Evaluating the predictive relationship between manifest refractive astigmatism, topographic astigmatism, and ocular residual astigmatism: A comparative study.

BackgroundThe interaction between manifest refractive astigmatism and topographic astigmatism is critical in planning refractive surgery. This study aimed to investigate the predictive relationship between manifest refractive astigmatism and topographic astigmatism across different age groups.MethodsThis is a retrospective observational study comprising 149 patients. Manifest refractive astigmatism was evaluated through subjective refraction methods, and topographic astigmatism was measured using corneal topography. Inclusion criteria were patients aged 20-41 years without a history of ocular surgery or severe corneal pathology. The main outcome was to determine the relationship between manifest refractive astigmatism and topographic astigmatism and to test whether manifest refractive astigmatism served as a reliable predictor of topographic astigmatism in two age groups (≤30 and >30 years).ResultsPearson correlation analysis revealed a strong positive correlation between manifest refractive astigmatism and topographic astigmatism (r = 0.846, p < 0.001). Linear regression analysis indicated that manifest refractive astigmatism accounted for 71.7% of the variance in topographic astigmatism. No significant differences were observed between younger and older age groups in the predictive relationship.ConclusionsManifest refractive astigmatism is a reliable predictor of topographic astigmatism, and it is not a substitute for topographic astigmatism in surgical practice but serves as a supportive measure. The strong correlation across age groups highlights its value in clinical practice.