BackgroundToday, identified risk factors for normal-tension glaucoma (NTG) include abnormal ocular blood flow, abnormal blood coagulation, systemic hypotension, ischemic vascular disorders, and autoimmune diseases. However, pathogenesis of the condition remains unclear. On the other hand, there are also a few studies suggesting that the obstructive sleep apnea syndrome (OSAS) may compromise optic nerve head perfusion and cause glaucomatous optic neuropathy by creating transient hypoxemia and increasing vascular resistance. In this study, we evaluated the possible association between OSAS and NTG.MethodsWe recruited 24 patients with NTG and 24 age and sex matched controls who were also similar for systemic risk factors such as diabetes mellitus (DM), hypertension (HT) and hypercholesterolemia. All patients and controls underwent over-night polysomnography (PSG) for the diagnosis of OSAS and calculation of Apnea-Hypopnea Index (AHI).ResultsPatients and controls were statistically similar in terms of age, sex, gender, smoking, systemic risk factors, neck circumference and body mass index. The subjects with AHI ≥ 20 were accepted as OSAS. Ten (41.7%) of 24 patients with NTG and 3 (12.5%) of 24 controls had OSAS (p < 0.05).ConclusionsThe prevalence of OSAS was higher in patients with NTG and the difference between patient and control groups was statistically significant (p < 0.05).

The prevalence of OSAS was higher in patients with NAION, and the difference between patient and control groups was statistically significant (P < 0.05). This result supports prior series suggesting the association between NAION and OSAS.

Primary optic nerve gliomas are most commonly benign pilocytic astrocytomas (World Health Organization [WHO] Grade I) occurring in childhood and following an indolent course. Malignant optic gliomas occur in adulthood and follow an extremely aggressive course, with rapid infiltration of the chiasm, blindness, and death typically within months. A third category of optic glioma, occurring in adulthood, histopathologically benign (WHO Grade I-II) but following an aggressive course, has been rarely reported. The authors describe clinical and histopathologic features of clinically aggressive but histopathologically benign optic nerve gliomas of adulthood. Retrospective review of cases of biopsy-proven optic nerve glioma in the neuro-ophthalmology division of the Jules Stein Eye Institute from 1990 to 2011 was carried out. Cases following an aggressive course were selected for review of clinical, neuroradiologic, and histopathologic features. Three cases were selected for detailed study. Ages ranged from 31 to 45 years. All were initially diagnosed with optic nerve inflammation or benign neoplasm based on clinical and neuroradiologic features, but all suffered neuroradiologic extension and rapid deterioration of vision in the affected eye to no light perception over 3-8 weeks. Optic nerve biopsies were undertaken for the suspicion of malignancy. Features ranged from WHO Grade I (pilocytic astrocytoma, ganglioglioma) in two cases, to WHO Grade II in one case (diffuse astrocytoma, histopathologically benign, but associated with aggressive features such as high p53 [13-21%] and ). The diffuse astrocytoma case subsequently developed extensive intracranial extension suspicious for malignant transformation. These findings indicate that benign optic nerve glioma in adults may be initially misdiagnosed as inflammation, be clinically aggressive, and require excision to prevent further intracranial involvement.