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.

Cupped disc with normal intraocular pressure: The long road to avoid misdiagnosis.

We present a series of six patients who had been receiving treatment for normal tension glaucoma (NTG; five patients) or primary open angle glaucoma (one patient). All of them were found to have optic neuropathy secondary to compression of the anterior visual pathway. Even though uncommon, compression of the anterior visual pathway is an important differential diagnosis of NTG. Diagnosis of NTG should be by exclusion. Here the possible causes of misdiagnosis are discussed. We present an approach to distinguish glaucomatous from nonglaucomatous optic neuropathy. The article also emphasizes how important it is for the clinicians to consider the total clinical picture, and not merely the optic disc morphology, to avoid the mismanagement of glaucoma, especially the NTG.

Comparison of Retinal Nerve Fiber Layer Thickness between Stratus and Spectralis OCT

PURPOSE: To compare the peripapillary retinal nerve fiber layer (RNFL) thickness of normal patients and those with various glaucoma diseases by time domain (Stratus) and spectral domain (Spectralis) optical coherence tomography (OCT). METHODS: The RNFL thickness as measured by the Stratus and Spectral OCT was compared (paired t-test). The relationship and agreement of RNFL thickness between the two OCT modalities were evaluated by Pearson correlation, Bland-Altman plot, and area under the receiver operating characteristic curve. RESULTS: Two-hundred seventeen eyes of 217 patients, including twenty-four normal eyes, ninety-one glaucoma suspects, seventy-six normal tension glaucoma cases, and twenty-six primary open angle glaucoma cases (POAG) were analyzed. The peripapillary RNFL thicknesses as measured by Stratus OCT were significantly greater than those measured by Spectralis OCT. However, in quadrant comparisons, the temporal RNFL thickness obtained using Stratus OCT were significantly less than those obtained using Spectralis OCT. Correlations between RNFL parameters were strong (Pearson correlation coefficient for mean RNFL thickness = 0.88); a high degree of correlation was found in the POAG group. Bland-Altman plotting demonstrated that agreement in the temporal quadrant was greater than any other quadrant. CONCLUSIONS: Both OCT systems were highly correlated and demonstrated strong agreement. However, absolute measurements of peripapillary RNFL thickness differed between Stratus OCT and Spectralis OCT. Thus, measurements with these instruments should not be considered interchangeable. The temporal quadrant was the only sector where RNFL thickness as measured by Spectralis OCT was greater than by Stratus OCT; this demonstrated greater agreement than other sectors.