Estudo do comportamento da PIO de 24 horas e frequência de glaucoma em pacientes com síndrome da apnéia obstrutiva do sono

Purpose: To determine the frequency of glaucoma and evaluate the behavior of 24-hour intraocular pressure in patients with the obstructive sleep apnea syndrome (OSAS). Methods: Eleven consecutive patients with OSAS, diagnosed by polysonography, were avaliated in a cross-sectional study. Demographic data were analyzed: age, sex, race/color, weight, height and associated diseases. The patients were submitted to complete ophthalmologic examination, including the visual field, as well as to 24-hour intra-ocular pressure (IOP) evaluation by an applanation tonometer at 9h, 12h, 15h, 18h, 24h and 6h in the lying and sitting positions. The diagnostic criterion for glaucoma was alteration of the visual field (VF) compatible with glaucoma and one or more of the following alterations: cup-disc ratio >= 0.7, hemorrhage, wedge-shaped defect, bayonet-shaped vessels, Hoyt's sign, asymmetry > than 0.2 between cup/disc ratio of the eyes. The angle should be opened without alterations. Results: 9 (82%) of 11 patients showed glaucoma or were suspected to have glaucoma, 9% of which exhibited normal tension glaucoma and 73% were suspected to have glaucoma for presenting alterations in the optic nerve or ocular hypertension. The mean for the IOP values of the 11 patients was observed to be the highest at 6 o'clock, when they were lying down. Variations of IOP >= 5 mmHg occurred in 7 (64%) of the patients, and variations of up to 14 mmHg and IOP peaks of up to 32 mmHg were observed. Conclusion: OSAS may be an important risk factor for the development of glaucoma, particularly that of normal tension glaucoma. Patients with OSAS must be referred to an ophthalmologist and those professionals must be attentive to the association of sleep disorders in patients with open-angle glaucoma.

Conjunctival inflammation in patients under topical glaucoma treatment with indication to surgery

PURPOSE: To compare the frequency of conjunctival HLA-DR expression (a surrogate marker for inflammation) in eyes treated with topical prostaglandin analogues versus eyes treated with other topical antiglaucomatous drugs. METHODS: Patients diagnosed with primary open-angle glaucoma presenting indication for trabeculectomy were divided in groups according to the use or not of prostaglandin analogues. All subjects were treated with the maximum tolerated dose of antiglaucomatous drugs until the date of the surgery. At the beginning of the surgical procedure, a 5 x 5 mm biopsy of the bulbar conjunctiva was collected, incubated with monoclonal anti-HLA-DR antibody and processed for histological analysis. RESULTS: Of the 31 eyes included (31 patients), 25 were under topical prostaglandin analogues (Group 1) and six under other topical pharmacological agents (Group 2). Fourteen eyes of Group 1 (56%) and three of Group 2 (50 %) were positive for the inflammatory marker HLA-DR (P=1.0). The percentage of stained cells ranged from 15.49 to 48.09% (median: 27.61) in Group 1, and from 18.35 to 28 (median: 20.71) in Group 2, with no differences statistically significant (p=0.33). CONCLUSION: The use of prostaglandin analogues did not increase conjunctival expression of HLA-DR compared to other topical antiglaucomatous agents.

Cirurgia de catarata e glaucoma

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Picos de pressão intra-ocular: comparação entre curva tensional diária, minicurva e medida da pressão intra-ocular às 6 horas

INTRODUÇÃO: A pressão intra-ocular (Po) é o fator de risco isolado mais importante para o desenvolvimento do glaucoma primário de ângulo aberto (GPAA). O controle da Po é o objetivo principal da terapia antiglaucomatosa até o momento. A curva tensional diária (CTD) é de grande importância para o diagnóstico e seguimento do glaucoma primário de ângulo aberto. Métodos simplificados como a minicurva têm sido utilizados em seu lugar por serem mais práticos. OBJETIVO: Comparar curva tensional diária, minicurva e medida isolada às 6 horas quanto à detecção de picos pressóricos e verificar a influência da variação postural na medida das 6 horas da manhã. MÉTODOS: Sessenta e quatro pacientes (126 olhos) com glaucoma primário de ângulo aberto ou suspeita de glaucoma foram submetidos à curva tensional diária. A minicurva considerou as medidas das 9, 12, 15 e 18 horas da mesma curva tensional diária. A medida das 6 horas foi realizada no escuro, com o paciente deitado, utilizando o tonômetro de Perkins. Logo após, foi feita nova medida, com o paciente sentado, usando o tonômetro de Goldmann. A Po média e a ocorrência de picos (Po > 21 mmHg) da curva tensional diária e minicurva foram comparados, assim como o horário de ocorrência dos picos. RESULTADOS: A Po média foi maior no glaucoma primário de ângulo aberto do que nos suspeitos tanto na minicurva como na curva tensional diária Quando comparadas, a curva tensional diária apresentou médias de Po maiores que a minicurva. A medida das 6 horas foi maior quando feita com o paciente deitado. A minicurva não detectou 60,42% dos picos nos pacientes com glaucoma primário de ângulo aberto e 88,24% dos picos nos suspeitos. CONCLUSÃO: 1. A curva tensional diária detectou mais picos pressóricos do que a minicurva; 2. A média de Po das 6 horas foi maior com o paciente deitado; 3. A Po das 6 horas com o paciente deitado foi maior do que a Po média da curva tensional diária e da minicurva.

Nerve fiber layer in glaucomatous hemifield loss: a case-control study with time- and spectral-domain optical coherence tomography

Purpose: To evaluate the retinal nerve fiber layer measurements with time-domain (TD) and spectral-domain (SD) optical coherence tomography (OCT), and to test the diagnostic ability of both technologies in glaucomatous patients with asymmetric visual hemifield loss. Methods: 36 patients with primary open-angle glaucoma with visual field loss in one hemifield (affected) and absent loss in the other (non-affected), and 36 age-matched healthy controls had the study eye imaged with Stratus-OCT (Carl Zeiss Meditec Inc., Dublin, California, USA) and 3 D OCT-1000 (Topcon, Tokyo, Japan). Peripapillary retinal nerve fiber layer measurements and normative classification were recorded. Total deviation values were averaged in each hemifield (hemifield mean deviation) for each subject. Visual field and retinal nerve fiber layer "asymmetry indexes" were calculated as the ratio between affected versus non-affected hemifields and corresponding hemiretinas. Results: Retinal nerve fiber layer measurements in non-affected hemifields (mean [SD] 87.0 [17.1] mu m and 84.3 [20.2] mu m, for TD and SD-OCT, respectively) were thinner than in controls (119.0 [12.2] mu m and 117.0 [17.7] mu m, P<0.001). The optical coherence tomography normative database classified 42% and 67% of hemiretinas corresponding to non-affected hemifields as abnormal in TD and SD-OCT, respectively (P=0.01). Retinal nerve fiber layer measurements were consistently thicker with TD compared to SD-OCT. Retinal nerve fiber layer thickness asymmetry index was similar in TD (0.76 [0.17]) and SD-OCT (0.79 [0.12]) and significantly greater than the visual field asymmetry index (0.36 [0.20], P<0.001). Conclusions: Normal hemifields of glaucoma patients had thinner retinal nerve fiber layer than healthy eyes, as measured by TD and SD-OCT. Retinal nerve fiber layer measurements were thicker with TD than SD-OCT. SD-OCT detected abnormal retinal nerve fiber layer thickness more often than TD-OCT.

Efeito da brimonidina na circulação retrobulbar em pacientes com glaucoma: estudo com Doppler colorido

Objetivo: Avaliar o efeito do tartarato de brimonidina a 0,2% tópico, instilado de 12/12 horas, na circulação retrobulbar em pacientes portadores de glaucoma. Métodos: Foram estudados os 2 olhos de 16 pacientes portadores de glaucoma primário de ângulo aberto e glaucoma crônico de ângulo estreito com iridotomia. Usando o Doppler colorido foram avaliados: velocidade sistólica máxima, velocidade diastólica final e índice de resistência das artéria central da retina, artéria ciliar posterior curta temporal e artéria oftálmica. As avaliações foram feitas antes e depois do uso da brimonidina. Resultados: O tartarato de brimonidina a 0,2% aumentou significativamente a velocidade sistólica máxima (28,24 para 34,23 cm/seg) e velocidade diastólica final (6,62 para 8,10 cm/seg) no olho direito e reduziu o índice de resistência (0,75 para 0,71) no olho esquerdo da artéria oftálmica. Conclusão: O tartarato de brimonidina 0,2% 2x/dia aumentou significativamente a velocidade sistólica máxima e velocidade diastólica final e reduziu índice de resistência da artéria oftálmica de pacientes glaucomatosos. Este efeito sugere que a brimonidina pode beneficiar pacientes glaucomatosos com insuficiência vascular na cabeça do nervo óptico.

Alterações morfométricas do endotélio corneano no glaucoma pseudoesfoliativo

Introdução: Com este trabalho pretende-se analisar a morfometria das células endoteliais corneanas e espessura central da córnea em doentes com glaucoma pseudoesfoliativo (GPX) e glaucoma primário de ângulo aberto (GPAA). Materiais e Métodos: Estudo retrospectivo com 40 doentes. Os parâmetros avaliados, através de microscopia especular, foram: densidade de células endoteliais, coeficiente de variação, percentagem de células hexagonais e espessura central da córnea. Resultados e Conclusões: Não se verificaram diferenças estatisticamente significativas no que diz respeito à densidade e coeficiente de variação das células endoteliais corneanas entre o grupo com GPX e GPAA. Contudo, a percentagem de células hexagonais foi significativamente inferior no GPX, o que poderá constituir um indício de alguma disfunção endotelial.Em relação à espessura central da córnea, verificou-se uma diminuição estatisticamente significativa no grupo GPX. Assim, no glaucoma pseudoesfolitaivo a presença de material fibrilhar na câmara anterior pode contribuir para alterações nas células endoteliais mais rápidas do que seria espectável e em alterações estruturais que se reflectem na menor espessura central da córnea.

Pico e flutuação da pressão intra-ocular: comparação entre curva tensional diária e teste de sobrecarga hídrica e comparação entre 2 testes de sobrecarga hídrica em horários diferentes

Pós-graduação em Bases Gerais da Cirurgia - FMB

Macrodisco y glaucoma en individuos estudiados con tomografía óptica coherente

Introducción: El glaucoma representa la tercera causa de ceguera a nivel mundial y un diagnóstico oportuno requiere evaluar la excavación del nervio óptico que está relacionada con el área del mismo. Existen reportes de áreas grandes (macrodiscos) que pueden ser protectoras, mientras otros las asocian a susceptibilidad para glaucoma. Objetivo: Establecer si existe asociación entre macrodisco y glaucoma en individuos estudiados con Tomografía Optica Coherente (OCT ) en la Fundación Oftalmológica Nacional. Métodos: Estudio transversal de asociación que incluyó 25 ojos con glaucoma primario de ángulo abierto y 74 ojos sanos. A cada individuo se realizó examen oftalmológico, campo visual computarizado y OCT de nervio óptico. Se compararon por grupos áreas de disco óptico y número de macrodiscos, definidos según Jonas como un área de la media más dos desviaciones estándar y según Adabache como área ≥3.03 mm2 quien evaluó población Mexicana. Resultados: El área promedio de disco óptico fue 2,78 y 2,80 mm2 glaucoma Vs. sanos. De acuerdo al criterio de Jonas, se observó un macrodisco en el grupo sanos y según criterio de Adabache se encontraron ocho y veinticinco macrodiscos glaucoma Vs. sanos. (OR=0,92 IC95%=0.35 – 2.43). Discusión: No hubo diferencia significativa (P=0.870) en el área de disco entre los dos grupos y el porcentaje de macrodiscos para los dos grupos fue similar, aunque el bajo número de éstos no permitió concluir en términos estadísticos sobre la presencia de macrodisco y glaucoma.

Desenvolvimento de um rastreador solar do tipo polar com ajuste do ângulo de inclinação

The use of solar energy for electricity generation has shown a growing interest in recent years. Generally, the conversion of solar energy into electricity is made by PV modules installed on fixed structures, with slope determined by the latitude of the installation site. In this sense, the use of mobile structures with solar tracking, has enabled increased production of the generated energy. However, the performance of these structures depends on the type of tracker and the position control used. In this work, it is proposed position control a strategy applied for a solar tracker, which will be installed in Laboratory of Power Electronics and Renewable Energy (LEPER), located in the Federal University of Rio Grande do Norte (UFRN). The tracker system is of polar type with daily positioning east-west and tilt angle manual adjustment in the seasonal periods, from north to south

Controlador adaptativo por modelo de referência e estrutura variável aplicado ao controle de ângulo de carga e fluxo de campo de um gerador síncrono

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Ativador elástico aberto de Klammt no tratamento da má oclusão de classe II divisão 1

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Combining ganglion cell topology and data of patients with glaucoma to determine a structure-function map

PURPOSE: To introduce techniques for deriving a map that relates visual field locations to optic nerve head (ONH) sectors and to use the techniques to derive a map relating Medmont perimetric data to data from the Heidelberg Retinal Tomograph. METHODS: Spearman correlation coefficients were calculated relating each visual field location (Medmont M700) to rim area and volume measures for 10 degrees ONH sectors (HRT III software) for 57 participants: 34 with glaucoma, 18 with suspected glaucoma, and 5 with ocular hypertension. Correlations were constrained to be anatomically plausible with a computational model of the axon growth of retinal ganglion cells (Algorithm GROW). GROW generated a map relating field locations to sectors of the ONH. The sector with the maximum statistically significant (P < 0.05) correlation coefficient within 40 degrees of the angle predicted by GROW for each location was computed. Before correlation, both functional and structural data were normalized by either normative data or the fellow eye in each participant. RESULTS: The model of axon growth produced a 24-2 map that is qualitatively similar to existing maps derived from empiric data. When GROW was used in conjunction with normative data, 31% of field locations exhibited a statistically significant relationship. This significance increased to 67% (z-test, z = 4.84; P < 0.001) when both field and rim area data were normalized with the fellow eye. CONCLUSIONS: A computational model of axon growth and normalizing data by the fellow eye can assist in constructing an anatomically plausible map connecting visual field data and sectoral ONH data.

Contrast sensitivity changes due to glaucoma and normal aging: low-spatial-frequency losses in both magnocellular and parvocellular pathways

PURPOSE: To explore the effects of glaucoma and aging on low-spatial-frequency contrast sensitivity by using tests designed to assess performance of either the magnocellular (M) or parvocellular (P) visual pathways. METHODS: Contrast sensitivity was measured for spatial frequencies of 0.25 to 2 cyc/deg by using a published steady- and pulsed-pedestal approach. Sixteen patients with glaucoma and 16 approximately age-matched control subjects participated. Patients with glaucoma were tested foveally and at two midperipheral locations: (1) an area of early visual field loss, and (2) an area of normal visual field. Control subjects were assessed in matched locations. An additional group of 12 younger control subjects (aged 20-35 years) were also tested. RESULTS: Older control subjects demonstrated reduced sensitivity relative to the younger group for the steady (presumed M)- and pulsed (presumed P)-pedestal conditions. Sensitivity was reduced foveally and in the midperiphery across the spatial frequency range. In the area of early visual field loss, the glaucoma group demonstrated further sensitivity reduction relative to older control subjects across the spatial frequency range for both the steady- and pulsed-pedestal tasks. Sensitivity was also reduced in the midperipheral location of "normal" visual field for the pulsed condition. CONCLUSIONS: Normal aging results in a reduction of contrast sensitivity for the low-spatial-frequency-sensitive components of both the M and P pathways. Glaucoma results in a further reduction of sensitivity that is not selective for M or P function. The low-spatial-frequency-sensitive channels of both pathways, which are presumably mediated by cells with larger receptive fields, are approximately equivalently impaired in early glaucoma.