Keratoconus associated with CSNB1.

A 35-year-old man with best corrected visual acuities of -18.00/+10.00×180 (6/60) OD and -10.00/+8.00×5 (6/36) OS. Bilateral steep central corneal thinning, paracentral ectasia and Vogts striae were present; normal fundi. Corneal topography disclosed 7.4 dioptres of irregular astigmatism in the central 3 mm with thinning (335 μm). Electroretinography (ERG) showed no response. There were no medical or environmental influences for his keratoconus. Occurrence of keratoconus and CSNB in the patient may represent a chance association, but keratoconus has not been previously linked with CSNB1 either as a chance or true association though both show genetic predisposition.