Zhang Minfang, Ouyang Wangbin, Wang Hao, Meng Xiaohong, Li Shiying, Yin Zheng Qin
Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, PR China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, PR China.
Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, PR China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, PR China.
Clin Neurophysiol. 2021 Feb;132(2):392-403. doi: 10.1016/j.clinph.2020.11.023. Epub 2021 Jan 13.
The current methods used to assess visual function in blind retinitis pigmentosa (RP) patients are mostly subjective. We aimed to identify effective, objective methods.
We enrolled patients diagnosed with blindness associated with RP; we finally selected 26 patients (51 eyes) with a visual field radius less than 10 degrees and divided them into the following 4 groups by best-corrected visual acuity (BCVA): group 1, no light perception (NLP, 4 eyes); group 2, light perception (LP, 12 eyes); group 3, hand movement or finger counting (faint form perception, FFP, 22 eyes); and group 4, BCVA from 0.1 to 0.8 (form perception, FP, 13 eyes). All patients underwent optometry, optical coherence tomography (OCT), color fundus photography, fundus autofluorescence (FAF), full field electroretinography (ffERG), pattern electroretinography (PERG), multifocal electroretinography (mf-ERG), pattern visual evoked potential (PVEP), flash visual evoked potential (FVEP), and pupillary light response (PLR) assessments. Five patients in groups 1, 2, and 3 (1, 2, and 2 subjects, respectively) underwent functional magnetic resonance imaging (fMRI) scans and were compared with five healthy subjects.
The outer plexiform layer was thinner in group 1, and the outer nuclear layer was thinner in groups 1 and 2. The ffERG, PERG, and mf-ERG findings were unrecordable in all four groups. The P2 amplitude of the FVEP was significantly lower in groups 1 and 2, while the P100 amplitude of the PVEP was higher in groups 2, 3 and 4 than in group 1. After white- and blue-light stimuli, the PLR thresholds in the patients without form perception were significantly higher. The threshold of the PLR stimulated by blue and white light was negatively correlated with the amplitudes of P2 and P100. Moreover, the fMRI findings showed that some RP patients have significant visual cortex activation in response to certain types of stimulation. However, statistical analysis was not performed because of the small number of cases.
OCT, VEP, PLR and fMRI assessments can evaluate residual visual pathway function in blind RP patients.
Our study may have clinical significance for the potential prediction of RP patient prognoses and the effects after clinical trials.
目前用于评估盲人视网膜色素变性（RP）患者视觉功能的方法大多是主观的。我们旨在确定有效、客观的方法。
我们招募了被诊断为与RP相关的失明患者；最终选择了26例患者（51只眼），其视野半径小于10度，并根据最佳矫正视力（BCVA）将他们分为以下4组：第1组，无光感（NLP，4只眼）；第2组，光感（LP，12只眼）；第3组，手动或指动计数（微弱形态感知，FFP，22只眼）；第4组，BCVA为0.1至0.8（形态感知，FP，13只眼）。所有患者均接受了验光、光学相干断层扫描（OCT）、彩色眼底照相、眼底自发荧光（FAF）、全视野视网膜电图（ffERG）、图形视网膜电图（PERG）、多焦视网膜电图（mf-ERG）、图形视觉诱发电位（PVEP）、闪光视觉诱发电位（FVEP）和瞳孔光反应（PLR）评估。第1、2和3组中的5例患者（分别为1、2和2名受试者）接受了功能磁共振成像（fMRI）扫描，并与5名健康受试者进行了比较。
第1组的外丛状层较薄，第1组和第2组的外核层较薄。所有四组的ffERG、PERG和mf-ERG结果均无法记录。第1组和第2组的FVEP的P2波幅显著降低，而第2、3和4组的PVEP的P100波幅高于第1组。在白光和蓝光刺激后，无形态感知的患者的PLR阈值显著更高。蓝光和白光刺激的PLR阈值与P2和P100的波幅呈负相关。此外，fMRI结果显示，一些RP患者在对某些类型的刺激做出反应时具有显著的视觉皮层激活。然而，由于病例数较少，未进行统计分析。
OCT、VEP、PLR和fMRI评估可以评估盲人RP患者的残余视觉通路功能。
我们的研究可能对RP患者预后的潜在预测以及临床试验后的效果具有临床意义。
