Cataract patients suspected of having disease which might interfere with good postoperative visual function were referred for evaluation. Monocular steady-state luminance visual evoked potentials (VEPs) were elicited with closed eyes at a stimulus rate of 10 flashes/sec. VEPs were rated as either normal or abnormal. Patients with normal VEPs were predicted to have an acuity of 6/15 (20/50) or better. Patients with abnormal VEPs were predicted to have acuities of 6/18 (20/60) or worse. Postoperative acuities were determined for all patients who underwent surgery and who had no intraoperative or early postoperative complications. The association of preoperative VEPs and observed postoperative acuities were quantitatively compared by a 2 x 2 contingency table for the 59 eyes which met these criteria. The chi-square was significant (p less than 0.001). The overall accuracy of prediction was 76%. Accuracy was 80% for patients with a preoperative acuity of 6/60 (20/200) or better and 75% for those whose postoperative acuity was 6/120 (20/400) or worse. This difference was not statistically significant.

No abstract

Many tests of visual function have been proposed as means of preoperatively evaluating cataract patients' surgical outcomes. It is impractical to compare all of these tests simultaneously on the same group of patients. Quantitative reviews apply quantitative methods to comparisons across studies. We compared the results of 52 reports in which cataract patients' postoperative acuity was predicted by means of visually evoked potential, laser interferometry, or projection tests (potential acuity meters-pinhole). The results of each study were summarized in a 2 x 2 contingency table. Summary statistics were compared by means of analysis of variance and post hoc tests. Despite difficulties in metaanalysis, we found the visually evoked potential a better predictor with dense opacities. We recommend standardization in a quest for more precise predictions of postoperative visual acuity.

Cataract patients whose surgical outcomes were in question were referred for testing by visual evoked potentials, elicited through closed eyelids by a luminance stimulus (flash) that appeared 10 times per second. Visual evoked potentials were rated as normal (predicted acuity of 20/50 or better) or abnormal (predicted acuity of 20/60 or worse). Postoperative Arden and Optronix contrast sensitivities and visual acuities were determined in 37 patients who had no intraoperative or early postoperative complications. Arden grating scores of less than 100 were rated as normal. The optimal and cutoff spatial frequency values were determined for the Optronix scores. Optimal and cutoff values of greater or equal to 1 c/deg and 12 c/deg, respectively, were rated as normal. Visual acuities were considered normal at 20/50 or better. Preoperative visual evoked potentials were quantitatively compared to the postoperative contrast sensitivities and visual acuities by 2 x 2 contingency tables. The accuracy of prediction was 79% for the visual acuities, 62% for the Optronix optimal values, 70% for the Optronix cutoff values and 62% for the Arden gratings.