Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York City, New York, USA.
Ophthalmology, Icahn School of Medicine at Mount Sinai, New York City, New York, USA.
Br J Ophthalmol. 2020 Apr;104(4):473-479. doi: 10.1136/bjophthalmol-2019-314567. Epub 2019 Jul 23.
BACKGROUND/AIMS: To assess foveal avascular zone (FAZ) morphology and parafoveal capillary perfusion in patients with various stages of sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A).
This is a multi-institutional retrospective study of patients with various stages of SCR compared with healthy controls. Parafoveal OCT-A images obtained using a commercial spectral domain-OCT system were reviewed. Foveal-centred 3×3 mm full vascular slab OCT-As were used for image processing and data analysis. FAZ area, perimeter, and acircularity index were determined on the OCT-A image after manual delineation of the FAZ border. Quadrant-based parafoveal capillary density and per cent area deviating from normal distribution were also measured.
Fifty-two patients with SCR (33 non-proliferative and 19 proliferative) and 20 age and race-matched healthy controls were included. One randomly selected eye per study participant was analysed. FAZ perimeter and acircularity index were significantly greater in SCR eyes when compared with the controls. While parafoveal capillary density was significantly lower, per cent area deviated from normal distribution was significantly higher in SCR eyes than that of the control. However, no statistically significant difference between the two SCR stages was observed. In quadrant-based analysis, the temporal quadrant showed greater parafoveal capillary dropout due to SCR, with the most profound effect in patients with proliferative SCR.
Abnormal FAZ morphology and altered parafoveal capillary perfusion were found in patients with SCR. Our customised OCT-A image analysis method uniquely highlights significant quantitative alterations in perfusion density mapping in a qualitative display, with minimal obscuration of OCT-A image detail.
背景/目的：利用光相干断层扫描血管造影术（OCT-A）评估各种镰状细胞视网膜病变（SCR）患者的中心凹无血管区（FAZ）形态和旁中心凹毛细血管灌注。
这是一项多中心回顾性研究，比较了各种阶段 SCR 患者与健康对照者。使用商业谱域-OCT 系统获得旁中心凹 OCT-A 图像。使用 3×3mm 全血管 OCT-A 进行图像处理和数据分析。在手动描绘 FAZ 边界后，在 OCT-A 图像上确定 FAZ 区域、周长和非圆度指数。还测量了基于象限的旁中心凹毛细血管密度和偏离正常分布的百分比区域。
共纳入 52 例 SCR 患者（33 例非增殖性和 19 例增殖性）和 20 例年龄和种族匹配的健康对照者。每位研究参与者随机选择一只眼进行分析。与对照组相比，SCR 眼的 FAZ 周长和非圆度指数明显更大。而旁中心凹毛细血管密度明显降低，SCR 眼偏离正常分布的百分比区域明显高于对照组。然而，两个 SCR 阶段之间没有统计学上的显著差异。在基于象限的分析中，由于 SCR，颞象限的旁中心凹毛细血管丢失更明显，而增殖性 SCR 患者的影响最为严重。
在 SCR 患者中发现了异常的 FAZ 形态和旁中心凹毛细血管灌注改变。我们的定制化 OCT-A 图像分析方法独特地突出了在定性显示中灌注密度图的显著定量改变，同时最小化了 OCT-A 图像细节的遮挡。
