Objectives: To study the virtual reality-pattern visual evoked potential (VR-PVEP) P100 waveform characteristics of monocular visual impairment with different impaired degrees under simultaneous binocular perception and monocular stimulations.
Methods: A total of 55 young volunteers with normal vision (using decimal recording method, far vision ≥0.8 and near vision ≥0.5) were selected to simulate three groups of monocular refractive visual impairment by interpolation method. The sum of near and far vision ≤0.2 was Group A, the severe visual impairment group; the sum of near and far vision <0.8 was Group B, the moderate visual impairment group; and the sum of near and far vision ≥0.8 was Group C, the mild visual impairment group. The volunteers' binocular normal visions were set as the control group. The VR-PVEP P100 peak times measured by simultaneous binocular perception and monocular stimulation were compared at four spatial frequencies 16×16, 24×24, 32×32 and 64×64.
Results: In Group A, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 24×24, 32×32 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group B, the differences between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at 16×16, 24×24 and 64×64 spatial frequencies were statistically significant (P<0.05); and the P100 peak time of normal vision eyes at 64×64 spatial frequency was significantly different from the simulant visual impairment eyes (P<0.05). In Group C, there was no significant difference between P100 peak times of simulant visual impairment eyes and simultaneous binocular perception at all spatial frequencies (P>0.05). There was no significant difference in the P100 peak times measured at all spatial frequencies between simulant visual impairment eyes and simultaneous binocular perception in the control group (P>0.05).
Conclusions: VR-PVEP can be used for visual acuity evaluation of patients with severe and moderate monocular visual impairment, which can reflect the visual impairment degree caused by ametropia. VR-PVEP has application value in the objective evaluation of visual function and forensic clinical identification.
目的: 研究单眼不同程度视觉损伤情况下，双眼同时刺激与单眼刺激时虚拟现实-图像视觉诱发电位（virtual reality-pattern visual evoked potential，VR-PVEP） P100波形的特点。方法: 选取视力正常（采用小数记录法，远视力≥0.8且近视力≥0.5）的青年志愿者55名，使用插片法模拟单眼屈光不正视觉损伤，分别使单眼近视力与远视力之和≤0.2（A组，即重度视觉损伤）、0.2<近视力与远视力之和<0.8（B组，即中度视觉损伤）、近视力与远视力之和≥0.8（C组，即轻度视觉损伤）。同时，将双眼正常视力设为对照组。在16×16、24×24、32×32、64×64 4种空间频率下对单眼和双眼同时刺激所测得的VR-PVEP P100峰时进行比较。结果: A组中视觉损伤眼与双眼同时视测得的P100峰时在24×24、32×32和64×64空间频率下的差异均有统计学意义（P<0.05），视觉损伤眼与健眼测得的P100峰时在64×64空间频率下的差异具有统计学意义（P<0.05）。B组中视觉损伤眼与双眼同时视测得的P100峰时在16×16、24×24和64×64空间频率下的差异均有统计学意义（P<0.05），视觉损伤眼与健眼测得的P100峰时在64×64空间频率下的差异具有统计学意义（P<0.05）。C组中视觉损伤眼与双眼同时视测得的P100峰时在全空间频率下的差异均无统计学意义（P>0.05）。对照组的单眼视与双眼同时视测得的P100峰时在全空间频率下的差异均无统计学意义（P>0.05）。结论: VR-PVEP可用于对单眼中、重度视觉损伤者进行视力评估，能够反映屈光不正导致的视觉损伤眼的视力损伤程度，在视觉功能客观评定及法医临床鉴定中具有应用价值。.
Keywords: ametropia; forensic medicine; virtual reality-pattern visual evoked potential; vision; visual impairment; wounds and injuries.