A profile of keratoconus in New Zealand

Purpose. To examine the characteristics and risk factors for keratoconus in a New Zealand population. Methods. A one-page questionnaire was designed and sent to optometrists and ophthalmologists in New Zealand. Eye care practitioners then issued questionnaires to their keratoconic patients over a 6-month period. Results. A total of 673 completed questionnaires were received from patients with keratoconus. A male bias (59%) was apparent in the sample. In line with previous work, a high proportion of the keratoconic cohort rubbed their eyes and suffered from atopy. A familial rate of 23.5% was evident, with several families reporting multiple keratoconus cases. Eleven pairs of twins were identified with at least one keratoconic sibling. Multivariate statistical analysis revealed significant independent correlations between the early development of keratoconus and gender, allergy, asthma, and latitude of childhood domicile. Conclusion. Results from the survey concur with a previous local report that keratoconus affects males more frequently and earlier in life than females in New Zealand. The concurrence of atopic disease and eye rubbing with keratoconus was as expected, and an association between the early development of the disease and latitude of the childhood domicile emerged. A strong familial component, exceeding previously reported figures, was evident in the cohort