Application Of Flash Visual Evoked Potentials Examination For Postoperative Visual Acuity Estimation In Cataract Eyes

Objective To evaluate the preoperative flash visual evoked potentials (FVEP) estimation for postoperative visual acuity in cataract eyes.Methods 130 cataract eyes (95 patients) underwent preoperative routine FVEP examinations.62 eyes (38 patients) were presented as normal control group.All best corrected visual acuities(BCVA) were obtained 1 month after operation and all eyes underwent FVEP examinations again 1 week after operation.Latency and amplitude would be analyzed as well as the integrality of the wave P₂.Results In the 78 eyes with normal preoperative FVEP compared with the normal control group, there were 3 eyes with postoperative BCVA≤0.1(3.85% ), 2 eyes 0.2-0.3(2.56% ), 5 eyes 0.4-0.8(17% ), and 68 eyes>0.8 (87.2% ) .Yet in the 52 cases with abnormal preoperative FVEP, there are 9 eyes with postoperative BCVA≤0.1 (17.3%), 6 eyes 0.2-0.3 (11.5%),17 eyes 0.4-0.8 (32.7%), and 20 eyes>0.8 (38.5%) .The FVEP's pseudo-positive ratio is 28.5% for the postoperative estimation of visual acuity in cataract eyes and the pseudo-negative ratio is 3.9%.And the predictive reliability of FVEP is 66.9%.The difference to latency and amplitude was not significant among different lens opacity, and the same to the pre- and postoperative eyes. Amplitude of FVEP kept more consistency to BCVA compared with latency.Conclusion The normality of preoperative FVEP highly indicates good prognosis of visual acuity.However the prognostic value in preoperative abnormal cases is still to be investigated.So Clinically attentions should be paid especially in abnormal FVEP eyes to insure that the chances should never be given up easily.