Diabete Melito (DM) é uma endocrinopatia frequentemente diagnosticada na clínica de pequenos animais e desenvolve-se pela deficiência relativa ou absoluta de insulina, sendo caracterizada pela hiperglicemia crônica. Complicações associadas ao DM são frequentes, dentre elas podemos citar catarata e retinopatia. A catarata, que é a oftalmopatia mais frequente nos cães, impossibilita à fundoscopia e nestes casos a avaliação da função retiniana pode ser feita com o auxílio do eletrorretinograma de campo total. O objetivo deste estudo foi avaliar a progressão da retinopatia diabética por meio de eletrorretinograma (ERG) de campo total pré e pós-operatória (180 dias) em cães portadores de catarata madura e hipermadura submetidos à facoemulsificação. Vinte e quatro cães (Grupo Diabético (DM) = 12 cães; Grupo Não Diabético (NDM) = 12 cães) de raças diversas foram avaliados. Previamente ao ERG, todos os cães foram submetidos ao exame oftalmológico completo e ultrassom ocular. Todos os cães foram sedados seguindo o mesmo protocolo. ERG de campo total foi realizado com sistema eletrodiagnóstico Veris 2000 e cúpula de estimulação (Ganzfeld), segundo o protocolo da ISCEV contendo 5 respostas. Para obtenção dos registros utilizou-se eletrodo bipolar Burian Allen. Avaliou-se a amplitude pico a pico das 5 respostas e o tempo de culminação da onda-b na resposta de bastonetes, máxima resposta, cones e flicker para cada registro em condições escotópicas e fotópicas. As respostas obtidas em cada olho no momento basal e após 6 meses foram comparadas por meio do teste de Wilcoxon. O teste de Mann-Whitney foi utilizado para comparação de respostas dos olhos operados (OP) com os olhos contralaterais (OC), assim como para comparação entre os grupos DM e NDM. O efeito da cirurgia e do tempo de DM foi ainda avaliado por meio do cálculo das diferenças entre as respostas no momento pré e pós 6 meses de cada olho (delta OP e delta OC). Observou-se diferenças entre OP e OC, no momento pré, nas respostas dos bastonetes e da máxima resposta (amplitude e tempo de culminação onda-b). No momento pós, foram observados diferenças entre OP e OC no tempo de culminação dos bastonetes e flicker, e nas amplitudes do potencial oscilatório, cones e flicker. No grupo NDM, não foram observados diferenças entre os momentos pré e pós assim como entre OP e OC. Quando comparadas as respostas dos grupos DM e NDM, observou-se valores significativamente maiores no grupo DM, no tempo de culminação da onda-b na máxima resposta do OP no momento pós, no tempo de culminação da onda-b na máxima resposta OC no momento pós e no tempo de culminação da onda-b da resposta de cones no momento pré cirurgia. Não foram observados diferenças entre delta OP e delta OC dentro de cada grupo e entre os grupos. Todos os pacientes que participaram do estudo recuperaram a visão após a cirurgia, sugerindo que a inflamação pós cirúrgica foi controlada com a medicação prescrita nos 2 grupos estudados. Conclui-se que a facoemulsificação representa mínimo impacto na evolução da retinopatia diabética em cães. A remoção cirúrgica da catarata não deve ser contraindicada nesta espécie, independentemente se o animal é ou não portador de DM, por resultar em melhoria da visão. / Diabetes mellitus (DM) is a common endocrinopathy in the small animals practice and it develops as a relative or absolute insulin deficiency characterized by a chronic hyperglycemia. There are frequent complications, such as cataracts, retinopathy, resulting in visual impairment. Cataracts are dogs most frequent ophthalmic affection and, since it prevents fundoscopic examination, full-field electroretinography is used for retinal functional evaluation. Therefore, to provide a better understanding of diabetic retinopathy (DR) progression in dogs with mature and hypermature cataracts undergoing phacoemulsification surgery, this study aims to analyze the full-field electroretinogram prior and 180 days post cataracts removal. Twenty four dogs (diabetic group (DM) = 12 dogs and non-diabetic group (NDM) = 12 dogs), from different breeds were evaluated. Before the ERG, all animals were submitted to a complete ophthalmic examination and ocular ultrasonography. All dogs were sedated following the same anesthetic protocol. The full-field ERG was recorded using 2000 VERIS system and a dome stimulator (ganzfeld) according to ISCEV five response standard. The recordings were obtained using bipolar Burian Allen electrodes. Peak to peak amplitude five response and b-wave culmination time in rod responses, maximum response, cone and flicker were evaluated in scotopic and photopic conditions. The responses obtained in each eye at baseline and after 6 months were compared using the Wilcoxon test. The Mann-Whitney test was used to compare the responses of the operated eyes (OP) and the contralateral eyes (OC) as well as for comparison between groups DM and NDMAs. The effect of surgery and duration of DM was assessed by calculating the differences between the responses prior and six months after surgery, of each eye (delta delta OP and OC). There were differences between OP and OC, in the baseline values, in rod responses and maximum response (amplitude values and b-wave implicit time). After phacoemulsification, differences were observed between OP and OC in b-wave implicit time of rods and flicker, and the amplitudes of the oscillatory potentials, cone and flicker. In the NDM group, no differences were observed between pre and post evaluations between OP and OC. Comparing the responses of DM and NDM groups, there were significantly higher values in the DM group, in b-wave implicit time and in maximum response of OP after caratact removal, and also, of the b-wave implicit time in the maximum response in OC after surgery and, finally, in the b-wave implicit time of cone response prior to the surgery. No differences were observed between delta OP and delta OC within each group and between groups. All patients recovered vision after surgery, suggesting that post-surgery inflammation was controlled by the prescribed medication in both groups. The phacoemulsification surgery did not appear to have a great impact on diabetic retinopathy evolution in dogs. Cataract surgery should not be contraindicated in this species, regardless of the presence of DM, as it can result in sight improvement.

A retinopatia da prematuridade é uma doença ocular do desenvolvimento associada a um crescimento vascular retiniano anormal e ocorre somente em recém-nascidos com menos de 32 semanas de gestação e submetidos a longos períodos em incubadoras, tipicamente ricas em oxigênio. A doença possui duas fases: (1) a inibição do desenvolvimento normal de vasos na retina, decorrente da hiperóxia induzida pelo ambiente da incubadora; (2) neovascularização retiniana devido ao aumento de fatores de crescimento desencadeados pela pouca disponibilidade de oxigênio fora da incubadora. O objetivo deste trabalho é avaliar a função visual em um modelo animal de retinopatia da prematuridade, comparando-o a animais sadios. Eletrorretinogramas (ERGs) de campo total foram realizados em camundongos (Mus musculus) controle e camundongos submetidos hiperoxigenação em câmara hiperbárica (75% de oxigênio) durante o desenvolvimento retiniano pós-natal para entender as perdas visuais que ocorrem na retinopatia da prematuridade. Foram utilizados 122 animais, divididos em dois grupos: no grupo controle¸ ERGs foram realizados em P17 (n = 32), P30 (n = 26) e P60 (n = 44) com estimulação em comprimentos de onda distintos (LEDs com pico de emissão em 365 nm, 459 nm, 525 nm e 635 nm) para avaliação da atividade funcional da retina ao longo do desenvolvimento, não passando por nenhuma manipulação experimental adicional; no grupo experimental, os animais foram submetidos à hiperoxigenação de P7 a P12 para indução da angiogênese e avaliados com ERGs com estimulação em 459 nm em P17 (n = 7), P30 (n = 6) e P60 (n = 7), para acompanhar o desenvolvimento retiniano. Todos os animais foram adaptados ao escuro por pelo menos duas horas antes da realização dos experimentos. Em sessão de 40 a 60 minutos de duração, os animais foram submetidos a flashes de luz em intensidades crescentes. Amplitudes e latências das ondas a, b e potenciais oscilatórios foram medidas, e relações intensidade-resposta ajustadas com modelos matemáticos diferentes para comparação entre indivíduos e entre grupos. Os parâmetros obtidos com os ajustes foram comparados através de ANOVA e testes T de Student com as devidas correções de Bonferroni. Nos níveis luminosos testados, a onda b do ERG murino é majoritariamente dominada pela atividade dos bastonetes e a onda a majoritariamente dominada pelos cones. Os registros em animais em P17 e P30 do grupo controle foram similares aos realizados em P60 quanto à latência e amplitude de resposta, bem como quanto à sensibilidade e grau de cooperação entre os distintos elementos do ERG. Entretanto, as amplitudes máximas de resposta foram ligeiramente maiores em P30 para todos os comprimentos de onda e houve ligeira redução da sensibilidade absoluta ao longo do desenvolvimento. Para o grupo experimental, os animais em P17 sofreram as maiores perdas, com diminuições nas amplitudes de todos os componentes do ERG, sem prejuízo das latências ou sensibilidade. Também houve uma sucessiva recuperação das respostas ao longo do desenvolvimento animal. Esses achados indicam que o modelo de ROP em camundongos reproduz aspectos essenciais ao quadro patológico severo humano / The retinopathy of prematurity is an ocular developmental disorder associated with abnormal retinal vascular growth and occurs only in neonates younger than 32 weeks of gestation and undergoing long periods in incubators, typically rich in oxygen. The disease has two phases: (1) the inhibition of the normal development of vessels in the retina, due to the hyperoxia induced by the incubator environment; (2) retinal neovascularization due to the increase in growth factors triggered by the low availability of oxygen outside the incubator. The objective of this study is to evaluate the visual function in an animal model of retinopathy of prematurity, comparing it to healthy animals. Full-field electroretinogram (ERGs) were performed on control mice (Mus musculus) and that were exposed to a hyperbaric chamber (75% oxygen) during post-natal retinal development to understand the visual losses that occur in retinopathy of prematurity. We used 122 animals, divided into two groups: in the control group, ERGs were performed at P17 (n = 32), P30 (n = 26) and P60 (n = 44) with stimulation at different wavelengths (LEDs with peak of emission at 365 nm, 459 nm, 525 nm and 635 nm) for evaluation of the functional activity of the retina throughout the development, without any additional experimental manipulation; in the experimental group, animals were submitted to hyperoxogenation of P7 to P12 for induction of angiogenesis and evaluated with ERGs with stimulation at 459 nm in P17 (n = 7), P30 (n = 6) and P60 (n = 7) to follow up retinal development. All animals were dark adapted for at least two hours prior to the experiments. In sessions with 40 to 60 minutes, the animals were subjected to flashes of light at increasing intensities. Amplitudes and latencies of a-waves, b-waves and oscillatory potentials were measured, and intensity-response relationships adjusted with different mathematical models for comparison between individuals and between groups. The parameters obtained with the adjustments were compared through ANOVA and Student\'s T tests with the appropriate Bonferroni correction. In the light levels tested, the murine ERG b-wave is dominated by rod activity and the a-wave is dominated by the cones. The records in animals at P17 and P30 of the control group were similar to those performed at P60 regarding the latency and amplitude of response, as well as the sensitivity and degree of cooperation between the different ERG elements. However, the maximum response amplitudes were slightly higher at P30 at all wavelengths and there was slight reduction of absolute sensitivity throughout development. For the experimental group, the animals at P17 suffered the greatest losses, with decreases in the amplitudes of all the components of the ERG, without prejudice to the latencies or sensitivity. There was also a successive recovery of responses throughout animal development. These findings indicate that the ROP model in mice reproduces aspects essential to the severe human pathology

The murine eye naturally undergoes post-natal changes in eye size. This dissertation quantifies longitudinal structural and functional changes in control mice (C57BL/6J (B6), D2-Gpnmb+/SjJ) and in DBA/2J (D2) mice, which spontaneously develop elevated intraocular pressure (IOP). IOP elevation results in abnormal eye elongation, retinal nerve fiber layer (RNFL) thickness thinning and retinal ganglion cell (RGC) dysfunction and demise resembling human glaucoma. I measured structural changes with Optical Coherence Tomography (OCT), and RGC function with Pattern Electroretinogram (PERG). I also developed and refined provocation approaches (IOP elevation with changes in body posture; metabolic load with flickering light) to probe susceptibility of RGC function in D2 mice prone to glaucoma. Finally, I developed a novel system for recording, simultaneously but independently, the PERG from both eyes using asynchronous visual stimuli and deconvolution analysis. Simultaneous PERG recording from each eye was hitherto impossible due to the interocular cross-talk of the PERG signal. Altogether, the combination of these measures (OCT, PERG) and provocative conditions may represent powerful tools for glaucoma research using mouse models.

Inherited retinal degenerative diseases can affect various components of the retina leading to blindness. Five different mutant strains of chicken have been studied extensively as potential models for inherited retinal degeneration. The Smoky Joe (SJ) chicken is a sixth genetically blind strain of White Leghorns that shows various degrees of blindness at hatch and by 8 weeks post-hatch, have complete blindness for those that are homozygous. The objective of this study was to characterize the retinal degeneration in these birds by histology, both during embryonic and post-hatch development, and to the retinal function using electroretinograms (ERG). For both embryonic and post-hatch development, a significantly lower number of cells were found in the retina of blind birds compared to sighted (both p<0.0001). The significant contributor to cell number decrease was the loss of amacrine cells located in the inner nuclear layer. Photoreceptors were also found to potentially decrease in number, but at a later stage. ERG recordings revealed decreases in amplitudes of b-waves and oscillatory potentials in blind birds, but not in sighted. Both histology and ERG findings support the idea that the inner retinal cells are affected. The results indicate that degeneration in the Smoky Joe retina occurs mostly within the inner nuclear layer affecting amacrine cells. This hampers the functional capacity of the retina, causing blindness.

Sensory adaptation to blur improves visual acuity under defocused conditions. This phenomenon has been successfully demonstrated using subjective measures of acuity and is known as blur adaptation. This study investigates aspects of the mechanism of blur adaptation in human vision using subjective and objective methods. Parafoveal visual acuity measured under defocused conditions demonstrates that blur adaptation is not limited to the fovea. The presence of the adaptive mechanism in the parafovea also suggests that the neural compensation that takes places under defocused conditions acts across a spatial range and is not limited to specific frequency bands. An evaluation of the contrast sensitivity function under defocus provides further evidence. Electrophysiological methods measure the effect of blur adaptation at the retina and at the visual cortex to provide objective evidence for the presence of the blur adaptation mechanism. Finally enhanced-depth imaging optical coherence tomography examines whether a period of prolonged defocus triggers any short-term changes in choroidal thickness in a similar manner to that reported in animal emmetropisation.

Inherited retinal degenerative diseases can affect various components of the retina leading to blindness. Five different mutant strains of chicken have been studied extensively as potential models for inherited retinal degeneration. The Smoky Joe (SJ) chicken is a sixth genetically blind strain of White Leghorns that shows various degrees of blindness at hatch and by 8 weeks post-hatch, have complete blindness for those that are homozygous. The objective of this study was to characterize the retinal degeneration in these birds by histology, both during embryonic and post-hatch development, and to the retinal function using electroretinograms (ERG). For both embryonic and post-hatch development, a significantly lower number of cells were found in the retina of blind birds compared to sighted (both p<0.0001). The significant contributor to cell number decrease was the loss of amacrine cells located in the inner nuclear layer. Photoreceptors were also found to potentially decrease in number, but at a later stage. ERG recordings revealed decreases in amplitudes of b-waves and oscillatory potentials in blind birds, but not in sighted. Both histology and ERG findings support the idea that the inner retinal cells are affected. The results indicate that degeneration in the Smoky Joe retina occurs mostly within the inner nuclear layer affecting amacrine cells. This hampers the functional capacity of the retina, causing blindness.

Developmental studies on elasmobranchs are challenging due to the difficulties in obtaining sufficient numbers of animals of different age cohorts. The brown banded bamboo shark, Chiloscyllium punctatum is a good model in this regard as it is abundant and readily available in the wild, is quick to mature, is frequently housed and bred in captivity and is a relatively small species of shark. Whilst there are important factors that must be considered when comparing the retinal development of animals raised in captivity to those caught from the wild, the use of C. punctatum represents an outstanding opportunity to study the development of the elasmobranch visual system from pre-hatching embryonic to adult life stages. In this study, the developing eye and retina of C. punctatum were studied using light and electron microscopy, electroretinography (ERG) and microspectrophotometry (MSP). To provide a source of early-stage animals, and to investigate the effects of environmental factors (such as temperature) on physical development, a captive breeding program was established at the University of Queensland. Sharks sourced from this facility were supplemented with animals bred at UnderWater World, Sea World and caught from the wild. Monitoring the fecundity, embryonic development, growth and viability of captive C. punctatum showed that females lay an average of 115.3 eggs, 38 of which were viable and 21.4% of which hatched. Embryos have an average gestation of 153 days post deposition (dpd; temp: 21 - 25º C) and embryonic growth is most rapid from 99 dpd until hatching. The eye of C. punctatum develops early in embryogenesis, with visible optic vesicles bulging at 27 dpd. Recent advances in fixation and processing techniques for transmission electron microscopy (TEM) have yielded improved levels of ultrastructural detail in a variety of tissue types. Consequently, in addition to conventional chemical fixation (CF) methods, the retina of C. punctatum was also processed using microwave chemical fixation (MCF) and high pressure freezing (HPF), and the resulting ultrastructure compared. Both MCF and HPF produced superior retinal ultrastructure compared to conventional CF, evidenced by higher resolution of ultrastructural detail and fewer artefacts. MCF provided the best, consistent ultrastrucutral results. By examining the time-course of retinal cell differentiation, it was found that ganglion and Müller cells are the first to differentiate, at approximately 81 dpd. The interneurons differentiate next, beginning with the amacrine cells (81 dpd), followed by the bipolar cells (101 dpd) and horizontal cells (124 dpd). The adult retina is duplex and rod and cone photoreceptors are differentiated and synaptic connections are formed by 124 dpd. Topographic analysis of retinal neuron sub-types reveals that C. punctatum undergoes rapid changes in ganglion cell distribution during embryogenesis. High levels of apoptosis, especially around the retinal periphery, result in relatively higher cell densities in the central retina, which progressively extend nasally and temporally to form a meridional band. C. punctatum develops a horizontal streak and shows only minor changes in topography during growth. Only basal levels of apoptosis are seen post-hatching. In the adult shark, the total ganglion cell number reaches 547,881. The mean and highest retinal ganglion cell densities reach a peak around hatching (3,228 cells mm-2 and 4,983 cells mm-2, respectively). Using measurements of lens focal length and ganglion cell density, the calculated maximum spatial resolving power (assuming a hexagonal mosaic) increases from 1.47 cycles degree-1 during embryogenesis to 4.29 cycles degree-1 in adults. The addition of a high ganglion cell density area within the visual streak and an increasing spatial resolving power over post-hatching development suggest an increased prey targeting and capture ability for this species. Using ERG, it is shown that C. punctatum becomes responsive to light at 127 dpd and light sensitivity peaks around the time of hatching, with a slight decrease post-hatching. C. punctatum maintains a flicker fusion frequency (FFF; an indicator for temporal resolution) at 7 - 22 Hz through juvenile stages), which is relatively low compared to other marine predators. ERG results suggest that this species is adapted to low light vision with low temporal resolution. The early differentiation, development and functionality of the visual system in C. punctatum allows for a period of synaptic maturation and potentially the ability of embryonic predator avoidance. The retina of C. punctatum contains a rod visual pigment with a wavelength of maximum absorbance (λmax) at 500 nm and cone visual pigment with a λmax at 532 nm; the max values of these pigments do not change during development. Rod and cone outer segments differentiate at 113 days post deposition (dpd), lengthen during embryogenesis and accumulate pigment throughout life. Although the photoreceptors develop and differentiate well in advance of hatching, there is considerable variation in outer segment length and pigment density during embryogenesis, which suggests that these cells are developing up until hatching. C. punctatum does not appear to have the potential for colour vision based on the lack of two cone photoreceptor types each containing a visual pigment maximally sensitive to different parts of the visual spectrum, but appears specialised for dim-light contrast vision.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-09-12T17:52:19Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Priscila Rafaela Leão Soares.pdf: 2736692 bytes, checksum: e5e6dccbb19782134f0827b7361fb245 (MD5) / Made available in DSpace on 2016-09-12T17:52:19Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Priscila Rafaela Leão Soares.pdf: 2736692 bytes, checksum: e5e6dccbb19782134f0827b7361fb245 (MD5) Previous issue date: 2016-02-25 / Capes / O lufenuron é um inseticida benzoilureia e uma substância tóxica que interfere na síntese de quitina nos insetos. Apesar do lufenuron ser um inseticida amplamente utilizado na agricultura e aquicultura, estudos relacionados aos possíveis efeitos tóxicos em diferentes grupos de animais são escassos na literatura. Este trabalho teve por objetivo avaliar os efeitos tóxicos agudo e crônico do pesticida benzoilureia (lufenuron) sobre os parâmetros biológicos de Colossoma macropomum (Tambaqui). Para realização do teste agudo, juvenis de tambaqui foram divididos em um grupo controle e cinco grupos experimentais com exposição de 0,1 a 0,9 mg/L de lufenuron por 96 h, com replicata (n = 120). Os animais também foram submetidos a teste de toxicidade crônica por quatro meses em concentrações de 0,1 e 0,3 mg/L de lufenuron, e também um grupo controle (n = 60). A última concentração corresponde a 50% da CL50 96 h (0,58 mg/L) determinada no teste agudo. A presença de hemorragias foi observada nos olhos (hifema), nas nadadeiras e nos opérculos dos peixes expostos a 0,7 e 0,9 mg/L de lufenuron no teste agudo. Análises histológicas mostraram alterações na morfologia das brânquias dos peixes submetidos ao teste de toxicidade aguda, como aneurisma lamelar e congestionamento de sangue nas lamelas. No teste crônico, a análise de glicose no sangue e os parâmetros morfométricos não apresentaram diferenças significativas pelo teste de Tukey (p > 0,05). Em geral, C. macropomum exibiram comportamentos associados ao estresse quando exposto ao lufenuron em ambos os testes. O lufenuron promoveu danos na retina dos peixes como na capacidade de responder aos estímulos nas células fotorreceptoras e ON-bipolares no teste agudo. Deste modo, o lufenuron apresentou vários efeitos tóxicos em relação aos parâmetros biológicos em C. macropomum. Esta preocupação com o uso e descarte do lufenuron indica a exigência de ações ambientais, com a mitigação, para prevenir a bioacumulação e/ou biomagnificação. / Lufenuron is a benzoylurea insecticide and a toxic substance that interfere in chitin synthesis in insects. Although lufenuron is an insecticide widely used in agriculture and aquaculture, rare are studies described in the literature that relates to possible toxic effects on different groups of animals. This work aimed to evaluate acute and chronic toxic effects of benzoylurea pesticide (lufenuron) on biological parameters of Colossoma macropomum (Tambaqui). To do the acute test, Tambaqui juveniles were divided into a control group and five experimental groups with exposure to from 0.1 to 0.9 mg/L of lufenuron for 96 h, with replicate (n = 120). Animals were also submitted to chronic toxicity test for four months in concentrations of 0.1 and 0.3 mg/L of lufenuron, also a control group was done (n = 60). This last concentration corresponded to 50% of LC50 96 h (0.58 mg/L) determined in the acute test. The presence of hemorrhages was observed in eyes (hyphema), fins and operculum of fish exposed to 0.7 and 0.9 mg/L of lufenuron in acute test. Histological analysis showed changes in the morphology of fish gills submitted to acute toxicity test, as lamellar aneurysm and blood congestion inside lamellae. In chronic test, blood glucose analysis and morphometric parameters showed no significant differences by Tukey test (p > 0.05). In general, C. macropomum exhibit behaviors associated with stress when exposed to lufenuron in both tests. Lufenuron promoted damage in fish retina as in ability to respond to stimuli in photoreceptors and in ON-bipolar cells in acute test. Thus, lufenuron showed several toxic effects in relation to biological parameters in C. macropomum. This concern about the use and discard of lufenuron indicates the requirement of environmental actions, as mitigation, to prevent bioaccumulation and/or biomagnification.

Diabete Melito (DM) é uma endocrinopatia frequentemente diagnosticada na clínica de pequenos animais e desenvolve-se pela deficiência relativa ou absoluta de insulina, sendo caracterizada pela hiperglicemia crônica. Complicações associadas ao DM são frequentes, dentre elas podemos citar catarata e retinopatia. A catarata, que é a oftalmopatia mais frequente nos cães, impossibilita à fundoscopia e nestes casos a avaliação da função retiniana pode ser feita com o auxílio do eletrorretinograma de campo total. O objetivo deste estudo foi avaliar a progressão da retinopatia diabética por meio de eletrorretinograma (ERG) de campo total pré e pós-operatória (180 dias) em cães portadores de catarata madura e hipermadura submetidos à facoemulsificação. Vinte e quatro cães (Grupo Diabético (DM) = 12 cães; Grupo Não Diabético (NDM) = 12 cães) de raças diversas foram avaliados. Previamente ao ERG, todos os cães foram submetidos ao exame oftalmológico completo e ultrassom ocular. Todos os cães foram sedados seguindo o mesmo protocolo. ERG de campo total foi realizado com sistema eletrodiagnóstico Veris 2000 e cúpula de estimulação (Ganzfeld), segundo o protocolo da ISCEV contendo 5 respostas. Para obtenção dos registros utilizou-se eletrodo bipolar Burian Allen. Avaliou-se a amplitude pico a pico das 5 respostas e o tempo de culminação da onda-b na resposta de bastonetes, máxima resposta, cones e flicker para cada registro em condições escotópicas e fotópicas. As respostas obtidas em cada olho no momento basal e após 6 meses foram comparadas por meio do teste de Wilcoxon. O teste de Mann-Whitney foi utilizado para comparação de respostas dos olhos operados (OP) com os olhos contralaterais (OC), assim como para comparação entre os grupos DM e NDM. O efeito da cirurgia e do tempo de DM foi ainda avaliado por meio do cálculo das diferenças entre as respostas no momento pré e pós 6 meses de cada olho (delta OP e delta OC). Observou-se diferenças entre OP e OC, no momento pré, nas respostas dos bastonetes e da máxima resposta (amplitude e tempo de culminação onda-b). No momento pós, foram observados diferenças entre OP e OC no tempo de culminação dos bastonetes e flicker, e nas amplitudes do potencial oscilatório, cones e flicker. No grupo NDM, não foram observados diferenças entre os momentos pré e pós assim como entre OP e OC. Quando comparadas as respostas dos grupos DM e NDM, observou-se valores significativamente maiores no grupo DM, no tempo de culminação da onda-b na máxima resposta do OP no momento pós, no tempo de culminação da onda-b na máxima resposta OC no momento pós e no tempo de culminação da onda-b da resposta de cones no momento pré cirurgia. Não foram observados diferenças entre delta OP e delta OC dentro de cada grupo e entre os grupos. Todos os pacientes que participaram do estudo recuperaram a visão após a cirurgia, sugerindo que a inflamação pós cirúrgica foi controlada com a medicação prescrita nos 2 grupos estudados. Conclui-se que a facoemulsificação representa mínimo impacto na evolução da retinopatia diabética em cães. A remoção cirúrgica da catarata não deve ser contraindicada nesta espécie, independentemente se o animal é ou não portador de DM, por resultar em melhoria da visão. / Diabetes mellitus (DM) is a common endocrinopathy in the small animals practice and it develops as a relative or absolute insulin deficiency characterized by a chronic hyperglycemia. There are frequent complications, such as cataracts, retinopathy, resulting in visual impairment. Cataracts are dogs most frequent ophthalmic affection and, since it prevents fundoscopic examination, full-field electroretinography is used for retinal functional evaluation. Therefore, to provide a better understanding of diabetic retinopathy (DR) progression in dogs with mature and hypermature cataracts undergoing phacoemulsification surgery, this study aims to analyze the full-field electroretinogram prior and 180 days post cataracts removal. Twenty four dogs (diabetic group (DM) = 12 dogs and non-diabetic group (NDM) = 12 dogs), from different breeds were evaluated. Before the ERG, all animals were submitted to a complete ophthalmic examination and ocular ultrasonography. All dogs were sedated following the same anesthetic protocol. The full-field ERG was recorded using 2000 VERIS system and a dome stimulator (ganzfeld) according to ISCEV five response standard. The recordings were obtained using bipolar Burian Allen electrodes. Peak to peak amplitude five response and b-wave culmination time in rod responses, maximum response, cone and flicker were evaluated in scotopic and photopic conditions. The responses obtained in each eye at baseline and after 6 months were compared using the Wilcoxon test. The Mann-Whitney test was used to compare the responses of the operated eyes (OP) and the contralateral eyes (OC) as well as for comparison between groups DM and NDMAs. The effect of surgery and duration of DM was assessed by calculating the differences between the responses prior and six months after surgery, of each eye (delta delta OP and OC). There were differences between OP and OC, in the baseline values, in rod responses and maximum response (amplitude values and b-wave implicit time). After phacoemulsification, differences were observed between OP and OC in b-wave implicit time of rods and flicker, and the amplitudes of the oscillatory potentials, cone and flicker. In the NDM group, no differences were observed between pre and post evaluations between OP and OC. Comparing the responses of DM and NDM groups, there were significantly higher values in the DM group, in b-wave implicit time and in maximum response of OP after caratact removal, and also, of the b-wave implicit time in the maximum response in OC after surgery and, finally, in the b-wave implicit time of cone response prior to the surgery. No differences were observed between delta OP and delta OC within each group and between groups. All patients recovered vision after surgery, suggesting that post-surgery inflammation was controlled by the prescribed medication in both groups. The phacoemulsification surgery did not appear to have a great impact on diabetic retinopathy evolution in dogs. Cataract surgery should not be contraindicated in this species, regardless of the presence of DM, as it can result in sight improvement.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12917号 / 論医博第2092号 / 新制||医||1009(附属図書館) / 32127 / 京都大学大学院医学研究科医学専攻 / (主査)教授 河野 憲二, 教授 大森 治紀, 教授 渡邉 大 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM