摘要： PURPOSE. To determine the normal variation in central retinal thickness asymmetry in healthy Caucasian adults using the posterior pole asymmetry analysis (PPAA) of a SPECTRALIS spectral-domain optical coherence tomography (SD-OCT) device. METHODS. Healthy Caucasian individuals aged between 18 and 45 years with a visual acuity of minimum 20/20 and a spherical equivalent between (cid:2)1.5 and t1.5 diopters were recruited. Retinal thickness and retinal nerve ?ber layer thickness (RNFL) were using measured SPECTRALIS SD-OCT. Inter- and intraocular differences in central retinal thickness were calculated using the PPAA. The association between age, sex, and interocular asymmetry was evaluated by a linear model with Gaussian correlation structure. RESULTS. A total of 105 individuals, 30 men and 75 women, were studied. The mean age 6 SD was 28.8 6 7.87 years. The grand mean interocular retinal thickness asymmetry was 5.6 lm (95% con?dence interval [CI]: 4.6–6.5) and the grand mean intraocular retinal thickness asymmetry was 8.3 lm (95% CI: 6.8–9.9) in the right eye and 8.4 lm (95% CI: 6.7–10.0) in the left eye. The highest local asymmetries were found in the nasal corners of macula were the posterior pole thickness map overlaps the temporal vascular arches. A slight general age and sex effect on the mean interocular retinal thickness asymmetry was found to be respectively 0.04 lm/year (95% CI: 0.02–0.06 lm) and 0.54 lm (95% CI: 0.19–0.88 lm) for men compared with women. CONCLUSIONS. Statistically signi?cant physiological asymmetries in inter- and intraocular central retinal thickness exist. This must be considered when early signs of glaucoma or other pathologies are evaluated based on the retinal thickness asymmetry.