Purpose: To study the influence of age, sex, refractive error and axial length on choroidal thickness in normal myopic eyes, among Egyptian population, using swept-source optical coherence tomography (SS-OCT).
Methods: Choroidal thickness (CT) was measured by a SS-OCT in 97 eyes of 49 normal myopic volunteers. The subjects were classified into groups according to age, the degree of myopia and axial length. Correlation between CT and age, axial length and myopia were done for different groups. Axial length 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 ETDRS-style grid.
Results: CT tends to decrease with advance of age. A negative correlation found between the central subfoveal CT 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 axial length increase. A negative correlation was found between the central subfoveal CT and axial length (r= -0.340, P= 0.001, R²= 0.115).
Conclusion: Axial length and age have a negative correlation with choroidal thickness, while the sex and spherical equivalent of refractive error in myopes don’t affect choroidal thickness.
Keywords: Choroidal thickness, swept source, OCT, myopic eyes.