Axial Length, Retinal Function, and Oxygen Consumption: A Potential Mechanism for a Lower Risk of Diabetic Retinopathy in Longer Eyes
Axial Length, Retinal Function, and Oxygen Consumption: A Potential Mechanism for a Lower Risk of Diabetic Retinopathy in Longer Eyes
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DOI：
10.1167/iovs.13-12412
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发表时间：
2013-11-01
影响因子：
4.4
通讯作者：
Luu, Chi D.
中科院分区：
文献类型：
--
作者：
Man, Ryan Eyn Kidd;Lamoureux, Ecosse L.;Luu, Chi D.
目的。为了更好地了解轴向伸长对糖尿病视网膜病变发展的保护作用，确定轴向伸长（AL）、视网膜功能和相对氧（O-2）消耗的关系。对50名健康个体进行了AL、多焦视网膜电图（mfERG）和相对O-2消耗（动脉和静脉O-2饱和度水平的差异或A-V差异）的测量。采用线性回归模型分析AL、mfERG振幅和A-V差异之间的关系。通径分析确定AL对A-V差异的直接和间接影响（通过mfERG振幅）。mfERG P1振幅与A-V差异呈正相关（β = 0.33； 95%可信区间[CI]: 0.23-0.42）。AL升高与a - v差降低（β = -1.08; 95% CI: -1.52至-0.65）以及视网膜功能降低（β = -3.14, 95% CI: -4.07至-2.20）显著相关。包括AL（研究因素）、视网膜功能（中间变量）和A-V差异（结局变量）在内的通径分析模型显示，AL与A-V差异的直接关联不大（β (p) = -0.002），而AL通过视网膜功能改变对A-V差异的间接影响很大（β (p) = 0.51）。在AL较长的眼睛中，A-V差的减少可以用视网膜功能的平行减少来解释。这些发现表明，长眼睛的视网膜功能和O-2消耗下降，因此在糖尿病患者中相对较少缺氧，这可能部分解释了长眼睛的DR风险降低的原因。
PURPOSE. To determine the relationship between axial length (AL), retinal function, and relative oxygen (O-2) consumption to better understand the protective effect of axial elongation on diabetic retinopathy development.METHODS. Measurements of AL, multifocal electroretinogram (mfERG), and relative O-2 consumption (difference between arteriolar and venular O-2 saturation levels or A-V difference) were performed on 50 healthy individuals. The relationships between AL, mfERG amplitude, and A-V difference were analyzed using linear regression models. Path analysis was performed to determine the direct and indirect effects (via mfERG amplitude) of AL on A-V difference.RESULTS. mfERG P1 amplitude was positively associated with A-V difference (beta = 0.33; 95% confidence interval [CI]: 0.23-0.42). Increased AL was significantly associated with a decrease in A-V difference (beta = -1.08; 95% CI: -1.52 to -0.65) as well as a decrease in retinal function (beta = -3.14, 95% CI: -4.07 to -2.20). Path analysis models including AL (study factor), retinal function (intermediate variable), and A-V difference (outcome variable) showed that AL had little direct association with A-V difference (beta(p) = -0.002), while the indirect effect of AL on A-V difference via changes in retinal function were substantial (beta(p) = 0.51).CONCLUSIONS. In eyes with longer AL, the reduction in A-V difference is explained by the parallel reduction in retinal function. These findings suggest that longer eyes have decreased retinal function and O-2 consumption, and thus are relatively less hypoxic in the presence of diabetes, which may partly explain the reduced risk of DR in these eyes.