A large retrospective database analysis comparing outcomes of intraoperative aberrometry with conventional preoperative planning

Visual Function After Implantation of Trifocal and Trifocal Toric Intraocular Lenses Using Intraoperative Aberrometry

Purpose

To evaluate patient outcomes and visual function following trifocal and trifocal toric intraocular lens (IOL) implantation using intraoperative aberrometry at a single site in the US.

Methods

This prospective, single arm study included 21 subjects that completed 3 month follow-up. Inclusion criteria were visually significant cataract and potential post-operative visual acuity of 20/25 or better. Endpoints included postoperative prediction error, refractive outcomes, uncorrected visual acuities at distance (UDVA), intermediate (UIVA), and near (UNVA), contrast sensitivity, and subject responses on the modified Visual Function Quality of Life Questionnaire (VF-14 QOL).

Results

Binocular UDVA, UIVA, and UNVA were 20/25 or better in 100% (21/21), 100% (21/21), 90% (19/21) of subjects. The absolute prediction error was 0.50 D or less in 79% (33/42) of eyes, and 81% (34/42) and 86% (36/42) of eyes achieved ≤0.5 D of residual astigmatism and manifest refraction spherical equivalent, respectively. On the modified VF-14 QOL, driving at night, reading small print, and reading a newspaper or book were the tasks that had the lowest percentages of subjects reporting no difficulty or a little difficulty.

Conclusion

Implantation with trifocal and trifocal toric IOLs using intraoperative aberrometry can provide high refractive precision, leading to excellent visual performance and low visual task difficulty at all ranges (distance, intermediate, and near).

Comparing clinical outcomes of Optiwave Refractive Analysis, Lenstar, and surgeon's modified method for intraocular lens power calculation in Asian eyes

The study aimed to compare the accuracy of intraocular lens (IOL) calculation to predict postoperative refraction by Optiwave Refractive Analysis (ORA), Lenstar LS 900, and the surgeon's Modify method in normal Asian eyes. The IOL power of the Lenstar group was calculated according to Lenstar LS 900, whereas the surgeon's Modify group used topography, axial length (AL) of Lenstar, and Barrett Universal II online formula. Intraoperative aphakic measurements and IOL power calculations were obtained with the ORA system. From the results acquired through Lenstar, Modify, and ORA, the surgeon used his judgment to select the actual IOL power. Postoperative manifest refraction spherical equivalent (MRSE) was obtained 2 months after surgery. The prediction error (PE) was calculated as the difference between the postoperative MRSE and the target refraction proposed by three methods. AL, anterior chamber depth (ACD, measured from corneal endothelium to lens), lens thickness (LT), and ACD + 1/2LT were also included in the survey. In 67 eyes, the average real PE was smaller for the Lenstar (0.06 ± 0.44) and Modify (- 0.05 ± 0.40) than for the ORA group (- 0.25 ± 0.60, p < 0.05). The ORA system demonstrated the best results of IOL power selection in eyes with a normal range of ACD + 0.5 LT (5.2-5.6 mm) in Asian eyes.

Prediction accuracy of intraoperative aberrometry compared with preoperative biometry formulae for intraocular lens power selection

OBJECTIVE

To compare the accuracy of intraoperative wavefront aberrometry to preoperative biometry formulae for predicting intraocular lens power.

DESIGN

Retrospective, consecutive case series.

PARTICIPANTS

Eyes undergoing cataract extraction with at least 1 month of follow-up after surgery at an ambulatory surgical centre in Toronto.

METHODS

Consecutive sample of 228 cataract extractions with monofocal, trifocal, or toric intraocular lens implantation from November 1, 2017, to December 31, 2019. The spherical equivalent was predicted preoperatively with Barrett Universal II, Hill-Radial Basis Function (RBF), SRK/T, Holladay I, Holladay II, Haigis, and HofferQ using biometry measurements and intraoperatively with wavefront aberrometry. The primary outcomes were mean prediction error and proportion of eyes with a spherical equivalent within 0.5 D of the refractive target at postoperative month 1.

RESULTS

The analysis included 159 eyes with 52% females and a mean age of 69.4 years. Formulae with the lowest mean prediction error were Hill-RBF (0.32 D ± 0.02 D), Barrett Universal II (0.32 D ± 0.02 D), intraoperative aberrometry (0.32 D ± 0.02 D), SRK/T (0.33 D ± 0.02 D), Holladay II (0.34 D ± 0.03 D), Holladay I (0.35 D ± 0.02 D), Haigis (0.37 D ± 0.02 D), and HofferQ (0.42 D ± 0.02 D). There were no statistically significant differences between intraoperative aberrometry and the preoperative formulae. Formulae with the highest proportion of eyes within 0.5 D of the refractive target were intraoperative aberrometry (82%), Barrett Universal II (81%), Hill-RBF (80%), SRK/T (77%), Holladay II (76%), Holladay I (75%), Haigis (71%), and HofferQ (70%).

CONCLUSIONS

Intraoperative aberrometry and modern preoperative biometry formulae are equally effective at reaching the refractive target. In normal eyes, intraoperative aberrometry does not appear to provide any additional benefit to modern prediction formulae.

Intraoperative aberrometry: an update on applications and outcomes

PURPOSE OF REVIEW

There is now a large body of experience with intraoperative aberrometry. This review aims to synthesize available data regarding intraoperative aberrometry applications and outcomes.

RECENT FINDINGS

The Optiwave Refractive Analysis (ORA) System utilizes Talbot-moiré interferometry and is the only commercially available intraoperative aberrometry device. There are few studies that include all-comers undergoing intraoperative aberrometry-assisted cataract surgery, as most studies examine routine patients only or atypical eyes only. In non-post-refractive cases, studies have consistently shown a small but statistically significant benefit in spherical equivalent refractive outcome for intraoperative aberrometry versus preoperative calculations. In studies examining axial length extremes, most studies have shown intraoperative aberrometry to perform similarly to preoperative calculations. Amongst post-refractive cases, post-myopic ablation cases appear to benefit the most from intraoperative aberrometry. For toric intraocular lenses (IOLs), intraoperative aberrometry may be used for refining IOL power (toricity and spherical equivalent) and alignment, and most studies show intraoperative aberrometry to achieve low postoperative residual astigmatism.

SUMMARY

Intraoperative aberrometry can be utilized as an adjunct to preoperative planning and surgeon's judgment to optimize cataract surgery refractive outcomes. Non-post-refractive cases, post-myopic ablation eyes, and toric intraocular lenses may have the greatest demonstrated benefit in intraoperative aberrometry studies to date, but other eyes may also benefit from intraoperative aberrometry use.

Impact of Global Optimization of Lens Constants on Absolute Prediction Error for Final IOL Power Selection When Using Intraoperative Aberrometry

Purpose

To evaluate absolute prediction errors following phacoemulsification with implantation of a multifocal toric intraocular lens (IOL) using intraoperative aberrometry for IOL power selection and to compare findings with the globally optimized and manufacturer’s recommended lens constants and regression coefficients.

Methods

Data from the Optiwave Refractive Analysis (ORA SYSTEM) were analyzed retrospectively. Absolute prediction errors from surgeries performed before and after the first optimization of the manufacturer’s recommended lens constant and non-optimized regression coefficients for the multifocal toric IOL (SND1T3-6) were compared. Optimization was based on outcomes of procedures performed using the ORA SYSTEM and archived in its database (AnalyzOR). Outcome measures included the proportion of eyes with absolute ORA SYSTEM prediction errors ≤0.25 D and ≤0.5 D and the mean and median absolute prediction errors.

Results

The pre-optimization group included 1027 eyes operated on by 184 surgeons, and the optimized group included 419 eyes operated on by 143 surgeons. The proportions of eyes achieving absolute ORA SYSTEM prediction errors ≤0.25 D (52.5% vs 35.0%, p < 0.0001) and ≤0.50 D (83.1% vs 66.2%, p < 0.0001) were significantly higher in the optimized than in the pre-optimization group. The mean ± standard deviation (0.30 ± 0.25 D vs 0.43 ± 0.32 D, p < 0.0001) and median (0.24 D vs 0.36 D, p < 0.0001) absolute ORA SYSTEM prediction errors were significantly lower after than before optimization. Prediction errors following optimization were reduced more in eyes of average than of long and short axial lengths.

Conclusion

Global optimization of the manufacturer’s IOL lens constants and regression coefficients resulted in lower absolute prediction errors when compared with the initial manufacturer labeled lens constants and non-optimized regression coefficients. Reductions in absolute prediction error can result in lower postoperative residual refractive error, which can improve post-operative uncorrected visual acuity and provide the potential for greater patient satisfaction following cataract surgery.

Evaluation of Refractive Accuracy of ORA and the Factors Impacting Residual Astigmatism in Patients Implanted with Trifocal IOLs During Cataract Surgery: A Retrospective Observational Study

Purpose

Patients and Methods

Results

Conclusion

Refractive Outcomes Following Trifocal Intraocular Lens Implantation in Post-Myopic LASIK and PRK Eyes

Purpose

To assess refractive outcomes of a trifocal intraocular lens (IOL) in post-myopic laser refractive surgery eyes.

Methods

This was a retrospective chart review of 35 eyes (21 patients), with history of laser refractive surgery, who were implanted with a trifocal IOL. Surgeon’s standard procedure included femtosecond laser (FLACS), digital registration, and intraoperative aberrometry (IA). The primary outcome measure was absolute prediction error. Secondary measures were refractive outcomes, postoperative residual astigmatism (PRA), monocular uncorrected visual acuity at distance (UDVA; 4m), intermediate (UIVA; 60cm), and near (UNVA; 40cm), and monocular best-corrected visual acuity at distance (BCVA; 4m).

Results

At 3 months postoperatively, 71% and 68% of eyes had absolute prediction error 0.5 D or less with IA and preoperative planning respectively, which was not statistically significant (p > 0.05). The PRA was 0.5 D or less in 91% of eyes with IA and 56% of eyes with preoperative planning. The PRA differences between IA and preoperative planning were statistically significant (p < 0.002). The percentage of eyes 20/20 or better for monocular UCVA, BCVA, UIVA, and UNVA was 29%, 77%, 78%, and 66%, respectively. Absolute prediction error 0.5 D or less was significantly higher in post-LASIK eyes versus post-PRK eyes (p < 0.003), at 85% and 56% of eyes, respectively.

Conclusion

Implantation with a trifocal IOL can provide acceptable refractive and visual outcomes with minimal residual astigmatism in post-myopic LASIK and PRK eyes.

Predictability of combined cataract surgery and trabeculectomy using Barrett Universal Ⅱ formula

PURPOSE

To compare the predictability of intraocular lens (IOL) power calculation using the Barrett Universal II and the SRK/T formulas in eyes undergoing combined cataract surgery and trabeculectomy.

METHODS

We retrospectively reviewed the clinical charts of 56 consecutive eyes undergoing cataract surgery and trabeculectomy. IOL power calculations were performed using the Barrett Universal II and SRK/T formulas. We compared the prediction error, the absolute error, and the percentages within ± 0.5 D and ±1.0 D of the targeted refraction, 3 months postoperatively, and also investigated the relationship of the prediction error with the keratometric readings and axial length, using the two formulas.

RESULTS

The prediction error using the SRK/T formula was significantly more myopic than that using the Barrett Universal II formula (paired t-test, p<0.001). The absolute error using the Barrett Universal II formula was significantly smaller than that using the SRK/T formula (p = 0.039). We found significant correlations of the prediction error with the axial length (Pearson correlation coefficient, r = 0.273, p = 0.042), and the keratometric readings (r = -0.317, p = 0.017), using SRK/T formula, but no significant correlations between them (r = 0.219, p = 0.167, and r = -0.023, p = 0.870), using the Barrett Universal II formula.

CONCLUSIONS

The Barrett Universal II formula provides a better predictability of IOL power calculation and is less susceptible to the effect of the axial length and the corneal shape, than the SRK/T formula. The Barrett Universal formula, rather than the SRK/T formula, may be clinically helpful for improving the refractive accuracy in such eyes.

The Use of Intraoperative Aberrometry in Normal Eyes: An Analysis of Intraocular Lens Selection in Scenarios of Disagreement

PURPOSE

To compare prediction error outcomes between the Optiwave Refractive Analysis System (ORA) (Alcon Laboratories, Inc) and two modern intraocular lens (IOL) formulas (Hill-RBF2.0 [HRBF] and Barrett Universal II [BUII]), and further analyze IOL selection in scenarios of disagreement between methods.

METHODS

Patients with no previous history of corneal refractive surgery who underwent cataract extraction and had intraoperative aberrometry measurements between October 2016 and December 2019 were analyzed. The prediction error for the ORA, HRBF, and BUII were calculated based on the postoperative manifest refraction. Further analysis was performed evaluating prediction error for scenarios of disagreement between the three methods.

RESULTS

After exclusions, 281 eyes were included. The mean absolute prediction errors were 0.28 diopters (D) (ORA), 0.31 D (HRBF), and 0.33 D (BUII) (P < .05). In instances when the IOL recommended by the ORA was in disagreement with what was selected preoperatively, there was no benefit when the lens recommended by the ORA was selected based on anecdotal experience. When further analyzing these instances of disagreement, selecting the ORA-recommended lens when it is higher in power results in improved refractive outcomes: the ORA resulted in more eyes within ±0.25 diopters (D) of predicted spherical error (65% ORA, 37% HRBF, 32% BUII; P = .004) and fewer hyperopic surprises (5% ORA, 15% HRBF, 24% BUII; P = .009).

CONCLUSIONS

In normal eyes without previous corneal refractive surgery, intraoperative aberrometry is not different from to two modern preoperative IOL formulas. Placing the ORA-recommended lens when it is higher in power than that selected preoperatively results in better refractive outcomes. [J Refract Surg. 2022;38(5):304-309.].

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

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.

Predictive accuracy of an intraoperative aberrometry device for a new monofocal intraocular lens

PURPOSE

To evaluate refractive outcomes for the Clareon monofocal intraocular lens (IOL) in terms of achieved target refraction for the ORA (ALCON) intraoperative wavefront aberrometry device and preoperative noncontact biometry.

SETTING

University Eye Clinic Maastricht, Maastricht University Medical Center+, the Netherlands.

DESIGN

Prospective observational clinical trial.

METHODS

Patients with bilateral age-related cataracts undergoing phacoemulsification, either by delayed sequential surgery or on the same day, were included in the study. Exclusion criteria were an increased risk for refractive surprise or complicated surgery. Implanted IOL power was based on noncontact optical biometry data using the Barrett Universal II (BU-II) formula, optimized for the Clareon IOL. Postoperative subjective refraction was measured 4 to 6 weeks after surgery. Catquest-9SF questionnaires were completed preoperatively and 3 months after surgery.

RESULTS

100 eyes (51 patients) were included. The percentages of eyes within 1.0 diopters (D), 0.75 D, 0.50 D, and 0.25 D of target for ORA vs BU-II were 84% (84 eyes), 72% (72 eyes), 57% (57 eyes), and 21% (21 eyes) vs 97% (97 eyes), 88% (88 eyes), 77% (77 eyes), and 53% (53 eyes), respectively. Mean absolute prediction error was significantly higher for ORA vs preoperative biometry (P < .001). After global optimization, the prediction accuracy of ORA improved significantly (P < .001). Catquest-9SF questionnaires showed improved levels of ability at 3 months after surgery (P < .001).

CONCLUSIONS

This study showed lower percentages of eyes within target refraction for ORA (prior to lens constant optimization) compared with the BU-II formula when implanting the Clareon IOL. However, prediction accuracy of ORA improved significantly after global optimization. Therefore, further intraoperative measurements, postoperative measurements, and optimization are needed to improve the ORA prediction for this IOL.

Refractive Accuracy of Barrett True-K vs Intraoperative Aberrometry for IOL Power Calculation in Post-Corneal Refractive Surgery Eyes

Purpose

To compare the refractive predictability of intraoperative aberrometry (IA, ORA, Alcon) and Barrett True-K/Universal II formulas for intraocular lens (IOL) power calculations in post-corneal refractive surgery and normal eyes.

Methods

Retrospective study of normal and post-corneal refractive surgery eyes that underwent cataract surgery with IA at tertiary academic center. Preoperatively, IOL power calculations were performed using Barrett Universal II (normal eyes) or Barrett True-K (post-corneal refractive surgery eyes) formulas. Intraoperatively, aphakic IA measurements were used for IOL power calculations. Mean absolute refractive prediction error (MAE) and the percentage of eyes with prediction error within ±0.50, ±0.75 and ±1.00 D were calculated. Refractive predictability was also evaluated in short, normal, and long eyes.

Results

Two hundred and seventy-three eyes were included in the analysis. No statistically significant differences were observed between the MAE of preoperative formulas and IA for post-hyperopic laser vision correction (LVC), post-myopic LVC, post-radial keratotomy (RK) and normal eyes. For prediction error within ±0.5 D in post-corneal refractive surgery eyes, range of agreement between Barrett True-K and IA ranged from 28% (7/25) of the time in post-RK eyes to 49% (40/81) of the time in post-hyperopic LVC; the corresponding value for Barrett Universal II/IA was 62% (64/103) in normal eyes. When there was disagreement, IA outperformed Barrett True-K in post-hyperopic LVC eyes and Barrett formula outperformed IA in post-myopic LVC, post-RK, and normal eyes.

Conclusion

IA appears to be comparable to Barrett formulas for IOL power calculations in post-corneal refractive surgery and normal eyes. In post-hyperopic LVC, IA yields better results compared to Barrett True-K formula; in real-life scenarios, IA reveals statistical advantage over the Barrett True-K no history formula for eyes post-hyperopic LVC.

Refractive Outcomes Using Intraoperative Aberrometry for Highly Myopic, Highly Hyperopic, and Post-refractive Eyes

PURPOSE

To evaluate whether intraoperative aberrometry improves the accuracy of refractive outcomes after cataract surgery in highly myopic, highly hyperopic, and post-refractive eyes.

METHODS

This single-center, retrospective review compared the spherical equivalent of postoperative refraction to that predicted by the Barrett Universal II formula versus Optiwave Refractive Analysis (ORA) (Alcon Laboratories, Inc) for highly myopic and hyperopic eyes and to the Barrett True K formula versus ORA for post-refractive eyes. The number and magnitude of lens changes were analyzed and used to determine in how many cases refractive surprises were affected by ORA, with additional subanalysis of outcomes based on average keratometry values.

RESULTS

ORA led to a change in the lens power implanted in 48% (96 of 198) of eyes, and prevented hyperopic surprise in 27% (15 of 55) and excess myopia in 46% (19 of 41). Steeper keratometry values correlated with more frequent changes on ORA-recommended implanted intraocular lens (P = .0031). ORA led to a similar percentage of eyes falling within ±0.50, ±0.75, and ±1.00 diopters compared to the Barrett Universal II and Barrett True K formulas. In post-refractive eyes, ORA led to a similar mean absolute error when compared to the Barrett True K formula (P = .62). For highly myopic eyes with an axial length of greater than 27 mm, ORA demonstrated a trend toward lower mean absolute error when compared to the Barrett Universal II formula (P = .076).

CONCLUSIONS

ORA demonstrated similar refractive results to the Barrett True K formula in post-refractive eyes and to the Barrett Universal II formula in highly myopic and hyper-opic eyes and may provide additional benefit for eyes with steeper corneas or an axial length of greater than 27 mm. [J Refract Surg. 2021;37(9):609-615.].

Clinical Outcomes of Monofocal Toric IOLs Using Digital Tracking and Intraoperative Aberrometry

Purpose

To evaluate clinical outcomes of a toric IOL using digital tracking (DT) and intraoperative aberrometry (IA).

Methods

This was a retrospective, single surgeon study examining 151 eyes of 106 patients. Inclusion criteria were subjects who presented with visually significant cataracts (or as a candidate for clear lens extraction) and were implanted with a toric intraocular lens. Spherical equivalent prediction errors for IA and preoperative planning were calculated and compared. Preoperative and postoperative refractive data and monocular uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were also collected at 3 months postoperatively.

Results

Postoperative actual residual refractive astigmatism with IA was 0.50 D or less in 140 eyes (92.8%) and was 0.50 D or less in 88 eyes (58.3%) with back-calculations based on preoperative planning. The absolute spherical equivalent prediction error was 0.50 D or less in 135 eyes (89.4%) for IA compared to 123 eyes (85.4%) for preoperative planning. Postoperative monocular UDVA was 0.10 logMAR or better in 124 eyes (82.1%) and 0.00 logMAR or better in 90 eyes (59.6%). Postoperative CDVA was 0.10 logMAR or better in 147 eyes (97.4%) and 134 eyes (88.7%) were 0.00 logMAR or better.

Conclusion

The results demonstrate that toric implantation with DT and IA can provide excellent refractive and visual outcomes.

Repeatability of intraoperative Hartmann-Shack wavefront sensing in cataract surgery

PURPOSE

To evaluate the repeatability of aphakic intraoperative wavefront aberrometry and compare it with preoperative and postoperative aberrometry.

SETTING

Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

Patients scheduled for cataract surgery were each measured 3 consecutive times using Hartmann-Shack wavefront sensing (HS-WFS) preoperatively, intraoperatively in aphakia, and 2 months postoperatively after intraocular lens implantation by a single examiner. Intraclass correlation coefficients (ICCs) of spherical equivalent (SE) values were evaluated for each timepoint. Intrasubject standard deviation (Sw) as repeatability (Sr) with corresponding repeatability limit () and mean SE differences with corresponding limits of agreement (LoA) were calculated for comparison.

RESULTS

A high consistency of repeated measurements was found with ICCs above 0.9 for each of the 3 timepoints. Intraobserver repeatability (Sr) and repeatability limit (r) of intraoperative aberrometry SE measurements (30 eyes of 30 patients) were 0.34 diopters (D) and 0.95 D, respectively. The LoA for intraoperative aphakic SE across 3 consecutive measurements were -0.71 to +0.85 D. For comparison, Sr and r for phakic preoperative measurements in the cataractous state (30 eyes of 30 patients) and postoperative measurements in the pseudophakic state (24 eyes of 24 patients) were 0.33 D and 0.93 D and 0.23 D and 0.64 D, respectively. Similarly, the LoA for preoperative and postoperative SE measurements were -0.66 to +0.60 D and -0.27 to +0.45 D, respectively.

CONCLUSIONS

HS-WFS test-retest reliability was high for all 3 timepoints, but the intraoperative setting resulted in a lower repeatability and broadened the agreement range.

Clinical outcomes of a diffractive trifocal intraocular lens with femtosecond laser, digital tracking, and intraoperative aberrometry

OBJECTIVE

To evaluate clinical outcomes of a trifocal intraocular lens using femtosecond laser-assisted cataract surgery (FLACS), digital tracking (DT), and intraoperative aberrometry (IA).

SETTING

One site (Abbotsford, B.C., Canada) DESIGN: Retrospective, single-surgeon study.

METHODS

This was a retrospective, single-surgeon study examining 200 eyes of 100 bilaterally implanted patients. Eligible participants were those presenting with visually significant cataracts or as a candidate for clear lens extraction who were interested in implantation of a diffractive toric or non-toric intraocular lens. Preoperative and postoperative data were collected for manifest refraction spherical equivalent (MRSE), refractive astigmatism (RA), and monocular uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA).

RESULTS

Mean postoperative MRSE was 0.006 ± 0.27 D. The absolute prediction error was 0.50 D or less in 88.0% (176/200) of eyes. Postoperative RA was 0.50 D or less in 98.5% (197/200) of eyes. Postoperative UDVA was 0.10 logMAR or better in 86% (172/200) of eyes, and 66.0% (132/200) of eyes were 0.00 logMAR or better. Postoperative UIVA was 0.10 logMAR or better in 99.5% (199/200) of eyes, and 95.0% (190/200) of eyes were 0.00 logMAR or better. Postoperative UNVA was 0.10 logMAR or better in 91.5% (183/200) of eyes, and 73.5% (147/200) of eyes were 0.00 logMAR or better.

CONCLUSION

The results demonstrate that trifocal implantation with FLACS, DT, and IA can provide excellent refractive and visual outcomes.

Comparison of Preoperative Measurements with Intraoperative Aberrometry in Predicting Need for Correction in Eyes with Low Astigmatism Undergoing Cataract Surgery

Purpose

To determine whether intraoperative aberrometry during cataract surgery measures higher levels of absolute astigmatism than preoperative biometry readings and which method yields a lower, final level of astigmatism if the two do not agree.

Patients and Methods

Retrospective record review of all patients who underwent uncomplicated cataract surgery from February 2015 to May 2019 with planned intraoperative aberrometry. Data analysis included preoperative keratometry, total astigmatism as measured by intraoperative aberrometry, intraocular lens model and power used, and postoperative manifest refraction ≥1 month after surgery. The primary outcome measure was the proportion of patients requiring astigmatism correction (≥0.5 D) when measured by preoperative keratometry vs intraoperative aberrometry. Secondary outcomes included postoperative residual astigmatism, where adjusted preoperative astigmatism fell below the 0.5 D threshold for treatment but the intraoperative measurement was ≥0.5 D or ≥1.0 D.

Results

A total of 451 patient records were evaluated. Intraoperative aberrometry measured statistically higher levels of mean astigmatism than keratometry (0.86 D vs 0.79 D, respectively; P < 0.0001) and significantly greater astigmatism among patients with 0.5–1.5 D of adjusted preoperative astigmatism (P < 0.0001). Significantly more patients qualified for with-the-rule astigmatism correction when measured by intraoperative aberrometry (n=339; 75%) than by preoperative keratometry alone (n=314; 70%); P < 0.03. This difference did not hold for against-the-rule or oblique astigmatism. For patients whose preoperative biometry astigmatism differed from intraoperative biometry, final postoperative astigmatism was lower when corrected if the adjusted preoperative and intraoperative measurements had a vector difference of <0.5 D, but there was no additional benefit in final astigmatism reduction when the vector difference was ≥0.5 D.

Conclusion

Using intraoperative biometry readings can produce lower postoperative astigmatism than using preoperative biometry readings, but caution should be used when interpreting intraoperative readings that disagree with preoperative measurements with a vector magnitude of >0.5 D.

Time Utilization and Refractive Prediction Enhancement Associated with Intraoperative Aberrometry Use During Cataract Surgery

Purpose

To evaluate the time cost of intraoperative aberrometry (IA), to compare IA prediction error to the prediction error associated with conventional formulas using preoperative calculations (PC) and evaluate when IA provides clinically relevant benefit.

Methods

This is a retrospective study of eyes that underwent cataract phacoemulsification surgery with IA at an academic eye center. IA versus PC prediction error were compared amongst various preoperative and intraoperative characteristics. Additionally, a dichotomous variable indicating clinically relevant benefit of IA, where IA absolute prediction error was less than 0.5D and PC absolute prediction error greater than 0.5D, was associated with clinical factors.

Results

Five hundred eyes of 341 patients were included in the analysis. The quantitative difference between mean absolute prediction errors for IA versus PC was between 0.0D and 0.03D in most subgroups. For the 11.0% of eyes that had clinically relevant benefit to IA, the multivariable model identified the following strongest predictors: prior myopic corneal refractive surgery (Odds ratio (OR) 3.9, p<0.01 for myopic LASIK/PRK, OR 5.5, p=0.01 for radial keratotomy), toric or multifocal/EDOF lens implantation (OR 2.7, p=0.03 for toric monofocal lenses, OR 3.1, p=0.01 for EDOF/multifocal lenses), and short and long axial lengths (p<0.01). On average, IA implementation added 3.0 minutes to surgery (p<0.01).

Conclusion

For greatest likelihood of a clinically meaningful improvement in outcomes despite increased surgical time, surgeons and patients should consider using IA for eyes with extremes in axial length, eyes with prior myopic corneal refractive surgery, or when implanting lenses with toric or extended-depth-of-focus/multifocal properties.

Intraocular Lens Power Formulas, Biometry, and Intraoperative Aberrometry: A Review

The refractive outcome of cataract surgery is influenced by the choice of intraocular lens (IOL) power formula and the accuracy of the various devices used to measure the eye (including intraoperative aberrometry [IA]). This review aimed to cover the breadth of literature over the previous 10 years, focusing on 3 main questions: (1) What IOL power formulas currently are available and which is the most accurate? (2) What biometry devices are available, do the measurements they obtain differ from one another, and will this cause a clinically significant change in IOL power selection? and (3) Does IA improve refractive outcomes? A literature review was performed by searching the PubMed database for articles on each of these topics that identified 1313 articles, of which 166 were included in the review. For IOL power formulas, the Kane formula was the most accurate formula over the entire axial length (AL) spectrum and in both the short eye (AL, ≤22.0 mm) and long eye (AL, ≥26.0 mm) subgroups. Other formulas that performed well in the short-eye subgroup were the Olsen (4-factor), Haigis, and Hill-radial basis function (RBF) 1.0. In the long-eye group, the other formulas that performed well included the Barrett Universal II (BUII), Olsen (4-factor), or Holladay 1 with Wang-Koch adjustment. All biometry devices delivered highly reproducible measurements, and most comparative studies showed little difference in the average measures for all the biometric variables between devices. The differences seen resulted in minimal clinically significant effects on IOL power selection. The main difference found between devices was the ability to measure successfully through dense cataracts, with swept-source OCT-based machines performing better than partial coherence interferometry and optical low-coherence reflectometry devices. Intraoperative aberrometry generally improved outcomes for spherical and toric IOLs in eyes both with and without prior refractive surgery when the BUII and Hill-RBF, Barrett toric calculator, or Barrett True-K formulas were not used. When they were used, IA did not result in better outcomes.

Clinical outcomes after aphakic versus aphakic/pseudophakic intraoperative aberrometry in cataract surgery with toric IOL implantation

PURPOSE

To determine if there was a clinically significant difference in clinical outcomes after toric IOL implantation based on intraoperative aberrometry (IA), where eyes were measured either in the aphakic state only or both the aphakic and pseudophakic states.

METHODS

A prospective, randomized, contralateral eye study was performed at one site in Poughkeepsie, NY, USA. Subjects included patients presenting for uncomplicated bilateral cataract surgery eligible for toric lens implantation with regular corneal astigmatism in both eyes whose toric IOL implantation was based on IA. One eye was measured when aphakic and the other when both aphakic and pseudophakic. The primary outcome measure was the magnitude of residual refractive astigmatism. Secondary measures included the percentage of eyes with 0.50D or less of residual refractive astigmatism, the spherical equivalent refraction and the time for IA measurement.

RESULTS

Mean residual refractive astigmatism was not statistically significantly different between groups (0.32D ± 0.46D IA_1 vs. 0.23D ± 0.35D IA_2, p = 0.25), nor was the percentage of eyes with a residual refractive cylinder of 0.50D or less (94% in both groups, p = 1.0). The average time to measure the pseudophakic eye was 3 min, 46 s. Aphakic IA measurements appeared to produce better spherical equivalent refractive results relative to preoperative calculations.

CONCLUSION

Pseudophakic IA measurements took nearly 4 min per case. Residual refractive astigmatism was not appreciably lower when pseudophakic IA measurements were made after aphakic IA measurements, which suggests aphakic IA measurements alone provide good clinical results with toric IOLs.

Efficacy of astigmatic correction after femtosecond laser-guided cataract surgery using intraoperative aberrometry in eyes with low-to-moderate levels of corneal astigmatism

PURPOSE

To evaluate the efficacy of astigmatic correction with two types of toric intraocular lenses (IOLs) after femtosecond laser-assisted cataract surgery (FLACS) in eyes with low-to-moderate corneal astigmatism using intraoperative aberrometry for optimizing the position of the toric IOL.

METHODS

Retrospective study includes a total of 99 eyes of 73 patients with anterior keratomeric astigmatism ≤ 3 D and undergoing FLACS (Catalys, Johnson & Johnson Vision) with implantation of a monofocal (Ankoris, PhysIOL) or a multifocal toric IOL with the same platform (Pod FT, PhysIOL). In all cases, intraoperative aberrometry was used (Optiwave refractive analysis, ORA, system, Alcon). Visual and refractive outcomes were evaluated preoperatively and at 4 months after surgery with vector analysis of astigmatic changes.

RESULTS

A total of 89.9%, 93.9% and 97.0% showed a postoperative sphere, cylinder and spherical equivalent within ± 0.50 D, respectively. Mean difference vector (DV) was 0.22 ± 0.27 D, mean magnitude of error (ME) was 0.13 ± 0.29 D, and mean angle of error (AE) was 1.52 ± 11.64°. Poor correlations of preoperative corneal astigmatism with DV (r = - 0.032, p = 0.833), ME (r = - 0.344, p = 0.001) and AE (r = - 0.094, p = 0.377) were found. Likewise, no statistically significant differences were found between monofocal and multifocal toric IOL subgroups in DV (p = 0.580), ME (p = 0.702) and AE (p = 0.499).

CONCLUSIONS

The combination of FLACS and intraoperative aberrometry to optimize the position of a toric IOL allows a very efficacious correction of preexisting low-to-moderate corneal astigmatism.

Retrospective analysis of an intraoperative aberrometry database: a study investigating absolute prediction in eyes implanted with low cylinder power toric intraocular lenses

Purpose

To evaluate the spherical equivalent outcomes of intraoperative aberrometry (IA) power calculations compared with the surgeons' preoperative power calculations in eyes implanted with AcrySof^® IQ T3 intraocular lenses (IOLs).

Patients and methods

We assessed data collected by an IA system from multiple centers in the United States. Data was from patients who had undergone cataract extraction by phacoemulsification with the use of the Optiwave Refractive Analysis System and whose eyes had been implanted with model SN6AT3 (1.5 diopter [D] at IOL plane) aspheric lenses. The analysis was performed in 2 stages: hypothesis generation and confirmatory testing. Confirmatory endpoints were a comparison of absolute prediction errors for IA for the implanted IOL versus preoperative formula power calculations.

Design

Retrospective analysis of preoperative, intraoperative, and postoperative data concerning eyes implanted with model SN6AT3 (1.5 D) aspheric lenses from the AnalyzOR™ database.

Results

Mean absolute IA prediction error was significantly lower than preoperative prediction error (paired difference: -0.06 D; p<0.0001); this was mirrored by the median paired difference of -0.04 D (p<0.0001). For eyes where the power of the implanted IOL differed from the power of the preoperatively planned lens, mean and median paired differences in prediction errors were greater: -0.13 D (p<0.0001) and -0.15 D (p<0.0001), respectively. The percentage of eyes with prediction error ≤0.50 D was significantly higher with IA (83.4%, n=5388/6460) than with the preoperative formula (76.5%, n=4942/6460, p<0.0001). When the powers of the implanted IOL and the preoperatively planned lens were different, the percentage of eyes with prediction error ≤0.50 D was 83.3% (2155/2587) for IA and 68.8% (1781/2587, p<0.0001) for the preoperative formula.

Conclusion

IA produces more accurate spherical equivalent outcomes for eyes implanted with a low toric IOL than the preoperative formulas.

Clinically relevant differences in the selection of toric intraocular lens power in normal eyes: preoperative measurement vs intraoperative aberrometry

Purpose: To assess the value of intraoperative aberrometry (IA) in determining toric intraocular lens (IOL) power in eyes with no previous ocular surgery.

Patients and methods: This was a retrospective data review at one US clinical site of eyes that underwent uncomplicated cataract surgery with toric IOL implantation where standard preoperative and IA measurements were available. Calculated IOL sphere and cylinder powers and orientation were compared based on the measurement method and the postoperative refraction, using both actual and simulated (back-calculated) results. Comparisons were between the surgeon’s preoperative calculations, IA measurements, the actual IOL implanted and results from the Barrett toric calculator.

Results: There was no significant difference (p>0.7) in the number of eyes expected to have, or having, a spherical equivalent refraction within 0.50D of the target between Actual (92%), IA (93%) or Preoperative calculation results (86%). The percentage of eyes with expected residual refractive astigmatism ≤0.50D was significantly higher for the IA vs Preoperative calculations (75% vs 53%, p<0.01). There was no significant difference in expected results between the Actual, IA and Barrett toric calculations (p>0.65).

Conclusion: Modern IOL calculations for sphere produced results comparable to those achieved with IA. The value of IA in determining IOL cylinder power and orientation was more evident when comparing expected results between IA and a preoperative method based on measured total corneal astigmatism than when comparing to expected results from the Barrett toric calculator.