Study Subjects

A total of 94 unrelated native Spanish patients diagnosed with NAION and 204 healthy controls recruited at Fernández-Vega Ophthalmological Institute, Oviedo, Spain were included in the present case-control study. Control subjects were selected from patients undergoing cataract surgery without history or clinical evidence of ischemic optic neuropathy. Complete ophthalmic examinations were performed for both patients and controls, who were also subjected to a detailed interview aimed at collecting the presence of risk factors, including arterial hypertension, dyslipidemia, and DM, as well as their clinical history of heart and vascular diseases.

NAION patients were diagnosed at Fernández-Vega Ophthalmological Institute by visual field examination, determination of nerve fiber layer thickness by optical coherence tomography, visual acuity, evoked potentials, examination of the papilla with identification of the edematous stages with or without peripapillary hemorrhages evolving to optic nerve atrophy, and papillary pallor. Finally, a complete neurological study including magnetic resonance imaging was carried out. Exclusion criteria for patients and controls included any history of ocular vascular disease such as retinal vein occlusion or retinal artery occlusion. The demographic characteristics of the NAION patients and control subjects are shown in Table ​Table11

Demographic characteristics of the recruited NAION patients and control subjects

Values are presented as n (%), mean ± standard deviation, or range. NAION, nonarteritic anterior ischemic optic neuropathy.

Given that the clinical factors hypertension, dyslipidemia, DM, heart diseases (including coronary heart disease, arrhythmias, atrial fibrillation, and hypertensive heart disease), and cerebrovascular disease are influenced by sex and age, we performed our association study using 72 patients with NAION and 72 sex- and age-matched controls. The remaining 22 NAION subjects were excluded from this specific analysis owing to lack of appropriate controls to perform matching. When more than one control had the sex and age appropriate for matching with a specific NAION patient, the first one who came to the ophthalmologic examination was included. No characteristic or condition of the individuals other than sex or age was considered for pairing. The demographics and clinical characteristics of the sex- and age-matched NAION and control groups are reported in Table ​Table22

Demographic and clinical characteristics of the sex- and age-matched NAION patients and controls

Values are presented as n (%), mean ± standard deviation, or range. NAION, nonarteritic anterior ischemic optic neuropathy.