Macular thickness variations with sex, age, and axial length in healthy subjects: A spectral domain-optical coherence tomography study

PURPOSE. To assess the relationship between macular retinal thickness and volume and age, sex, and refractive error/axial length with spectral domain-optical coherence tomography (SD-OCT). METHODS. One randomly selected eye of 198 consecutive ophthalmically normal subjects (104 men, 94 women) between July 2008 and January 2009, with corrected visual acuities better than 20/30 were included in this cross-sectional study. Complete ophthalmic examination, axial length measurement with a laser interferometer, and macular cube 512×128 scan by SD-OCT were performed. RESULTS. The mean age was 55.6±16.4 years (range, 17-83), average refractive error was -2.17±4.82 (range, -23.50-3.75), and average axial length was 24.73±1.98 mm (range, 21.52-32.51). The central subfield thickness, average inner macular thickness, and overall macular volume were significantly lower in the female subjects (partial correlation: P=0.009, P=0.027, and P= 0.042, respectively). As age increased, average inner macular thickness, average outer macular thickness, overall average macular thickness, and macular volume decreased significantly (partial correlation: P= 0.002, P= 0.002, P= 0.002, and P= 0.000, respectively). Refractive error had no significant influence in partial correlation analysis. Axial length correlated negatively with average outer macular thickness, overall average macular thickness, and macular volume (partial correlation: P= 0.006, P =0.044, and P=0.003, respectively). CONCLUSIONS. In normal subjects, SD-OCT showed that retinal thickness is related to age, sex, and axial length, with regional variations.