Fig. 4.

Electronmicrograph from the inferior pole of the optic nerve of our Case with secondary angle closure glaucoma demonstrating primarily retrograde axonal transport block in the temporal lamina cribrosa. The accumulation of intra-axonal debris is most prominent posterior to a glial-collagen beam (blue arrows) and confined to the axonal bundle in between horizontally oriented glial column cells. Vitreous up. (X 4600). Reproduced by Permission of the Survey of Ophthalmology.^1. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)