Keratoconus is the most common cause of corneal transplant in developing countries. It is a noninflammatory, mostly asymmetric, progressive disease, resulting in corneal thinning, irregular astigmatism, and eventually severe vision loss. This multifactorial disease, which is influenced by
environmental and genetic factors, usually starts in the second or third decade of life and imposes heavy financial burdens on economically active groups of the society. Although many studies have shown that keratoconus affects both sexes with no significant difference,5,6 a few studies have reported a sexual predilection. It has been shown that eye rubbing, atopy, exposure to sunlight, miscellaneous factors(including the use of environmental and industrial toxins), age, family history of the disease, ethnic differences, and contact lens use are the most important environmental risk
factors for keratoconus. Moreover, there is evidence of the role of VXX1 and SOD1 (1%) in the pathogenesis of keratoconus, highlighting the effect of genetic factors. An autosomal dominant and sporadic pattern is the most common pattern in familial keratoconus
