The effect of choroidal congestion in retinal pigment epithelium function and the electroretinogram.

Increased choroidal pressure and choroidal stasis were induced in Dutch rabbit eyes by tying off vortex veins. Ligating one to three vortex veins caused a progressive diminution in the b- and c-waves of the electroretinogram so that the amplitudes were approximately half of control values when three vortices had been ligated. After ligation of four vortex veins, the responses rapidly disappeared. Release of the occlusion twenty minutes later caused the b-wave to return to normal over a few hours' time, but the c-wave showed variable recovery and was replaced by a large slow pIII response in half of the experiments. These observations may reflect a combination of hypoxia and alterations in fluid movement that affect the status of the subretinal space.