Vu Alexander F, Alber Susan A, Chang Melinda Y, Park Susanna S
Department of Ophthalmology and Vision Science (AFV, MYC, SSP), University of California Davis Eye Center, Sacramento, California; Department of Public Health Sciences/Biostatistics (SAA), Clinical and Translational Science Center, University of California Davis, Sacramento, California; Vision Center (MYC), Children's Hospital of Los Angeles, Los Angeles, California; and Department of Ophthalmology (MYC), Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California.
J Neuroophthalmol. 2022 Mar 1;42(1):73-78. doi: 10.1097/WNO.0000000000001216. Epub 2021 Apr 14.
Optical coherence tomography angiography (OCTA) is a new noninvasive imaging modality that provides high resolution images of the optic nerve head and peripapillary retinal capillary vasculature which can be affected by optic nerve or retinal pathologies. High repeatability of peripapillary capillary density measurement using OCTA has been demonstrated in normal eyes and eyes with glaucoma. The purpose of our study was to quantify the repeatability of peripapillary capillary density measurement using OCTA in both normal eyes and eyes with optic atrophy, optic disc edema, and retinal vasculopathy.
This prospective cross-sectional study enrolled 31 patients (59 eyes) including 16 eyes with optic nerve pathology (7 with disc edema from papilledema and 9 with optic atrophy), 35 eyes with retinal vascular disease, and 8 normal eyes. All eyes were imaged twice (30 minutes apart) with the Optovue AngioVue OCTA instrument to obtain 4.5 × 4.5 mm peripapillary scans. Scans were considered good quality if signal strength was 6 or greater. The OCTA parameters obtained include the radial peripapillary capillary (RPC) density of the whole disc, inside the disc, peripapillary region, and the 4 quadrants of the disc (superior, nasal, inferior, and temporal). A Student's t test was used to compare means. Intraclass correlation coefficient (ICC) was calculated to measure repeatability.
Repeatability of RPC density measurements for all regions analyzed demonstrated good to excellent repeatability for the whole cohort {ICC for the whole image was 0.915 (95% confidence interval [CI] = 0.855-0.951)}; ICC for the peripapillary region was 0.945 (95% CI = 0.905-0.969). In the subset of eyes with good image quality (i.e., signal strength ≥ 6), ICC was slightly higher for all regions, with excellent repeatability of the peripapillary region (ICC was 0.971 [95% CI = 0.943-0.986]). Conversely, for eyes with poor image quality scans (i.e., signal strength < 6), ICC was lower, corresponding to moderate to good repeatability for most parameters. For the subset of eyes with optic atrophy, disc edema from papilledema or retinal vasculopathy, all had good to excellent repeatability of the vessel density of the entire disc (ICC values were 0.954 [95% CI = 0.804-0.990], 0.921 [95% CI = 0.711-0.982], and 0.895 [95% CI = 0.788-0.951, respectively]) and of the peripapillary region (ICC values were 0.980 [95% CI = 0.904-0.996], 0.966 [95% CI = 0.854-0.993], and 0.916 [95% CI = 0.827-0.961], respectively).
The peripapillary capillary density measurement obtained using a commercial OCTA instrument is highly repeatable in eyes with optic nerve atrophy, disc edema from papilledema, or retinal vasculopathy.
光学相干断层扫描血管造影（OCTA）是一种新型无创成像方式，可提供视神经乳头和视乳头周围视网膜毛细血管脉管系统的高分辨率图像，而这些结构可能会受到视神经或视网膜病变的影响。在正常眼睛和青光眼患者的眼睛中，已证实使用OCTA测量视乳头周围毛细血管密度具有较高的可重复性。本研究的目的是量化在正常眼睛以及患有视神经萎缩、视盘水肿和视网膜血管病变的眼睛中，使用OCTA测量视乳头周围毛细血管密度的可重复性。
这项前瞻性横断面研究纳入了31例患者（59只眼睛），其中包括16只患有视神经病变的眼睛（7只因视乳头水肿导致视盘水肿，9只患有视神经萎缩）、35只患有视网膜血管疾病的眼睛以及8只正常眼睛。使用Optovue AngioVue OCTA仪器对所有眼睛进行两次成像（间隔30分钟），以获取4.5×4.5mm的视乳头周围扫描图像。如果信号强度为6或更高，则认为扫描图像质量良好。获得的OCTA参数包括整个视盘、视盘内部、视乳头周围区域以及视盘的四个象限（上、鼻、下、颞）的视乳头周围放射状毛细血管（RPC）密度。使用Student t检验比较均值。计算组内相关系数（ICC）以测量可重复性。
对于所有分析区域的RPC密度测量，整个队列显示出良好至极好的可重复性{整个图像的ICC为0.915（95%置信区间[CI]=0.855 - 0.951）}；视乳头周围区域的ICC为0.945（95%CI = 0.905 - 0.969）。在图像质量良好（即信号强度≥6）的眼睛子集中，所有区域的ICC略高，视乳头周围区域具有极好的可重复性（ICC为0.971[95%CI = 0.943 - 0.986]）。相反，对于图像质量较差的扫描眼睛（即信号强度<6），ICC较低，大多数参数对应中等至良好的可重复性。对于患有视神经萎缩、视乳头水肿导致的视盘水肿或视网膜血管病变的眼睛子集，整个视盘的血管密度（ICC值分别为0.954[95%CI = 0.804 - 0.990]、0.921[95%CI = 0.711 - 0.982]和0.895[95%CI = 0.788 - 0.951]）以及视乳头周围区域的血管密度（ICC值分别为0.980[95%CI = 0.904 - 0.996]、0.966[95%CI = 0.854 - 0.993]和0.916[95%CI = 0.827 - 0.961]）均具有良好至极好的可重复性。
使用商用OCTA仪器获得的视乳头周围毛细血管密度测量在患有视神经萎缩、视乳头水肿导致的视盘水肿或视网膜血管病变的眼睛中具有高度可重复性。
