OcuTOP: a novel handheld corneal topography device with misalignment correction.

From Earlier to Updated Quadrifocal Intraocular Lens Designs: An Objective Optical Metrology Analysis.

PURPOSE To compare the optical performance of the Clareon PanOptix and Clareon PanOptix Pro intraocular lenses (IOLs) using interferometric metrology and identify measurable optical differences. SETTING Physiological Optics Laboratory, Daegu, Republic of Korea. DESIGN Experimental optical-bench investigation. METHODS Three +20.0 D samples each of the PanOptix and PanOptix Pro IOLs (Alcon) were analyzed using a Mach-Zehnder interferometer in a model eye incorporating +0.27 µm corneal spherical aberration. Microscopic imaging, wavefront reconstruction with Zernike analysis, diffractive-step profile reconstruction, point-spread function (PSF)-based retinal image simulation, halo analysis, and through-focus modulation transfer function (TF-MTF) analysis were performed. RESULTS Both IOLs showed broadly similar diffractive architecture and spherical aberration profiles. Peak-to-valley step-profile amplitudes were comparable, although the PanOptix Pro showed localized differences in the reconstructed step-height contour. PSF-based analyses showed broadly similar focal behavior, but the PanOptix Pro demonstrated clearer Sloan F contour preservation and more evident central PSF-core brightness at the far-intermediate position. In through-focus average MTF (aMTF) profiles, the PanOptix Pro showed a modestly higher far-focus peak and a less pronounced post-peak dip, particularly at 4.5- and 3.0-mm pupils. MTF50 analysis showed a similar overall pattern, with greater variability and more apparent inter-model differences at larger pupil sizes. CONCLUSIONS The PanOptix Pro preserves the fundamental design and spherical aberration profile of the original PanOptix, while showing localized diffractive step-height modifications. Together with clearer far-intermediate F-image preservation, sustained central PSF-core brightness, and a shallower post-peak aMTF dip, these findings are consistent with a relative redistribution of optical energy toward the far-intermediate region, supporting greater far-intermediate optical continuity without substantial changes in nominal add power or overall focal structure.

axial length measurement acquisition rates of two optical biometers in cataractous eyes

Design and validation of a mechanically scanning Hartmann–Shack system for peripheral aberration measurement

Peripheral refraction is thought to play an important role in the onset and progression of myopia, highlighting the need for reliable methods to quantify peripheral optical aberrations in the eye. We present a mechanically scanning Hartmann–Shack system and validates it using a model eye. The system coordinates the mirror rotation and translation with synchronous motion of the wavefront sensor to perform peripheral aberration measurements. For a 6-mm entrance pupil, central field refractive errors from −6 to +6 D were measured, and horizontal meridian peripheral aberrations were acquired over a 0- to 30-deg field of view in 2.5-deg steps. The experimental measurements were compared with corresponding Zemax-based simulations. Five repeated measurements showed good agreement with the simulated central field defocus, with a linear fit slope close to 1. In off-axis fields, the experimental and simulated results demonstrated reliable measurement performance, with spherical equivalent differences below 0.10 D and a maximum astigmatic component J0 difference of 0.19 D. These results demonstrate the accuracy and repeatability of the proposed mechanically scanning approach under model eye conditions and support its further development as a platform for future peripheral aberration studies.

A comparative analysis of predicted spherical refractive outcomes between two swept-source optical biometers.

PURPOSE To compare the predicted spherical equivalent (PSEq) between the ANTERION® anterior segment OCT device (Heidelberg Engineering GmbH, Heidelberg, Germany) and the IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany) in patient undergoing cataract surgery. METHODS Ocular biometry was performed by a single investigator for each patient scheduled for cataract surgery, with ANTERION and IOLMaster 700. Intraocular lens (IOL) power for TECNIS® 1-Piece Aspheric IOL (Model ZCB00) and corresponding PSEq were calculated using IOL formulas including Barrett Universal II, Cooke K6, EVO 2.0, Hill-RBF 3.0, Hoffer®QST, Kane, Pearl-DGS and SRK/T. The main outcomes assessed were the mean difference in PSEq between the two devices and the proportion of eyes where the PSEq difference exceeded 0.35 dioptres (D), considered clinically significant as it would likely result in a different IOL power being implanted. RESULTS A total of 155 right eyes from 155 patients were analysed. The ANTERION consistently produced more hyperopic PSEq compared to the IOLMaster, with mean differences across all IOL formulas ranging from + 0.11 to + 0.18 D. These differences were statistically significant (P < 0.05). Agreement analysis demonstrated that the majority of data points between the devices were within the 95% limits of agreement (- 0.39 D to 0.79 D), regardless of the IOL power calculation formula applied. However, 15-25% of eyes showed a PSEq difference greater than 0.35 D. CONCLUSIONS PSEq derived from ANTERION is slightly hyperopic compared to IOLMaster, with discrepancies significant enough to affect IOL power selection in up to 25% of eyes.

Clinical Outcomes of a Novel Customized Multifocal Corneo-Scleral Contact Lens With Spherical Aberration Control.

PURPOSE To evaluate the objective and subjective clinical outcomes of a customized multifocal corneo-scleral contact lens (CLs) with spherical aberration (SA) control in presbyopic patients. METHODS A pilot observational clinical study was conducted in 27 presbyopic subjects (54 eyes). All participants were fitted with a customized multifocal corneo-scleral rigid gas-permeable (RGP) CLs designed to induce controlled SA. Binocular visual acuity (VA) was assessed under photopic conditions for distance, intermediate (67 cm), and near (40 cm) vision after a minimum wear period of 2 months and binocular defocus profile was constructed by plotting mean visual acuity (logMAR) as a function of induced defocus from +2.00 to -2.50 D. Ocular aberrations with the lens in situ were measured using a Hartmann-Shack aberrometer. Subjective visual quality and comfort were evaluated using the Quality of Vision (QoV) questionnaire and the eight-item Contact Lens Dry Eye Questionnaire (eCLDEQ-8). Spearman correlation analyses were performed to explore relationships between visual outcomes and optical parameters. RESULTS Mean binocular VA was 0.03±0.06 for distance vision, 0.10±0.12 for intermediate vision, and 0.32±0.17 for near vision. The binocular defocus profile showed preserved visual performance from distance to intermediate defocus levels, with a marked reduction at-2.50 D. A weak but statistically significant positive correlation was found between the sign of induced SA and distance VA (ρ=0.303, P=0.026), indicating poorer distance vision with positive SA induction. Near VA was weakly and positively correlated with mean pupil diameter (ρ=0.301, P=0.027). No significant associations were observed between VA and total higher-order aberration (HOAs) magnitude. Subjective symptoms were generally mild, with difficulty focusing being the most frequently reported complaint. CONCLUSIONS The customized multifocal corneo-scleral CLs with SA control evaluated can provide good distance and intermediate visual performance in presbyopic patients, but limited near visual performance and symptom tolerance. The sign of induced SA and pupil size seem to influence visual outcomes, supporting the value of individualized optical design. Further controlled studies with larger samples and extended follow-up are warranted.

A New Algorithm for Management of Corneal Astigmatism Using Toric Intraocular Lenses

Background and Objectives: To assess refractive and visual outcomes following phacoemulsification using a novel algorithm for toric intraocular lens (IOL) surgery. Setting: Private practice, Spain. Design: Prospective observational study. Materials and Methods: The algorithm was designed to control the topographic position of the principal meridians (flat and steep) after cataract surgery in eyes without associated corneal pathology or previous corneal surgery. It is well known that a toric IOL must be positioned along the steep meridian. Therefore, it is crucial to predict both the postoperative position of the steep meridian and its magnitude. Data from patients who were planned for refractive lens exchange or cataract surgery using the Pešić-Barraquer algorithm and implantation of a toric IOL in eyes with different degrees of astigmatism were used to assess the effect of residual astigmatism on 6-month postoperative monocular uncorrected and corrected distance logMAR visual acuity values (UDVA and CDVA). Vector analysis was performed with J0 and J45 evaluations, and centroid errors in postoperative refractive astigmatism prediction error were calculated in the spectacle plane using the “Astigmatism Double-Angle Plot Tool”. Results: Three hundred and six eyes of 250 patients with a mean age of 69.0 years ± 8.6 were enrolled in the study. The mean preoperative corneal astigmatism measured with Pentacam was 1.43 D ± 0.83 (SD). One hundred and eighty-four eyes (60.13%) had “against-the-rule” (ATR) astigmatism, 67 (21.90%) had “with-the-rule” (WTR) astigmatism, and 55 (17.97%) eyes had “oblique” corneal (OBL) astigmatism preoperatively. The mean absolute astigmatic prediction error in residual astigmatism was 0.31 D ± 0.28. Eyes with preoperative ATR corneal astigmatism had lower mean absolute errors compared to the eyes with WTR astigmatism (0.29 D ± 0.26 and 0.34 D ± 0.31, respectively). Centroid error in predicted residual astigmatism was 0.08 D ± 0.41 @4°. All eyes achieved residual refractive astigmatism within the 1.00 D range, and 55.23% had no residual astigmatism in the spectacle plane. Mean postoperative refractive astigmatism at the spectacle plane was 0.24 D ± 0.29. There were no postoperative complications. Additional statistical analysis of 310 eyes confirmed that when the main incision is not placed on one of the three meridians (flat, steep, or 45-degree bisector), the axis of astigmatism induced by the incision is significantly altered. Exploratory subgroup analyses demonstrated comparable prediction accuracy across incision positions, preoperative astigmatism types, and surgeons, further supporting the robustness of the proposed algorithm. Conclusions: In addition to enabling more accurate prediction of postoperative refractive residual astigmatism in patients undergoing toric IOL implantation, our newly proposed algorithm provides surgical pearls to facilitate preoperative and intraoperative management of corneal astigmatism, highlighting the importance of precise incision placement for optimal refractive outcomes.