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.

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

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.

Influência da idade no comportamento da pressão intraocular em uma população da região Sul-brasileira

OBJETIVO: Verificar influência da idade no comportamento da pressão intraocular (PIO) em população acima de 40 anos. MÉTODOS: Neste estudo observacional transversal realizado no município de Piraquara - PR, a PIO foi aferida através da tonometria de Goldmann. Todos os indivíduos foram submetidos a exame de triagem, sendo os suspeitos de glaucoma ou hipertensão ocular encaminhados ao atendimento de retorno para realização de exame oftalmológico completo. Para fins de análise estatística, os pacientes foram divididos em grupos etários (40-49; 50-59; 60-69 e acima de 70 anos). Posteriormente todos os pacientes portadores de glaucoma ou suspeita, hipertensão arterial sistêmica (HAS) ou Diabetes mellitus (DM) foram excluídos. RESULTADOS: Avaliaram-se 3360 indivíduos com média de idade de 54,04 ± 10,52 anos, sendo 59,79% do sexo feminino. Não se observou diferença estatisticamente significativa entre a média da PIO nos diferentes grupos etários (p=0,19; teste ANOVA). da mesma forma, não foi observada correlação significativa entre a PIO e a idade (p = 0,11; correlação linear de Pearson). Após exclusão dos indivíduos portadores de HAS (1671), DM (n=360), glaucoma ou suspeita de glaucoma (n=161) não se observou diferença estatisticamente significativa entre a média da PIO e a idade (p=0,17; teste ANOVA). No entanto, uma fraca correlação negativa, porém significativa, foi encontrada entre PIO e idade (p=0,03; R=-0,055, correlação linear Pearson). CONCLUSÃO: Na presente amostra, não foi observada influência significativa da idade na PIO, entretanto, após a exclusão de indivíduos com glaucoma, HAS e DM, observou-se uma fraca correlação linear negativa e significativa entre as duas variáveis.

Efeitos do citrato de sildenafila sobre a neuroproteção na neuropatia óptica, em ratos (Lewis/SsNHsd) com glaucoma agudo

Pós-graduação em Cirurgia Veterinária - FCAV

Cirurgia de catarata e glaucoma

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

Efeito de drogas utilizadas no tratamento de hipertensão arterial sistêmica sobre a pressão intra-ocular: Estudo experimental no cão

Purpose: To study the effects of two drugs (captopril and propranolol) used in the treatment of systemic hypertension, on the intraocular pressure (IOP) of anesthetized dogs. Methods: 24 dogs, divided into 3 groups of 8 each. In the first group, 1.5 mg/kg IV of captopril (an angiotensin converting enzyme inhibitor) was administered. In the second group, 1.5 mg/kg IV of propranolol (a beta-blocker) was administered. The third group was the control. IOP and blood pressure (BP) were measured by manometry. The perfusion pressure was calculated by the difference between BP and IOP (BP-IOP). The parameters were studied at 6 moments (0, 10, 30, 60, 90 and 120 minutes). Results: There was significant reduction of IOP (p<0.05) with captopril and propranolol, without difference between the drugs. With captopril the BP and PP decreased markedly at 10 and 30 minutes. With propranolol there was no reduction of BP or PP. Conclusions: Captopril and propranolol reduced IOP. However, the marked reduction of BP, and consequently of PP caused by captopril may be undesirable for irrigation of the optic nerve.

Cistinose : a propósito de uma doença renal de longa evolução com repercussões sobre o globo ocular

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

Peripheral ocular monochromatic aberrations

Aberrations affect image quality of the eye away from the line of sight as well as along it. High amounts of lower order aberrations are found in the peripheral visual field and higher order aberrations change away from the centre of the visual field. Peripheral resolution is poorer than that in central vision, but peripheral vision is important for movement and detection tasks (for example driving) which are adversely affected by poor peripheral image quality. Any physiological process or intervention that affects axial image quality will affect peripheral image quality as well. The aim of this study was to investigate the effects of accommodation, myopia, age, and refractive interventions of orthokeratology, laser in situ keratomileusis and intraocular lens implantation on the peripheral aberrations of the eye. This is the first systematic investigation of peripheral aberrations in a variety of subject groups. Peripheral aberrations can be measured either by rotating a measuring instrument relative to the eye or rotating the eye relative to the instrument. I used the latter as it is much easier to do. To rule out effects of eye rotation on peripheral aberrations, I investigated the effects of eye rotation on axial and peripheral cycloplegic refraction using an open field autorefractor. For axial refraction, the subjects fixated at a target straight ahead, while their heads were rotated by ±30º with a compensatory eye rotation to view the target. For peripheral refraction, the subjects rotated their eyes to fixate on targets out to ±34° along the horizontal visual field, followed by measurements in which they rotated their heads such that the eyes stayed in the primary position relative to the head while fixating at the peripheral targets. Oblique viewing did not affect axial or peripheral refraction. Therefore it is not critical, within the range of viewing angles studied, if axial and peripheral refractions are measured with rotation of the eye relative to the instrument or rotation of the instrument relative to the eye. Peripheral aberrations were measured using a commercial Hartmann-Shack aberrometer. A number of hardware and software changes were made. The 1.4 mm range limiting aperture was replaced by a larger aperture (2.5 mm) to ensure all the light from peripheral parts of the pupil reached the instrument detector even when aberrations were high such as those occur in peripheral vision. The power of the super luminescent diode source was increased to improve detection of spots passing through the peripheral pupil. A beam splitter was placed between the subjects and the aberrometer, through which they viewed an array of targets on a wall or projected on a screen in a 6 row x 7 column matrix of points covering a visual field of 42 x 32. In peripheral vision, the pupil of the eye appears elliptical rather than circular; data were analysed off-line using custom software to determine peripheral aberrations. All analyses in the study were conducted for 5.0 mm pupils. Influence of accommodation on peripheral aberrations was investigated in young emmetropic subjects by presenting fixation targets at 25 cm and 3 m (4.0 D and 0.3 D accommodative demands, respectively). Increase in accommodation did not affect the patterns of any aberrations across the field, but there was overall negative shift in spherical aberration across the visual field of 0.10 ± 0.01m. Subsequent studies were conducted with the targets at a 1.2 m distance. Young emmetropes, young myopes and older emmetropes exhibited similar patterns of astigmatism and coma across the visual field. However, the rate of change of coma across the field was higher in young myopes than young emmetropes and was highest in older emmetropes amongst the three groups. Spherical aberration showed an overall decrease in myopes and increase in older emmetropes across the field, as compared to young emmetropes. Orthokeratology, spherical IOL implantation and LASIK altered peripheral higher order aberrations considerably, especially spherical aberration. Spherical IOL implantation resulted in an overall increase in spherical aberration across the field. Orthokeratology and LASIK reversed the direction of change in coma across the field. Orthokeratology corrected peripheral relative hypermetropia through correcting myopia in the central visual field. Theoretical ray tracing demonstrated that changes in aberrations due to orthokeratology and LASIK can be explained by the induced changes in radius of curvature and asphericity of the cornea. This investigation has shown that peripheral aberrations can be measured with reasonable accuracy with eye rotation relative to the instrument. Peripheral aberrations are affected by accommodation, myopia, age, orthokeratology, spherical intraocular lens implantation and laser in situ keratomileusis. These factors affect the magnitudes and patterns of most aberrations considerably (especially coma and spherical aberration) across the studied visual field. The changes in aberrations across the field may influence peripheral detection and motion perception. However, further research is required to investigate how the changes in aberrations influence peripheral detection and motion perception and consequently peripheral vision task performance.

Eyelid pressure and contact with the ocular surface

Purpose To investigate static upper eyelid pressure and contact with the ocular surface in a group of young adult subjects. Methods Static upper eyelid pressure was measured for 11 subjects using a piezoresistive pressure sensor attached to a rigid contact lens. Measures of eyelid pressure were derived from an active pressure cell (1.14 mm square) beneath the central upper eyelid margin. To investigate the contact region between the upper eyelid and ocular surface, we used pressure sensitive paper and the lissamine-green staining of Marx’s line. These measures combined with the pressure sensor readings were used to derive estimates of eyelid pressure. Results The mean contact width between the eyelids and ocular surface estimated using pressure sensitive paper was 0.60 ± 0.16 mm, while the mean width of Marx’s line was 0.09 ± 0.02 mm. The mean central upper eyelid pressure was calculated to be 3.8 ± 0.7 mmHg (assuming that the whole pressure cell was loaded), 8.0 ± 3.4 mmHg (derived using the pressure sensitive paper imprint widths) and 55 ± 26 mmHg (based on contact widths equivalent to Marx’s line). Conclusions The pressure sensitive paper measurements suggest that a band of the eyelid margin, significantly larger than the anatomical zone of the eyelid margin known as Marx’s line, has primary contact with the ocular surface. Using these measurements as the contact between the eyelid margin and ocular surface, we believe that the mean pressure of 8.0 ± 3.4 mmHg is the most reliable estimate of static upper eyelid pressure.

Describing ocular aberrations with wavefront vergence maps

A common optometric problem is to specify the eye’s ocular aberrations in terms of Zernike coefficients and to reduce that specification to a prescription for the optimum sphero-cylindrical correcting lens. The typical approach is first to reconstruct wavefront phase errors from measurements of wavefront slopes obtained by a wavefront aberrometer. This paper applies a new method to this clinical problem that does not require wavefront reconstruction. Instead, we base our analysis of axial wavefront vergence as inferred directly from wavefront slopes. The result is a wavefront vergence map that is similar to the axial power maps in corneal topography and hence has a potential to be favoured by clinicians. We use our new set of orthogonal Zernike slope polynomials to systematically analyse details of the vergence map analogous to Zernike analysis of wavefront maps. The result is a vector of slope coefficients that describe fundamental aberration components. Three different methods for reducing slope coefficients to a spherocylindrical prescription in power vector forms are compared and contrasted. When the original wavefront contains only second order aberrations, the vergence map is a function of meridian only and the power vectors from all three methods are identical. The differences in the methods begin to appear as we include higher order aberrations, in which case the wavefront vergence map is more complicated. Finally, we discuss the advantages and limitations of vergence map representation of ocular aberrations.