Related Experiment Video
Updated: Jan 5, 2026
05:14
Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter
Published on: September 16, 2025
523
Intraoperative Aberrometry Versus Preoperative Biometry for IOL Power Selection After Radial Keratotomy: A
Journal of Refractive Surgery (Thorofare, N.J. : 1995)
|October 15, 2019
Summary
Accurate cataract surgery outcomes depend on precise refractive error prediction. In eyes with prior radial keratotomy, the Barrett True-K formula demonstrated superior accuracy compared to other methods, including intraoperative aberrometry.
Area of Science:
- Ophthalmology
- Refractive Surgery
- Biometry
Background:
- Radial keratotomy (RK) can complicate intraocular lens (IOL) power calculations for cataract surgery.
- Accurate prediction of postoperative refractive error is crucial for achieving desired visual outcomes.
Purpose of the Study:
- To compare the accuracy of intraoperative aberrometry (ORA) with traditional preoperative biometry formulas in predicting residual refractive error after cataract surgery in eyes with a history of RK.
- To evaluate the performance of the Barrett True-K formula against other established formulas and ORA in this specific patient cohort.
Main Methods:
- A prospective study involving 52 eyes of 34 patients with cataract and prior RK.
- Preoperative IOL power calculation using partial coherence interferometry (IOLMaster) and the Barrett True-K formula.
- Prediction of residual refractive error using SRK/T, Hoffer Q, Haigis, Holladay 1 & 2 formulas preoperatively, and ORA intraoperatively.
- Comparison of predicted refraction with actual postoperative refraction 8-12 weeks after surgery.
Main Results:
- The Barrett True-K formula showed the lowest median absolute error (0.34 D).
- A significantly higher proportion of eyes achieved a refractive outcome within ±0.50 D using the Barrett True-K formula (63.5%) compared to SRK/T, Hoffer Q, and Holladay 1 formulas (P=.03).
- ORA aberrometry performance was comparable to the Barrett True-K and other formulas regarding median absolute error.
Conclusions:
- The Barrett True-K formula is a highly accurate method for IOL power calculation in eyes with prior RK.
- ORA aberrometry offers comparable accuracy to established formulas in this challenging patient group.
- Achieving refractive targets in post-RK eyes requires careful consideration of specialized formulas like the Barrett True-K.
