Characteristics of 244 patients with keratoconus seen in an optometric contact lens practice.

Background: The purpose of this study was to describe the characteristics of keratoconic patients seen in a specialised contact lens practice from a general population with a high prevalence of the disease.

Methods: Patients attending a contact lens practice for management of keratoconus were asked to complete a questionnaire. Data were collected on demographic characteristics, general health, family history, eye rubbing, allergy, asthma, eczema, education level, history of keratoplasty and smoking.

Results: Two hundred and forty-four patients completed the questionnaire. There was a male bias (54.5 per cent). The majority of the patients (78.7 per cent) wore contact lenses, of whom 67.7 per cent wore hard, 13 per cent soft and 4.2 per cent scleral contact lenses. Some of the patients (21.3 per cent) had undergone corneal graft surgery. Eighteen per cent had an associated systemic disease, the most common of which was type 2 diabetes, although this disease was less prevalent, but not significantly, in the keratoconic sample than in the general population (p = 0.19). The prevalence of eye rubbing (65.6 per cent) was similar to other studies. Compared to the general population, asthma (13.2 per cent) was slightly, but not significantly, less prevalent (p = 0.17), eczema (6.6 per cent) was significantly less (p < 0.001) and allergy (34.4 per cent) was more prevalent (p < 0.001). A high proportion of patients reported a family history of the disease (27.9 per cent) and most were better educated than the general population.

Conclusion: The results of this survey concur with those of other studies with regard to most known characteristics of keratoconus; however, the proportion of asthma and eczema tended to be less than in other surveys and may be linked to the environmental influence of a hot and sunny country. The high prevalence of positive family history of the disease in this cohort suggests a genetic influence.