Rod-cone differences in response to retinal ischemia in rabbit.

Two series of experiments are reported on incremental increases of ischemia and monitoring of recovery from total ischemia of varying duration. In the first, rods show hyper-responses and cones do not; changes in amplitude and delays appear at higher levels of ischemia in cones than they do in rods. In the second series, cones do not recover up to control values with total ischemias of 30 min or more, while rods do recover and even show hyper-responses. Cones appear more resistant than rods to ischemia, but once affected do not recover as well as rods. Discussion proposes that these differences are specific to receptor systems of each rather than secondary to vascularization patterns.