Purpose: To analyze the characteristics and factors associated with intraocular lens (IOL) tilt and decentration after uneventful phacoemulsification with IOL implantation. Setting: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Design: Cross-sectional study. Methods: All patients underwent a general ophthalmologic examination and anterior segment photography. IOL tilt and decentration were measured with a second-generation anterior segment optical coherence tomography (Casia2). Univariate and multivariate regression analyses were performed to assess the association between IOL tilt and decentration with ocular biometric and systemic parameters, and the visual acuity. Results: A total of 196 eyes of 196 patients were enrolled in this study. IOLs showed a mean tilt of 4.8 degrees toward the inferotemporal direction, and the mean decentration was 0.21 mm. Both eyes presented a mirror symmetry relationship. Twenty-two eyes (11.22%) had a tilt greater than 7 degrees, and 21 eyes (10.72%) had a decentration more than 0.4 mm. Multivariate regression analysis showed previous pars plana vitrectomy (PPV) and short axial length (AL) were associated with greater IOL tilt (P = .014 and P < .001). In addition, long AL, thicker lens, and less capsulorhexis–IOL overlap were positively correlated with decentration (P < .001, P = .029, and P = .026). Corrected distance visual acuity did not directly correlate with IOL tilt and decentration (P = .417 and P = .550). Conclusions: PPV history and short AL were associated with greater IOL tilt, whereas longer AL, thicker lens, and overlarge capsulorhexis contribute to greater decentration. Implantation of toric and multifocal IOLs in these patients should be cautious.

Super formula (LSF), and Emmetropia Verifying Optical formulas in highly myopic eyes.DESIGN: Retrospective, consecutive case-series study. METHODS: A total of 164 eyes of 164 patients with AL ‡26.0 mm were included and divided into 2 groups: AL <28.0 mm (Group 1) and AL ‡28.0 mm (Group 2). The average arithmetic spherical equivalent prediction error (PE), mean absolute PE, median absolute error (MedAE), and the percentage of eyes within ±0.25 diopter (D), ±0.50 D, and ±1.0 D of PE were determined. RESULTS: The Holladay 1 formulas showed the smallest MedAE when combined with the first linear or nonlinear version of Wang-Koch AL adjustment methods, both in total and in subgroups. The SRK/T formula displayed the highest prediction accuracy in combination with the first linear version of Wang-Koch adjustment method in total and subgroups. The CMAL reduced the absolute PE of LSF in total (P [ .003) and in Group 1 (P [ .017).CONCLUSIONS: The Holladay 1 and SRK/T formulas combined with specific AL adjustment methods had accuracy similar to the fourth-generation formulas for highly myopic eyes. Moreover, the CMAL can improve the accuracy of the LSF for highly myopic eyes.

Background: To identify the main determinants of intraocular lens (IOL) tilt and decentration after cataract surgery using a novel anterior segment optical coherence tomography (AS-OCT) method.Methods: Fifty-six patients who underwent phacoemulsification with IOL implantation in one eye were continuously enrolled in this cohort study. Axial length (AL) was measured with IOL Master 700. The tilt and decentration of patients' preoperative crystalline lenses and postoperative IOLs, as well as crystalline lens thickness (LT), were measured using AS-OCT before surgery and 1 week after surgery. Results:The mean tilt and decentration of the patients' preoperative crystalline lenses were 4.90°±1.81° and 0.21±0.02 mm, and the mean tilt and decentration of IOLs were 4.75°±1.66° and 0.21±0.02 mm, respectively. There were no significant differences in magnitude, direction of tilt, or decentration between crystalline lenses and IOLs. The strongest determinant of IOL tilt was preoperative crystalline lens tilt (R²=0.512, P<0.001), followed by AL (R²=0.154, P=0.003). Additionally, crystalline lens decentration and AL explained 54.6% of the variability in IOL decentration. AL was the factor most highly associated with IOL decentration (R 2 =0.332, P<0.001), rather than crystalline lens decentration (R 2 =0.214, P<0.001). Conclusions:The position of the preoperative crystalline lens and AL were the critical determinants of IOL tilt and decentration. The tilt and decentration of IOLs will be greater in patients with larger tilt and decentration of crystalline lenses, or shorter and longer AL.

Background: To assess the radius of anterior lens surface curvature (RAL) measurements with anterior segment optical coherence tomography (AS-OCT) in comparison with Scheimpflug imaging.Methods: This prospective, cross-sectional study was carried out at Zhongshan Ophthalmic Center, Guangzhou, China. We enrolled 59 eyes, including 30 eyes from 30 cataractous volunteers (59 to 87 years) and 29 eyes from 29 young participants (19 to 49 years). After mydriasis, the RAL was measured automatically by the built-in software in the AS-OCT (CASIA 2). The Scheimpflug images were measured with the build-in caliper tool of the Scheimpflug camera (Pentacam), and RAL were further calculated with the principle of best-fitted circle. Intraobserver and interobserver reproducibility of RAL measurement using Scheimpflug camera were evaluated with limit of agreement (LoA) and intraclass correlation coefficient (ICC).Consistency between RAL measurement of Scheimpflug camera and AS-OCT were assessed with LoA, correlation analysis and linear regression.Results: For all subjects, intraobserver (LoA: −0.25 to 0.23 mm, ICC: 0.996) and interobserver reproducibility (LoA: −0.85 to 0.92 mm, ICC: 0.947) of RAL were good using Scheimpflug imaging. Both AS-OCT and Scheimpflug imaging found that the age-related cataract participants had smaller RAL (P=0.010, P=0.001 respectively). LoA of RAL measurement between AS-OCT and Scheimpflug imaging was −3.83 to −0.79 mm, and the Pearson correlation efficient was 0.909 (P<0.001). The RAL values measured by AS-OCT were significantly greater than that by Scheimpflug camera with a mean difference of 2.31 mm for all participants (P<0.001). The RAL measurement could be converted using the equation: Y CASIA 2 =1.155 × X Pentacam + 1.060.Conclusions: Both Scheimpflug camera system with internal caliper tool and the AS-OCT are fast and non-contact tools that could measure RAL successfully. The two measurement results are highly correlated and interchangeable through linear regression equation.

No abstract

In humans, the lens is the organ with the ability to change morphology and refractive power, designated as accommodation, to focus light from various distances and obtain clear retinal image. The accommodative ability of the lens depends on its structure and biological parameters. The lens grows throughout the life, forming specific lens sutures and a unique gradient refractive index, and possesses regenerative ability under certain circumstances. Minimally invasive lens surgery that preserves endogenous lens epithelial stem/progenitor cells (LECs) can achieve functional lens regeneration in humans. The lens is the main source of intraocular aberration, especially intraocular higher-order aberrations (IHOAs) which is found to be binocularly symmetrical in phakic eyes. There is a compensation mechanism between corneal aberrations and lens aberrations. Therefore, the structure and the biological parameters of the lens, the binocular relationship of the lens and the correlation between the lens and cornea affect visual quality. This paper summarises the above findings and their current and potential applications in refractive surgeries, providing a comprehensive understanding of the lens as a strong determinant of visual quality in the optical system.

Purpose: To compare the efficacy and safety of a fluid-jet technique with capsular polish in reducing residual lens fibers (RLFs) in phacoemulsification surgery. Setting: Single center. Design: Prospective nonrandomized comparative study. Methods: Patients receiving phacoemulsification were included. Consecutive eligible patients alternately underwent either removal of RLFs on the posterior capsule using capsular polish after irrigation and aspiration, and before intraocular lens (IOL) implantation, or RLF removal using a fluid-jet technique after IOL implantation. Posterior capsular images were used to quantify RLFs. Visual parameters were evaluated at 1 day, 1 week, and 1 year postoperatively. The proportion of capsule occupied by posterior capsule opacification (PCO) (area %) and incidence of protocol-driven laser posterior capsulotomy were recorded at 1 year in masked fashion. Results: Seven hundred forty eyes were allocated to polishing (n = 370) or fluid-jet technique (n = 370). Polishing required 70.4 ± 17.5 seconds and fluid-jet 32.2 ± 9.9 seconds (P ≤ 0.001). Compared with the polishing group, capsular area occupied by RLFs in the fluid-jet group was significantly smaller (3.5% vs 0.5%, P = .031) at the end of surgery. One day postoperatively, the fluid-jet group had more desirable corrected distance visual acuity, objective scattering index, and Strehl ratio (all P < .05). PCO area percentage did not differ between groups (6.5% vs 4.5%, P = .252) 1 year postoperatively, but incidence of posterior capsulotomy was lower in the fluid-jet group (3.2% vs 0.8%, P = .019). Conclusions: Fluid-jet removed RLFs effectively and had lower incidence of postoperative capsulotomy than capsular polishing.

Background and AimTo assess the reproducibility of the novel ultrasound biomicroscopy, Insight 100 and its agreement with a swept-source optical coherence tomography, CASIA2.MethodsA total of 96 volunteers (96 eyes) were enrolled. The radius of anterior lens curvature (RAL), the radius of posterior lens curvature (RPL), lens thickness (LT), and lens diameter (LD) were measured with Insight 100 and CASIA2. A semiautomated software was used to adjust the measurement of LT (LTS) and LD (LDS) by Insight 100. Intraobserver and interobserver reproducibility of Insight 100 measurements, and the agreement of results from Insight 100 and CASIA2 were assessed with 95% limit of agreement (LoA), intraclass correlation coefficient (ICC), Pearson correlation, and linear regression.ResultsFor Insight 100 measurements, the intraobserver ICCs of RAL, RPL, LTS, and LDS measurement were 0.996, 0.973, 0.936, and 0.889, and the interobserver ICCs were 0.987, 0.890, 0.974, and 0.816, respectively. There was an excellent correlation in LT measurements (R = 0.961, P &lt; 0.001) but poor agreements in other parameters between the two devices. The LD measurements tended to be larger (95% CI: 0.768–0.928) in CASIA2 when compared with Insight 100.ConclusionInsight 100 could obtain highly repeatable lens biometry in vivo. With better signal penetration, it shows promising potential in future clinical applications.