September 2019

ASCRS NEWS

Using the first eye prediction error in cataract surgery to refine the refractive outcome of the second eye


by Andrew Turnbull, FRCOphth, Graham Barrett, MD

Purpose: To refine the refractive outcome of the second eye following cataract surgery, by deriving adjustment coefficients for intraocular lens selection based on the prediction error (PE) of the first eye.
Setting: University Hospital Southampton, Southampton, U.K.; Lions Eye Institute, Perth, Australia
Design: Retrospective study of two heterogeneous datasets
Methods: 139 patients who underwent delayed sequential bilateral cataract surgery (DSBCS) in Australia were retrospectively analyzed. PE was determined by comparing postoperative subjective refraction with the predicted postoperative refraction (PPOR) calculated by the Barrett Universal II (BUII), Hoffer Q, Holladay I, and SRK/T formulae. Adjustment coefficients were derived for each formula and applied to the second eye’s IOL calculation. Separately, patient-specific optimized IOL constants were derived from the first eye PE and applied to the second eye calculation. The same adjustments were applied to a dataset of 605 U.K. patients, to test the validity of the Australian results.
Results: Australian-derived adjustment coefficients based on PE ranged from 0.30 to 0.56 (BUII 0.30; Hoffer Q 0.56; Holladay I 0.53; SRK/T 0.48). Applying these to the U.K. dataset led to the percentage of patients within 0.50 D of PPOR with their second eye improving from 70.74%, 65.29%, 69.09%, 67.77%, with BUII, Hoffer Q, Holladay I, and SRK/T respectively, to 72.73%, 68.76%, 71.57%, and 72.56%. Using patient-specific optimized IOL constants derived from the first eye had similar efficacy to formula-specific adjustment.
Conclusions: Second-eye refinement via either formula-specific PPOR adjustment or patient-specific IOL constant adjustment improves the percentage of patients achieving the refractive target with their second eye.

Using the first eye prediction error in cataract surgery to refine the refractive outcome of the second eye Using the first eye prediction error in cataract surgery to refine the refractive outcome of the second eye
Ophthalmology News - EyeWorld Magazine
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2019-09-03T10:42:37Z
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