Neural canal crowding at lamina cribrosa may predispose to nonarteritic anterior ischemic optic neuropathy

   Researchers at the New York Eye and Ear Infirmary and colleagues have found that neural canal crowding at the lamina cribrosa level may predispose to nonarteritic anterior ischemic optic neuropathy (NAION).

   They compared neural canal dimensions between NAION and healthy subjects using enhanced depth imaging OCT. Horizontal and vertical diameters of the optic disc, Bruch membrane opening, lamina cribrosa, and narrowest neural canal opening were compared between the two groups. 

   Twenty-seven NAION eyes (27 subjects) and 43 healthy eyes (43 controls) were included. The researchers found that the mean horizontal (1575 vs 1854 um) and vertical (1666 vs 1932 um) diameters of the lamina cribrosa were significantly smaller in NAION eyes than in healthy eyes, both before and after controlling for age and gender (all P <0.001). The other parameters were similar between the two groups (all P  >0.1).