Sensitivities of ocular tissues to acute pressure-induced ischemia
D. R. Anderson and E. B. Davis
Intraocular pressure was artificially elevated for eight hours in eight owl
monkeys. The first permanent effect (produced at a perfusion pressure of
plus 15 mm Hg) was partial necrosis of iris stroma and ciliary processes,
associated with microscopic lesions in the photoreceptors and retina
pigment epithelium around the disc and in the retinal periphery. At a
slightly higher pressure, visual nerve fibers in the retina and optic nerve
and their ganglion cells were affected. Simultaneously, the outer retinal
layers showed damage to the pigment epithelium, photoreceptors, and other
nuclear layers. At even higher pressures, nearly all the other intraocular
tissues were affected except for Muller cells, astroglia in the optic nerve
head, epithelium of the pars plana, and the pigment cells of the choroid.
The possibility is raised of a nonischemic pressure-induced mechanism for
destruction of disc astrocytes in human chronic glaucoma.
