RESUMEN
BackgroundSweep pattern visual evoked potential(SPVEP) acuity,as an objective detective technique of visual function,can be used to measure visual acuity in children and uncooperative adults.Recent studies have shown that the amplitude-logarithm of the visual angle (A-LogVA) function regression method was more accurate than the amplitude-spatial frequency (A-SP)function regression method in evaluating SPVEP acuity.Objective This study was to explore the clinical use of SPVEP acuity in visual developing children and compare the evaluating the SPVEP acuity of children between A-SP function regression method and A-LogVA function regression method.Methods Twenty-six eyes of 26 asthenopic children with age range of 3-12 years and 31 age-matched normal children were enrolled in this study.SPVEP acuity was recorded with GT-2000 NV ( GUOTE MEDICAL APPARATUS LTD,China) using sinusoidally modulated horizontal gratings of 10 different spatial frequencies from 0.99 to 12.89 cpd as stimulus.The responses were averaged and displayed through discrete Fourier transformations (DFT) on the monitor display.SPVEP acuity was estimated by using both the SPVEP A-SP function regression method and the SPVEP A-LogVA function regression method.The LogMAR chart was used to acquire LogMAR visual acuity.ResultsIn the normal group,the correlation coefficient between LogMAR visual acuity and acuity calculated by the A-SP function regression method was 0.600 (P＜0.01).The correlation coefficient between LogMAR visual acuity and acuity calculated by the A-LogVA function regression method was 0.733 ( P＜0.01 ).The ANOVA of the LogMAR acuity and the SPVEP acuity calculated from the A-SP function regression method and A-LogVA function regression method were 113.173 (P＜0.01 ),which indicated that there were significant difference among all of subjects.The differences of the mean values of LogMAR visual acuity and the SPVEP acuity calculated from the A-SP function regression method and A-LogVA function regression method were respectively 0.40±0.02,0.26 ±0.02 and 0.14 ± 0.02.In the amblyopia group,the correlation coefficient between LogMAR visual acuity and acuity calculated by the A-SP function regression method was 0.134 (P =0.515 ).The correlation coefficient between LogMAR visual acuity and acuity calculated by the A-LogVA function regression method was 0.456 ( P＜0.05 ).The ANOVA of the LogMAR acuity and the SPVEP acuity calculated from the A-SP function regression method and A-LogVA function regression method were 3.433 (P＜0.05),indicating that there were significant difference among all of subjects.The differences of the mean values of LogMAR visual acuity and the SPVEP acuity calculated from the A-SP function regression method and A-LogVA function regression method were 0.07±0.05,0.12±0.05 and 0.05 ±0.01 respectively.Conclusions SPVEP can evaluate the visual acuity in children,although SPVEP acuity may overestimate or underestimate acuity in comparison with different LogMAR visual acuities.The amplitude-LogVA function regression method is more accurate in extrapolating SPVEP acuity.