Impact of Best Corrected Final Visual Acuity on the Performance of Intraocular Lens Power Calculations.

Abstract

Purpose: To evaluate the impact of the best-corrected final visual acuity (BCFVA) on the accuracy of intraocular lens (IOL) power calculations.

Design setting and methods: This is a retrospective observational study in a private practice setting, Lynwood, California, USA. We analyzed 1107 eyes undergoing standard monofocal cataract surgery, with IOL power calculated using the Barrett Universal II formula. We evaluated the Mean Prediction Error (MPE) and its standard deviation (SD), the Mean Absolute Error (MAE) and its SD and the percentage of eyes within ±0.50D and ±1.00D in relation to BCFVA.

Results: We analyzed 4 groups with BCFVA noted in LogMAR of ≤0.00, 0.02-0.10, 0.12-0.20 and 0.22-0.30. MPE was -0.030±0.321, -0.018±0.353, 0.015±0.369 and 0.070±0.421 D, respectively. MAE was 0.263±0.186, 0.282±0.213, 0.301±0.214 and 0.354±0.236 D, respectively. The percentage of eyes within ±0.50D was 85.9%, 82.6%, 81.5% and 75.5%, respectively. A subgroup analysis of the 1005 eyes with BCFVA of 0.20 LogMAR or better resulted in an MPE of -0.007±0.354 D, a MAE of 0.285±0.209 D and a percentage of eyes within ±0.50D of 82.8%. The difference between this subgroup and the group of eyes with a BCFVA 0.22-0.30 was statistically significant (p<0.001).

Conclusion: Better IOL power predictions were noted by limiting the study to eyes with BCFVA of 0.20 LogMAR or better.