Department of Medical Electronics, B.M.S. College of Engineering, Bangalore, India; University Eye Clinic Maastricht, Maastricht University, Maastricht, the Netherlands.
Dept. of Psychiatry, National Institute of Mental Health and Neurosciences, Bangalore, India.
Schizophr Res. 2019 Oct;212:26-32. doi: 10.1016/j.schres.2019.08.020. Epub 2019 Aug 26.
The micro-vasculature of retina and brain share common morphological, physiological, and pathological properties. Retina being easily accessible, retinal vascular examination provides an indirect assessment of cerebral vasculature. Considering the high prevalence of vascular morbidity in SCZ and BD a few studies have examined retinal vascular caliber and have reported increased retinal venular caliber in schizophrenia (SCZ). Retinal vascular tortuosity could serve as a better structural measure than caliber as it is static and less susceptible to pulse period variations. However, to date, no study has examined retinal vascular tortuosity in SCZ and bipolar disorder (BD). Hence, we examined retinal vascular tortuosity in comparison with healthy volunteers (HV). We included 255 subjects (78 HV, 79 SCZ, and 86 BD) in the age range of 18 to 50 years. Trained personnel acquired images using a non-mydriatic fundus camera. To measure the average retinal arteriolar tortuosity index (RATI) and retinal venular tortuosity index (RVTI), we used a previously validated, semi-automatic algorithm. The results showed significant differences across the three groups in RATI but not in RVTI; both BD and SCZ had significantly increased RATI compared to HV. There was also a significant difference between SCZ and BD, with BD having higher RATI. If shown to be of predictive utility in future longitudinal studies, it has the potential to identify patients at risk of development of adverse vascular events. As retinal vascular imaging is non-invasive and inexpensive, it could serve as a proxy marker and window to cerebral vasculature.
视网膜和大脑的微血管具有共同的形态、生理和病理特征。由于视网膜容易接近，因此对视网膜血管的检查可以间接评估脑血管。鉴于精神分裂症和双相情感障碍患者的血管发病率较高，一些研究已经检查了视网膜血管口径，并报告精神分裂症患者视网膜静脉口径增加。与口径相比，视网膜血管迂曲度可以作为更好的结构测量指标，因为它是静态的，不易受到脉搏周期变化的影响。然而，迄今为止，尚无研究检查过精神分裂症和双相情感障碍患者的视网膜血管迂曲度。因此，我们将视网膜血管迂曲度与健康志愿者进行了比较。我们纳入了年龄在 18 至 50 岁之间的 255 名受试者（78 名健康志愿者、79 名精神分裂症患者和 86 名双相情感障碍患者）。经过培训的人员使用非散瞳眼底相机获取图像。为了测量平均视网膜小动脉迂曲指数（RATI）和视网膜小静脉迂曲指数（RVTI），我们使用了先前验证的半自动算法。结果显示，在 RATI 方面，三组之间存在显著差异，但在 RVTI 方面没有差异；与健康志愿者相比，双相情感障碍和精神分裂症患者的 RATI 均显著增加。精神分裂症和双相情感障碍患者之间也存在显著差异，双相情感障碍患者的 RATI 更高。如果在未来的纵向研究中显示出预测效用，它有可能识别出有发生不良血管事件风险的患者。由于视网膜血管成像具有非侵入性和低成本的特点，它可以作为脑血管的替代标志物和窗口。
