Immediate Sequential Bilateral Implantable Collamer Lens Surgery Is Safe and Effective.

PURPOSE: To assess the clinical outcomes and safety profiles of patients who underwent immediate sequential bilateral phakic lens surgery. METHODS: This retrospective multicenter study included 254 consecutive patients (508 eyes) who underwent bilateral same-day Implantable Collamer Lens (ICL) (STAAR Surgical) surgery. The authors focused on 1-year postoperative clinical outcomes and adverse events. RESULTS: In the initial cohort, 176 patients (352 eyes) met inclusion criteria. Of these, 335 eyes underwent myopic ICL placement, and 17 eyes received a hyperopic ICL. Notably, 87% of eyes achieved ±0.50 diopters (D) and 95% achieved ±1.00 D of the intended refraction. One year postoperatively, 78% of eyes demonstrated optimal vaulting (250 to 750 µm), with a significant 19% reduction in vaulting observed over the 12 months (P < .001). Only minor adverse events, including early cataract formation (1 case), secondary toric ICL rotation (3 cases), and ICL exchange due to inappropriate vaulting (6 cases), were noted. CONCLUSIONS: The findings corroborate the safety and efficacy of immediate sequential bilateral phakic lens surgery and indicate its potential as a treatment option. The low incidence of minor adverse events further reinforces its favorable safety profile. [J Refract Surg. 2024;40(5):e313-e320.].

Evaluating keratometry and corneal astigmatism data from biometers and anterior segment tomographers and mapping to reconstructed corneal astigmatism.

BACKGROUND: To compare results from different corneal astigmatism measurement instruments; to reconstruct corneal astigmatism from the postimplantation spectacle refraction and toric intraocular lens (IOL) power; and to derive models for mapping measured corneal astigmatism to reconstructed corneal astigmatism. METHODS: Retrospective single centre study involving 150 eyes treated with a toric IOL (Alcon SN6AT, DFT or TFNT). Measurements included IOLMaster 700 keratometry (IOLMK) and total keratometry (IOLMTK), Pentacam keratometry (PK) and total corneal refractive power in 3 and 4 mm zones (PTCRP3 and PTCRP4), and Aladdin keratometry (AK). Regression-based models mapping the measured C0 and C45 components (Alpin's method) to reconstructed corneal astigmatism were derived. RESULTS: Mean C0 components were 0.50/0.59/0.51 dioptres (D) for IOLMK/PK/AK; 0.2/0.26/0.31 D for IOLMTK/PTCRP3/PTCRP4; and 0.26 D for reconstructed corneal astigmatism. All corresponding C45 components ranged around 0. The prediction models had main diagonal elements lower than 1 with some crosstalk between C0 and C45 (nonzero off-diagonal elements). Root-mean-squared residuals were 0.44/0.45/0.48/0.51/0.50/0.47 D for IOLMK/IOLMTK/PK/PTCRP3/PTCRP4/AK. CONCLUSIONS: Results from the different modalities are not consistent. On average IOLMTK/PTCRP3/PTCRP4 match reconstructed corneal astigmatism, whereas IOLMK/PK/AK show systematic C0 offsets of around 0.25 D. IOLMTK/PTCRP3/PTCRP4. Prediction models can reduce but not fully eliminate residual astigmatism after toric IOL implantation.

An analysis of the factors involved in IOL decentration after phacoemulsification using CASIA 2 anterior segment optical coherence tomography.

PURPOSE: To evaluate the magnitude of IOL transversal shift (ITS) after phacoemulsification and to analyse the factors contributing to IOL decentration and ITS. METHODS: 94 consecutive patients who underwent cataract surgery and IOL implantation was enrolled. Each patient underwent anterior segment optical coherence tomography with CASIA 2 (Tomey, Nagoya, Japan) to assess crystalline lens decentration, thickness and diameter seven days preoperatively and at one and sixty days postoperatively. Univariate and multivariate linear regression analysis were performed to evaluate the determinants of ITS and final decentration. RESULTS: The preoperative crystalline lens diameter was associated with the ITS and with the IOL final decentration. A positive association between the final IOL decentration and the first post-surgical day decentration was found (p < 0.0001). CONCLUSION: Greater crystalline lens diameter was associated with greater decentration and with greater ITS. Day-one IOL decentration seems to be the main determinant of final IOL decentration.

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

PURPOSE: 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. DESIGN: Retrospective case series. SETTING: Private practice, Buenos Aires, Argentina. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Evaluation of the Agreement Between a New Pyramid Wavefront Sensor Aberrometer and Scheiner-Smirnov Aberrometers.

PURPOSE: To assess agreement between a new aberrometer (Osiris-T; CSO) employing pyramid wavefront sensor technique and Scheiner-Smirnov aberrometer (OPD-Scan III; Nidek) on measuring ocular, corneal, and internal aberrations in healthy participants. METHODS: The measurements were conducted three times consecutively by an experienced examiner. The total root mean square (RMS) aberrations, higher order aberration RMS, coma Z3±1, trefoil Z3±3, spherical aberration Z40, and astigmatism II Z4±2 up to 7th order were exported in both 4-and 6-mm pupil zones. The parameters between the two devices were statistically compared using the paired t-test, and the differences assessed with Bland-Altman plots and 95% limits of agreement. RESULTS: This prospective study included 70 right eyes of 70 healthy participants with an average age of 25.94 ± 6.59 years (range: 18 to 47 years). The mean difference in the two devices ranged from 0.01 µm for astigmatism II Z4±2 to 0.63 µm for total RMS in 4 mm and from 0.01 to 1.41 µm in 6-mm pupil size. The Bland-Altman analysis of ocular, corneal, and internal aberrations indicated high agreement between the two devices and the maximum absolute values for 95% limits of agreement ranged from 0.03 to 1.06 µm for 4-mm pupil diameters and 0.12 to 1.13 µm for 6-mm pupil diameters. CONCLUSIONS: The newly developed pyramid wavefront sensor technique aberrometer demonstrated a high agreement with a Scheiner-Smirnov aberrometer when measuring ocular, corneal, and internal aberrations in healthy participants. Thus, the two aberrometers may be considered interchangeable for clinical applications. [J Refract Surg. 2024;40(4):e218-e228.].

Differences Between Simulated Keratometry and Total Corneal Power in Eyes With Keratoconus and a Formula to Improve IOL Power Calculation Results.

PURPOSE: To compare simulated keratometry (SimK) and total corneal power (TCP) in keratoconic eyes, to determine whether the differences are systematic and predictable and to evaluate an adjusted TCP-based formula for intraocular lens (IOL) power calculation. METHODS: In a consecutive series of keratoconic eyes, measurements of SimK, TCP, posterior keratometry, and anterior and posterior corneal asphericities (Q-values) were retrospectively collected. The difference between SimK and TCP was linearly correlated to the biometric parameters. In a separate sample of keratoconic eyes that had undergone cataract surgery, IOL power was calculated with the Barrett Universal II, Hoffer QST, Holladay 1, Kane, and SRK/T formulas using the SimK and an adjusted TCP power. The respective prediction errors were calculated. RESULTS: A total of 382 keratoconic eyes (271 patients) were enrolled. An increasing overestimation of SimK by TCP was detected from stage I to III, with a significant correlation between the SimK and TCP difference and SimK in the whole sample (P < .0001, r2 = 0.1322). Approximately 7% of cases presented an underestimation of SimK by TCP. IOL power calculation with the adjusted TCP improved outcomes, achieving a maximum of 80% of eyes with a prediction error within ±0.50 diopters with the Hoffer QST, Holladay 1, and Kane formulas. CONCLUSIONS: Overall, SimK overestimated TCP. Such a difference could not be predicted by any variable. The proposed TCP-adjustment formula (TCPadj = TCP + 0.56 diopters) in keratoconic eyes for IOL power calculation might be valuable for improving refractive outcomes. [J Refract Surg. 2024;40(4):e253-e259.].

Evaluation of a new dynamic real-time visualization 25 kHz swept-source optical coherence tomography based biometer.

BACKGROUND: To evaluate the intraobserver repeatability and interobserver reproducibility of a newly developed dynamic real-time visualization 25 kHz swept-source optical coherence tomography (SS-OCT) based biometer (ZW-30, TowardPi Medical Technology Ltd, China) and compare its agreement with another SS-OCT based biometer (IOLMaster 700, Carl Zeiss Meditec AG, Jena, Germany). METHODS: Eighty-two healthy right eyes were enrolled in this prospective observational study. Measurements were repeated for three times using the ZW-30 and IOLMaster 700 in a random order. Obtained parameters included axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), anterior chamber depth (ACD), lens thickness (LT), mean keratometry (Km), astigmatism magnitude (AST), vector J0, vector J45, and corneal diameter (CD). The within-subject standard deviation (Sw), test-retest (TRT) variability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were adopted to assess the intraobserver repeatability and interobserver reproducibility. The double-angle plot was also used to display the distribution of AST. To estimate agreement, Bland-Altman plots were used. RESULTS: For the intraobserver repeatability and interobserver reproducibility, the Sw, TRT and CoV for all parameters were low. Meanwhile, the ICC values were all close to 1.000, except for the J45 (ICC = 0.887 for the intraobserver repeatability). The double-angle plot showed that the distribution of AST measured by these two devices was similar. For agreement, the Bland-Altman plots showed narrow 95% limits of agreements (LoAs) for AL, CCT, AQD, ACD, LT, Km AST, J0, J45, and CD (- 0.02 mm to 0.02 mm, - 7.49 µm to 8.08 µm, - 0.07 mm to 0.04 mm, - 0.07 mm to 0.04 mm, - 0.07 mm to 0.08 mm, - 0.16 D to 0.30 D, - 0.30 D to 0.29 D, - 0.16 D to 0.16 D, - 0.23 D to 0.13 D, and - 0.39 mm to 0.10 mm, respectively). CONCLUSIONS: The newly dynamic real-time visualization biometer exhibited excellent intraobserver repeatability and interobserver reproducibility. The two devices both based on the SS-OCT principle had similar ocular parameters measurement values and can be interchanged in clinical practice.

The Influence of Lens Position, Vault Prediction, and Posterior Cornea on Phakic Posterior Chamber Intraocular Lens Power.

BACKGROUND: Achieving precise refractive outcomes in phakic posterior chamber intraocular lens (pIOL) implantation is crucial for patient satisfaction. This study investigates factors affecting pIOL power calculations, focusing on myopic eyes, and evaluates the potential benefits of advanced predictive models. DESIGN: Retrospective, single-center, algorithm improvement study. METHODS: Various variations with different effective lens position (ELP) algorithms were analyzed. The algorithms included a fixed constant model, and a multiple linear regression model and were tested with and without incorporation of the posterior corneal curvature (Rcp). Furthermore, the impact of inserting the postoperative vault, the space between the pIOL and the crystalline lens, into the ELP algorithm was examined, and a simple vault prediction model was assessed. RESULTS: Integrating Rcp and the measured vault into pIOL calculations did not significantly improve accuracy. Transitioning from constant model approaches to ELP concepts based on linear regression models significantly improved pIOL power calculations. Linear regression models outperformed constant models, enhancing refractive outcomes for both ICL and IPCL pIOL platforms. CONCLUSIONS: This study underscores the utility of implementing ELP concepts based on linear regression models into pIOL power calculation. Linear regression based ELP models offered substantial advantages for achieving desired refractive outcomes, especially in lower to medium power pIOL models. For pIOL power calculations in both pIOL platforms we tested with preoperative measurements from a Scheimpflug device, we found improved results with the LION 1ICL formula and LION 1IPCL formula. Further research is needed to explore the applicability of these findings to a broader range of pIOL designs and measurement devices.

Assessing progression limits in different grades of keratoconus from a novel perspective: precision of measurements of the corneal epithelium.

BACKGROUND: To assess repeatability and reproducibility of corneal epithelium thickness (ET) measured by a spectral-domain optical coherence tomographer (SD-OCT)/Placido topographer (MS-39, CSO, Florence, Italy) in keratoconus (KC) population at different stages, as well as to determine the progression limits for evaluating KC progression. METHODS: A total of 149 eyes were enrolled in this study, with 29 eyes in the forme fruste keratoconus (FFKC) group, 34 eyes in the mild KC group, 40 eyes in the moderate KC group, and 46 eyes in the severe KC group. Employing the within-subject standard deviation (Sw), test-retest variability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) to evaluate intraoperator repeatability and interoperator reproducibility. RESULTS: The repeatability and reproducibility of MS-39 in patients with KC were acceptable, according to ICC values ranging from 0.732 to 0.954. However, patients with more severe KC and progressive peripheralization of the measurement points had higher TRTs but a thinning trend. The current study tended to set the cut-off values of mild KC, moderate KC, and severe KC to 4.9 µm, 5.2 µm, and 7.4 µm for thinnest epithelium thickness (TET). When differences between follow-ups are higher than those values, progression of the disease is possible. As for center epithelium thickness (CET), cut-off values for mild KC, moderate KC, and severe KC should be 2.8 µm, 4.4 µm, and 5.3 µm. This might be useful in the follow-up and diagnosis of keratoconus. CONCLUSIONS: This study demonstrated that the precision of MS-39 was reduced in measuring more severe KC patients and more peripheral corneal points. In determining disease progression, values should be differentiated between disease-related real changes and measurement inaccuracies. Due to the large difference in ET measured by MS-39 between various stages of disease progression, it is necessary to accurately grade KC patients to avoid errors in KC clinical decision-making.

Differences Between Keratometry and Total Keratometry Measurements in a Large Dataset Obtained With a Modern Swept Source Optical Coherence Tomography Biometer.

PURPOSE: This study aimed to explore the concept of total keratometry (TK) by analyzing extensive international datasets representing diverse ethnic backgrounds. The primary objective was to quantify the disparities between traditional keratometry (K) and TK values in normal eyes and assess their impact on intraocular lens (IOL) power calculations using various formulas. DESIGN: Retrospective multicenter intra-instrument reliability analysis. METHODS: The study involved the analysis of biometry data collected from ten international centers across Europe, the United States, and Asia. Corneal power was expressed as equivalent power and astigmatic vector components for both K and TK values. The study assessed the influence of these differences on IOL power calculations using different formulas. The results were analyzed and plotted using Bland-Altman and double angle plots. RESULTS: The study encompassed a total of 116,982 measurements from 57,862 right eyes and 59,120 left eyes. The analysis revealed a high level of agreement between K and TK values, with 93.98% of eyes exhibiting an absolute difference of 0.25 D or less. Astigmatism vector differences exceeding 0.25 D and 0.50 D were observed in 39.43% and 1.08% of eyes, respectively. CONCLUSIONS: This large-scale study underscores the similarity between mean K and TK values in healthy eyes, with rare clinical implications for IOL power calculation. Noteworthy differences were observed in astigmatism values between K and TK. Future investigations should delve into the practicality of TK values for astigmatism correction and their implications for surgical outcomes.

Evaluation of a New All-in-One Optical Biometer and Comparison With a Validated Swept-source OCT Biometer.

PURPOSE: To assess agreement between a new all-in-one non-contact optical biometer based on optical low coherence reflectometry (SW-9000 µm Plus; Suoer) and a swept-source optical coherence tomography biometer (OA-2000; Tomey). METHODS: Each eye was scanned three times in a row by each device at random. The measured ocular parameters included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), flat keratometry (Kf), steep keratometry (Ks), mean keratometry (Km), astigmatism, corneal diameter (CD), and pupil diameter (PD). The paired t test was used to show the differences between the SW-9000 and OA-2000. Bland-Altman plots and the 95% limits of agreement (LoA) were applied to assess the consistency of the measurements. RESULTS: Sixty eyes from 60 healthy participants were examined, with a mean spherical equivalent refraction of -5.58 ± 2.31 diopters and a mean age of 30.40 ± 6.07 years. The Bland-Altman plots showed high agreement for AL, ACD, LT, Kf, Ks, Km, astigmatism, and CD measurements (95% LoA: -0.06 to 0.04 mm, -0.10 to 0.06 mm, -0.12 to 0.11 mm, -0.30 to 0.29 D, -0.35 to 0.38 D, -0.29 to 0.30 D, -0.30 to 0.34 D, and -0.50 to 0.06 mm, respectively), whereas the agreement for CCT and PD were moderate (95% LoA: 7.12 to 20.43 µm, -0.75 to 1.19 mm, respectively). CONCLUSIONS: The new all-in-one non-contact biometer had high agreement with the OA-2000 biometer on the AL, ACD, LT, Kf, Ks, Km, astigmatism, and CD measurements. For most of the ocular parameters assessed, they were clinically interchangeable. [J Refract Surg. 2023;39(12):825-830.].

Comparison of Automated Keratometer and Scheimpflug Tomography for Predicting Refractive Astigmatism in Pseudophakic Eyes.

PURPOSE: To analyse the correspondence between refractive astigmatism and corneal astigmatism in pseudophakic eyes with non-toric intraocular lenses. SETTING: Yeouido St. Mary hospital, Seoul, Republic of Korea. DESIGN: Evaluation of a diagnostic test instrument. METHODS: This retrospective study included 95 eyes of 95 patients. Corneal astigmatism was measured with an automated keratometer (RK-5, Canon) and Scheimpflug tomography (Pentacam HR, Oculus). Refractive astigmatism was compared to keratometric astigmatism (based on anterior corneal measurements only), equivalent K-reading, and total corneal astigmatism (both based on anterior and posterior corneal measurements). Vector analysis was carried out by Næser's polar value method. The accuracy was defined as the average magnitude of the vectorial difference in astigmatism (DA). Each corneal measurement was optimized in retrospect by a multiple linear regression equation between refractive and corneal astigmatism. RESULTS: Keratometric astigmatism overestimated with-the-rule (WTR) refractive astigmatism and underestimated against-the-rule (ATR) refractive astigmatism. Several measurements based on both corneal surfaces' values did not show any statistically significant difference with respect to refractive astigmatism. The mean corneal astigmatism by total corneal refractive power (TCRP) at 4.0 mm (zone/pupil) produced the lowest mean arithmetic DA and the highest percentage of eyes with a DA ≤ 0.50 dioptre. After optimization, the accuracies of automated KA and TCRP 4.0 mm (zone/pupil) were similar. CONCLUSIONS: Total corneal astigmatism measured by Scheimpflug tomography at a 4.0 mm zone centered on the pupil accurately reflects the refractive astigmatism in pseudophakic eyes. However, the accuracy of total corneal astigmatism is not different from automated KA after optimization.

Repeatability and Interobserver Reproducibility of a Swept-Source Optical Coherence Tomography for Measurements of Anterior, Posterior, and Total Corneal Power.

INTRODUCTION: The aim of this work is to evaluate the intraobserver repeatability and interobserver reproducibility of corneal power measurements obtained with a swept-source optical coherence tomographer (CASIA 2, Tomey, Japan) in healthy subjects. METHODS: A total of 67 right eyes from 67 healthy subjects were enrolled. Two experienced observers measured each eye three times consecutively with the CASIA 2. Corneal power values were recorded as simulated keratometry, anterior, posterior, and total corneal power. Parameters were flattest keratometry (Kf), steepest keratometry (Ks), mean keratometry (Km), astigmatism magnitude, astigmatism power vectors J0 and J45. Intraobserver repeatability and interobserver reproducibility of the CASIA 2 were assessed by the within-subject standard deviation (Sw), test-retest repeatability (TRT), coefficients of variation (CoV), and intraclass correlation coefficients (ICCs). Double-angle plots were used for astigmatism vector analysis. RESULTS: The CASIA 2 had high repeatability for all corneal power values, with Sw values ≤ 0.17 diopters (D), TRT ≤ 0.46 D, and ICCs ranging from 0.866 to 0.998. Interobserver reproducibility was also high, showing all Sw values ≤ 0.10 D, TRT ≤ 0.27 D, and ICCs ≥ 0.944. The reproducibility of the average of three consecutive measurements (Sw 0.01-0.10 D, TRT 0.03-0.27 D, ICC 0.944-0.998) was higher than the reproducibility of single measurements (Sw 0.01-0.17 D, TRT 0.03-0.47 D, ICC 0.867-0.996). CONCLUSIONS: The CASIA 2 showed high intraobserver repeatability and interobserver reproducibility for anterior, posterior, and total corneal power measurements in 6.0-mm diameter area. In addition, we suggest that using the average of three consecutive measurements can improve reproducibility between observers, compared to single measurements only.

Comparison of a New Scheimpflug Camera and Swept-Source Optical Coherence Tomographer for Measurements of Anterior Segment Parameters.

INTRODUCTION: This study evaluated the differences and agreement between a new Scheimpflug camera (Scansys) and a swept-source anterior segment optical coherence tomographer (CASIA 2) for measurements of the anterior segment of the eye in normal subjects. METHODS: This prospective study included 84 eyes from 84 normal adult subjects who underwent three consecutive measurements with the Scansys and the CASIA 2 in random order. The mean keratometry (Km), astigmatism magnitude (AST), J0, and J45 vectors for both anterior and posterior corneal surfaces, central corneal thickness (CCT), thinnest corneal thickness (TCT), and anterior chamber depth (ACD) were obtained by both devices. The difference between these two devices was assessed using paired t test and violin plots. Bland-Altman plots and 95% limits of agreement (LoAs) were used to evaluate agreement. RESULTS: No statistically significant differences between the two devices were found for the anterior AST, anterior J45, and posterior J45 (P > 0.05). The remaining parameters were statistically significant (P ≤ 0.05), but the differences not clinically significant. The violin plots showed that the distribution and probability density of the measured parameters were similar for both devices. Bland-Altman plots revealed high agreement for the measured parameters between the Scansys and CASIA 2, with narrow 95% LoAs. CONCLUSIONS: In terms of assessing parameters for the anterior segment, our study indicated that Scansys and CASIA 2 generally showed significant agreement. The two devices used in this study's assessment of all the parameters can be used interchangeably in refractive analysis.

The Current Burden and Future Solutions for Preoperative Cataract-Refractive Evaluation Diagnostic Devices: A Modified Delphi Study.

Purpose: To obtain consensus on the key areas of burden associated with existing devices and to understand the requirements for a comprehensive next-generation diagnostic device to be able to solve current challenges and provide more accurate prediction of intraocular lens (IOL) power and presbyopia correction IOL success. Patients and Methods: Thirteen expert refractive cataract surgeons including three steering committee (SC) members constituted the voting panel. Three rounds of voting included a Round 1 structured electronic questionnaire, Round 2 virtual face-to-face meeting, and Round 3 electronic questionnaire to obtain consensus on topics related to current limitations and future solutions for preoperative cataract-refractive diagnostic devices. Results: Forty statements reached consensus including current limitations (n = 17) and potential solutions (n = 23) associated with preoperative diagnostic devices. Consistent with existing evidence, the panel reported unmet needs in measurement accuracy and validation, IOL power prediction, workflow, training, and surgical planning. A device that facilitates more accurate corneal measurement, effective IOL power prediction formulas for atypical eyes, simplified staff training, and improved decision-making process for surgeons regarding IOL selection is expected to help alleviate current burdens. Conclusion: Using a modified Delphi process, consensus was achieved on key unmet needs of existing preoperative diagnostic devices and requirements for a comprehensive next-generation device to provide better objective and subjective outcomes for surgeons, technicians, and patients.

Precision of Corneal Aberrations Measured by a New SD-OCT/Placido Topographer and Its Agreement With a Scheimpflug/Placido Topographer.

PURPOSE: To evaluate the precision of corneal aberrations measured by a new SD-OCT/Placido topographer, the MS-39 (CSO), and to compare them with those provided by a Scheimpflug/Placido device, the Sirius (CSO), in normal eyes. METHODS: This study enrolled 90 normal eyes of 90 patients. Total root mean square (RMS), higher order RMS, coma, trefoil, spherical aberration, and astigmatism II were analyzed. The within-subject standard deviation (Sw), test-retest repeatability, and intraclass correlation coefficient (ICC) were calculated to assess the precision. Bland-Altman plots and 95% limits of agreement (LoAs) were calculated to assess the agreement. RESULTS: For intraobserver repeatability of anterior and total corneal aberrations, most of the ICCs were greater than 0.869, except for trefoil and astigmatism II. Regarding the posterior corneal surface, the ICCs of total RMS, coma, and spherical aberration were higher than 0.878, whereas the ICCs of higher order RMS, trefoil, and astigmatism II were lower than 0.626. All test-retest repeatability values were 0.17 µm or less. In terms of interobserver reproducibility, the Sw values were 0.04 µm or less, Test-retest repeatability values were less than 0.11 µm, and all ICCs ranged from 0.532 to 0.996. Regarding agreement, 95% LoAs were small for all Zernike coefficients, and the mean difference was close to zero. CONCLUSIONS: The new SD-OCT/Placido device exhibited excellent repeatability and reproducibility for anterior and total surface, whereas total RMS, coma, and spherical aberrations showed high precision on the posterior surface. High agreement was confirmed between the SD-OCT/Placido and Scheimpflug/Placido devices. [J Refract Surg. 2023;39(6):405-412.].

Rotational Stability of a New Progressive Toric Hydrophobic Intraocular Lens With Gradually Decreasing Cylinder Power.

PURPOSE: To investigate the rotational stability of a new hydrophobic C-loop one-piece toric intraocular lens (IOL). METHODS: In this retrospective multicenter case series, the Avansee Preload1P Toric Clear (Kowa Co Ltd) was implanted using a digital marking system. Its orientation was assessed with retroillumination photographs at 1 hour, 1 day, 1 week, 1 month, 3 months, and 6 months. The mean rotation at each follow-up examination and percentage of eyes with a rotation within 5° and 10° were recorded. RESULTS: Seventy-two eyes were enrolled and completed the 3-month follow-up examination; data for the 6-month follow-up examination were obtained in 56 eyes. From the first postoperative to the 3-month examination, the mean arithmetic and absolute rotations were 0.58° ± 2.97° and 1.44° ± 2.65°, respectively. During this period, the rotation was 10° or less in 71 of 72 eyes (98.6%) and 5° or less in 67 of 72 eyes (93.1%). In the subgroup of 56 eyes with a 6-month follow-up, the mean arithmetic and absolute rotations were 0.95° ± 2.86° and 2.27° ± 1.96°, respectively, from the first to the last examination. During this period, the rotation was 10° or less in 100% of eyes and 5° or less in 53 of 56 eyes (94.6%). CONCLUSIONS: The new toric IOL has high rotational stability. The measured values were better than the corresponding values previously reported for other toric IOLs at all times considered up to 3 months and similar to them at 6 months. It satisfies the International Organization of Standardization and American National Standards Institute requirements. [J Refract Surg. 2023;39(6):374-380.].