Intraoperative aberrometry compared to preoperative Barrett True-K formula for intraocular lens power selection in eyes with prior refractive surgery

Abstract

To compare the predictive refractive accuracy of intraoperative aberrometry (ORA) to the preoperative Barrett True-K formula in the calculation of intraocular lens (IOL) power in eyes with prior refractive surgery undergoing cataract surgery at the Loma Linda University Eye Institute, Loma Linda, California, USA. We conducted a retrospective chart review of patients with a history of post-myopic or hyperopic LASIK/PRK who underwent uncomplicated cataract surgery between October 2016 and March 2020. Pre-operative measurements were performed utilizing the Barrett True-K formula. Intraoperative aberrometry (ORA) was used for aphakic refraction and IOL power calculation during surgery. Predictive refractive accuracy of the two methods was compared based on the difference between achieved and intended target spherical equivalent. A total of 97 eyes (69 patients) were included in the study. Of these, 81 eyes (83.5%) had previous myopic LASIK/PRK and 16 eyes (16.5%) had previous hyperopic LASIK/PRK. Median (MedAE)/mean (MAE) absolute prediction errors for preoperative as compared to intraoperative methods were 0.49 D/0.58 D compared to 0.42 D/0.51 D, respectively (P = 0.001/0.002). Over all, ORA led to a statistically significant lower median and mean absolute error compared to the Barrett True-K formula in post-refractive eyes. Percentage of eyes within ± 1.00 D of intended target refraction as predicted by the preoperative versus the intraoperative method was 82.3% and 89.6%, respectively (P = 0.04). Although ORA led to a statistically significant lower median absolute error compared to the Barrett True-K formula, the two methods are clinically comparable in predictive refractive accuracy in patients with prior refractive surgery.

Intraoperative aberrometry: an update on applications and outcomes

“…They also reported that the percentage of patients within ±0.5D of target was 56% for intraoperative aberrometry and 47% for Barrett-True K ( P = 0.289) [28 ▪ ]. Other studies with smaller numbers of post-hyperopic ablation patients have shown a similar mean absolute error of approximately 0.5D without significant difference from preoperative calculations [20 ▪▪ ,29,45]. Intraoperative aberrometry may be more accurate in post-hyperopic ablation cases with short axial length in comparison to those with intermediate or long axial length [28 ▪ ].…”

“…Post-myopic ablation patients are the largest subset of post-refractive patients undergoing cataract surgery, and early approaches to IOL calculation in these patients were unreliable [48]. There has been significant interest in using intraoperative aberrometry in post-myopic ablation patients to improve outcomes, and multiple studies have examined utility in these patients [20 29,42,[45][46][47][48][49][50][51]55]. In fact, the ORA device was initially validated based on a study of its use in post-myopic ablation eyes [48].…”

Advanced Optical Wavefront Technologies to Improve Patient Quality of Vision and Meet Clinical Requests

“…Here, we outline that wavefront-guided devices do not stop with custom ablation. Wavefront devices have come a long way since the original bulky prototypes first used, and now researchers are experimenting with numerous exciting prospects [ 140 , 141 , 142 ]. Now that some of the devices are so small, the possibilities are virtually limitless.…”

Intraocular lens power calculation in eyes with previous corneal refractive surgery

“…Therefore, the authors attribute clinically comparable predictive refractive accuracy to both approaches. 56 …”

“…Therefore, the authors attribute clinically comparable predictive refractive accuracy to both approaches. 56 IOL power calculation after SMILE SMILE as the latest development in the field of laser-ablative CRS has become clinically available in 2011. The technique employs a femtosecond (fs) laser, which in contrast to the excimer laser is capable of dissecting spherocylindrical and aspheric lenticule fragments instead of just planar sections.…”