Resultado da pesquisa (3)
Termo utilizado na pesquisa retinal atrophy
#1 - Vitamin A deficiency as a cause of blindness in feedlot calves
Abstract in English:
Vitamin A is an essential micronutrient to reproduction, development, normal growth, and function of the nervous system and vision, especially in growing animals. Hypovitaminosis A can affect any of these functions. The aim of this study was to describe the epidemiology, clinical signs, pathological aspects, and diagnostic approach in an outbreak of blindness in feedlot calves fed only grain. Five of 57 ten-month-old calves became blind after eight months at the feedlot. Clinical signs were mydriasis, absent pupillary and menace reflexes, bilaterally. Hypovitaminosis A was suspected and subsequently confirmed by low serum levels of vitamin A. One calf was euthanized and necropsied, and no gross findings were present. Histopathological lesions were restricted to the retina and characterized by degeneration and atrophy of the photoreceptor layer and some retinal scars. The calves were treated with intramuscular vitamin A injection at a dose of 5,000 international units (IU) per kilogram of body weight (kg BW) every 60 days until slaughter. Affected calves did not recover visual capacity, but no other cases occurred.
Abstract in Portuguese:
Vitamina A é um micronutriente essencial para reprodução, desenvolvimento, crescimento normal, além de participar do funcionamento do sistema nervoso central e visão, especialmente em animais em crescimento. Hipovitaminose A pode afetar qualquer uma dessas funções. O objetivo desse artigo é descrever a epidemiologia, sinais clínicos, aspectos patológicos e abordagem diagnóstica em um surto de cegueira em bezerros confinados alimentados apenas com grãos. De 57 bezerros de dez meses de idade, cinco ficaram cegos após oito meses no confinamento. Os sinais clínicos eram midríase, ausência de reflexo pupilar a luz e de ameaça, bilateralmente. Suspeitou-se de hipovitaminose A, que foi subsequentemente confirmada pelos baixos níveis séricos de vitamina A. Um bezerro foi eutanasiado e necropsiado, e alterações macroscópicas não foram encontradas. Lesões histopatológicas estavam restritas a retina e caracterizavam-se por degeneração e atrofia da camada de fotorreceptores, além de cicatrizes na retina. Os bezerros foram tratados com injeção intramuscular de vitamina A, na dose de 5.000 unidades internacionais (UI) por quilograma de peso vivo (Kg PV) a cada 60 dias, até o dia do abate. Os bezerros afetados não recuperaram a capacidade visual, mas novos casos não ocorreram.
#2 - Retina assessment by optical coherence tomography of diabetic dogs, 38(10):1966-1971
Abstract in English:
ABSTRACT.- Braga-Sá M.B.P., Barros P.S.M., Jorge J.S., Dongo P., Finkensieper P., Bolzan A.A., Watanabe S.S. & Safatle A.M.V. 2018. Retina assessment by optical coherence tomography of diabetic dogs. [Avaliação da retina de cães diabéticos pela tomografia de coerência óptica.] Pesquisa Veterinária Brasileira 38(10):1966-1971. Laboratório de Investigação em Oftalmologia Comparada, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenida Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270, Brazil. E-mail: michellebarbosa@usp.br
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.
Abstract in Portuguese:
RESUMO.- Braga-Sá M.B.P., Barros P.S.M., Jorge J.S., Dongo P., Finkensieper P., Bolzan A.A., Watanabe S.S. & Safatle A.M.V. 2018. Retina assessment by optical coherence tomography of diabetic dogs. [Avaliação da retina de cães diabéticos pela tomografia de coerência óptica.] Pesquisa Veterinária Brasileira 38(10):1966-1971. Laboratório de Investigação em Oftalmologia Comparada, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Avenida Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270, Brazil. E-mail: michellebarbosa@usp.br
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.
#3 - Aspects of optical coherence tomography in retinopathy in dogs, 35(2):153-159
Abstract in English:
ABSTRACT.- Safatle A.M.V., Braga-Sá M.B.P. & Barros P.S.M. 2015. [Aspects of optical coherence tomography in retinopathy in dogs.] Aspectos da tomografia de coerência óptica em cães com retinopatia. Pesquisa Veterinária Brasileira 35(2):153-159. Laboratório de Investigação em Oftalmologia Comparada, Faculdade de Medicina Veterinária, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270, Brazil. E-mail: angsaf@usp.br
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.
Abstract in Portuguese:
RESUMO.- Safatle A.M.V., Braga-Sá M.B.P. & Barros P.S.M. 2015. [Aspects of optical coherence tomography in retinopathy in dogs.] Aspectos da tomografia de coerência óptica em cães com retinopatia. Pesquisa Veterinária Brasileira 35(2):153-159. Laboratório de Investigação em Oftalmologia Comparada, Faculdade de Medicina Veterinária, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, São Paulo, SP 05508-270, Brazil. E-mail: angsaf@usp.br
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.
