眼轴长度变化对使用光学相干断层扫描血管造影术测量视网膜浅表血管密度和黄斑无血管区面积的影响。

Axial Length Variation Impacts on Superficial Retinal Vessel Density and Foveal Avascular Zone Area Measurements Using Optical Coherence Tomography Angiography.

作者信息

Sampson Danuta M, Gong Peijun, An Di, Menghini Moreno, Hansen Alex, Mackey David A, Sampson David D, Chen Fred K

机构信息

Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia 2Lions Eye Institute, Perth, Western Australia, Australia.

Optical+Biomedical Engineering Laboratory, School of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, Western Australia, Australia.

出版信息

Invest Ophthalmol Vis Sci. 2017 Jun 1;58(7):3065-3072. doi: 10.1167/iovs.17-21551.

DOI:10.1167/iovs.17-21551

PMID:28622398

Abstract

PURPOSE

To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA).

METHODS

Participants with healthy retinas were recruited for ocular biometry, refraction, and RTVue XR Avanti OCTA imaging with the 3 × 3-mm protocol. The foveal and parafoveal SRVD and FAZA were quantified with custom software before and after correction for magnification error using the Littman and the modified Bennett formulae. Relative changes between corrected and uncorrected SRVD and FAZA were calculated.

RESULTS

Forty subjects were enrolled and the median (range) age of the participants was 30 (18-74) years. The mean (range) spherical equivalent refractive error was -1.65 (-8.00 to +4.88) diopters and mean (range) axial length was 24.42 mm (21.27-28.85). Images from 13 eyes were excluded due to poor image quality leaving 67 for analysis. Relative changes in foveal and parafoveal SRVD and FAZA after correction ranged from -20% to +10%, -3% to +2%, and -20% to +51%, respectively. Image size correction in measurements of foveal SRVD and FAZA was greater than 5% in 51% and 74% of eyes, respectively. In contrast, 100% of eyes had less than 5% correction in measurements of parafoveal SRVD.

CONCLUSIONS

Ocular biometry should be performed with OCTA to correct image magnification error induced by axial length variation. We advise caution when interpreting interocular and interindividual comparisons of SRVD and FAZA derived from OCTA without image size correction.

摘要

目的

使用光学相干断层扫描血管造影（OCTA）评估图像放大率校正对视网膜浅表血管密度（SRVD）和黄斑无血管区面积（FAZA）测量的影响。

方法

招募视网膜健康的参与者进行眼部生物测量、验光，并采用3×3-mm方案进行RTVue XR Avanti OCTA成像。使用Littman公式和改良的Bennett公式在校正放大率误差前后，用定制软件对黄斑和黄斑旁的SRVD以及FAZA进行量化。计算校正前后SRVD和FAZA的相对变化。

结果

纳入40名受试者，参与者的年龄中位数（范围）为30（18 - 74）岁。平均（范围）等效球镜屈光不正为-1.65（-8.00至+4.88）屈光度，平均（范围）眼轴长度为24.42 mm（21.27 - 28.85）。由于图像质量差，排除了13只眼的图像，剩余67只眼用于分析。校正后黄斑和黄斑旁SRVD以及FAZA的相对变化分别为-20%至+10%、-3%至+2%和-20%至+51%。在测量黄斑SRVD和FAZA时，分别有51%和74%的眼图像大小校正大于5%。相比之下，在测量黄斑旁SRVD时，100%的眼校正小于5%。