方法：对146名健康年轻人进行横断面观察研究，采用新型频域相关断层扫描对其双眼视网膜参数(视网膜神经纤维层厚度、视盘、黄斑)进行扫描。通过右眼减去左眼所得参数值的平均差进行配对t检验。两眼间的差异采用2.5%～97.5%之间进行评估。视网膜参数相关。通过回归分析，评价性别和血压对视网膜参数的影响。

结果：两眼的视网膜神经纤维层平均厚度无统计学差异(+0.7μm，P=0.09)。两眼视网膜颞侧象限(+2.51μm，P=0.02)，鼻侧象限(+2.50μm，P=0.04)，钟表位右眼2点与左眼10点(+5.85μm，P=0.002)，右眼3点与左眼9点(+3.20μm，P=0.005)，右眼11点与左眼1点(+3.80μm，P=0.024)，平均厚度(-0.034μm，P=0.013)和垂直方向杯盘比(-0.028μm，P=0.008)，黄斑部鼻侧象限(+7.76μm，P=0.003)。左眼上方视网膜明显较薄(-2.40μm，P=0.03)。平均视网膜神经纤维层厚度和黄斑厚度分别为11μm和18μm。视网膜参数在双眼有中度的相关性(0.41～0.6)，而两眼视网膜参数与性别、血压不相关(P<0.05)。研究表明通过新型频域相关断层扫描发现健康年轻人的视网膜神经纤维层厚度和黄斑厚度两眼间的差异分别不应超过11μm和18μm。

结论：视网膜参数的不对称性存在于健康视网膜，并对早期视网膜病变的诊断提供有价值的评估。

METHODS: In this cross-sectional observational study we included 146 normal young adults. Bilateral eyes retinal parameters such as retinal nerve fiber layer thickness, optic nerve head and macula were assessed with OCT and mean differences for all parameters were established by subtracting the values of left eye from the right eye parameters and evaluated by paired sample t-test. Interocular differences were evaluated and cut off points at 2.5^th and 97.5^th percentiles were produced. Retinal parameters were correlated. Effects of gender and blood pressure on retinal parameters were evaluated by regression analysis.

RESULTS:Average retinal nerve fiber layer(RNFL)thickness was not statistically significant(+0.7 μm, P=0.09). Significant thickness was present in temporal quadrant(+2.51 μm, P=0.02), nasal quadrant(+2.50 μm, P=0.04), clock hours 2/10(+5.85 μm, P=0.002), 3/9(+3.20 μm, P=0.005), 11/1(+3.80 μm, P=0.024), average(-0.034 μm, P=0.013)and vertical cup-to-disc ratio(-0.028 μm, P=0.008), macular inner nasal quadrant(+7.76 μm, P=0.003)in right eyes. Superior quadrant was significantly thicker in left eyes(-2.40 μm, P=0.03). Cut-off values for average RNFL and macular thicknesses were 11.00 μm and 18.00 μm, respectively. Bilateral eyes have moderate interocular correlation(0.41-0.6)for retinal parameters and not correlated with gender and blood pressure(P<0.05 regression). The interocular differences in average RNFL and macular thickness of normal adults should not exceed 11 μm and 18 μm, respectively, if measured with Cirrus HD-OCT.

CONCLUSION: Asymmetry in retinal parameters exists in healthy eyes and provides valuable assessments in diagnosing retinopathies at early stage.