For Publishers
DiscoveryMetadataPeer reviewHostingPublishing
For Researchers
JoinPublishReviewCollect
Register
Blog
About
Search
Advanced search
My ScienceOpen
Search
For Publishers
For Researchers
Blog
About
4
views
21
references
 Top references
cited by
6
    
0 reviews
 Review
0
comments
 Comment
0
recommends
+1 Recommend
0 collections
    0
    shares
      149
      similar
       All similar
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Distributions of crystalline lens tilt and decentration and associated factors in age-related cataract

      research-article
      Author(s): , MD, PhD, , MD , , MD, PhD, , MD, PhD, , MD, PhD, , MBBS, , MBBS, , MD, PhD, , MD, PhD , , MD, PhD
      Publication date (Electronic):
      Journal: Journal of Cataract and Refractive Surgery
      Publisher: Wolters Kluwer

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Approximately 10% of cataract patients have a tilt of 7 degrees or greater and decentration of 0.4 mm or greater. Axial length, front curvature radius, lens thickness, and age correlate with tilt and decentration.

          Purpose:

          To investigate the characteristics and factors associated with crystalline lens tilt and decentration measured by CASIA2 anterior segment optical coherence tomography.

          Setting:

          Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

          Design:

          Cross-sectional study.

          Methods:

          1097 eyes of 1097 patients who planned to undergo cataract surgery were enrolled. All patients underwent a general ophthalmologic examination. Lens thickness (LT), front curvature radius (FCR), back curvature radius, lens equator diameter (LED), tilt, and decentration of preoperative crystalline lenses were measured by CASIA2. Univariate and multivariate regression analyses were performed to evaluate the relationships between the tilt and decentration of crystalline lens with related factors.

          Results:

          The natural crystalline lenses showed a mean tilt of 5.16 degrees toward the inferotemporal direction and a mean decentration of 0.22 mm toward the temporal direction. Of the total 1097 eyes, 119 eyes (10.85%) had a tilt greater than 7 degrees, and 89 eyes (8.11%) had a decentration more than 0.4 mm. Multivariate regression analysis showed that larger decentration, thicker LT, shorter axial length (AL), and FCR were associated with greater lens tilt ( P < .001, P = .007, P = .006, and P = .003, respectively). In addition, greater tilt, older and thinner LT were correlated with larger decentration (all P < .001).

          Conclusions:

          Preoperative crystalline lens had a certain degree of tilt and decentration in age-related cataract. The greater tilt of the crystalline lens was, the larger decentration of it was. In addition, AL, FCR, LT, and age also correlated with tilt and decentration.

          Related collections

          Most cited references21

          • Record: found
          • Abstract: found
          • Article: not found

          Tilt and decentration of intraocular lenses in vivo from Purkinje and Scheimpflug imaging. Validation study.

          Susana Marcos, Alberto Pochini, P Cháidez-Rosales (2007)
          To measure tilt and decentration of intraocular lenses (IOLs) with Scheimpflug and Purkinje imaging systems in physical model eyes with known amounts of tilt and decentration and patients. Instituto de Optica Daza de Valdés, Consejo Superior de Investigaciones Científicas, Madrid, Spain. Measurements of IOL tilt and decentration were obtained using a commercial Scheimpflug system (Pentacam, Oculus), custom algorithms, and a custom-built Purkinje imaging apparatus. Twenty-five Scheimpflug images of the anterior segment of the eye were obtained at different meridians. Custom algorithms were used to process the images (correction of geometrical distortion, edge detection, and curve fittings). Intraocular lens tilt and decentration were estimated by fitting sinusoidal functions to the projections of the pupillary axis and IOL axis in each image. The Purkinje imaging system captures pupil images showing reflections of light from the anterior corneal surface and anterior and posterior lens surfaces. Custom algorithms were used to detect the Purkinje image locations and estimate IOL tilt and decentration based on a linear system equation and computer eye models with individual biometry. Both methods were validated with a physical model eye in which IOL tilt and decentration can be set nominally. Twenty-one eyes of 12 patients with IOLs were measured with both systems. Measurements of the physical model eye showed an absolute discrepancy between nominal and measured values of 0.279 degree (Purkinje) and 0.243 degree (Scheimpflug) for tilt and 0.094 mm (Purkinje) and 0.228 mm (Scheimpflug) for decentration. In patients, the mean tilt was less than 2.6 degrees and the mean decentration less than 0.4 mm. Both techniques showed mirror symmetry between right eyes and left eyes for tilt around the vertical axis and for decentration in the horizontal axis. Both systems showed high reproducibility. Validation experiments on physical model eyes showed slightly higher accuracy with the Purkinje method than the Scheimpflug imaging method. Horizontal measurements of patients with both techniques were highly correlated. The IOLs tended to be tilted and decentered nasally in most patients.
          Article 0 comments Cited 42 times – based on 0 reviews     Review now
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Prediction of the effective postoperative (intraocular lens) anterior chamber depth.

            Thomas Gramstad (2006)
            To investigate methods to predict the effective postoperative anterior chamber depth (ACD) based on a large patient sample. University Eye Clinic, Aarhus Kommunehospital, Aarhus, Denmark. Based on 6698 consecutive cataract operations with recorded postoperative refractive results, the postoperative effective ACD was calculated in each case and studied by multiple linear regression for covariance with a number of preoperatively defined variables including the axial length by ultrasonography, preoperative ACD, lens thickness, corneal radius by keratometry, subjective refraction, patient age, and corneal white-to-white diameter, the latter of which was available in a subgroup of 900 cases. The postoperative effective ACD was significantly correlated with 6 preoperative variables (in decreasing order): axial length, preoperative ACD, keratometry reading, lens thickness, refraction, and patient age (R = 0.49, P < .000001). Age showed the weakest correlation (P = .02) and could be omitted with no significant decrease in the total correlation coefficient. Using the 5 most significant variables, the ACD could be predicted according to a regression formula with an accuracy of 82.1% of the predictions within 0.5 mm. When this ACD algorithm was used in retrospect in the intraocular lens (IOL) power calculation, the refractive prediction error decreased by 10% from the error associated with a previously published 4-variable algorithm and decreased 28% from the error using no individual ACD method other than the average ACD (P < .00001). The postoperative ACD was significantly correlated with and hence predictable by a 5-variable regression method incorporating the preoperative axial length, ACD, keratometry reading, lens thickness, and refraction as the most significant variables. The statistical relationship can be used to create a new ACD prediction algorithm to incorporate in a modern "thick lens" IOL power calculation formula with significant improvement in the accuracy of the refractive predictions as a result.
            Article 0 comments Cited 40 times – based on 0 reviews     Review now
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Corneal and crystalline lens dimensions before and after myopia onset.

              Laura Sinnott, S Cotter, James Mitchell … (2012)
              To describe corneal and crystalline lens dimensions before, during, and after myopia onset compared with age-matched emmetropic values. Subjects were 732 children aged 6 to 14 years who became myopic and 596 emmetropic children participating between 1989 and 2007 in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error Study. Refractive error was measured using cycloplegic autorefraction, corneal power using a hand-held autokeratometer, crystalline lens parameters using video-based phakometry, and vitreous chamber depth (VCD) using A-scan ultrasonography. Corneal and crystalline lens parameters in children who became myopic were compared with age-, gender-, and ethnicity-matched model estimates of emmetrope values annually from 5 years before through 5 years after the onset of myopia. The comparison was made without and then with statistical adjustment of emmetrope component values to compensate for the effects of longer VCDs in children who became myopic. Before myopia onset, the crystalline lens thinned, flattened, and lost power at similar rates for emmetropes and children who became myopic. The crystalline lens stopped thinning, flattening, and losing power within ±1 year of onset in children who became myopic compared with emmetropes statistically adjusted to match the longer VCDs of children who became myopic. In contrast, the cornea was only slightly steeper in children who became myopic compared with emmetropes (<0.25 D) and underwent little change across visits. Myopia onset is characterized by an abrupt loss of compensatory changes in the crystalline lens that continue in emmetropes throughout childhood axial elongation. The mechanism responsible for this decoupling remains speculative but might include restricted equatorial growth from internal mechanical factors.
              Article 0 comments Cited 38 times – based on 0 reviews     Review now
                Bookmark
                All references

                Author and article information

                Contributors
                Xiaoyun Chen
                Xiaoxun Gu
                Wei Wang
                Guangming Jin
                Lanhua Wang
                Enen Zhang
                Jingmin Xu
                Zhenzhen Liu
                Yizhi Liu
                Journal
                Journal ID (nlm-ta): J Cataract Refract Surg
                Journal ID (iso-abbrev): J Cataract Refract Surg
                Journal ID (coden): JCRS
                Journal ID (pmc): JCRS
                Journal ID (publisher-id): JCRS
                Title: Journal of Cataract and Refractive Surgery
                Publisher: Wolters Kluwer (Maryland, MD )
                ISSN (Print): 0886-3350
                ISSN (Electronic): 1873-4502
                Publication date (Print): October 2021
                Publication date (Electronic): 05 March 2021
                Volume: 47
                Issue: 10
                Pages: 1296-1301
                Affiliations
                From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
                Author notes
                Corresponding author: Lixia Luo, MD, PhD, Zhenzhen Liu, MD, PhD, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Centre, Sun Yat-sen University, No.7 Jinsui Road, Guangzhou 510060, China. Email: luolixia@ 123456gzzoc.com ; liuzhenzhen@ 123456gzzoc.com .
                Article
                Publisher ID: JCRS-20-1173 Accession ID: 00010
                DOI: 10.1097/j.jcrs.0000000000000631
                PMC ID: 8500366
                PubMed ID: 33769775
                SO-VID: 1e1549ad-ee59-41c7-920e-68c9f0cd82f5
                Copyright © Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of ASCRS and ESCRS
                License:

                This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

                History
                Date received : 31 August 2020
                Date revision received : 22 February 2021
                Date accepted : 23 February 2021
                Categories
                Subject: Article
                Custom metadata
                OPEN-ACCESS TRUE

                Data availability:

                Comments

                Comment on this article

                scite_

                Similar content149

                See all similar

                Cited by6

                See all cited by

                Most referenced authors173

                See all reference authors