Keratoconus associated with congenital stationary night blindness type 1.

A 35-year-old man presented with keratoconus; his best corrected visual acuities were -18.00/+10.00 ×180 (6/60) oculus dexter and -10.00/+8.00 ×5 (6/36) oculus sinister. 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 congenital stationary night blindness (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.