PHACOEMULSIFICATION, CAPSULORHEXIS, AND INTRAOCULAR-LENS POWER PREDICTION ACCURACY

Phacoemulsification with capsulorhexis reduces the surgical variabilit y and may result in a more predictable refractive outcome. To evaluate the prediction accuracy with current lOL power prediction formulas, w e reviewed a retrospective series of 628 phacoemulsification cases, in cluding 148 short (<22 mm) and 80 long (>25 mm) eyes. Using the Binkho rst II formula and the manufacturer's recommended anterior chamber dep th (ACD) values, the mean absolute refractive prediction error was 0.5 6 diopters (D). This error could be reduced to 0.51 D by retrospective ly optimizing the ACD values for each lens type. Under similar least e rror conditions, the mean error was 0.51 D with the SRK/T formula and 0.47 D with the Olsen formula (P <.01). The Binkhorst formula overesti mated the refraction in short eyes and underestimated the refraction i n long eyes. The SRK/T and the Olsen formula were unbiased with the ax ial length. We hypothesize that the high prediction accuracy may be pa rtially explained by a more predictable pseudophakic ACD with the curr ent surgical technique.