Corneal edema in phakic and aphakic eyes.
Explanations are given for the physiological behavior of the cornea in the phakic and aphakic eye and for a cornea covered by a contact lens that causes epithelial anoxia. The normal, constant hydration of the cornea is a result of active ion transport by the endothelial layer. The hypoxic epithelium under a contact lens produces lactate ion that migrates to the posterior portion of the cornea where it modifies the normal stromal balance between osmotic and inhibition pressures. A consequence of this modification can be corneal swelling. A reduction in cell count of the endothelial layer, together with a possible increase in aqueous humor oxygen tension is believed to be responsible for the smaller amount of swelling caused by epithelial hypoxia in the aphakic eye.
D001036:Aphakia, Postcataract / Q000150:complications*; D003315:Cornea / Q000502:physiology; D003316:Corneal Diseases / Q000150:complications / Q000503:physiopathology*; D004487:Edema / Q000150:complications / Q000503:physiopathology*; D004727:Endothelium / Q000502:physiology; D006801:Humans