Department of Ophthalmology, University of Health Sciences, Ulucanlar Eye Education and Research Hospital, Ankara, Turkey.
Department of Biophysics, Faculty of Medicine, Gazi University, Ankara, Turkey.
Eye (Lond). 2022 Aug;36(8):1615-1622. doi: 10.1038/s41433-021-01700-0. Epub 2021 Jul 23.
To analyse choroidal vascular properties using an image binarization tool in patients with asymmetric pseudoexfoliative glaucoma (PXG) and compare them with healthy individuals.
This cross-sectional study included 144 eyes of 96 patients. The eyes were divided into three groups: 48 glaucomatous eyes and 48 non-glaucomatous contralateral eyes with no clinically observable pseudoexfoliation material of patients with asymmetric PXG, and 48 control eyes. Enhanced depth imaging optical coherence tomography scans of the macula and 3.4-mm diameter, 360-degree circle scans of the optic nerve head were binarized using ImageJ software (National Institutes of Health, Bethesda, MD, USA). The choroidal vascularity index (CVI) was calculated as the ratio of the luminal area to the total circumscribed choroidal area.
The macular CVI (mCVI) was significantly lower in the glaucomatous eyes than in the fellow eyes (p = 0.007) and the control eyes (p = 0.001). The peripapillary CVI (pCVI) in all sectors was significantly lower in the glaucomatous eyes than in the other two groups (all p < 0.05). Non-glaucomatous fellow eyes had lower CVI values in the macula and in the peripapillary region, except for the superior-nasal and nasal sectors, compared to the control eyes (all p < 0.05). In multivariate regression analysis, while the cup-to-disc ratio was negatively associated with the pCVI, AL was negatively associated with the mCVI in both eyes of patients with PXG.
CVI was decreased in the macula and peripapillary area in glaucomatous eyes. Furthermore, the CVI tended to decrease in non-glaucomatous fellow eyes of PXG patients. This finding may suggest subclinical involvement and require further exploration into the pathogenesis of glaucoma.
利用图像二值化工具分析不对称性假性剥脱性青光眼（PXG）患者的脉络膜血管特性，并与健康个体进行比较。
本横断面研究纳入了 96 例患者的 144 只眼。将这些眼分为三组：48 只青光眼眼和 48 只非青光眼对侧眼，这些眼的患者均无临床可见的假性剥脱物质，但存在不对称性 PXG；48 只对照眼。使用 ImageJ 软件（美国国立卫生研究院，贝塞斯达，MD）对黄斑和视神经头 3.4mm 直径、360°圆形扫描的增强深度成像光学相干断层扫描图像进行二值化处理。脉络膜血管指数（CVI）计算为管腔面积与总脉络膜面积的比值。
青光眼眼的黄斑 CVI（mCVI）明显低于对侧眼（p=0.007）和对照眼（p=0.001）。所有象限的视盘周围 CVI（pCVI）在青光眼眼中均明显低于其他两组（均 p<0.05）。除了上鼻侧和鼻侧象限外，非青光眼对侧眼的黄斑和视盘周围区域的 CVI 值均低于对照眼（均 p<0.05）。多元回归分析显示，在 PXG 患者的双眼中，杯盘比与 pCVI 呈负相关，而眼轴长度与 mCVI 呈负相关。
青光眼眼中黄斑和视盘周围区域的 CVI 降低。此外，PXG 患者的非青光眼对侧眼的 CVI 也有降低的趋势。这一发现可能提示存在亚临床受累，需要进一步探讨青光眼的发病机制。
