Katsumi O, Arai M, Wajima R, Denno S, Hirose T
Department of Ophthalmology, Harvard Medical School, Boston, Massachuetts 02114, USA.
Vision Res. 1996 Mar;36(6):903-9. doi: 10.1016/0042-6989(95)00187-5.
The effect of artificially induced image defocusing on visual acuities (VAs) measured by spatial frequency sweep pattern reversal visual evoked response (SPVER) and Snellen measurement was studied in six normal subjects. The steady-state SPVER was recorded using vertical gratings of 10 different spatial frequencies ranging from 0.52 to 30.36 c/deg. The SPVER acuity was compared with Snellen acuity (SA) measured under the same conditions of optical defocus. With moderate defocusing [< + 1.0 diopter (D), VA > 20/40], the SPVER acuities were equal to or poorer than the SAs. With more defocus (> + 1.5 D, VA < 20/70), the SPVER acuities became better than the SAs. The discrepancies between the SA and SPVER acuities may be the result of the influence of the parafoveal area on the SPVER at lower visual acuity levels.
在六名正常受试者中，研究了人工诱导图像散焦对通过空间频率扫描模式反转视觉诱发电位（SPVER）和斯内伦测量法所测得的视力（VA）的影响。使用10种不同空间频率（范围为0.52至30.36周/度）的垂直光栅记录稳态SPVER。将SPVER视力与在相同光学散焦条件下测得的斯内伦视力（SA）进行比较。在中度散焦[< + 1.0屈光度（D），视力> 20/40]时，SPVER视力等于或低于SA。在散焦程度更大（> + 1.5 D，视力< 20/70）时，SPVER视力变得优于SA。SA和SPVER视力之间的差异可能是由于在较低视力水平时旁中央凹区域对SPVER产生影响的结果。
