Age-related changes in corneal parameters in the Turkish population: A pentacam-based study

Objective: To determine the anterior and posterior surface and anterior segment parameters of the cornea in the Turkish population using Pentacam topography device and to determine the changes in these parameters according to age groups. Material-Method: Corneal topographies of patients who were admitted to Dokuz Eylul University Faculty of Medicine Ophthalmology Outpatient Clinic without any ocular pathology were obtained with PENTACAM corneal topography device. Anterior and posterior corneal surface keratometry values (K1, K2 and Kmean), astigmatism and axes, anterior and posterior corneal surface axes, radius of curvature (Rflat, Rsteep, Rmean), asphericity values (Q value), thinnest point of the cornea, corneal volume, anterior chamber volume and depth (ACV, ACD) and ophthalmologic examination findings were retrospectively analyzed. Patients were divided into 4 groups as 3-19, 20-39, 40-59 and 60 years and older and corneal parameter values and changes in these parameters with age were investigated according to age groups. Results: A total of 1202 eyes of 601 patients were included in the study. Of the patients, 295 (49.1%) were male and 306 (50.9%) were female. The mean age was 35.99 ± 23.79 years for males and 34.53 ± 22.27 years for females. When the relationships between the paired groups according to age groups were evaluated, statistically significant differences were observed between the groups aged 60 years and older, 20-39 years and 40-59 years for the corneal anterior surface K1 and Kaverage parameters. For the anterior surface K2 parameter, a statistically significant difference was observed between the 20-39 age group and the 3-19 and 60 years and older groups. There was no significant difference between the age groups for the posterior surface K1 and Kaverage parameters. For the posterior surface K2 value, a statistically significant difference was observed between the 3-19 age group and the 60 years and older group. The corneal anterior surface and posterior surface radii, Rflat and Rmean parameters increased in the 20-39 age group, whereas a decrease was observed in the older age groups. The posterior surface Rsteep parameter increased gradually with age. On the anterior surface of the cornea, with the rule astigmatism decreased and against the rule and oblique astigmatism increased with increasing age. On the posterior surface of the cornea, with the rule astigmatism and oblique astigmatism increased and against the rule astigmatism decreased. The cornea was more prolate in the 3-19 age group. Corneal anterior surface asphericity was -0.39 in the 3-19 age group, -0.31 in the 20-39 age group, -0.30 in the 40-59 age group, and -0.31 in the 60 years and older group. Posterior corneal asphericity was -0.34 in the 3-19 age group, -0.35 in the 20-39 age group, -0.45 in the 40-59 age group, and -0.48 in the 60 years and older age group. In our study, a significant negative posterior surface Q value was observed after 40 years of age, while the difference between anterior and posterior surface Q values increased gradually. It was observed that the cornea became more prolate with age. ACV, ACD, corneal volume and the thinnest point of the cornea decreased with age. Discussion: In our study, corneal parameters and their changes with age were investigated in Turkish population. It was observed that the cornea became more prolate with age, the corneal anterior surface of the cornea showed a decrease in with-the-rule astigmatism and an increase in against-the-rule and oblique astigmatism. On the posterior surface of the cornea, it was observed that with-the-rule and oblique astigmatism increased, whereas against the rule and oblique astigmatism decreased. There was a negative correlation between age and ACV, ACD, corneal volume and the thinnest point of the cornea. Key words: Cornea, Corneal Topography, Pentacam.