The authors recorded electroretinograms for 27 autistic patients and 20
age- and sex-matched healthy volunteers. Thirteen (48%) of the autistic
patients demonstrated subnormal b-wave amplitudes, which may indicate
abnormal retinal function. One patient was tested serially at two sites;
his low b-wave amplitude did not vary over time or between the two sites.
If this retinal finding can be confirmed at other laboratories and in
larger samples of autistic patients, it might provide a marker for a
specific subtype of autism.