Objective To evaluate the estimated lens diameter (eLD) of the crystalline lens in a large European cohort. Methods and analysis Data sets from an Austrian population acquired between 2020 and 2022 were analysed in this study. Measurements included optical biometry (IOLMaster 700, Carl Zeiss Meditec AG, Germany) as well as anterior segment optical coherence tomography (CASIA2, Tomey, Japan). For eLD prediction, three different machine learning approaches were implemented. Results In total, 2352 eyes of 2352 patients were included in this study. The eLD was normally distributed with a mean value of 10.18±0.56 mm, showing a statistically significant difference (p=0.008) between females and males (10.16±0.54 mm and 10.22±0.57 mm, respectively). There was a low but significant correlation (p

To investigate the IOLMaster 700 variability of posterior curvature readings in relation to ocular surface parameters.

Purpose: To present a concept for interconverting constants of disclosed lens power formulas and to simplify these conversions to linear prediction models for clinical use. Setting: Augen- und Laserklinik Castrop-Rauxel, Castrop-Rauxel, Germany. Design: Retrospective single-center case series. Methods: Analysis based on a dataset with biometric measurements of 19 472 eyes in a cataractous population performed with the IOLMaster 700. The formula constant conversion from formula A to B includes 2 steps: calculation of the lens power using formula A with variation of formula A constant and back calculation of the constant for formula B for all constant values of formula A using nonlinear iterative optimization techniques to minimize the sum of squared formula B prediction error. Results: Formula conversion was calculated for the SRK/T A-constant (A = 117 to 121), Hoffer Q (pACD = 4.2 to 6.8), Holladay 1 (SF 0.5 to 3.0), Haigis (a0 0.0 to 2.5 with a1/a2 = 0.4/0.1), and Castrop (C 0.15 to 0.50 with H/R = 0.0) formulas. As the conversions follow linear dependencies, linear regression models were fitted to simplify formula constant conversions in clinical routine. Conclusions: Conversions of formula constants could be used in cases where, for example, new lens models are launched with only the nominal SRK/T A-constant available or in situations where constants for some of the formulas are not available. Conversions to constant triplets for the Haigis or Castrop formula require additional nonlinear boundary conditions to take full advantage of formulas with multiple constants.

Purpose: To evaluate the repeatability of measurements obtained with a new spectral-domain optical coherence tomography-based biometer (Colombo IOL II) and assess their agreement with those provided by the IOLMaster 700. Setting: I.R.C.C.S. Bietti Foundation, Rome, Italy. Design: Prospective evaluation of diagnostic test. Methods: Patients underwent 3 consecutive scans with the Colombo IOL II and 1 with the IOLMaster 700. 2 groups were analyzed: Group A included a series of consecutive patients undergoing phacoemulsification and Group B a series of participants with a clear lens. Axial length (AL), keratometry (K), keratometric astigmatism, anterior chamber depth (ACD), lens thickness (LT), corneal diameter, central corneal thickness (CCT), and retinal thickness (RT) were analyzed. The within-subject SD, intrasession test variability, coefficient of variation (CoV), and intraclass correlation coefficient were calculated for repeatability analysis. 95% limits of agreement were calculated to assess agreement with the IOLMaster 700. Results: 96 unoperated eyes of 96 patients were enrolled (Group A: 45 Group B: 51). The CoV was low for most parameters because it ranged between 0.04% (AL) and 4.47% (RT) in Group A and from 0.03% (AL) to 2.23% (LT) in Group B. Keratometric astigmatism measurements were less repeatable. Good agreement with the IOLMaster 700 was found for K, LT, and AL, whereas the mean ACD was higher by 0.07 ± 0.11 mm with the Colombo IOL II (P < .0001). Conclusions: Measurements by the Colombo IOL II showed high repeatability and good agreement with those provided by the IOLMaster 700.

To compare axial length (AL) estimates of myopic eyes obtained using an axial length estimator (ALE) and AL measurements made with the IOLMaster 700 in India and the Lenstar 900 in Vietnam.

Purpose: To comprehensively evaluate the tilt of the crystalline lens in phakic eyes and its relationship with optical biometry parameters. Setting: The retrospective analysis was conducted at the Department for Ophthalmology and Optometry, Kepler University Clinic, in Linz, Austria. Design: Lens tilt assessment was performed through a combined analysis of optical biometry (IOLMaster 700) and anterior segment optical coherence tomography (AS-OCT) data to understand its relationship. Methods: The study analyzed preoperative biometry data and AS-OCT images from 4689 eyes of 2489 patients before cataract surgery. The optical biometry parameters were correlated with the degree of lens tilt using logistic regression and machine learning techniques. Results: The mean lens tilt was 4.9 degrees, with 6.7% of eyes showing a tilt greater than 7 degrees. Significant associations were found with specific biometry parameters, such as anterior chamber depth, axial length, equator thickness, and lens decentration. The developed predictive model for assessing tilt risk demonstrated a high accuracy with an area under the curve of 0.862. Conclusions: The findings highlight the mean lens tilt of 4.9 degrees in a cataract patient cohort. This analysis contributes to a broader understanding of lens orientation and its interactions with biometric parameters.

Purpose: To compare 3 biometers equipped with swept-source optical coherence tomography (OCT), including ARGOS (OCTB1), IOLMaster 700 (OCTB2), and Anterion (AS-OCTB). The primary aim was to assess the axial length (AL) acquisition success rates, and secondary aims included comparing parameters obtained from the 3 devices and evaluating postoperative refractive prediction errors. Setting: Chukyo Eye Clinic, Nagoya, Japan. Design: Retrospective observational study. Methods: The study included patients undergoing preoperative assessments for cataract surgery using the 3 biometers. The AL acquisition success rates and parameters obtained from the 3 devices were compared, and the postoperative refractive prediction errors (defined as the difference between subjective refractive error and predicted refractive error) were assessed at 1 month postoperatively. Results: 361 eyes from 361 patients were included in this study. The AL acquisition success rates for all patients were 100.0% (n = 361) (OCTB1), 98.6% (n = 356) (OCTB2), and 96.7% (AS-OCTB) (P < .0001), and those for nuclear sclerosis of grade 4 or higher were 100.0%, 87.8%, and 87.8%, respectively (P = .007). The AL of mature cataract was measurable only with OCTB1 using the enhanced retina visualization mode. Although there were significant differences in parameters obtained on the 3 devices, there were no significant differences in postoperative refractive prediction errors. Conclusions: OCTB1 demonstrated the highest AL acquisition success rate and was able to measure AL even in eyes with dense or mature cataract. AS-OCTB using a wavelength of 1300 nm showed lower AL acquisition success rates compared with the other 2 devices probably due to reduced light transmission through the vitreous body.

Purpose: To compare the refractive accuracy of the Barrett True axial length (BTAL) formula, newly integrated into ARGOS, with that of the Barrett Universal II (BUII) formula calculated using axial length (AL) from IOLMaster 700. Setting: Private clinics in Kanagawa, Japan. Design: Retrospective observational study. Methods: Eyes of patients who underwent cataract surgery with SY60WF IOL implantation, using ARGOS and IOLMaster 700, were assessed. The predicted refraction for BTAL was back-calculated. Refractive prediction errors (RPEs) for BTAL, BUII with ARGOS (segmented BUII), and BUII with IOLMaster 700 (composite BUII) were compared. The authors primarily aimed to demonstrate the noninferiority of BTAL to composite BUII in absolute RPE. Results: 209 eyes from 209 patients were included. BTAL met the noninferiority criteria, as the upper CI boundary was below the noninferiority margin of 0.10 diopters (D) for the difference in absolute RPE (−0.03 D; 95% CI, −0.06 to 0.01). In short eyes (AL ≤22.5 mm), the median absolute RPEs for BTAL, segmented BUII, and composite BUII were 0.25 D, 0.18 D, and 0.37 D, respectively, with significant differences between BTAL and composite BUII (P = .028) and segmented BUII and composite BUII (P = .018). In long eyes (AL >26 mm), the median absolute RPEs were 0.21 D, 0.20 D, and 0.28 D for BTAL, segmented BUII, and composite BUII, respectively. Conclusions: BTAL was noninferior to composite BUII in absolute RPE. BTAL is an accurate and useful intraocular lens power calculation formula, even in eyes with short and long AL.

Purpose: To characterize the variability of keratometry measurements on the IOLMaster 700 and relate it to device image quality indicators (QIs). Setting: 2 academic centers and 1 private practice. Design: Multicenter, retrospective consecutive…