Amega Dillys A D, Haldina Julia, Toews Ingrid, Philippin Heiko, Hoffmann Michael B, Morny Enyam K A, Heinrich Sven P
Department of Vision Science, School of Optometry and Vision Science, University of Cape Coast, Cape Coast, Ghana.
Eye Center, Medical Center, University of Freiburg, Killianstr. 5, 79106, Freiburg, Germany.
Doc Ophthalmol. 2025 Jul 31. doi: 10.1007/s10633-025-10044-z.
Objective estimation of visual acuity (VA) based on visual evoked potentials (VEPs) has become an established technique for cases where psychophysical VA might be unreliable. Refractive errors and improper accommodation could undesirably affect the outcome of VA measurements. Consequently, it is of interest whether a VA reduction due to dioptric blur is reflected by VEP-based estimation of VA.
We degraded vision in 19 participants to nearly 1.0 logMAR by using either plus lenses or a filter that creates Gaussian blur. For both types of degradation, we compared the outcomes of objective VEP-based VA testing to standard psychophysical VA. For comparison, we also obtained psychophysical grating VA.
With Gaussian blur, both values, VEP-based VA and psychophysical Landolt-C VA, were nearly identical. With dioptric blur, VEP-based VA was better than psychophysical Landolt-C VA in all participants by an average of 0.37 logMAR with some interindividual variability. Psychophysical grating VA was only relatively mildly affected by blur with no sizable differential effect of blur type.
VEP-based estimation of VA does not reveal the full amount of VA reduction in the case of dioptric blur. On the one hand, this decreases VEP-based methods' susceptibility to incorrect refraction and mis-accommodation, which are not normally the targeted causes of VA reduction. On the other hand, it reduces the accuracy in quantifying refraction-related impairments of vision with VEPs.
基于视觉诱发电位（VEP）对视敏度（VA）进行客观评估，已成为一种成熟的技术，适用于心理物理学视敏度可能不可靠的情况。屈光不正和不适当的调节可能会对视敏度测量结果产生不良影响。因此，基于VEP的视敏度评估是否能反映因屈光性模糊导致的视敏度降低，这一点备受关注。
我们通过使用正透镜或产生高斯模糊的滤光片，将19名参与者的视力降低至接近1.0 logMAR。对于这两种类型的视力降低，我们将基于VEP的客观视敏度测试结果与标准心理物理学视敏度进行了比较。为作比较，我们还获得了心理物理学光栅视敏度。
在高斯模糊的情况下，基于VEP的视敏度和心理物理学兰多尔特C视敏度这两个值几乎相同。在屈光性模糊的情况下，所有参与者基于VEP的视敏度均优于心理物理学兰多尔特C视敏度，平均相差0.37 logMAR，个体间存在一定差异。心理物理学光栅视敏度仅受到模糊的相对轻微影响，且模糊类型没有显著的差异效应。
在屈光性模糊的情况下，基于VEP的视敏度评估并未揭示视敏度降低的全部程度。一方面，这降低了基于VEP的方法对不正确验光和调节异常的敏感性，而这些通常不是视敏度降低的目标原因。另一方面，它降低了用VEP量化与屈光相关的视力损害的准确性。
