Internal carotid artery aneurysm mimicking normal-tension glaucoma / Aneurisma de carótida interna simulando glaucoma de pressão normal

ABSTRACT Differentiating glaucomatous from nonglaucomatous optic disc cupping remains challenging. We present a case of a 48-year-old woman with an internal carotid aneurysm of approximately 3.5 mm × 6.5 mm that mimicked normal-tension glaucoma. The patient had a 2-year history of low vision acuity in her left eye and frontal oppressive headache. Owing to the carotid aneurysm, she developed an asymmetric vertical cup-to-disc ratio above 0.2, and marked inferotemporal neuronal rim loss and pallor of the residual rim were noted in the left disc. She also developed a visual field defect with an arcuate scotoma in the left eye. The patient was referred to a neurosurgeon and underwent endovascular aneurysm occlusion. This case highlights the diagnostic importance of recognizing that many neurological defects remain underdiagnosed.

RESUMO diferenciação de escavações glaucomatosas e não glaucomatosas ainda permanece um desafio ainda nos dias de hoje. Nos descrevemos um caso de aneurisma de carótida interna medindo 3.5mm x 6.5mm que simulava um glaucoma de pressão normal. O caso é sobre uma paciente feminino de 48 anos com história de 2 anos de baixa acuidade visual no olho esquerdo e cefaléia frontal. Devido ao aneurisma de carótida a paciente desenvolveu uma assimetria de escavação vertical maior que 0.2 no olho esquerdo em relação ao direito com defeito localizado da camada de fibras nervosas temporal inferior. Ela também apresentava um defeito arqueado temporal superior a esquerda, cruzando a linha média vertical consistente. Após o diagnostico confirmado pela ressonância magnética funcional, a paciente foi enviada para o neurocirurgião para realização de uma oclusão endovascular do aneurisma. Esse caso nos alerta da importância de se lembrar que não apenas o glaucoma gera escavações suspeitas no disco óptico e que ainda muitos defeitos por causas neurológicas são subdiagnosticados.

Normal-tension glaucoma: an update / Glaucoma de pressão normal: atualização

ABSTRACT Normal-tension glaucoma (NTG) is a progressive optic neuropathy with intraocular pressure (IOP) within the statistically normal range (≤21 mmHg). The prevalence of NTG varies widely among different population studies, being the most prevalent open-angle glaucoma subtype in some reports. The etiology of NTG possibly is multifactorial and still not well defined. Alternative treatments have been proposed based on pathogenesis details. However, in clinical practice, adequate reduction of IOP remains the keystone of managing patients with NTG. We review the pathogenesis of NTG and the available therapies for this optic neuropathy.

RESUMO O glaucoma de pressão normal (GPN) é uma neuropatia óptica progressiva que cursa com a pressão intraocular (PIO) dentro da faixa de normalidade (≤21 mmHg). A prevalência do glaucoma de pressão normal varia entre os estudos populacionais, sendo em alguns o principal subtipo de glaucoma primário de ângulo aberto. A etiologia do glaucoma de pressão normal possivelmente é multifatorial e ainda não foi totalmente esclarecida. Tratamentos alternativos baseados nos diferentes detalhes da patogenia foram recentemente propostos. Entretanto, na prática clínica, a redução adequada da pressão intraocular continua sendo a base do tratamento do glaucoma de pressão normal. O objetivo deste artigo é revisar a patogênese do glaucoma de pressão normal e as formas de terapia disponíveis.

Depth and Area of Retinal Nerve Fiber Layer Damage and Visual Field Correlation Analysis

PURPOSE: To evaluate the relationship between the structural damage as assessed by time-domain optical coherence tomography (OCT) and functional changes in glaucoma. METHODS: In total, 190 patients with normal tension glaucoma or primary open angle glaucoma were included in this study. The thickness of retinal nerve fiber layer (RNFL) around the optic disc and the area of RNFL defect were determined using OCT scans. The relationships between the RNFL thickness or area of the defect and visual field (VF) indices were assessed using the Lowess function, regression analysis and partial Spearman correlation. The differences between these associations depending on the stage of VF damage were further analyzed. Age, optic disc size, refraction, central corneal thickness and the presence of systemic disease were corrected for in order to exclude confounding factors. RESULTS: A logarithmic scale of RNFL thickness showed a negative linear relationship with VF indices. The area of the RNFL defect showed a weak correlation with the pattern of standard deviation, whereas the remnant RNFL thickness was moderately correlated with the pattern of standard deviation (partial Spearman correlation coefficient, 0.39, -0.47, respectively; p < 0.0001). Many outliers were detected in the Lowess-plotted graphs. Multiplication of the area and the inverted RNFL thickness showed a moderately correlated logarithmic relationship with the VF indices (partial Spearman correlation coefficient, 0.46; 95% confidence interval, 0.34 to 0.57; p < 0.0001). In the severe stage of VF damage, correlation between the area of the RNFL defect and mean deviation was significantly greater than in other stages (partial Spearman correlation coefficient, -0.66; p = 0.02). CONCLUSIONS: The thickness of the RNFL had a negative logarithmic correlation with the VF indices and was more relevant to the VF indices than the area of the RNFL defect, as measured by OCT.

Circadian Blood Pressure and Intraocular Pressure Patterns in Normal Tension Glaucoma Patients with Undisturbed Sleep

PURPOSE: To investigate and compare the circadian pattern of blood pressure (BP), intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) while experiencing undisturbed sleep in normal-tension glaucoma (NTG) and non-glaucoma control patient groups. METHODS: Twenty-four eyes from 24 patients diagnosed with NTG and 22 eyes from 22 control group patients were enrolled. Systolic BP, diastolic BP and IOP were measured every two hours except for the period of time from 1 AM to 7 AM in the NTG group and from 11 PM to 7 AM in the control group over a one-day period. IOP and hemodynamic parameters were then compared between the two groups. NTG patients were subdivided according to the degree of morning BP dip and IOP, and hemodynamic parameters and visual field indices (mean deviation and pattern standard deviation) were also compared among these subgroups. RESULTS: There were no significant differences in mean systolic BP, mean diastolic BP and mean arterial pressure (MAP) between the NTG and the control groups. The NTG group showed a significantly large morning BP dip compared to the control group (7.1+/-4.2% vs. 3.8+/-3.4%, p=0.022). However, there were no significant differences in mean or fluctuation of MOPP between the two groups. Morning over-dippers showed significantly large MAP and MOPP fluctuations compared to non-dippers and dippers, while there were no significant differences in visual field indices among the three subgroups. CONCLUSIONS: NTG patients showed significant morning BP dips compared to the control group. The marked morning BP dip was associated with significantly large MAP or MOPP fluctuations but was not associated with visual field indices.