Ataş Ferdane, Kayabaşı Mustafa, Saatci Ali Osman
Department of Ophthalmology, Çerkezköy State Hospital, Tekirdağ, Turkey.
Department of Ophthalmology, Dokuz Eylul University, Mustafa Kemal Sahil Bulvarı, No:73 A Blok, Daire 9, Narlıdere-Izmir, Izmir, Turkey.
Photodiagnosis Photodyn Ther. 2022 Dec;40:103181. doi: 10.1016/j.pdpdt.2022.103181. Epub 2022 Nov 1.
To evaluate and compare the vessel density (VD) using swept-source optical coherence tomography angiography (OCT-A) and the choroidal vascularity index (CVI) using spectral-domain optical coherence tomography (SD-OCT) in patients with Bietti crystalline dystrophy (BCD) and retinitis pigmentosa (RP).
A cross-sectional retrospective study was conducted on 26 eyes of 13 BCD patients, 26 eyes of 13 RP patients, and 26 eyes of 13 age- and gender-matched healthy individuals. BCD patients were further staged as having early, intermediate, and advanced disease. VD was assessed in five quadrants of the macula (superior, temporal, inferior, nasal, and center) using a modified ETDRS technique with OCT-A. SD-OCT scans were binarized using Niblack's autolocal threshold, and CVI was determined as the ratio of the luminal area to the total choroidal area.
A significant difference was found in VD in all quadrants of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) slabs among the three groups (p < 0.001). A statistically significant difference was noted in the mean VD of temporal and inferior quadrants of the SCP and between the BCD and RP groups (p = 0.005, p = 0.015, respectively). A statistically significant difference was observed in the mean VD of the temporal, inferior, and nasal quadrants between the BCD and RP groups on DCP slabs (p = 0.002, p = 0.003, p = 0.003, respectively). The mean central choroidal thickness was 214.65±87.10 μm in the BCD group, 351.69±67.94 μm in the RP group, and 320.92±59.26 μm in the control group (p < 0.001). We found that CVI was significantly higher in the control group than BCD group (p < 0.001), and it was significantly lower in the BCD group when compared to the RP group (p < 0.001).There was no difference in CVI between RP and control groups (p = 0.948). Furthermore, the CVI was significantly lower in the intermediate and advanced disease stages than the early disease stage in the subgroup analysis of BCD patients (p < 0.001, p < 0.001, respectively).
CVI is a novel investigative tool to monitor disease progression. The CVI value was lower in BCD and RP patients than in the healthy subjects, and lower CVI values seem to be related to the disease severity in BCD patients. VD was also significantly lower in BCD patients when compared to RP patients, and VD analysis may help clinicians better understand the disease pathophysiology.
使用扫频源光学相干断层扫描血管造影（OCT-A）评估和比较比埃蒂结晶状营养不良（BCD）和视网膜色素变性（RP）患者的血管密度（VD），并使用频域光学相干断层扫描（SD-OCT）评估和比较脉络膜血管指数（CVI）。
对13例BCD患者的26只眼、13例RP患者的26只眼以及13例年龄和性别匹配的健康个体的26只眼进行了横断面回顾性研究。BCD患者进一步分为早期、中期和晚期疾病阶段。使用改良的ETDRS技术和OCT-A在黄斑的五个象限（上方、颞侧、下方、鼻侧和中心）评估VD。使用Niblack自动局部阈值对SD-OCT扫描进行二值化处理，并将CVI确定为管腔面积与脉络膜总面积的比值。
三组之间浅表毛细血管丛（SCP）和深部毛细血管丛（DCP）层所有象限的VD均存在显著差异（p < 0.001）。SCP颞侧和下方象限的平均VD以及BCD组和RP组之间存在统计学显著差异（分别为p = 0.005，p = 0.015）。在DCP层上，BCD组和RP组之间颞侧、下方和鼻侧象限的平均VD存在统计学显著差异（分别为p = 0.002，p = 0.003，p = 0.003）。BCD组的平均脉络膜中央厚度为214.65±87.10μm，RP组为351.69±67.94μm，对照组为320.92±59.26μm（p < 0.001）。我们发现对照组的CVI显著高于BCD组（p < 0.001），与RP组相比，BCD组的CVI显著更低（p < 0.001）。RP组和对照组之间的CVI无差异（p = 0.948）。此外，在BCD患者的亚组分析中，中期和晚期疾病阶段的CVI显著低于早期疾病阶段（分别为p < 0.001，p < 0.001）。
CVI是一种监测疾病进展的新型研究工具。BCD和RP患者的CVI值低于健康受试者，较低的CVI值似乎与BCD患者的疾病严重程度相关。与RP患者相比，BCD患者的VD也显著更低，VD分析可能有助于临床医生更好地理解疾病病理生理学。
