Intraoperative Aberrometry Research Articles

Accuracy of intraoperative aberrometry versus preoperative biometry for intraocular lens power selection in short and long eyes.

To compare the accuracy of intraoperative wavefront aberrometry using the ORA VLynk system with different biometry-based formulas in short and long eyes after cataract surgery. This prospective study considered 48 eyes with axial lengths of <22.1 mm and 48 eyes with axial lengths of >25.0 mm. All eyes were implanted with the monofocal AcrySof IQ IOL, the power being determined using the ORA VLynk. The postoperative spherical equivalent (SE) at 3 months was compared to that predicted preoperatively using the SRK/T, Hoffer Q, Haigis, Holladay 2, Barrett Universal II, and Barrett True K formulas and intraoperatively using the ORA VLynk. Mean numerical and absolute errors and the percentage of eyes within ±0.50 D/1.00 D of their target were obtained. For long eyes, the mean absolute error values were 0.35, 0.52, 0.34, 0.30, 0.29, 0.27, and 0.24D for SRK/T, Hoffer Q, Haigis, Holladay 2, Barrett Universal II, Barrett True K, and ORA VLynk, respectively (p < 0.001). These values were 0.55, 0.45, 0.49, 0.40, 0.44, 0.44 and 0.50 D for short eyes, respectively (p < 0.001). The proportions of long eyes within ±0.50 D of the target were 77.08, 50, 75, 85.42, 83.33, 79.17, and 87.50%, respectively; and 50, 66.67, 60.42, 66.67, 60.42, 60.42, and 58.33%, respectively, for short eyes. The ORA VLynk performs better than all biometry-based formulas in long eyes and, in short eyes, it is as effective as SRK/T, Haigis, Barrett Universal II, and Barrett true K, with the Hoffer Q and Holladay 2 being the most accurate; however, the differences between the calculation methods were small. Identifier DRKS000028106.

Intraoperative Aberrometry versus Preoperative Biometry for Intraocular Lens Power Calculations: A Report by the American Academy of Ophthalmology

To evaluate the published literature to compare intraoperative aberrometry (IA) with preoperative biometry-based formulas with respect to intraocular lens (IOL) power calculation accuracy for various clinical scenarios. Literature searches in the PubMed database conducted in August 2022, July 2023, and February 2024 identified 157, 18, and 6 citations, respectively. These were reviewed in abstract form, and 61 articles were selected for full-text review. Of these, 29 met the criteria for inclusion in this assessment. The panel methodologists assigned a level of evidence rating to each of the articles; 4 were rated level I, 19 were rated level II, and 6 were rated level III. Intraoperative aberrometry performed better than traditional vergence formulas, including the Haigis, HofferQ, Holladay, and SRK/T, and similarly to the Barrett Universal II and Hill-RBF with respect to minimization of spherical equivalent (SE) refractive error. For toric IOLs, IA outperformed formulas that only considered anterior corneal astigmatism and was similar to formulas like the Barrett Toric Calculator (BTC), which empirically account for the contribution from the posterior cornea. In eyes with a history of corneal refractive surgery, IA performed similarly to the Barrett True-K and slightly better than other tested methods, including the Haigis-L, Shammas, and Wang-Koch-Maloney formulas. Intraoperative aberrometry corresponds well with modern vergence formulas, including the Barrett Universal II, Hill-RBF, BTC, and Barrett True-K. It has greater accuracy than traditional vergence-based IOL power calculation formulas in eyes with and without a history of corneal refractive surgery. Proprietary or commercial disclosure may be found after the references.

Accuracy of the Majority Voting Method with Multiple IOL Power Formulae.

This study aimed to evaluate the efficacy of a majority decision algorithm that integrates intraoperative aberrometry (IA) and two intraocular lens (IOL) frequency formulas. The primary objective was to compare the accuracy of three formulas (IA; Sanders, Retzlaff, and Kraff/Theoretical (SRK/T); and Barrett Universal II (BUII)), in achieving emmetropia in eyes implanted with TFNT lenses (Alcon). A total of 145 eyes of 145 patients were included in the evaluation. Preoperative data were obtained from IOLMaster 700, while intraoperative data were collected from ORA SYSTEMTM. Visual acuity ≥0.8 at the 3-month post-surgery mark was confirmed. We assessed refractive prediction error (RPE), which is the difference between predicted refraction (PR) and postoperative subjective refraction. This evaluation aimed to identify the optimal IOL power with the implemented algorithm. Among the 145 eyes evaluated, 55.9%, 78.7%, and 97.2% achieved postoperative subjective refraction within ±0.13 Diopters (D), ±0.25 D, and ±0.50 D, respectively. The percentages of eyes within ±0.25 D of PR varied by formula type, with values of 57%, 57%, and 54% for IA, BUII, and SRK/T, respectively. For eyes with short to medium axial length (AL<26.00 mm), the percentages within ±0.25 D of RPE were 52%, 58%, and 58% for IA, SRK/T, and BUII, respectively. In contrast, for eyes with long axial length (≥26.00 mm) the percentages were 68%, 52%, and 45% for IA, BUII, and SRK/T, respectively. The proposed majority decision algorithm incorporating IA and two IOL frequency formulas was effective in reducing postoperative refractive error. IA was particularly beneficial for eyes with long axial length. These findings suggest the algorithm has potential to optimize IOL power selection to improve quality of life of patients and clinical practice outcomes.

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

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. 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). 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. 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).

Outcomes After Implantation of a Trifocal Toric Intraocular Lens Using Intraoperative Aberrometry, Digital Image Tracking, and Femtosecond Laser.

To evaluate the refractive and visual acuity outcomes when using trifocal toric intraocular lenses (IOLs), femtosecond laser assisted cataract surgery (FLACS), swept-source optical coherence tomography (SS-OCT) biometry, digital image tracking (DT) and intraoperative aberrometry (IA). This prospective, single-arm, observational study of refractive and visual outcomes included 40 eyes of 34 subjects. Preoperative biometry was performed with the Argos, FLACS and digital marking with LenSx, and IA and DT with ORA. Eyes were implanted with the Clareon PanOptix toric IOL. Study outcome measures included absolute prediction error, residual refractive astigmatism, and monocular uncorrected and distance corrected visual acuity at distance (UDVA, CDVA), intermediate (UIVA, DCIVA; 60cm), and near (UNVA, DCNVA; 40cm). Mean absolute prediction error (spherical equivalent) was 0.43 ± 0.36 D, and the percentage of eyes with absolute prediction error ≤ 0.5 D was 72.5% (29/40 eyes). Mean residual astigmatism was 0.36 ± 0.65 D, and the percentage of eyes with residual astigmatism ≤ 0.5 D was 80% (32/40 eyes). Monocular UDVA, UIVA, and UNVA was 20/25 or better in 75%, 64%, and 87% of eyes respectively. Monocular CDVA, DCIVA, and DCNVA was 20/25 or better in 95%, 64%, and 87% of eyes respectively. The results of this study suggest that trifocal toric implantation with SS-OCT, FLACS, DT, and IA can provide excellent refractive and visual outcomes.

Accuracy of intraoperative aberrometry versus modern preoperative methods in post-myopic laser vision correction eyes undergoing cataract surgery with capsular tension ring placement

PurposeTo assess the accuracy of intraoperative wavefront aberrometry (IWA) versus modern intraocular lens formulas in post-myopic laser vision correction (LVC) patients undergoing cataract surgery with capsular tension ring placement.MethodsThis is a retrospective chart review conducted at an academic outpatient center. All post-myopic LVC eyes undergoing cataract surgery with IWA from a single surgeon from 05/2017 to 12/2019 were included. All patients received a capsular tension ring (CTR). Mean numerical error (MNE), median numerical error (MedNE), and percentages of prediction error within 0.50D, 0.75D, and 1.00D were calculated for the above formulas.ResultsTwenty-seven post-myopic LVC eyes from 18 patients were included. In post-myopic LVC, MNE with Optiwave Refractive Analysis (ORA), Barrett True K (BTK), Haigis, Haigis-L, Shammas, SRK/T, Hill-RBF v3.0, and W-K AL-adjusted Holladay 1 were + 0.224, − 0.094, + 0.193, − 0.231, − 0.372, + 1.013, + 0.860, and + 0.630 (F = 8.49, p < 0.001). MedNE were + 0.125, − 0.145, + 0.175, + 0.333, + 0.333, + 1.100, + 0.880, and + 0.765 (F = 7.89, p < 0.001), respectively. BTK provided improved accuracy in both MNE (p < 0.001) and MedNE (p = .033) when compared to ORA in pairwise analysis. If the ORA vs. BTK-suggested IOL power were routinely selected, 30% and 15% of eyes would have projected hyperopic outcomes, respectively (p = 0.09).ConclusionsOur study suggests that in post-myopic LVC eyes undergoing cataract surgery with CTRs, BTK performed more accurately than ORA with regard to accuracy and yielded a lower percentage of eyes with hyperopic outcomes. Haigis, Haigis-L, and Shammas yielded similar results to ORA with regard to accuracy and percentage of eyes with hyperopic outcomes. On average, Shammas and Haigis-L suggested IOLs that would yield outcomes more myopic than expected when compared to BTK.

Visual and Refractive Outcomes of a Trifocal Toric Intraocular Lens Implanted in Eyes With High Corneal Astigmatism.

To analyze the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with high degrees of corneal astigmatism. A total of 29 eyes from 21 patients who underwent implantation of a trifocal toric IOL (FineVision PODFT; PhysIOL) were evaluated in this study. Phacoemulsification with femto-second laser and intraoperative aberrometry were performed in all cases. All IOLs used exhibited a cylinder power of 3.75 diopters (D) or greater. The main outcome measures were refractive error and corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA) values. Eyes were evaluated during a follow-up period of 5 years. A total of 96.30%, 100%, 95.83%, and 89.47% of eyes were within ±1.00 D at 1, 2, 3, and 5 years postoperatively, respectively. Furthermore, 92.31%, 86.36%, 82.61%, and 84.21% of eyes showed a refractive cylinder value of ±1.00 D at 1, 2, 3, and 5 years postoperatively, respectively. During the entire follow-up period, between 81.48% and 91.30% of eyes showed a CDVA of 20/25 or better. The mean monocular Snellen decimal CDVA values were 0.90 ± 0.12, 0.90 ± 0.11, 0.91 ± 0.11, and 0.90 ± 0.12 at 1, 2, 3, and 5 years postoperatively, respectively. No significant rotation was reported in any eye during follow-up. The current study suggests that use of this trifocal toric IOL in eyes with high amounts of corneal astigmatism provides accurate refractive outcomes with good distance visual acuity. [J Refract Surg. 2023;39(4):229-234.].

Cataract surgery with toric lens. Assessment through tomography and intraoperative aberrometry ORA

AbstractPurpose: Nowadays, cataract surgery not only aims at the extraction of the opacified lens. Promoted by advances in the last decade, this medical procedure has evolved into a refractive technique whose purpose is emmetropia. The current intention, from an optical point of view, is to obtain a residual refractive error within ±0.50 diopters of spherical equivalent, and &lt;0.75 diopters in the residual cylinder. Consequently, a prospective single‐center cross‐sectional study was performed at the Ophthalmology Department of the Lozano Blesa University Hospital of Zaragoza, which was conducted from July 2021 to February 2022.Methods: Including a total of 42 eyes of 34 patients (38% male, 62% female), with astigmatism greater than 2.00 keratometric diopters undergo cataract surgery. The surgical procedure is carried out using FLACS femtosecond laser‐assisted surgery, altogether with implantation of toric intraocular lenses (Alcon SN6AT2‐9). Inclusion criteria pursued uncomplicated interventions, performed by a single surgeon and with a NRR (No Rotation Recommended) outcome.Results: The mean ages were 69.5 ± 11.89 years (39–90), the mean axial length was 23.61 ± 2.38 mm. The corneal dioptric power was 3.10 ± 1.22 D anterior surface contribution, and 0.58 ± 0.40 D posterior surface contribution. It is worth highlighting that the contribution or the posterior surface in ATR eyes (against the rule) was only 0.21 ± 0.15 D. Using vector analysis, mean (standard deviation) and median (interquartile range) from a vector of astigmatism we obtained the following results: ORA's IOL recommendation and the preoperative prediction coincided in 50% of the cases (final astigmatism mean 0.76D ± 0.47 D). In the 50% remaining cases where they did not match, the biometer‐recommended IOL was inserted (final astigmatism mean 0.84 D ± 0.77 D).Conclusions: To sum up, compared with standard methods, we show that the use of ORA intraoperative aberrometry system increases predictability and safety during the intervention, improving efficacy and giving better outcomes. The use of FLACS femtosecond laser‐assisted surgery and intraoperative guidance systems make phacoemulsification surgery a more reproducible technique.

Intraoperative aberrometry versus preoperative biometry for intraocular lens power selection in patients with axial hyperopia.

This study was conducted to evaluate the accuracy of intraoperative aberrometry (IA) in intraocular lens (IOL) power calculation and compare it with conventional IOL formulas. This was a prospective case series. Eyes with visually significant cataract and axial hyperopia (AL <22.0 mm) underwent IA-assisted phacoemulsification with posterior chamber IOL (Alcon AcrySof IQ). Postoperative spherical equivalent (SE) was compared with predicted SE to calculate the outcomes with different formulas (SRK/T, Hoffer Q, Haigis, Holladay 2, Barrett Universal Ⅱ and Hill-RBF). Accuracy of intraoperative aberrometer was compared with other formulas in terms of mean absolute prediction error (MAE), percentage of patients within 0.5 D and 1 D of their target, and percentage of patients going into hyperopic shift. Sixty-five eyes (57 patients) were included. In terms of MAE, both Hoffer Q (MAE = 0.30) and IA (MAE = 0.32) were significantly better than Haigis, SRK/T, and Barrett Universal Ⅱ (P < 0.05). Outcomes within ±0.5 D of the target were maximum with Hoffer Q (80%), superior to IA (Hoffer Q > IA > Holladay 2 > Hill-RBF > Haigis > SRK/T > Barrett Universal Ⅱ). Hoffer Q resulted in minimum hyperopic shift (30.76%) followed by Hill-RBF (38.46%), Holladay 2 (38.46%), Haigis (43.07%), and then IA (46.15%), SRK/T (50.76%) and Barrett Universal Ⅱ (53.84%). IA was more effective (statistically significant) in predicting IOL power than Haigis, SRK/T, and Barrett Universal Ⅱ although it was equivalent to Hoffer Q. Hoffer Q was superior to all formulas in terms of percentage of patients within 0.5 D of their target refractions and percentage of patients going into hyperopic shift.

Influence of Ocular Surface Hydration on Intra-Operative Aberrometry Measurement and Toric Intraocular Lens Recommendation.

The purpose of this study was to examine the effect of intra-operative live refraction stability as a surrogate marker of ocular surface hydration on intra-operative aberrometry (IA) results and to quantify the minimum duration of stable refraction needed to achieve accurate intraocular lens (IOL) selection. In this nonrandomized consecutive retrospective chart review, 18,000 data points from 45 live refraction runs of 15 patients were digitized and analyzed. An objective automated moving average method of frames lengths of 88ms, 110ms, and 132ms with less than 0.5 diopters (D) of fluctuation was compared to raw IA capture data. The difference-vector (DV) of the predicted toric powers was compared among these groups. Subjectively, traces were classified as stable or unstable if the live refraction fluctuated less than 0.5D for 5 seconds. The DV based on the stable period was compared with the IA capture data. The DVs for all frame intervals showed no significant difference when compared with IA readings. In 15 of 45 (33.3%) cases, IA active refraction traces were stable and the DV (0.27D ± 0.15D) was significantly less than unstable traces (0.49D ± 0.28D). IOL recommendations from 14 (93.3%) of stable runs led to a <0.5D of postoperative cylinder compared to 14 (47.7%) in unstable runs. Intra-operative live refraction stability is affected by ocular hydration. Surgeons should look for periods of refractive stability for at least 5 seconds to better assess measurement quality. This can be facilitated by capturing and including the active refraction trace, which is currently unavailable for review. Graphing live refractive IA readings and determining refractive stability translates to more accurate IOL selection.

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

PurposeTo 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.MethodsData 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.ResultsThe 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.ConclusionGlobal 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.

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

PurposeTo assess refractive outcomes of a trifocal intraocular lens (IOL) in post-myopic laser refractive surgery eyes.MethodsThis 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).ResultsAt 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.ConclusionImplantation with a trifocal IOL can provide acceptable refractive and visual outcomes with minimal residual astigmatism in post-myopic LASIK and PRK eyes.

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.

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

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. 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. 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). 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.].

Comparison of the Accuracy of Intraoperative Aberrometry in Intraocular Lens Implantation Between Myopic Eyes with Emmetropia and Myopia Targets.

PurposeTo compare the accuracy of intraoperative aberrometry (IA) for predicting postoperative refraction between eyes with emmetropia and myopia targets.Patients and MethodsThis retrospective analysis included patients with axial myopia (axial length ≥ 25.0 mm) who underwent uncomplicated phacoemulsification cataract surgery with IA to achieve emmetropia (plano to −0.5 D) or intentional myopia (−2.5 D to −5.0 D). Preoperative ocular biometry was performed in all eyes using an IOLMaster. Refractive prediction errors in IA were compared between eyes with emmetropia and myopia targets. Refractive prediction errors in IA for both groups were also compared with those predicted by intraocular lens power calculation formulas including the SRK/T, Holladay 1, Hoffer Q, Holladay 2, Haigis, and Barrett Universal II formulas.ResultsThirty-nine eyes of 39 patients with a target of emmetropia and 22 eyes of 22 patients with a target of intentional myopia were included in the final analysis. The mean numerical error was significantly different from zero (myopic trend) in myopia-targeted eyes (−0.37 ± 0.54 D, one-sample t-test, P = 0.004, 95% confidence interval: −0.61 to −0.14), while it was close to zero in emmetropia-targeted eyes. The mean absolute error was significantly smaller in emmetropia-targeted eyes (0.28 ± 0.27 D) than in myopia-targeted eyes (0.51 ± 0.41 D, P = 0.01). IA was revealed as the most accurate method for predicting postoperative refraction in eyes with emmetropia target, whereas Barrett Universal II formula was found to be the most accurate for eyes with myopia target.ConclusionIn patients with axial myopia, the performance of IA was altered when targeting intentional myopia compared with emmetropia. Myopic shift in the refractive outcome should be considered when IA is used to target myopia.

Intraocular lens power calculation in eyes with previous corneal refractive surgery.

Intraocular lens (IOL) power calculation after corneal refractive surgery (CRS) becomes an expanding challenge for ophthalmologists as more and more cataract surgeries after CRS are required. These patients typically also have high expectations as to visual performance. Conventional IOL power calculation schemes frequently provide inaccurate results in these cases. This review aims to summarize and recommend currently available IOL power calculation methods for eyes with the most common CRS methods: radial keratotomy (RK), photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE). To this end, biometry measuring methods and IOL formulas will be explained and combinations of both are proposed. In synopsis, it is evident that the latest generation of vergence formulas exhibit favorable IOL power prediction accuracy in post-CRS eyes, even though the predictive precision of methods in eyes without CRS is not attained. Ray tracing computation, intraoperative aberrometry, and machine learning–based formulas hold potential to further improve refractive outcomes in post-CRS eyes.

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

PurposeTo 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.MethodsRetrospective 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.ResultsTwo 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.ConclusionIA 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.

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

Transitional conic toric intraocular lens evaluation after femtosecond laser-assisted cataract surgery using intraoperative aberrometry.

To assess refractive and visual outcomes following phacoemulsification with femtosecond laser-assisted cataract surgery (FLACS) using intraoperative aberrometry and implantation of a toric intraocular lens (IOL) in eyes with different degrees of astigmatism. One hundred two eyes of 70 patients who underwent implantation of the transitional toric 565 Precizon IOL (Ophtec BV) were enrolled. FLACS, capsular tension ring insertion, and intraoperative aberrometry were performed. Main outcome measures were refractive error, uncorrected- and corrected distance snellen decimal visual acuity values (UDVA and CDVA, respectively), and IOL rotation. Specifically, a vector analysis was carried out with J0 and J45 evaluation. Eyes were evaluated 1-year after surgery. Overall, 94.12% (96 eyes) and 100% (102 eyes) of the eyes showed a spherical equivalent (SE) within ± 0.50D and ± 1.00D, respectively. The mean SE and refractive cylinder were -0.06 ± 0.29D and -0.23 ± 0.37D, respectively. Vector analysis revealed that 100% of the eyes were within ± 0.50D for the J0 and J45 cylindrical components. The mean toric axis rotation was 1.10 ± 1.71° (from 0° to 5°), 77% (79 eyes), and 100% (102 eyes) of the eyes showed UDVA and CDVA of 20/25, respectively. The postoperative mean values of monocular UDVA and CDVA were 0.88 ± 0.17 and 0.96 ± 0.07 (about 20/20), respectively. No patient required IOL realignment during the postoperative follow-up. The present study suggests that the use of the Precizon IOL after FLACS, using intraoperative aberrometry in patients with different amounts of astigmatism, provides good visual acuity, accurate refractive outcomes, and excellent rotational stability.

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

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. University Eye Clinic Maastricht, Maastricht University Medical Center+, the Netherlands. Prospective observational clinical trial. 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. 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). 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.