: To compare optic disc size from BMO (bruch s membrain opening) between the affected eyes of patients with non-arteritic anterior ischemic optic neuropathy (NAION) and their unaffected fellow eyes and the eyes of healthy control participants.

In this cross-sectional case-control study we used Enhanced depth imaging of optical coherence tomography (EDI-OCT) to evaluate optic disc size of 25 eyes with NAION. Horizontal and vertical raster scan centered at optic disc was obtained and we measured optic disc diameter at horizontal and vertical meridian from BMO using caliper function of the device. We compared the measurements with unaffected fellow eyes, and normal control subjects.

Average horizontal optic disc size from BMO was 1760±271 µm, 1593±312 µm and 1532 ±178 µm in NAION eyes, in unaffected fellow eyes and in normal control eyes respectively. The mean of horizontal disc size was significantly greater in the NAION eyes than in the unaffected fellow eyes (P:0.005) and control eyes (P:0.001). Average vertical optic disc size from BMO in was 2003±694 µm, 1712±251 µm and 1665 ±166 µm NAION µm in NAION eyes, in unaffected eyes and in normal control eyes respectively. The mean values of vertical disc size were significantly greater in the NAION eyes than in the unaffected fellow eyes (P:0.011) and control eyes (P:0.002). The mean of horizontal and vertical disc size of un-affected fellow eyes was greater than normal control subject but wasn’t statistically significant. (p=1.000).

Horizontal and vertical optic disc size from BMO is greater in affected and fellow eyes of patients with AION than control eyes of normal subjects.