Etiology of optic atrophy: a prospective observational study from Saudi Arabia

BACKGROUND: Optic atrophy (OA) represents permanent retinal ganglion cell loss warranting study to establish etiology. OBJECTIVES: To describe neurogenic causes of OA. DESIGN: Prospective, observational. SETTING: Tertiary care center, Riyadh, Saudi Arabia. PATIENTS AND METHODS: We included consecutive patients of all ages with OA caused by lesions affecting the visual pathways who were referred over a 9-month period (November 2013 to July 2014). Diagnosis was based on visual acuity, ophthalmoscopic features and ancillary tests. Patient demographics, results of a clinical examination, test data and etiology were recorded. For each cause of OA, both gender and age group were analyzed as potential risk factors using simple univariate logistic regression. OA associated with glaucoma and retinal diseases was excluded. MAIN OUTCOME MEASURE: Description of causes of OA. RESULTS: Two hundred and four patients and 353 eyes met inclusion criteria. The median age was 27 years (range 3 months-77 years; interquartile range, 27 years) among 111(54.4%) females and 93(45.6%) males, with no statistically significant difference in age of presentation between the genders. The majority of lesions were bilateral (n=151, 74%). Tumors were the most common cause, accounting for 127 (62.2%) cases. These occurred mostly in adults (72.4%) compared to the pediatric group (OR=3.3, 95% CI: 1.79–6.03; P<.001). Hereditary neoplasia (OR=5.55; 95% CI: 1.67–18.42; P=.005) and metabolic diseases (OR=17.57; 95% CI: 2.15–143.62; P=.007) were more common causes in the pediatric group. There were no significant associations between gender or visual acuity and etiology of OA. In developed nations, OA is frequently the result of ischemia and neuritis. We found many other causes, especially orbital and intracranial tumors. CONCLUSIONS: The frequency of tumors as the cause of OA may represent a higher incidence of aggressive tumors coupled with poor recognition/acknowledgement of symptoms and limited access, resulting in late presentations. LIMITATIONS: These findings may reflect bias from selective referrals to a tertiary center and may not represent all of Saudi Arabia.