To determine the distribution of macular thickness in a healthy Iranian population aged 45-69 years and its association with certain determinants

All participants underwent optometric examinations including the measurement of uncorrected and corrected visual acuity, objective refraction by retinoscopy, and subjective refraction. Then, all participants underwent slit lamp biomicroscopy followed by fundus examination through direct and indirect ophthalmoscopy, and optical coherence tomography (OCT) imaging under pupil dilation

The mean central macular thickness was 255.4 microns (95% CI: 254.5-256.3), the average inner macular thickness was 316.5 microns (95% CI: 315.9-317.1), the average outer macular thickness was 275.3 (95% CI: 274.8 -275.8), and the overall average thickness was 278.6 microns (95% CI: 278.1 -279.1). A linear multiple regression model showed that all the indexes were significantly larger in male participants (P<0.001). The central macular thickness increased with age (coef=0.25, P<0.001) while the overall (coef=-0.18, P<0.001), inner (coef=-0.15, P<0.001) and outer macular thickness (coef=-0.19, P<0.001) decreased with age. The central (coef=3.8, P<0.001) and inner (coef=2.6, P<0.001) macular thickness had a direct and the outer macular thickness (coef=-1.6, P<0.001) had an inverse correlation with the axial length

The macular thickness in the 45- to 69-year-old Iranian population was different from that reported in other studies, which requires attention in OCT imaging of this population for diagnostic and treatment purposes. Age, gender, refractive error, axial length, and keratometry were found to be associated with macular thickness