No description available.

No description available.

No description available.

Our lab has shown that conditionally disrupting the tcfap2beta gene, responsible for the activating protein-2beta (AP-2beta) transcription factor, exclusively in the craniofacial neural crest cells, leads to anterior segment dysgenesis. Subsequent loss of the corneal endothelium results in the adherence of the iris to the corneal stroma, causing closure of the iridocorneal angle. The activating protein-2beta neural crest cell knockout (AP-2beta NCC KO) model involves a complete blockage of the both the conventional (through the trabecular meshwork) and non-conventional (uveoscleral) pathways for aqueous humor drainage, and therefore it could be used as a powerful experimental model for glaucoma. As shown by our previous work, elevated intraocular pressure (IOP) and a 35% decrease in the number of cells in the retinal ganglion cell (RGC) layer was observed in AP-2beta NCC KO mice by 2 months; 6 to 11 months sooner than other reported mouse models of glaucoma. These observations suggested that the AP-2beta NCC KO mouse could be a novel and cost-effective experimental model for glaucoma if the RGC loss occurred progressively rather than due to a congenital defect. The purpose of this research project was to investigate how the retinal ganglion cell layer and macroglial activity changes with respect to age in the AP-2beta NCC KO mutant through immunofluorescence. Specifically, it was investigated whether the loss of RGCs was progressive and due to the increased IOP caused by the blockage of the uveoscleral drainage pathway. A significant decrease in the number of RGCs was observed between P4 and P10 in the retinal periphery of both WT and AP-2beta NCC KO mice (p<0.05), which is indicative of the programmed cell death that occurs due to retinal pruning during development. No statistical difference between WT and AP-2beta NCC KO mice phenotypes was observed at postnatal day 4 (P4), suggesting that no developmental defect resulted in the significant loss of RGCs at 2 months. In all other time points investigated, while no statistical difference was found between WT and the AP-2 NCC KO mutant, a clear downward trend was present in the AP-2 NCC KO mutant retinal ganglion cell layer from P10 to P40. There was also an expression of glial fibrillary acidic protein (GFAP) by Müller cells, indicating the presence of neuroinflammation at P35 and P40. This substantiates the potential P42 starting point of neurodegeneration our lab previously observed. This was further corroborated with Müller cell-associated expression of GFAP at P35 and P40 exclusively in the AP-2beta NCC KO mouse. Overall, we have shown that the retinal damage observed in our AP-2beta NCC KO mouse is not due to a developmental defect, but rather occurs over time. Thus, this mouse model, which appears to block both the conventional and unconventional uveoscleral pathways, has a profound effect on aqueous humor drainage. As a result, the model requires relatively little time to observe an increase in IOP and subsequent RGC loss. Our findings suggest that the AP-2beta NCC KO mouse can be a novel, powerful, and extremely cost-effective experimental model for glaucoma. / Thesis / Master of Science (MSc)

Corneal ulceration with prolonged healing following Nd:YAG laser cyclophotocoagulation in dogs is a frequent complication. It is hypothesized that these corneal ulcerations may be a form of neurotrophic keratitis due to laser-induced damage to corneal innervation. Fifteen clinically normal dogs had the neodymium:yttrium aluminum garnet(Nd:YAG) laser cyclophotocoagulation performed on the left eye. Each treated eye received 100 Joules of laser energy. Corneal touch threshold (CTT) and Schirmer I tear tests (STT) were performed before the surgery and on days 1,3,5,7,9,11, and 13 post-laser treatment. Applanation tonometry was performed before surgery and twice daily for 14 days post-laser treatment. Eyes were enucleated after 14 days and corneal nerves were stained using a gold chloride technique. Major nerve bundles entering the cornea were quantitated by quadrant, using camera lucida reproductions. Nerve bundle diameters were measured using NIH image computer software on computer-scanned images. Statistical methods included repeated values for analysis of variance for CTT, STT and IOP, and a paired t-test for nerve diameters and bundles. All laser treated eyes had significantly higher CTTs (P<0.05) compared to control eyes for all measurements. Six out of fifteen dogs had evidence of ulcerative keratitis. Intraocular pressure was significantly lower in laser treated eyes compared to control eyes in the a.m. on days 2-9,and 14, and in the p.m. on days 2-11 using a Bonferroni-corrected alpha level (P<0.0039). A significant decrease of one nerve bundle per corneal quadrant was found between the laser treated and control eyes. There was no significant difference in STT or nerve bundle diameters between laser treated and control eyes. Nd:YAG laser cyclophotocoagulation effectively reduces IOP while increasing CTT. The procedure also causes a significant decrease in the number of major nerve bundles entering the cornea, but has no effect on the diameter of those bundles. These findings support the hypothesis that nerve damage and corneal hypoesthesia are etiologic factors in ulcerative keratitis following Nd:YAG laser cyclophotocoagulation. / Master of Science

OBJETIVO: avaliar a reprodutibilidade da curva tensional modificada e do teste de sobrecarga hídrica em portadores de glaucoma de ângulo aberto ou hipertensos oculares, sem uso de hipotensor ocular, em dois dias consecutivos. MÉTODOS: análise prospectiva de pacientes portadores de glaucoma de ângulo aberto ou hipertensos oculares, submetidos à curva tensional modificada (medida da pressão intraocular às 8h, 11h, 14h e 16h), seguida do teste de sobrecarga hídrica (três medidas com intervalo de 15 minutos, iniciando-se 15 minutos após a ingestão, em cinco minutos, de um litro de água em temperatura ambiente), realizados pelo mesmo examinador, em dois dias consecutivos. Foram avaliadas: a reprodutibilidade da pressão intraocular em cada horário de medida durante a curva tensional modificada; a reprodutibilidade da pressão intraocular média, flutuação e pico de pressão durante a curva tensional modificada; a reprodutibilidade da flutuação e do pico de pressão durante o teste de sobrecarga hídrica. Calculou-se o coeficiente de correlação intraclasse para cada parâmetro. RESULTADOS: oitenta e oito olhos de 88 pacientes foram estudados. Destes, 64 eram portadores de glaucoma de ângulo aberto. A média das idades dos participantes foi 68,7+10,8 (51-79) anos. 65% dos pacientes eram do sexo feminino. A curva tensional modificada apresentou coeficiente de correlação intraclasse igual a 0,80, 0,82, 0,83 e 0,86 para as medidas realizadas às 8h, 11h, 14h e 16h, respectivamente (p < 0,001). A flutuação da pressão durante a curva tensional modificada, calculada pela diferença entre as pressões máxima e mínima e pelo desvio-padrão da média das medidas diurnas de pressão, a pressão média e o pico pressórico apresentaram coeficientes 0,60, 0,62, 0,91 e 0,85, respectivamente (p < 0,001). Durante o teste de sobrecarga hídrica, a flutuação apresentou coeficiente de 0,37 e o pico pressórico, 0,79. (p < 0,001). CONCLUSÕES: neste estudo, as medidas de pressão intraocular realizadas durante a curva tensional modificada, a média e o pico apresentaram excelentes níveis de reprodutibilidade. O pico pressórico durante o teste de sobrecarga hídrica apresentou também excelente reprodutibilidade. A flutuação, tanto na curva tensional modificada, quanto no teste de sobrecarga hídrica, apresentou os menores índices de reprodutibilidade / OBJECTIVE: to evaluate the reproducibility of the modified daily tension curve and the water drinking test in patients with open-angle glaucoma or ocular hypertension, not under topical treatment, during two consecutive days. METHODS: prospective analysis of open-angle glaucoma or ocular hypertensive patients, submitted to a modified daily tension curve (intraocular pressure measurements at 8AM, 11AM, 2PM and 4PM), followed by the water drinking test (three intraocular pressure measurements with 15 minutes intervals, 15 minutes after ingestion of one liter of tap water), performed by the same examiner, within two consecutive days. The following parameters were evaluated for reproducibility: intraocular pressure obtained at each time-point during the modified daily tension curve; mean, peak and pressure fluctuation during the curve and peak and fluctuation during the water drinking test. Reproducibility was assessed using the intraclass correlation coefficient. RESULTS: eighty-eight eyes from 88 patients were studied. From these, 64 presented open-angle glaucoma. Mean age was 68.7+10.8 (51-79) years. 65% patients were female. Intraclass correlation coefficients were 0.80, 0.82, 0.83 and 0.86 for intraocular pressure measurements at 8AM, 11AM, 2PM and 4PM, respectively (p<0.001) Fluctuation calculated as the difference between maximum and minimum intraocular pressures, fluctuation calculated as the standard deviation of the four daily measurements, mean and peak pressures presented coefficients of 0.60, 0.62, 0.91 and 0.85, respectively (p<0.001). During the water drinking test, coefficient values for fluctuation and peak pressure were 0.37 and 0.79 (p<0.001). CONCLUSIONS: in this study, intraocular pressure measurements during a modified daily tension curve, mean intraocular pressure and pressure peaks presented excellent reproducibility levels; pressure peaks during the water drinking test also presented excellent reproducibility level, whereas fluctuation, both during the modified daily tension curve and during the water drinking test, was the least reproducible parameter

OBJETIVO: avaliar a reprodutibilidade da curva tensional modificada e do teste de sobrecarga hídrica em portadores de glaucoma de ângulo aberto ou hipertensos oculares, sem uso de hipotensor ocular, em dois dias consecutivos. MÉTODOS: análise prospectiva de pacientes portadores de glaucoma de ângulo aberto ou hipertensos oculares, submetidos à curva tensional modificada (medida da pressão intraocular às 8h, 11h, 14h e 16h), seguida do teste de sobrecarga hídrica (três medidas com intervalo de 15 minutos, iniciando-se 15 minutos após a ingestão, em cinco minutos, de um litro de água em temperatura ambiente), realizados pelo mesmo examinador, em dois dias consecutivos. Foram avaliadas: a reprodutibilidade da pressão intraocular em cada horário de medida durante a curva tensional modificada; a reprodutibilidade da pressão intraocular média, flutuação e pico de pressão durante a curva tensional modificada; a reprodutibilidade da flutuação e do pico de pressão durante o teste de sobrecarga hídrica. Calculou-se o coeficiente de correlação intraclasse para cada parâmetro. RESULTADOS: oitenta e oito olhos de 88 pacientes foram estudados. Destes, 64 eram portadores de glaucoma de ângulo aberto. A média das idades dos participantes foi 68,7+10,8 (51-79) anos. 65% dos pacientes eram do sexo feminino. A curva tensional modificada apresentou coeficiente de correlação intraclasse igual a 0,80, 0,82, 0,83 e 0,86 para as medidas realizadas às 8h, 11h, 14h e 16h, respectivamente (p < 0,001). A flutuação da pressão durante a curva tensional modificada, calculada pela diferença entre as pressões máxima e mínima e pelo desvio-padrão da média das medidas diurnas de pressão, a pressão média e o pico pressórico apresentaram coeficientes 0,60, 0,62, 0,91 e 0,85, respectivamente (p < 0,001). Durante o teste de sobrecarga hídrica, a flutuação apresentou coeficiente de 0,37 e o pico pressórico, 0,79. (p < 0,001). CONCLUSÕES: neste estudo, as medidas de pressão intraocular realizadas durante a curva tensional modificada, a média e o pico apresentaram excelentes níveis de reprodutibilidade. O pico pressórico durante o teste de sobrecarga hídrica apresentou também excelente reprodutibilidade. A flutuação, tanto na curva tensional modificada, quanto no teste de sobrecarga hídrica, apresentou os menores índices de reprodutibilidade / OBJECTIVE: to evaluate the reproducibility of the modified daily tension curve and the water drinking test in patients with open-angle glaucoma or ocular hypertension, not under topical treatment, during two consecutive days. METHODS: prospective analysis of open-angle glaucoma or ocular hypertensive patients, submitted to a modified daily tension curve (intraocular pressure measurements at 8AM, 11AM, 2PM and 4PM), followed by the water drinking test (three intraocular pressure measurements with 15 minutes intervals, 15 minutes after ingestion of one liter of tap water), performed by the same examiner, within two consecutive days. The following parameters were evaluated for reproducibility: intraocular pressure obtained at each time-point during the modified daily tension curve; mean, peak and pressure fluctuation during the curve and peak and fluctuation during the water drinking test. Reproducibility was assessed using the intraclass correlation coefficient. RESULTS: eighty-eight eyes from 88 patients were studied. From these, 64 presented open-angle glaucoma. Mean age was 68.7+10.8 (51-79) years. 65% patients were female. Intraclass correlation coefficients were 0.80, 0.82, 0.83 and 0.86 for intraocular pressure measurements at 8AM, 11AM, 2PM and 4PM, respectively (p<0.001) Fluctuation calculated as the difference between maximum and minimum intraocular pressures, fluctuation calculated as the standard deviation of the four daily measurements, mean and peak pressures presented coefficients of 0.60, 0.62, 0.91 and 0.85, respectively (p<0.001). During the water drinking test, coefficient values for fluctuation and peak pressure were 0.37 and 0.79 (p<0.001). CONCLUSIONS: in this study, intraocular pressure measurements during a modified daily tension curve, mean intraocular pressure and pressure peaks presented excellent reproducibility levels; pressure peaks during the water drinking test also presented excellent reproducibility level, whereas fluctuation, both during the modified daily tension curve and during the water drinking test, was the least reproducible parameter

Des microparticules de rifampicine pour l'administration intraoculaire ont été développées en vue du traitement prophylactique de l'endophtalmie post-chirurgicale. Ces microparticules à base d'un polymère biodégradable, le PLGA, sont produites par émulsion-diffusion. Tout d'abord l'influence des paramètres de formulation et de procédé sur les caractéristiques des microparticules (taille, charge, taux d'encapsulation…) a été étudiée. La formulation a par la suite pu être optimisée par la mise en place d'un plan d'expérience, ce qui a permis de mettre en valeur les paramètres clefs influençant les propriétés des microparticules (concentrations en PLGA et PVA, présence ou non d'un coeur huileux…) et donc d'optimiser la formulation pour obtenir des microparticules adéquates pour l'administration intraoculaire de rifampicine (1μm<taille<10μm, encapsulation maximale…). Les études de libération de la rifampicine in vitro, dans des conditions mimant celles physiologiques, ont montré que d'une part plus de 50% de la rifampicine était libérée en 1h permettant d'obtenir une dose "d'attaque" et d'autre part que les microparticules permettaient de maintenir une libération prolongée sur 24h avec une concentration > CMI50 de Staphylococcus epidermidis (pathogène modèle utilisé pour les études microbiologiques). Enfin, une évaluation de l'effet bactéricide et antiadhérent sur lentilles intraoculaires (IOLs) de la rifampicine microencapsulée a été menée en présence de S. epidermidis. Les microparticules de rifampicine présentent une efficacité nettement supérieure à la solution contrôle de rifampicine puisque une bactéricidie totale a pu être observée 30h après injection (contre 103 CFU/mL restantes avec la solution contrôle), avec une activité antiadhérente nettement plus marquée (aucune bactérie détectée sur IOLs après 18h). Les microparticules de rifampicine apparaissent donc comme système d'administration intraoculaire prometteur dans le traitement prophylactique de l'endophtalmie post-opératoire / In this study, rifampicin-loaded microparticles were designed for intra ocular injection after cataract surgery to prevent postoperative endophthalmitis. Microparticles were produced by emulsification diffusion method using PLGA as biodegradable polymer and PVA as stabilizer agent. Influence of formulation and process parameters on microparticle characteristics (size, zeta potential, encapsulation efficiency…) was firstly investigated. Main parameters influencing the properties of particles were then identified by experimental design and formulation parameters were optimized to get desired particle sizes for intraocular delivery (between 1 and 10 μm) and the highest encapsulation of rifampicin. In vitro release studies of rifampicin in BSS at 37°C were performed showing firstly a burst release in 1 hour (more than 50% of rifampicin released), followed by a sustained release with a rifampicin concentration in the medium higher than the ICM50 on Staphylococcus epidermidis during 24h. Finally, the antimicrobial efficiency of rifampicin microparticles was evaluated on S. epidermidis. The results showed a higher bactericidal effect of encapsulated rifampicin than the control rifampicin solution; no bacteria were retrieved after 30h in the medium. Moreover, the antiadhesive property of rifampicin microparticles on intraocular lens (IOLs) was demonstrated since no bacteria were found on IOLs after 18h of incubation. From these experimental results, rifampicin encapsulated polymeric microparticles seem to be a good candidate for intraocular delivery of rifampicin in postoperative endophthalmitis prophylaxis

O adalimumabe (Humira®, Abbott) é um antagonista do Fator de Necrose Tumoral- alpha (TNF-alfa ). É aprovado para o tratamento de artrite reumatoide, espondilite anquilosante, doença de Crohn, psoríase crônica e artrite reumatoide juvenil. É um anticorpo monoclonal que contém apenas sequências humanas de peptídeos contra a molécula do Fator de Necrose Tumoral-alfa. Na literatura, relatos e série de casos sugerem que os antagonistas do Fator de Necrose Tumoral-alfa são úteis no tratamento da inflamação ocular, edema macular cistoide e secundário à uveíte e degeneração macular relacionada à idade. Entretanto, a administração sistêmica do adalimumabe pode gerar efeitos adversos graves. A fim de diminuir esses efeitos adversos e aumentar a concentração da medicação no segmento posterior do olho, uma possível opção é a injeção intravítrea. O objetivo do presente estudo foi avaliar a toxicidade do adalimumabe intravítreo nas diferentes doses para a retina de coelhos por meio de avaliação clínica (biomicroscopia e oftalmoscopia indireta), funcional (eletrorretinograma) e histopatológica (microscopia óptica e eletrônica). Foram utilizados 30 coelhos albinos da raça Nova Zelândia divididos em cinco grupos de seis coelhos. Injeções intravítreas foram realizadas nas seguintes concentrações de adalimumabe: 0,5mg/0,1ml, 1mg/0,1ml, 2,5mg/0,1ml, 5,0mg/0,1ml e 10mg/0,2ml e 0,1ml de solução salina balanceada (BSS) foi injetada nos olhos esquerdos dos grupos 1 e 2 para constituir o grupo controle. Foram realizadas biomicroscopia e fundoscopia e sinais de inflamação, infecção ou toxicidade foram observados durante duas semanas. O eletrorretinograma foi realizado antes do tratamento e após 14 dias da injeção intravítrea. Os animais foram sacrificados, foi feita a enucleação dos olhos, e o tecido para a avaliação histopatológica foi preparado. A injeção intravítrea de adalimumabe (Humira®) nas doses estudadas até 5mg (0,5mg, 1,0mg, 2,5mg, 5mg) não apresentou sinais clínicos, eletrorretinográficos e histopatológicos de toxicidade para a retina de coelhos a curto prazo. No grupo de 10mg, foram observados sinais inflamatórios leves em três dos seis olhos e houve diminuição da amplitude da onda a na resposta fotópica do ERG, não foram observadas alterações na microscopia óptica / Adalimumab is a fully human anti-TNF alpha monoclonal antibody consisting of 100% human sequences developed using phage display technology. It is currently FDA approved for the treatment of rheumatoid arthritis, ankylosing spondylitis, Crohns disease, moderate to severe chronic psoriasis, and juvenile idiopathic arthritis. Anti-TNF alpha drugs may be an effective therapy for cystoid macular edema associated with uveitis. Significant improvements in chronic diabetic macular edema and regression of CNV from AMD have also been documented in small published series after systemic treatment with TNF-alpha antagonists. However the systemic administration of these drugs can have serious side effects. Intravitreous injection would assure delivery of high concentrations of medication at the posterior segment with minimum side effects.The aim of this study was to evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira®) in the rabbit eye. Thirty New Zealand albino rabbits received intravitreous injections of 0.1ml of adalimumab 0.5 mg (6 eyes), 1mg (6 eyes), 2.5mg (6 eyes), 5mg (6 eyes) and 0.2ml was injected in the10mg (6 eyes) group. BSS (0,1ml) was injected in the left eye of the rabbits from the groups 1 and 2 to serve as control group. Slit lamp biomicroscopy, fundoscopy were carried out at baseline, day 7 and 14 following intravitreous injection while electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14 and histopathological examination of the eyes was performed. The tested doses of intravitreous adalimumab up to 5mg (0.5mg, 1.0mg, 2.5mg, 5mg) had no associated ocular short-term toxicity in rabbit eyes. The 10mg group showed mild inflammatory reaction in 3 out of 6 eyes and showed decrease in the a wave amplitude in the photopic response, light microscopy was normal

No description available.