corneal refractive parameters with age in patients without corneal diseases based on Fourier analysis

Objectives: To investigate the distribution and trend of corneal parameters decomposed by Fourier analysis of videokeratography data in different age groups without corneal diseases.
Design: Cross-sectional study.
Setting: Peking University Third Hospital, Beijing, China.
Participants: We enrolled 2545 patients (5074 eyes) without corneal diseases (mean age 37.0 ± 26.8, range 4–95) between August 2018 and December 2022.
Outcome measures: The corneal refractive power parameters measured by pentacam were decomposed into Fourier transform. SphRMin, Asti.Central, Asti.Periph and Irregul obtained from the Fourier transform were selected for analysis. We compared the differences between SphRMin and Asti. Central, Asti.Periph and Irregul within different age groups and attempted to fit linear and nonlinear equations for the change of Fourier parameters with age.
Results: In people without corneal diseases of all ages, the mean values of SphRMin, Asti. Central, Asti. Periph and Irregul were 7.71±0.28, 0.10±0.062, 0.11±0.068 and 0.028±0.019, respectively. There are differences of Asti.Central, Asti.Periph and Irregul among the different age groups (all P < 0.001). SphRMin, Asti. Central, Asti. Periph and Irregul were correlated with age (all P < 0.001). Irregul increased with age after 30 years of age. what’s more, SphRMin, Asti. Central, Asti. Periph and Irregul were all correlated (all P < 0.05).
Conclusions: We report the mean value of corneal refractive parameters obtained by the Fourier transform in patients without corneal diseases at different ages, its changing trend with age, and important inflection points. This has great clinical implications for the diagnosis of abnormal refractive state corneas and the design of ophthalmic surgery.