A hospital based cross-sectional study to assess various types of non-glaucomatous optic neuropathies

Abstract

Purpose: There is paucity of data on nonglaucomatous optic neuropathy (NGON) from low and middle income countries (LMIC). This study was conducted with a purpose to collect a variety of NGON in the adult population, that presented at a tertiary level eye care center in Nepal. Method: This was a hospital based cross-sectional study conducted between June 2016 - December 2016. All adult patients diagnosed with NGON were included. A detailed history taking was done followed by, best corrected visual acuity testing, pupillary examination, color vision, contrast sensitivity, slit-lamp bio-microscopy and fundus evaluation under mydriasis. Visual field examination and brain/orbit imaging were performed according to necessity of the cases. Data were analysed using IBM-SPSS version 20. Results: There were altogether 130 patients with NGON, but only 117 cases that had adequate data to make a diagnosis were included into our study. The total number of eyes with NGON in our study were 166. Commonest diagnosis was non-arteritic ischemic optic neuropathy (45/117) and other common causes were traumatic optic neuropathy (16/117) and optic neuritis (11/117) subsequently. Alcohol induced optic neuropathy (3/117) and leber hereditary optic neuropathy (5/117) were also suspected. They were diagnosed on the basis of most relevant clinical findings and exclusion of other causes. Two cases of pregnancy induced pituitary apoplexy were also diagnosed. Patients with inadequate evidence to make a diagnosis were grouped as; bilateral disc edema (2), unilateral optic atrophy (2) and papilledema (19). Conclusion: The emerging burden of NGON in LMIC could not be neglected. Further research is necessary to understand the causative factors for underdiagnosis of NGON in LMIC.