of Yacare caiman (Caiman yacare) using scanning electron microscopy.

The objective of this study was to examine the endothelial surface morphology and to perform morphometric analysis of the corneal endothelial cells of Yacare caiman (Caiman yacare) using scanning electron microscopy. Morphometric analysis with regard to polygonality, mean cell area, cell density and coefficient of variation of mean cell area was performed. Cell areas were measured using image analysis software. The normal corneal endothelium of Yacare caiman consisted of polygonal cells of uniform size and shape with interdigitations of the cell borders. Microvilli appeared as protrusions on the cellular surface. The average cell area was 270 +/- 24 microm(2) and the endothelial cell density was 3704 +/- 324 cells/mm(2). The coefficient of variation of cell area was 0.22. This study demonstrates that the Yacare caiman corneal endothelium is similar to those described in other vertebrates.

Blood and aqueous humour antioxidants in cataractous poodles.

BACKGROUND: Cataract is an important cause of blindness in dogs and frequently develops in young animals of certain breeds, such as the English cocker spaniel and the poodle. Protein oxidation is one of the mechanisms involved in lens opacification and may be causally related to depleted or diminished endogenous antioxidant defences. We evaluated the levels of enzymatic and nonenzymatic antioxidants in blood and aqueous humour of cataractous poodles in comparison to noncataractous poodles. METHODS: We studied 35 cataractous poodles aged 2 to 11 years, 14 noncataractous poodles and 15 noncataractous mixed-breed dogs. The activity of erythrocyte antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glucose-6-phosphate dehydrogenase [G6PD]) was evaluated in 18 cataractous poodles and 14 noncataractous poodles. We evaluated ascorbic acid levels in plasma of all animals and in aqueous humour of cataractous poodles and mixed-breed dogs. The dogs were deprived of food for 12 hours before sampling. Blood samples were obtained from the jugular vein before and during anesthesia. Aqueous humour samples were obtained just before the anterior chamber was opened. RESULTS: The activity of superoxide dismutase, G6PD and catalase was significantly higher in noncataractous poodles than in cataractous poodles (p < or = 0.05). The activity of glutathione peroxidase was lower in noncataractous poodles than in cataractous poodles, but not significantly so. There was no difference in mean plasma ascorbic acid concentration between cataractous poodles (21.3 microM [standard deviation (SD) 7.4 microM]), noncataractous poodles (21.6 microM [SD 7.4 microM]) and non-cataractous mixed-breed dogs (25.8 microM [SD 7.5 microM]). Similarly, there was no difference in mean aqueous humour ascorbic acid concentration between cataractous poodles (191.7 microM [SD 62.0 microM] and noncataractous mixed-breed dogs (215.7 microM [SD 91.8 microM]). INTERPRETATION: The results indicate that, at least in the population studied here, no correlation exists between the onset of cataract and ascorbic acid concentration in blood and aqueous humour. The decreased activity of antioxidant enzymes may explain in part the onset of cataract in poodles.