Measurement and use of postoperative anterior chamber depth of fellow eye in refractive outcomes

Purpose To compare refractive outcomes using fellow-eye postoperative anterior chamber depth (ACD) in intraocular lens (IOL) power calculations with outcomes obtained without fellow-eye data and to assess postoperative ACD stability. Setting Johns Hopkins University, Baltimore, Maryland, USA. Design Consecutive case series. Methods The main outcome measures were the optimized median absolute error (MedAE) and ACD at postoperative day 1 and postoperative month 1 measured by optical biometry. A program using the Olsen IOL power formula predicted the postoperative ACD and refractive outcomes and calculated theoretical refractive outcomes of inputting fellow-eye ACD at postoperative day 1 and postoperative month 1. Theoretical results were subtracted from the observed manifest refraction and then optimized. Calculations were repeated for the other eye. Results In 102 paired eyes, the MedAE was 0.32 diopter (D) (interquartile range, 25% to 75%; range 0.12 to 0.54 D) for Olsen (without fellow-eye data), 0.33 D (range 0.20 to 0.57 D) using fellow-eye postoperative day 1 ACD, and 0.28 D (range 0.13 to 0.51 D) using fellow-eye postoperative month 1 ACD, with a significant difference between the latter 2 MedAE values (P <.0005). In eyes with an Olsen absolute error greater than 0.50 D, use of either ACD in the fellow eye resulted in a smaller MedAE (P ≤.01). The ACD shallowed by a mean of 148 μm 13 (SD). Conclusions Use of the fellow-eye postoperative month 1 ACD predicted refractive outcomes better than postoperative day 1 ACD. In eyes with a larger Olsen absolute error, use of either postoperative ACD from the fellow eye would have yielded better results. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.