Update on the keratoconus genetics.

Keratoconus (KC) is one of the leading causes for keratoplasty. While the genetic aetiology of more and more corneal dystrophies is revealed, KC falls behind. And it is not because of lack of effort. The diversity in the many published results from over two decades is discussed in relation to the present knowledge in molecular biology. Results that at first appear to be in conflict with each other make sense when placed in the right context. Ophthalmologists often refer to KC as a heterogeneous disease. This review demonstrates that it truly is a multifactorial disease. Despite the many attempts to reveal the aetiology of KC, the pathological mechanism(s) still remain to be solved.