Intraocular lens power selection in the second eye of patients undergoing bilateral, sequential cataract extraction

Purpose: To determine if the 1-month postoperative error of predicted refraction of the first eye can be used to alter intraocular lens (IOL) power selection and improve refractive results for the second eye in patients undergoing bilateral, sequential phacoemulsification with IOL implantation (phaco/IOL).

Design: Retrospective, consecutive, case series.

Participants: Three hundred consecutive patients who underwent uncomplicated bilateral, sequential phaco/IOL between January 1, 2006, and December 31, 2007, by a single surgeon using a single IOL platform.

Methods: The observed second eye 1-month postoperative spherical equivalent refractive error was compared with calculations of the hypothetic 1-month postoperative spherical equivalent refractive error if the first eye error had been fully or partially incorporated into the choice of IOL power for the second eye. The optimal amount of partial adjustment was determined.

Main outcome measures: The error of predicted refraction: the difference between the actual or hypothetic spherical equivalent refractive errors and those predicted by preoperative calculations.

Results: A total of 206 patients met inclusion criteria. The average of the absolute value of the unadjusted second eye error (|E(UNADJ)|) was +0.44 diopters (D) compared with +0.42 D for the fully adjusted second eye error (|E(FULL)|). The optimal amount of adjustment of the second eye IOL power was determined to be 50%; the average of the absolute value of this partially adjusted second eye error (|E(PARTIAL,50%)|) was +0.36 D; this was statistically different from |E(UNADJ)| (P<0.0001) and |E(FULL)| (P = 0.001). The statistically significant benefit was observed for patients with either myopic or hyperopic errors in the first eye. The percentages of patients achieving postoperative refractions within 0.5 D and 1.0 D of the predicted refraction were 66.5% and 90.3%, respectively, for the unadjusted second eye, 67.0% and 90.8%, respectively, for the hypothetic fully adjusted second eye, and 74.3% and 93.7%, respectively, for the hypothetic partially adjusted (50%) second eye.

Conclusions: Accounting for 50% of the observed error of predicted refraction of the first eye reduced the error of predicted refraction in the second eye. This novel methodology has the potential to improve the refractive outcomes in the second eye of patients with cataract.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.