Keratoconus in Asians: demographics, clinical characteristics and visual function in a hospital-based population

P>Background: To describe the demographics, clinical characteristics and visual function of Asian patients with keratoconus managed in a tertiary eye centre. Design: Prospective cross-sectional study. Participants: 116 patients with clinically evident or suspected keratoconus (on videokeratography) recruited over 11 months. Methods: A standardised interview, full ophthalmic examination, refraction and corneal topography were performed. Visual function was assessed with the VF-14 questionnaire. Main Outcome Measures: Demographics, clinical characteristics and visual function. Results: Mean age of our patients was 29.5 +/- 9.40 years on enrolment, 62.9% were male, and the ethnic distribution was 60.3% Chinese, 13.8% Malays and 9.5% Indians. Clinically evident keratoconus was present bilaterally in 65 patients (56.0%) and unilateral keratoconus in five patients (4.3%). Five patients (4.3%) had a family history of keratoconus. The majority of patients were managed with contact lenses (60.8%) or glasses (24.5%). Eye rubbing was common (68%) as were asthma (26.3%) and eczema (18.4%). Conical protrusion was the commonest sign (75.3%). The mean cylinder was higher in keratoconus eyes compared with keratoconus suspect eyes (-4.01 vs. -1.27, P < 0.001), and best-corrected visual acuity was poorer (0.19 vs. 0.05, P < 0.001). Unaided visual acuity was significantly worse with increasing age (P = 0.016). On the VF-14, 32% scored 90 or less (out of 100), reflecting difficulties with vision-related daily activities. Conclusions: Our Asian patients with keratoconus had similar demographic and clinical characteristics to patients in Western populations. Even with apparently good visual acuity, some patients still experience substantial impairment in vision-related activities.