Does gender affect intraocular lens power calculations? A comparative analysis of formula accuracy

Intraocular lens (IOL) power calculation is a crucial aspect of modern cataract surgery, directly affecting postoperative refractive outcomes. Due to anatomical and physiological differences between male and female eyes, neglecting gender-specific variations may lead to systematic refractive errors in IOL power selection. This research aimed to determine the necessity of incorporating gender as a variable in future IOL calculation algorithms to improve postoperative precision. This retrospective observational study analyzed data from 210 eyes that met predefined inclusion criteria. Biometric measurements for assessing intraocular lens power were obtained using the ARGOS optical biometer. The refractive power of the intraocular lenses was calculated using several established formulas, and these values were systematically compared to evaluate their predictive accuracy. A parametric statistical approach was employed, using repeated measures ANOVA to assess differences among multiple calculations. The homogeneity of covariances was examined to validate the design of the repeated measures. Pairwise comparisons of the outcomes from different formulas were performed using the Bonferroni correction to identify statistically significant differences. Additionally, paired-sample t-tests were conducted to compare the spherical equivalent values recorded during the initial and final follow-up examinations. Significant differences were observed between genders regarding descriptive features such as age, axial length, keratometry, and white-to-white measurements. Although notable biometric differences exist between genders, they do not seem to affect the discrepancies in intraocular lens power calculations using the tested formulas. However, intra-group differences in intraocular power values suggest that the choice of formula may impact predicted intraocular power differently for men and women.