Narayana Nethralaya, Rajajinagar, Bangalore, India.
Narayana Nethralaya, Hulimavu, Bangalore, India.
Br J Ophthalmol. 2018 Mar;102(3):352-357. doi: 10.1136/bjophthalmol-2017-310637. Epub 2017 Jul 24.
To compare the intrasession repeatability of peripapillary and macular vessel density measurements of optical coherence tomography angiography (OCTA) in normal and glaucoma eyes, and to evaluate the effect of signal strength of OCTA scans on the repeatability.
In a cross-sectional study, three optic nerve head scans each of 65 eyes (30 normal, 35 glaucoma eyes) and three macular scans each of 69 eyes (35 normal, 34 glaucoma eyes) acquired in the same session with OCTA were analysed. Repeatability was assessed using within-subject coefficient of repeatability (CRw) and variation (CVw). Effect of signal strength index (SSI) on repeatability was evaluated with repeated-measures mixed-effects models.
CRw (%) and CVw (%) of peripapillary measurements in normal eyes ranged between 3.3 and 7.0, and 2.5 and 4.4 respectively, and that in glaucoma eyes between 3.5 and 7.1, and 2.6 and 6.6. For the macular, these measurements ranged between 4.1 and 6.0, and 3.3 and 4.7 in normal eyes and 4.3 and 6.9, and 3.7 and 5.6 in glaucoma eyes. Repeatability estimates of most measurements were similar in normal and glaucoma eyes. Vessel densities of both peripapillary and macular regions significantly increased with increase in SSI of repeat scans (coefficients ranging from 0.15 to 0.38, p<0.01 for all associations).
Repeatability estimates of OCTA measured peripapillary and macular vessel densities were similar in normal eyes and eyes with glaucoma. SSI values of the scans had a significant effect on the repeatability of OCTA with the vessel density values increasing in scans with higher SSI values.
比较正常眼和青光眼眼中光学相干断层扫描血管造影（OCTA）的视盘周围和黄斑血管密度测量的日内重复性，并评估 OCTA 扫描信号强度对重复性的影响。
在一项横断面研究中，分析了同一次 OCTA 获得的 65 只眼（30 只正常眼，35 只青光眼眼）的 3 个视神经头扫描和 69 只眼（35 只正常眼，34 只青光眼眼）的 3 个黄斑扫描。使用个体内重复性系数（CRw）和变异系数（CVw）评估重复性。使用重复测量混合效应模型评估信号强度指数（SSI）对重复性的影响。
正常眼中视盘周围测量的 CRw（%）和 CVw（%）分别为 3.3%至 7.0%和 2.5%至 4.4%，青光眼眼中分别为 3.5%至 7.1%和 2.6%至 6.6%。对于黄斑，这些测量值在正常眼中分别为 4.1%至 6.0%和 3.3%至 4.7%，在青光眼眼中分别为 4.3%至 6.9%和 3.7%至 5.6%。大多数测量的重复性估计值在正常眼和青光眼眼中相似。随着重复扫描 SSI 的增加，视盘周围和黄斑区域的血管密度均显著增加（所有关联的系数范围为 0.15 至 0.38，p<0.01）。
在正常眼和青光眼眼中，OCTA 测量的视盘周围和黄斑血管密度的重复性估计值相似。扫描的 SSI 值对 OCTA 的重复性有显著影响，随着 SSI 值较高的扫描中血管密度值的增加，重复性也会增加。
