Electroretinogram and OCT testing of the patient from family E.

A. The electroretinogram (ERG) showed cone responses are more severely affected than rod responses (Only B wave has a small peak at 108 ms/56.6uv). This is the key clinical characteristics for diagnosis of CRD. B. OCT (Optical Coherence Tomography) testing of the patient from family E showed that photoreceptor segments and the retinal pigment epithelium were seriously affected.