Peripheral areas of nonperfusion can be seen. Another method of detecting heterozygous carriers is to use a psychophysical testing. Individuals without XJR exhibit a rod-cone interaction, whereby the ability of the photic system to detect flicker is suppressed as the rods adapt to dark conditions. However, in carriers of XJR, a complete loss of this interaction occurs. Color vision testing in XJR is normal with a mild dyschromatopsia, usually red-green.
Visual fields reveal an absolute scotoma in the area of the retinoschisis.
Electroretinography findings are diagnostic. Normally, the b wave has a greater amplitude than the a wave. In recessive XJR, the b-wave amplitude does not rise up to the level where the a wave began. In the late stages, the a wave also disappears. The visual-evoked response exhibits delayed peak times consistent with abnormal macular function.