PURPOSE To evaluate the corneal thickness and curvature of myopic and patients with keratoconus from two countries. METHODS This cross-sectional study was conducted at Cabinet Opale, Fort de France, French West Indies and University Hospital of Bordeaux, France. Corneal thickness and curvature were assessed in 170 keratoconic eyes of 89 residents of the French Caribbean Islands (FCI) and 159 keratoconic eyes of 91 residents of the Aquitaine region of southwest France. A group of age-matched keratoconus-free patients who had been referred for refractive surgery owing to myopia (173 FCI [173 eyes; 87 individuals] and Aquitaine [181 eyes; 93 individuals]) were also assessed. RESULTS The mean age at keratoconus diagnosis was significantly higher among FCI than Aquitaine residents (p = 0.009). The mean keratometric (Km) reading was statistically higher for keratoconic FCI than Aquitaine patients, at 48.06 versus 46.21 diopters (p = 0.001). This difference was more pronounced among patients aged >40 years than those ≤40 years (p = 0.009). Patients with keratoconus showed no significant difference in mean central corneal thickness and thinnest corneal point values, irrespective of region. Myopic individuals from the FCI, however, had significantly lower mean central corneal thickness and thinnest corneal point measurements than Aquitaine myopics, irrespective of age group (p ≤ 0.0008). CONCLUSION The corneas of patients with keratoconus of African-Caribbean and Caucasian origins are of similar thickness. Myopic African-Caribbean patients referred for refractive surgery tend to present with thinner corneas than Caucasians.