Joint hypermobility in keratoconus.

There are several reports linking keratoconus and connective tissue disorders, such as Ehlers-Danlos syndrome, osteogenesis imperfecta and mitral valve prolapse, suggesting that keratoconus may be the result of a localized dysfunction in collagen metabolism. In view of this the incidence of hypermobility of the joints among a group of patients with keratoconus was compared with a normal (matched) control group. Eighty-four patients were examined using the Beighton modification of the Carter and Wilkinson scoring system. A control group matched for sex, age and ethnic group was also assessed. No statistically significant difference between the groups was found for the trunk or knees; a difference was found for the metacarpo-phalyngeal and wrist joints. The findings support the theory that keratoconus is a localized manifestation of a mild connective tissue disorder. Also, it can be stated that patients with keratoconus are five times more likely to show hypermobility of the metacarpo-phalyngeal and wrist joints.