AIM: To discuss visual acuity assessment after cataract surgery by pattern reversal visual evoked potential.

METHODS:Data of 72 adult cataract patients received PRVEP before and after phaco and IOL in Department of Ophthalmology, Tongji Hospital from October 2012 to May 2013 was analyzed retrospectively. A total of 114 eyes were studied, including 76 eyes with senile cataract and 38 eyes with complicated cataract. According to the degree of lens opacity and the hardness of lens nucleus, these data were divided into two groups: Group 1(gradeⅠ, Ⅱ, Ⅲ )and Group 2(grade Ⅳ, Ⅴ )and was statistically studied with correlation analysis.

RESULTS: Group 1:(1)Preoperative: the average of visual acuity was 0.344, the incubation time of P₁₀₀ wave was 107ms and the amplitude of N₇₅- P₁₀₀ wave was 4.633μV; postoperative: the average of visual acuity was 0.672, the incubation time of P₁₀₀ wave was 104.37ms and the amplitude of N₇₅- P₁₀₀ wave was 4.400μV.(2)The visual acuity before and after operation were both significantly negatively correlated with the incubation time of P₁₀₀ wave(P<0.01)and significantly positively correlated with the amplitude of N₇₅- P₁₀₀ wave(preoperative: P<0.01,postoperative: P<0.05);(3)The improved rows of the visual acuity before and after operation showed no relationship with the change of the incubation time of P₁₀₀ wave. Group 2:(1)Preoperative: the average of visual acuity was 0.116,the incubation time of P₁₀₀ wave was 118.905ms and the amplitude of N₇₅-P₁₀₀ wave was 1.650μV; postoperative: the average of visual acuity was 0.576, the incubation time of P₁₀₀ wave was 108.429ms and the amplitude of N₇₅- P₁₀₀ wave was 5.132μV.(2)The visual acuity before operation was significantly negatively correlated with the incubation time of P₁₀₀ wave(P<0.05),while the visual acuity after operation showed no relationship with the incubation time of P₁₀₀ wave; the visual acuity before and after operation showed no relationship with the amplitude of N₇₅- P₁₀₀ wave.(3)The improved rows of the visual acuity before and after operation showed no relationship with the change of the incubation time of P₁₀₀ wave.

CONCLUSION:According to the correlation among the visual acuity, the incubation time of P₁₀₀ wave and the amplitude of N₇₅- P₁₀₀ wave, PRVEP is significantly affected by preoperative visual acuity(the degree of opacity in refractive media). PRVEP is not helpful as an indicator of visual prognosis after cataract surgery, and PRVEP before cataract surgery has no clinical significance.