Abstract:

Objective To describe the corneal Q value in Chinese older than 30 and to evaluate the associated factors. Design Cross-sectional study. Participants 1683 participants from the Handan Eye Study whose right eyes accepted the corneal topography, of which 955 were female and 728 were male. The average age was (53.6±11.0) years (30 ~ 107 years). Methods The corneal Q values of anterior surface and posterior surface were measured at the 3 mm, 5 mm and 7 mm diameter annulus by Orbscan corneal topography. The association of the corneal Q values with age, gender, and dioptre was analyzed. Main Outcome Measures The corneal Q value of anterior and posterior surface. Results The average corneal Q value of anterior surface at 3 mm, 5 mm and 7 mm diameter annulus was -0.28±0.175, -0.28±0.175, and -0.29±0.175 respectively and the values at 5 mm diameter annulus were negatively associated with age (B=-0.003, P<0.01) and dioptre (B=-0.013, P=0.016). The average Q value of posterior surface at 3 mm, 5 mm and 7 mm diameter annulus was -0.26±0.216, -0.26±0.214, and -0.26±0.215, respectively and the values at 5 mm diameter annulus were positively associated with age (B=0.002, P=0.036) and dioptre (B=0.016, P=0.043). Conclusion The corneal Q value in Chinese was different from that of Europeans and affected by age and dioptre.

Key words: cornea, Q value, age, dioptre