Factors affecting choroidal thickness in normal myopic eyes in Egyptians using swept-source optical coherence tomography

Abstract

Purpose: To study the influence of age, sex, refractive error, and axial length (AL) on choroidal thickness (CT) in normal myopic eyes, among Egyptian population, using swept-source optical coherence tomography (SS-OCT). Patients and Methods: CT was measured by an SS-OCT in 97 eyes of 49 normal myopic volunteers. The subjects were classified according to age, degree of myopia, and AL. Correlation between CT and age, AL, and myopia was done for different groups. AL was measured using IOL Master. OCT measurements were performed using Topcon DRI-1 SS-OCT. CT was automatically calculated and shown as a colored topographic map with nine subfields defined by the Early Treatment Diabetic Retinopathy Study style grid. Results: CT tends to decrease with advance of age. A negative correlation found between the central subfoveal CT (SFCT) and the age (r = −0.329, P = 0.001, R2 = 0.108). Although there was no significant correlation between CT and degree of myopia (r = 0.159, P = 0.120, R2 = 0.025), CT decreases with increase of myopia except with >−8 D group. CT tends to decrease as the AL increases. A negative correlation found between the central SFCT and AL (r = −0.340, P = 0.001, R2 = 0.115). Conclusions: AL and age have a negative correlation with CT, while the sex and spherical equivalent of refractive error in myopes do not affect CT.