Ultrastructural analysis of the lamina cribrosa after radial optic neurotomy

Only complete incision of the circular ring of collagen fibrils surrounding the lamina cribrosa via RON resulted in effective relaxation of the scleral outlet and was achieved in 60% of all eyes under standardized conditions. In all cases the adjacent tissue showed only minimal injury. The high rate of incomplete dissection of the scleral outlet may be an explanation for the variable outcome seen in different studies on RON.