Normative Pentacam anterior and posterior corneal elevation measurements: effects of age, sex, axial length and white-to-white.

Purpose: To provide normal corneal elevation data for a large Caucasian population and to determine the impacts on these data of age, sex, axial length (AXL) and horizontal white-to-white (WW).

Setting: Centro Internacional de Oftalmología Avanzada, Madrid, Spain.

Design: Retrospective, cross-sectional, observational.

Methods: In this retrospective, cross-sectional, observational study, anterior and posterior corneal elevations were measured in 789 right eyes of subjects with no ocular disease at the thinnest corneal location in relation to a fixed 8-mm best-fit sphere using the Pentacam, and AXL and WW were measured with the IOLMaster. A multiple linear regression model was used to assess the effects of age, sex, AXL and WW on the elevation data.

Results: Mean subject age was 50.5 ± 15 years (range 17-93 years); 64% were women. Mean anterior and posterior corneal elevations were 1.99 ± 1.75 µm (- 7 to 10 µm) and 7.70 ± 5.7 µm (- 6 to 28 µm). Anterior corneal elevations were higher by 0.165 μm and 0.033 μm for every mm reduction in AXL and every year reduction in age, respectively. Sex and WW were not significant predictors of anterior elevations (R = 7.7%). Posterior corneal elevation increased by 0.186 μm/year of age, 0.707 μm/mm reduction in WW and 0.819 μm/mm reduction in AXL. This variable was also 0.866 μm greater in men (R = 34.4%).

Conclusion: Anterior corneal elevations decrease with age and are higher for shorter AXL but are not influenced by sex or WW. Posterior corneal elevations increase with age, decreasing AXL, decreasing WW and are higher in men.