Postoperative Refractive Astigmatism Research Articles

Relation between change of effective lens position and toric IOL rotation after toric IOL implantation

PurposeTo evaluate the relationship between change of effective lens position (ELP) and toric intraocular lens (IOL) rotation in patients with increasing postoperative refractive astigmatism after successful toric IOL implantation. MethodsThe subjects include 61 people (61 eyes) with increasing residual astigmatism >0.5 D 3 months after successful toric IOL implantation. Clinical measurements included preoperative, 1-week, and 1-, 2-, and 3-month postoperative visual acuity; refraction; keratometer; anterior and posterior corneal astigmatism; ELP by Scheimpflug camera imaging; and IOL axis by slit-lamp biomicroscopic photograph with pupil dilation. ResultsResidual astigmatism in postoperative month 3 (0.81 ± 0.50 D) is higher than that at postoperative week 1 (0.41 ± 0.38 D; p < 0.05). ELP decreased by 264.44 ± 163.25 μm, and the IOL rotated by 2.91 ± 1.44 degrees from week 1 to month 3 (p < 0.05). The ELP change had a positive correlation with IOL rotation (R2 = 0.383; p = 0.006), and the postoperative refractive astigmatic change had a positive correlation with ELP change (R2 = 0.272; p = 0.027) and IOL rotation (R2 = 0.272; p = 0.0001) from week 1 to month 3. ConclusionELP change can influence toric IOL rotation and increase residual astigmatism after toric IOL implantation.

Refractive Astigmatism Outcomes of Femtosecond Laser-Assisted Arcuate Keratotomies Combined with Femtosecond Laser-Assisted Cataract Surgery: Two-Year Results

Purpose To evaluate the effectiveness and stability of refractive astigmatism reduction after penetrating femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery. Methods Non-randomized retrospective data analysis of all patients that underwent femtosecond laser-assisted cataract surgery with femtosecond laser-assisted arcuate keratotomy over a 4-year period with a non-toric monofocal intraocular lens (2017–2021) at a tertiary care academic center. Postoperative visual acuity, manifest refraction, and predicted residual refractive error were also recorded at 1 month, 3–6 months, 12–18 months, and 2 years postoperatively. Preoperative keratometric astigmatism was compared to postoperative refractive astigmatism using vector calculations and the ASCRS double-angle plot tool. Results This study comprised 266 eyes (179 patients) that met inclusion criteria. The mean preoperative keratometric astigmatism magnitude was 0.99 ± 0.53 D. At 1 month, 3–6 months, 12–18 months, and 2 years postoperatively, the mean refractive cylinder was 0.49 ± 0.45 D, 0.49 ± 0.45 D, 0.55 ± 0.54 D, and 0.52 ± 0.46 D, respectively. Horizontal against-the-rule astigmatism showed a higher tendency toward undercorrection than vertical with-the-rule astigmatism, which had a slightly higher tendency toward overcorrection. With-the-rule astigmatism had smaller difference vectors between target-induced astigmatism and surgically induced astigmatism. Conclusions Femtosecond laser-assisted arcuate keratotomy performed at the time of femtosecond laser-assisted cataract surgery was an effective option for correcting low-to-moderate corneal astigmatism for up to 2 years.

Accuracy of Toric Intraocular Lens Formulas With Measured Posterior Corneal Astigmatism of Different Orientations

PurposeTo assess whether the use of measured posterior corneal astigmatism (PCA) values improves the prediction accuracy of toric intraocular lens power formulas, compared to predicted PCA values, when the orientation of the steep axis of PCA is non-vertical. DesignRetrospective observational cohort study Methods418 eyes of 344 patients were included in the study. Prediction errors (PE) for postoperative refractive astigmatism at 4 weeks postoperatively were determined using vector analysis and compared for the following toric intraocular lens power formulas: Barrett Toric with predicted posterior corneal astigmatism (PPCA); Barrett Toric with measured posterior corneal astigmatism (MPCA); EVO Toric PPCA; EVO Toric MPCA; Holladay I with Abulafia-Koch regression. Subgroup analysis compared PEs for eyes with a vertically orientated steep axis of PCA (60-120o) to eyes with a non-vertically orientated steep axis of PCA. SettingCathedral Eye Clinic, Belfast, United Kingdom and Tan Tock Seng Hospital, Singapoore. ResultsStandard keratometry was with-the-rule in 48% of eyes, while the steep PCA axis was vertically orientated in 91% of eyes. For all eyes, EVO PPCA had a smaller mean absolute error than Barrett-MPCA, Barrett-PPCA and Abulafia-Koch (p < 0.01 for all). EVO-PPCA had the highest percentage of eyes within 0.50D of predicted postoperative astigmatism for eyes with vertical PCA (61%), while EVO-MPCA had the highest percentage for eyes with non-vertical PCA (54%). EVO-MPCA had the smallest centroid error for all eyes, and the subgroups (p < 0.01 for all). Eyes with non-vertical PCA had a lower percentage within 0.50D than eyes with vertical PCA when using PPCA (43% vs 61%, p = 0.034), but there was no significant difference between these groups when MPCA is used for eyes with non-vertical PCA (54% vs 61%, p = 0.40). ConclusionsWhen the steep axis of posterior corneal astigmatism is not vertically orientated, the use of measured posterior keratometry values improves prediction accuracy.

Meridional analysis for calculation of the toric power of phakic IOLs.

To present a reproducible method to calculate the toricity needed at the intraocular lens (IOL) plane with toric phakic IOLs (ICL, Staar Surgical) and compare its results with those obtained with the online calculator provided by the manufacturer. Retrospective case series. Private practice, Buenos Aires, Argentina. The formula originally described by Holladay to calculate the IOL power in phakic eyes was used to calculate the required spherical power along the less refractive meridian and along the more refractive meridian. Meridional analysis was applied to calculate the required toricity at the IOL plane and the surgically induced corneal astigmatism was incorporated into the calculations. The refractive cylinder predicted by this method and by the online calculator of the manufacturer were compared to the postoperative refractive cylinder by means of vector analysis. The possible changes in the ratio of toricity in patients with different amounts of astigmatism and anterior chamber depth are assessed in a theoretical section. In 35 eyes, the measured mean postoperative refractive cylinder was 0.09 D @ 99°, the mean predicted postoperative refractive astigmatism was 0.04 D @ 102° according to the manufacturer's online calculator and 0.09 D @100° according to our method. With both methods, 91.43% of eyes had an absolute cylinder prediction error within ±0.50 diopters. The method described in this article to calculate the toricity of phakic IOLs has a refractive accuracy similar to that of the original calculator developed by the manufacturer.

Sutured scleral fixation of existing subluxated/dislocated acrylic one-piece intraocular lenses.

To evaluate the visual and refractive outcomes in cases after sutured scleral fixation of existing subluxated or dislocated acrylic one-piece intraocular lenses (IOLs). This study retrospectively enrolled a consecutive series of patients who underwent a surgery of sutured existing subluxated or dislocated IOLs from October 2018 to June 2020. All patients underwent comprehensive preoperative and postoperative ophthalmologic examination, and data were collected including age, sex, surgical indications, best-corrected visual acuity, refractive error, intraocular pressure. Presence of intraoperative and postoperative surgical complications was documented. A total of 20 consecutive cases were enrolled for analysis with mean final follow-up period 9.8±5.3mo. Visual acuity improved from a mean of 0.35 (0.46±0.32 logMAR) preoperatively to 0.61 (0.21±0.18 logMAR) at the 3-month follow-up (P=0.002). The mean amount of preoperative keratometric astigmatism and total postoperative refractive astigmatism was -1.24±0.80 diopters (D) and -1.42±0.97 D, respectively. There was no statistically significant difference between preoperative and postoperative astigmatism (P=0.156). The mean IOL-induced astigmatism was -0.23±0.53 D. The mean spherical equivalent at the 3-month follow-up was -0.1±0.94 D. No major complications were noted during the follow-up period. Surgical techniques using sutured scleral fixation of existing subluxated or dislocated acrylic one-piece IOLs result in favorable visual and refractive outcomes without major complications.

Evaluation of statistical correction strategies for corneal back surface astigmatism with toric lenses: a vector analysis.

To compare actual and formula-predicted postoperative refractive astigmatism using measured posterior corneal power measurements and 4 different empiric posterior corneal astigmatism correction models. Tertiary care center. Single-center retrospective consecutive case series. Using a dataset of 211 eyes before and after tIOL implantation (Hoya Vivinex), IOLMaster 700 (IOLM) or Casia2 (CASIA) keratometric and front/back surface corneal power measurements were converted to power vector components C0 (0/90 degrees) and C45 (45/135 degrees). Differences between postoperative and Castrop formula predicted refraction at the corneal plane using the labeled parameters of the tIOL and the keratometric or front/back surface corneal powers were recorded as the effect of corneal back surface astigmatism (BSA). Generally, the centroid of the difference shifted toward negative C0 values indicating that BSA adds some against the rule corneal astigmatism (ATR). From IOLM/CASIA keratometry, the average difference in C0 was 0.39/0.32 diopter (D). After correction with the Abulafia-Koch, Goggin, La Hood, and Castrop nomograms, it was -0.18/-0.24 D, 0.27/0.18 D, 0.13/0.08 D, and 0.17/0.10 D. Using corneal front/back surface data from IOLM/CASIA, the difference was 0.18/0.12 D. The Abulafia-Koch method overcorrected the ATR, while the Goggin, La Hood, and Castrop models slightly undercorrected ATR, and using measurements from the CASIA tomographer seemed to produce slightly less prediction error than IOLM.

Total keratometry for toric intraocular lens calculation: comparison from two swept-source optical coherence tomography biometers.

To compare the astigmatism prediction accuracy of total keratometry (TK) from the IOLMaster 700 and total corneal power (TCP) from Anterion based on swept-source optical coherence tomography (SS-OCT) technology in toric intraocular lens (toric IOL) calculation. A retrospective observational study. Total corneal astigmatism (TCA) were obtained using IOLMaster 700 and Anterion. Z CALC 2.0 was used to calculate the expected postoperative refractive astigmatism in conjunction with TCA. Prediction errors (PE) in refractive outcomes was analyzed 1 month postoperatively using the vector analysis by the Holladay method, including the mean vector PE magnitude, percentage of cases with vector PE in certain intervals, and the centroid PE. A total of 56 eyes from 56 patients were enrolled in the study with an insertion of an AT TORBI 709 toric IOL. The difference in mean vector PE of postoperative refractive astigmatism between TK and TCP was not statistically significant (0.48D versus 0.46D, P = 0.281). TK and TCP yielded 27.3 and 40.0% of eyes with vector PE ≤ 0.25D, and 58.2 and 63.6% with vector PE ≤ 0.5D (both P > 0.05), respectively. TK and TCP resulted in similar ATR centroid PE of 0.10D@35° ± 0.60D and 0.15D@22° ± 0.57D, respectively, and there were no significant differences between x-PE component and y-PE component. IOLMaster 700 and Anterion provided comparable astigmatic predictability in toric IOL implantation using total keratometry and Z CALC 2.0.

Toric Monofocal Intraocular Lenses for the Correction of Astigmatism during Cataract Surgery: A Report by the American Academy of Ophthalmology

To review the published literature evaluating the visual and refractive outcomes and rotational stability of eyes implanted with toric monofocal intraocular lenses (IOLs) for the correction of keratometric astigmatism during cataract surgery and to compare those outcomes with outcomes of eyes implanted with nontoric monofocal IOLs and other astigmatism management methods performed during cataract surgery. This assessment was restricted to the toric IOLs available in the United States. A literature search of English-language publications in the PubMed database was last conducted in July 2022. The search identified 906 potentially relevant citations, and after review of the abstracts, 63 were selected for full-text review. Twenty-one studies ultimately were determined to be relevant to the assessment criteria and were selected for inclusion. The panel methodologist assigned each a level of evidence rating; 12 studies were rated level I and 9 studies were rated level II. Eyes implanted with toric IOLs showed excellent postoperative uncorrected distance visual acuity (UCDVA), reduction of postoperative refractive astigmatism, and good rotational stability. Uncorrected distance visual acuity was better and postoperative cylinder was lower with toric IOLs, regardless of manufacturer, when compared with nontoric monofocal IOLs. Correcting pre-existing astigmatism with toric IOLs was more effective and predictable than using corneal relaxing incisions (CRIs), especially in the presence of higher magnitudes of astigmatism. Toric monofocal IOLs are effective in neutralizing pre-existing corneal astigmatism at the time of cataract surgery and result in better UCDVA and significant reductions in postoperative refractive astigmatism compared with nontoric monofocal IOLs. Toric IOLs result in better astigmatic correction than CRIs, particularly at high magnitudes of astigmatism. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Comparison of toric intraocular lens calculation with the integrated K method and three single biometric devices.

To compare astigmatic outcomes using the Integrated K method and anterior surface keratometry from 3 different biometric devices. Lions Eye Institute, Perth, Australia. Retrospective case series. Eyes of patients who underwent uneventful cataract surgery were analyzed. Predicted postoperative astigmatism was calculated for Integrated K method, IOLMaster 700, Lenstar and Pentacam. The mean centroid error in predicted postoperative refractive astigmatism (PE), mean absolute PE and percentage of eyes within 0.5 diopter (D), 0.75 D and 1 D of absolute magnitude of PE were compared. A subset analysis was done where the difference in cylinder magnitude between the 2 methods was more than 0.25 D. Spherical prediction outcomes were also analyzed. 241 eyes of 139 patients were included in the study. The mean centroid PE of Integrated K method (-0.07 @ 69) was significantly different from IOLMaster and Pentacam. The mean absolute PE with Integrated K method (0.33 ± 0.17) was significantly lower than all 3 devices. The percentage of eyes within 0.5 D and 0.75 D of absolute magnitude of PE was 82% and 99% for Integrated K method, 76% and 95% for IOLMaster and Lenstar, and 60% and 86% for Pentacam. In the subset analysis, the improvement in accuracy of the Integrated K method compared with a single device was greater in terms of the percentage of eyes predicted within 0.5 D. The Integrated K method did not impact the spherical prediction outcomes. The integrated K method is more accurate and precise than anterior surface keratometry from a single biometric device.

Accuracy of Toric Intraocular Lens Calculations Using Estimated Versus Measured Posterior Corneal Astigmatism

To compare the prediction accuracy of toric intraocular lens calculations using estimated vs measured posterior corneal astigmatism (PCA). Retrospective case series. A total of 110 eyes of 110 patients with uncomplicated toric intraocular lens implantation were included in this study. Predicted postoperative refractive astigmatism was calculated with the Barrett Toric Calculator using the estimated PCA (E-PCA), the measured IOLMaster 700 PCA (I-PCA), and the measured Pentacam PCA (P-PCA). Refractive astigmatism prediction errors (RA-PEs), including their trimmed (tr-) centroid (mean vector), spread (precision), tr-mean absolute RA-PE (accuracy), and percentage within a certain threshold, were determined using vector analysis and compared between groups. University Eye Clinic, Maastricht University Medical Center+, the Netherlands. The tr-centroid RA-PEs of the E-PCA (0.02 diopter [D] at 82.2°), the I-PCA (0.08 D at 35.5°), and the P-PCA (0.09 D at 69.1°) were significantly different from each other (P < .01), but not significantly different from zero (P = .75, P = .05, and P = .05, respectively). The E-PCA had the best precision (tr-mean 0.40 D), which was not significantly lower than the I-PCA (0.42 D, P = .53) and P-PCA (0.43 D, P = .06). The E-PCA also had the best accuracy (0.40 D), which was not significantly different from the I-PCA (0.42 D, P = .26) and significantly better than the P-PCA (0.44 D, P < .01). The precision and accuracy of the I-PCA did not significantly differ from those of the P-PCA. There were no statistically significant differences in the percentage of eyes within a certain absolute RA-PE threshold. The Barrett Toric Calculator using the E-PCA, I-PCA, or P-PCA showed a comparable prediction of postoperative refractive astigmatism in standard clinical practice.

Comparison of the 1st Generation and 3rd Generation Wavefront-Guided LASIK for the Treatment of Myopia and Myopic Astigmatism.

To compare refractive, visual, and patient-reported outcomes associated with a 1st generation wavefront-guided (WFG) treatment with those associated with a 3rd generation WFG treatment. This retrospective study included patients who underwent femtosecond laser-assisted in situ keratomileusis (LASIK) for myopia/myopic astigmatism. Two random stratified samples of patients who underwent either 1stgeneration (WaveScan, Johnson & Johnson Vision, Santa Ana, CA) or 3rd generation (iDesign 2.0, Johnson & Johnson Vision, Santa Ana, CA) treatment matched on preoperative refraction were compared (4290 eyes of 2145 patients in each group). One-month postoperative visual, refractive, and patient-reported outcomes were analyzed. Refractive and monocular visual acuity analyses were performed using one random eye of each patient. The percentage of eyes achieving 20/20 or better uncorrected vision was 91.3% (1958/2145) in the 1st generation group and 95.9% (2056/2145) in the 3rd generation group (p<0.01). Binocularly, the percentage of patients with 20/20 or better UDVA was 97.0% (2080/2145) and 99.2% (2127/2145) in the 1st and 3rd generation groups, respectively (p<0.01). The mean postoperative MSE was -0.01 ± 0.33 D in the 1st generation group and +0.19 ± 0.33 D in the 3rd generation group (p<0.01). Postoperative refractive astigmatism had a mean value of -0.20 ± 0.26 D and -0.18 ± 0.24 D in the 1st and 3rd generation groups, respectively (p<0.01). The mean correction index of refractive astigmatism was 1.09 ± 0.53 in the 1st generation group and 1.02 ± 0.38 in the 3rd generation group, p<0.01. The overall percentage of patients satisfied with vision was 92.8% (1991/2145 patients) in the 1st generation group and 97.3% (2087/2145 patients) in the 3rd generation group (p<0.01). For the majority of postoperative variables, there were significant differences between 1st and 3rd generation treatments. The 3rd generation treatments had better visual acuity outcomes and higher patient satisfaction.

Effect of femtosecond laser-assisted arcuate keratotomy versus toric intraocular lens implantation on correction of astigmatism in cataract surgery: a systematic review and meta-analysis.

To compare the efficacy of femtosecond laser-assisted arcuate keratotomy (FSAK) combined with non-toric intraocular lens (IOL) implantation versus Toric IOL (TIOL) implantation in correcting corneal astigmatism in cataract patients. Relevant literature was searched in databases including PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and SinoMed. Data from the included studies were extracted. A meta-analysis was conducted to compare the correction performance of FSAK combined with non-toric IOL implantation and TIOL implantation using postoperative refractive astigmatism, correction index, and uncorrected distance visual acuity (UDVA) outcomes. Publication bias assessment and sensitivity analysis were also performed. Five comparative studies were ultimately included in the meta-analysis. The TIOL group had smaller postoperative refractive astigmatism and a greater correction index compared to the FSAK group. The mean differences in postoperative refractive astigmatism and correction index between the two groups were - 0.19D (95% CI = 0.12 to 0.26, P < 0.01, I2 = 7%) and - 0.09 (95% CI = - 0.18 to 0.00, P = 0.04, I2 = 0%), respectively. We found no statistically significant difference in UDVA between the two groups (95% CI = - 0.01 to 0.11, P = 0.09, I2 = 70%). FSAK combined with non-toric IOL implantation was found to be less effective than TIOL implantation in correcting preoperative corneal astigmatism in cataract patients. The difference in the effectiveness of astigmatism correction between the two surgical methods seems to diminish, as the degree of preoperative corneal astigmatism decreases.

Rotational stability of plate haptic toric intraocular lenses after combined 25-gauge vitrectomy and cataract surgery.

To evaluate the postoperative intraocular lens (IOL) rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL. In this retrospective case series, 32 eyes of 32 patients underwent a combined 25-gauge vitrectomy and phacoemulsification for vitreoretinal diseases and cataract with regular corneal astigmatism of at least 1 diopter (D). A plate haptic toric IOL (AT Torbi 709M, Carl Zeiss Meditec AG) was implanted in all eyes. The outcome measures were rotational stability and refractive astigmatism up to 6mo postoperatively as well as the best corrected visual acuity (BCVA). Preoperative refractive astigmatism was 2.14±1.17 D, which was significantly reduced to 0.77±0.37 D six to eight weeks postoperatively and remained stable throughout the observation period (0.67±0.44 D at three months and 0.75±0.25 D at six months; for all groups: P<0.0001 compared to baseline). BCVA improved significantly from 0.36±0.33 logMAR preoperatively to 0.10±0.15 logMAR following surgery (P=0.02). Mean IOL axis deviation from the target axis was 3.4°±2.9° after six to eight weeks and significantly decreased over time (2.4°±2.6° six months after surgery; P=0.04). In one patient IOL, re-alignment was performed. Corneal astigmatism is significantly reduced following combined 25-gauge vitrectomy and cataract surgery. The plate haptic toric IOL position and axis remain stable during the observation period of six months.

Comparison of astigmatism correction and visual outcomes in mix-and-match implantations of trifocal intraocular lenses with femtosecond laser-assisted arcuate keratotomy and contralateral bifocal Toric intraocular lenses.

Astigmatism reduces the postoperative visual performance after non-toric intraocular lenses (IOLs) implantation, and limits the use of refractive IOLs in cataract surgery. The purpose of this study was to compare the efficacy in astigmatism correction and the postoperative visual outcomes between the implantation of a trifocal IOL with femtosecond laser-assisted arcuate keratotomy (FSAK) in one eye and a bifocal toric IOL (TIOL) in the other, in patients with cataract and moderate astigmatism. This prospective observational paired-eye study enrolled patients with cataract and corneal astigmatism (CA) between 0.75 and 2.25 D in both eyes. The patients underwent a mix-and-match treatment comprising trifocal IOL implantation with FSAK and bifocal TIOL implantation. We compared the visual acuity (VA) at all distances, defocus curve, postoperative refractive astigmatism (RfA), CA, high-order aberrations, modulation transfer function (MTF) curve, and Strehl ratio between the two eye groups. In total, 41 patients (82 eyes) were enrolled and completed a 6-month follow-up. The 1- and 3-month uncorrected distance VA and 3-month uncorrected near VA were greater in eyes with bifocal TIOLs than with trifocal IOLs and FSAK (p = 0.036, 0.010, and 0.030, respectively), whereas the latter had greater uncorrected intermediate VA at every visit and greater VA in the intermediate range of defocus curve (at -1.50 and - 2.00 D) than the eyes with bifocal TIOLs. The postoperative RA of the eyes with trifocal IOL and FSAK was significantly higher than that of the bifocal TIOL-implanted eyes at the 3- and 6-month follow-ups. Both FSAK and TIOL implantation effectively reduce pre-existing moderate astigmatism in patients with cataract. The eyes with bifocal TIOLs had more stable long-term astigmatism correction, whereas those with trifocal IOLs and FSAK had better intermediate VA. Therefore, a mix-and-match implantation of trifocal IOL with FSAK and contralateral bifocal TIOL could achieve effective astigmatism correction and provide an overall optimal VA.

Outcomes of peripheral corneal relaxing incisions for residual astigmatism in patients after cataract surgery.

To evaluate the outcomes of peripheral corneal relaxing incisions (PCRIs) for correcting residual astigmatism in eyes after cataract surgery. Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. Retrospective case series. Retrospectively, we reviewed all consecutive cases that had previous cataract surgery and subsequent PCRIs by 1 surgeon. The PCRI length was determined according to a nomogram based on age and manifest refractive astigmatism. Visual acuity and manifest refractive astigmatism before and after the PCRIs were compared. Vector analysis was performed, and net refractive changes along the incision meridian were calculated. Criteria were met by 111 eyes. After the PCRIs, mean uncorrected visual acuity was significantly improved, and the percentage of eyes with uncorrected distance visual acuity of ≥20/20 increased significantly by 36%; the mean refractive astigmatism magnitude decreased significantly, and the percentages of eyes with refractive cylinder of ≤0.25 diopters (D) and ≤0.50 D increased significantly by 63% and 75%, respectively (all P < .05). The vector magnitude difference between pre- and post-operative refractive astigmatism was 0.88 ± 0.38 D. The postoperative refractive astigmatism had significantly smaller centroid and variance values than the preoperative refractive astigmatism ( P < .05). PCRIs are an effective approach for correcting low amounts of residual astigmatism in patients after cataract surgery.

Comparison of the Barrett toric calculator using measured and predicted posterior corneal astigmatism and the Kane and Abulafia-Koch calculators.

To compare the accuracy of the Barrett toric calculator with measured and predicted posterior corneal astigmatism (MPCA and PPCA, respectively), the Abulafia-Koch (AK) formula, and the toric Kane formula. Ein-Tal Eye Center, Tel-Aviv, Israel. Retrospective cohort. Consecutive cases of patients who underwent uneventful cataract extraction surgery with implantation of a toric intraocular lens between March 2015 and July 2019 were retrospectively reviewed. 1 eligible eye from each patient was included. The predicted postoperative refractive astigmatism was calculated using each method and compared with the postoperative refractive astigmatism to give the prediction error. 80 eyes of 80 patients were included in this study. The mean centroid and the mean and median absolute prediction errors using Kane (0.25 diopters [D] ± 0.54 @ 6 degrees, 0.50 D ± 0.31 and 0.45 D, respectively) were significantly different compared with MPCA (0.12 D ± 0.52 @ 16 degrees, P < .001, .44 D ± 0.28 and 0.36 D, P = .027, respectively), PPCA (0.09 D ± 0.49 @ 12 degrees, P < .001, .41 D ± 0.27 and 0.35 D, P < .001, respectively), and AK (0.11 D ± 0.49 @ 11 degrees, P < .001, .42 D ± 0.27 and 0.35 D, P = .004, respectively). No significant differences were found between the calculators in the predictability rates within ±0.25 D, ±0.50 D, ±0.75 D, and ±1.00 D. The measured posterior corneal curvature in the Barrett calculator yielded comparable outcomes to its prediction by the Barrett and AK formulas. The Kane calculator showed a slight against-the-rule prediction error compared with the other methods, resulting in a small higher median absolute error with marginal clinical importance.

Comparison of visual outcomes in adult patients with different types of developmental cataracts after toric multifocal intraocular lenses implantation

Purpose To analyze and compare the visual performance and patient satisfaction following the implantation of toric multifocal intraocular lenses (TMIOLs) in adult patients with different types of developmental cataracts (DC) accompanied by corneal astigmatism (CA).Methods This is a prospective observational cohort study. Patients diagnosed with DC aged 18–30 years were divided into three groups according to the anatomic location of the lens opacity: cortical, nuclear, and posterior subcapsular (PSC) groups, and implanted with TMIOLs. Visual acuity (VA), postoperative refractive astigmatism (RA), intraocular lens (IOL) rotation, high-order aberrations (HOAs), modulation transfer function (MTF) curve, and Strehl ratio were compared. The functional vision and incidence of photic phenomena were surveyed using questionnaires.Results Fifty-five eyes of 37 patients were enrolled and completed a 1-year follow-up. The mean CA was 2.06 ± 0.79 D preoperatively, and the mean RA was 0.29 ± 0.30 D 3-month postoperatively. The IOL rotation was 2.48° ± 1.89°, with no deviation > 10°. At 12 months, mean uncorrected distance VA improved from 0.93 ± 0.41 preoperatively to 0.08 ± 0.08 logarithm of the minimum angle of resolution (logMAR), mean uncorrected near VA increased from 0.45 ± 0.30 preoperatively to 0.12 ± 0.11 logMAR, and mean uncorrected intermediate VA was 0.14 ± 0.08 logMAR. The cortical and nuclear groups displayed better improvements in uncorrected near and intermediate VA than that in the PSC group. Similar results were observed in the 3-month defocus curves, HOAs, MTF curve, halo incidence, and near vision satisfaction.ConclusionIn adult patients with DC accompanied by CA, TMIOLs implantation achieved good postoperative visual outcomes and significantly reduced glasses dependency. Patients with cortical or nuclear lens opacity showed better whole-course VA and quality of vision, while patients with PSC opacity showed unsatisfactory near vision and suffered more photic phenomena.

Clinical Outcomes of Toric Intraocular Lenses in Patients with Fuchs Endothelial Corneal Dystrophy.

Implantation of toric intraocular lenses (IOLs) in patients with Fuchs endothelial corneal dystrophy (FECD) is still considered relatively contraindicated, without sufficient clinical evidence. Therefore, this study was designed to evaluate the results of toric IOL implantation in patients with FECD. A retrospective case-control study of 28 eyes of FECD patients and 84 eyes of healthy control patients who received toric IOLs during routine cataract surgery was performed. The outcome measures were uncorrected and corrected distance visual acuity, spherical equivalent, and refractive residual astigmatism. The mean postoperative uncorrected and corrected distance visual acuity in the FECD eyes compared to the control eyes were 0.15 ± 0.14 vs. 0.13 ± 0.17, respectively (P = 0.32), and 0.05 ± 0.08 vs. 0.06 ± 0.10, respectively (P = 0.95). The spherical equivalent in the FECD eyes compared to the control eyes was -0.29 ± 0.43 vs. -0.21 ± 0.50, respectively (P = 0.19). The preoperative corneal centroid astigmatism in the FECD eyes compared to the control eyes was 0.85D@93° ± 2.42° vs. 0.23D@68° ± 2.50°, respectively (P = 0.43), and the mean preoperative corneal astigmatism magnitude was 2.26 ± 1.1D vs. 2.28 ± 1.03D, respectively (P = 0.82). A trend toward higher postoperative refractive centroid astigmatism was found in the FECD eyes compared with the control eyes: 0.24D@28° ± 0.57° vs. 0.03D@127° ± 0.53°, respectively (P = 0.09). However, the mean refractive astigmatism magnitude was similar in FECD eyes and the healthy control eyes: 0.52 ± 0.31D vs. 0.42 ± 0.31D, respectively (P = 0.44) (D diopters). The postoperative refractive astigmatism (both centroid astigmatism and mean magnitude astigmatism) was no higher than 0.52D in both groups. Therefore, FECD patients without corneal edema can be considered for toric IOLs.

Total Keratometry Measured With a Swept-Source Optical Biometer Versus Anterior Keratometry: From Planning to Postoperative Results.

To compare the influence of total keratometry (TK) versus anterior keratometry (K) measured with the swept-source optical biometer IOLMaster 700 (Carl Zeiss Meditec AG) on the planning of toric intraocular lenses (IOLs), and the error in predicted residual astigmatism (PRA). This single-center retrospective study included 247 eyes of 180 patients. In eyes undergoing cataract surgery, the optimal toric IOL was calculated based on K or TK measured with the IOLMaster 700. Two formulas were used to estimate IOL power: Holladay and Barrett Toric. Optimal cylinder power and alignment axis change induced by using TK versus K were reported. PRA by each calculation method was compared with manifest refractive astigmatism. Postoperative refractive astigmatism prediction error was calculated using vector analysis. The optimal toric IOL based on TK compared with K was different in 39.3% of cases with the Holladay formula and 31.6% of cases with the Barrett Toric formula. The use of TK rather than K reduced the centroid error in PRA when calculated with the Holladay formula (P < .001), but not when calculated with the Barrett Toric formula (P = .19). The against-the-rule astigmatism subgroup analysis with the Barrett Toric formula showed a statistically significant decrease of centroid error in PRA with the use of TK compared with K (P = .01). TK compared with K measured with the IOL-Master 700 resulted in a change of optimal toric IOL in almost one-third of cases and decreased the error in PRA in patients with against-the-rule astigmatism. [J Refract Surg. 2023;39(4):257-264.].

Comparison of accuracy of a toric calculator with predicted vs measured posterior corneal astigmatism.

To compare the accuracy of postoperative residual astigmatism prediction using the Barrett toric calculator with predicted vs measured posterior corneal astigmatism (PCA). Cullen Eye Institute, Baylor College of Medicine, Houston, Texas. Retrospective case series. We included 602 eyes with monofocal nontoric intraocular lens implantation. Biometry and PCA were obtained from the IOLMaster 700. Anticipated postoperative refractive astigmatism was calculated with the Barrett toric calculator for predicted and measured PCA, and the astigmatism prediction errors (PEs) for each were calculated using vector analysis. The vector PE magnitudes and percentage of eyes within certain amounts of vector PEs were compared between 2 methods. Compared with the Barrett toric calculator with predicted PCA, the Barrett toric calculator with measured PCA produced significantly smaller mean vector PE (0.54 diopter [D] vs 0.57 D) and higher percentage of eyes with vector PE of ≤0.5 D (57.6% [347/602] vs 52.5% [316/602]) (both P < .05). In eyes with predicted residual astigmatism of ≥0.5 D, the Barrett toric calculator with measured PCA again yielded a significantly higher percentage of eyes with vector PE of ≤0.5 D (51.2% [226/441] vs 44.7% [197/441], P < .05). Accuracy of residual astigmatism prediction is improved using the Barrett toric calculator with measured PCA rather than predicted PCA.