Anesthetically blocked optic nerve conduction in congenital stationary night blindness

It has been hypothesized that the negative configuration of the electroretinogram (ERG) in congenital stationary night blindness (CSNB) may change to a positive configuration following loss of the inhibitory function of the optic nerve centrifugal fibers. In order to study this hypothesis, the ERGs before and after blocking optic nerve conduction by retrobulbar anesthesia were recorded in a patient with CSNB, who had retinal breaks and was being treated with cryopexy under retrobulbar anesthesia. After complete blockade of the optic nerve conduction induced by retrobulbar anesthesia, the ERG showed little change in comparison with that recorded before anesthesia. The above finding indicates that the temporary blockade of optic nerve conduction does not modify the ERG configuration in CSNB.