Unusual OCT findings in a patient with CABP4-associated cone-rod synaptic disorder.

OCT findings of foveal elevation and an underlying hypo-reflective zone are novel in this condition. Whilst the clinical history was similar to achromatopsia and other cone dysfunction syndromes, ERG findings suggested disease associated with CACNA1F or CABP4. As CACNA1F is X-linked, CABP4 was more likely, and confirmed on genetic testing. The patient saw better in dim light, confirming that night blindness is not a feature of CABP4-associated disease. Our case highlights the value of ERGs in discriminating between causes of cone dysfunction, and extends the range of retinal imaging phenotypes reported in this disorder.