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Abstract
Electron microscopic morphometry of untouched trabecular meshwork was done in nine eyes of six young cynomolgus monkeys trabeculectomized 329 to 447 days earlier, in two unoperated control eyes and one eye where a piece of ciliary muscle was excised. Outflow facility before and after pilocarpine had been repeatedly measured in all eyes. Correlations were computed between perfusion results and morphometric measurements and between different morphometric measurements. All operated eyes but not control eyes showed deposits beneath the inner wall endothelium of Schlemm's canal, previously found only in very old human and monkey eyes and in chronic simple glaucoma. In the uveal and corneoscleral trabeculae of operated eyes there was marked thickening of the sheaths covering intratrabecular elastic fibers. Thicker elastic fiber sheaths were seen in eyes with lower facilities and lower pilocarpine effects, both early and late after operation. A direct causal connection is improbable, however. Subendothelial deposits seemed to be more plentiful in eyes which had shown a high facility shortly (three months) after trabeculectomy. The amount did not correlate with facility at the time of enucleation. This suggests that the subendothelial deposits are due to underperfusion of the unoperated meshwork caused by a temporary bypass for the aqueous. The nature of the deposits remains to be established.