Che Ning-Ning, Jiang Qiu-Huan, Ding Guan-Xiao, Chen Si-Yuan, Zhao Zhen-Xiang, Li Xue, Malik Rayaz A, Ma Jian-Jun, Yang Hong-Qi
Department of Neurology, Henan Provincial People's Hospital, School of Clinical Medicine, Henan University, Zhengzhou, China.
Department of Neurology, Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China.
NPJ Parkinsons Dis. 2021 Sep 9;7(1):80. doi: 10.1038/s41531-021-00225-3.
Cognitive impairment in Parkinson's disease (PD) adversely influences quality of life. There is currently no available biomarker to predict cognitive decline in PD. Corneal confocal microscopy (CCM) has been used as a non-invasive tool for quantifying small nerve damage in PD. The present study investigated whether corneal nerve measures were associated with cognitive function in PD. Patients with PD were classified into those with normal cognitive function (PD-CN), mild cognitive impairment (PD-MCI), and dementia (PDD). Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) were quantified with CCM and compared with a control group. Sixty-five PD patients and thirty controls were studied. CNFD was decreased and CNBD was increased in PD patients compared to controls (P < 0.05). CNBD and CNBD/CNFD ratio was higher in PD-CN compared to controls. CNFD was positively correlated with the Montreal cognitive assessment (MoCA) score (r = 0.683, P < 0.001), but negatively associated with unified Parkinson disease rating scale (UPDRS)-part III (r = -0.481, P < 0.001) and total UPDRS scores (r = -0.401, P = 0.001) in PD patients. There was no correlation between CNFD and Levodopa equivalent daily dose (LEDD) (r = 0.176, P = 0.161). CNFD, CNBD, CNFL, and CNBD/CNFD ratio was lower with increasing Hoehn and Yahr stage. PD patients show evidence of corneal nerve loss compared with controls and corneal nerve parameters are associated with the severity of cognitive and motor dysfunction in PD. CCM could serve as an objective in vivo ophthalmic imaging technique to assess neurodegeneration in PD.
帕金森病（PD）中的认知障碍会对生活质量产生不利影响。目前尚无可用的生物标志物来预测PD患者的认知衰退。角膜共焦显微镜检查（CCM）已被用作一种非侵入性工具，用于量化PD中的小神经损伤。本研究调查了角膜神经测量指标是否与PD患者的认知功能相关。PD患者被分为认知功能正常（PD-CN）、轻度认知障碍（PD-MCI）和痴呆（PDD）三组。使用CCM对角膜神经纤维密度（CNFD）、角膜神经分支密度（CNBD）和角膜神经纤维长度（CNFL）进行量化，并与对照组进行比较。共研究了65例PD患者和30例对照。与对照组相比，PD患者的CNFD降低，CNBD增加（P < 0.05）。与对照组相比，PD-CN组的CNBD和CNBD/CNFD比值更高。在PD患者中，CNFD与蒙特利尔认知评估（MoCA）评分呈正相关（r = 0.683，P < 0.001），但与统一帕金森病评定量表（UPDRS）第三部分（r = -0.481，P < 0.001）和UPDRS总分（r = -0.401，P = 0.001）呈负相关。CNFD与左旋多巴等效日剂量（LEDD）之间无相关性（r = 0.176，P = 0.161）。随着Hoehn和Yahr分期增加，CNFD、CNBD、CNFL和CNBD/CNFD比值降低。与对照组相比，PD患者存在角膜神经丢失的证据，且角膜神经参数与PD患者认知和运动功能障碍的严重程度相关。CCM可作为一种客观的体内眼科成像技术，用于评估PD中的神经退行性变。
