A simple description of age-related changes in crystalline lens thickness

Purpose An increase in lens thickness is often described as a linear function of age. However, contradictory opinions exist about whether the lens thickness continues to increase after 50 years of age. Differences in slope exist between this increase in younger and older people, but these findings are inconsistent with the linear behavior of an increase in the lens thickness throughout life. We investigated among different functions, including slope variation, which would be the best to show the relation between lens thickness and age. An available model portraying lens growth could be advantageous in many practical applications. The possibility of differences between sexes in lens thickness growth is also analyzed. Methods We evaluated 102 eyes of patients aged between 15 and 84 years: 41 men, 61 women. The biometric measurements were performed with the aid of the OcuScan® (Alcon, USA). Results Both logarithmic and potential functions provide a good fit for the data (R2 = 0.905 and 0.906, respectively). The results do not show significant differences between men and women in any age range, nor when the data of the whole sample are considered (p = 0.29). Conclusions The best fits for the data are both logarithmic and double logarithmic functions. According to this model, lens growth continues throughout life, but after 50 years, age-related thickness variations are lower than statistical variability. No differences were found between the sexes.