Ethnic Differences of Corneal Parameters: A Cross-Sectional Study

Abstract

Purpose: To investigate the ethnic differences of corneal parameters in Arabs and other ethnicities. Methods: This study recruited 250 Saudi Arabian participants, 18–45 years of age. The McMonnies questionnaire was used to exclude participants with dry eye. The KR8800 auto refractometer (Topcon, Japan) was used to measure the refractive error. Oculus Keratograph 4 topography was used to assess 16 corneal parameters, including the k-readings, horizontal visible iris diameter, mean eccentricity index, asphericity, corneal shape factor, corneal flattening factor, sagittal height, sagittal curvature, and vertical palpebral aperture. Results: A statistically significant difference was found between male and female participants. Corneal parameters were compared to other ethnicities, including Caucasians and Asians, and those of Mongoloid origin. The horizontal visible iris diameter was wider in Saudi Arabians than in Asians but similar to Caucasians. The sagittal height was deeper and the corneal shape factor was higher than in the other ethnicities, and the eccentricity index was lower than that in Caucasians and Asians of Mongoloid origin. Conclusion: Our data provided normative corneal parameters of Saudi Arabians that may be useful for ophthalmic clinicians and designers of contact lenses. Furthermore, the parameters suggest that the corneal characteristics of Arabians are distinct from those of major ethnicities.