Age-Driven Changes in Corneal Morphology, Axial Length, and Refractive Error Correlations in Different Age Group

IntroductionOcular structures undergo continuous development and remodeling throughout life. At birth, the eye's average axial length (AXL) is approximately 16 mm, increasing to 19.5 mm in infancy and reaching 24–25 mm in adulthood. Any mismatch in ocular growth can result in refractive errors[RE]. Normally, refractive errors shift toward emmetropia, a process dependent on proper visual input. Disruptions in this process can impair emmetropization, leading to refractive anomalies. Newborns are typically hyperopic, transitioning to mild myopia by ages 7–8, with rapid increases in myopia from ages 9–11, stabilization in the 20s, and a return to hyperopia after age 40, as evidenced in various studies. Objective: To evaluate the influence of age on central corneal thickness (CCT), endothelial cell density (ECD), refractive error, and AXL, and to estimate average ECD and CCT across five age groups. Methods: This retrospective study analyzed case records of 198 eyes from healthy subjects aged 8–42 years who underwent routine eye examinations at a private hospital in the UAE. Participants were divided into five age groups: 8–14, 15–22, 23–28, 29–35, and 36–42 years. They were further categorized by refractive error type into myopia, emmetropia, and hyperopia groups, each stratified by age. Data collected included age, gender, refraction , CCT, ECD, and AXL. Results: AXL was longest in myopes and shortest in hyperopes, with no significant differences in CCT or ECD across refractive error groups. ECD and CCT decreased with age, while AXL varied by refractive error type. Conclusion: This study provides normative data on CCT and ECD across five age groups, demonstrating a decline in both with age. AXL was significantly longer in myopes than in emmetropes and hyperopes. No significant gender differences or correlations between refractive error and ECD/CCT were identified.