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Ye Y, Zhao Y, Zhang Z, Wei R, Xian Y, Huang Y, Liu F, Xu Y, Zhou X. Correlation analysis of angles κ and α with the refraction and anterior segment parameters in children. BMC Ophthalmol 2024; 24:143. [PMID: 38549060 PMCID: PMC10976721 DOI: 10.1186/s12886-024-03409-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Accepted: 03/24/2024] [Indexed: 04/01/2024] Open
Abstract
AIM To investigate the correlation of angles α and κ with the refractive and biological parameters in children. METHODS This case-series study included 438 eyes of 219 children (males/females = 105/114, age: 3-15 years). Ocular biometric parameters, including axial length, corneal radius of curvature (CR), white-to-white distance (WTW), angle κ and angle α, were measured using IOL Master 700; auto-refraction were assessed under cycloplegia. The eyes were assigned to different groups based on CR, WTW, and gender to compare the angles α and κ, and analyze the correlations between the differences of biological parameters on angles α and κ. RESULTS The means of axial length, CR, WTW, angle α, and angle κ were 23.24 ± 1.14 mm, 7.79 ± 0.27 mm, 11.68 ± 0.41 mm, 0.45 ± 0.25 mm, and 0.27 ± 0.22 mm, respectively. Angle α was correlated with CR and WTW (fixed effect coefficient [FEC] = 0.237, p = 0.015; FEC = -0.109, p = 0.003; respectively), and angle κ also correlated with CR and WTW (FEC = 0.271, p = 0.003; FEC = -0.147, p < 0.001, respectively). Comparing subgroups, the large CR and small WTW group had larger angles α (0.49 ± 0.27 vs. 0.41 ± 0.21, p < 0.001; 0.46 ± 0.27 vs. 0.44 ± 0.21, p < 0.05, respectively) and κ (0.29 ± 0.25 vs. 0.24 ± 0.15, p < 0.01; 0.29 ± 0.25 vs. 0.26 ± 0.19, p < 0.05, respectively). The differences in interocular angles α and κ showed correlation with interocular WTW (r = - 0.255, p < 0.001; r = - 0.385, p < 0.001). Eyes with smaller WTW tended to have larger angle κ (0.28 ± 0.27 vs. 0.25 ± 0.15, p < 0.05). CONCLUSION The size of angle α/κ may be correlated to CR and WTW, and a larger WTW eye may suggest a smaller angle κ compared with the fellow eye.
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Affiliation(s)
- Yuhao Ye
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yu Zhao
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Zhe Zhang
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Ruoyan Wei
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yiyong Xian
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Yangyi Huang
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Fang Liu
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
| | - Ye Xu
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China.
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China.
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Yoon H, Magnago T, Yeom DJ. Three-Month Clinical Outcomes to Correct Myopia or Myopic Astigmatism Using a Femtosecond Laser for Lenticule Creation With Automated Centration and Cyclotorsion Compensation. J Refract Surg 2024; 40:e30-e41. [PMID: 38190561 DOI: 10.3928/1081597x-20231212-03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
PURPOSE To individually evaluate the clinical outcomes for right and left eyes in the first 3 months after laser-assisted lenticule extraction for myopia and myopic astigmatism with the use of the new ATOS femtosecond laser system (Smart-Sight; SCHWIND eye-tech-solutions). METHODS A total of 331 eyes from 168 patients (166 right eyes and 165 left eyes) consecutively treated with SmartSight lenticule extraction were retrospective analyzed after a 3-month follow-up period. Patients' mean age was 26 ± 6 years (range: 18 to 47 years) and mean preoperative spherical equivalent (SEQ) was -5.07 ± 1.92 diopters [D] (range: -1.50 to -11.25 D) with a mean astigmatism of -1.04 ± 0.85 D (range: 0.00 to -4.00 D). At 3 months of follow-up, visual acuity, SEQ and cylinder, safety index, efficacy index, corneal higher order aberrations, and intraocular pressure (IOP) were analyzed. Furthermore, refractive and visual outcomes were also analyzed for the right and left eyes individually. All lenticule extraction treatments were performed with the SmartSight treatment method of the SCHWIND ATOS femtosecond laser. RESULTS At 3 months after surgery, mean SEQ was -0.12 ± 0.19 D and 98% of eyes were within ±0.50 D of the SEQ. All eyes were within ±1.00 D of the SEQ. Astigmatism of 0.50 D or less was achieved in 99% of eyes. The change in Snellen lines (difference between preoperative corrected distance visual acuity and postoperative uncorrected distance visual acuity) showed a gain of one or more lines in 13% and in 85% of the eyes the same was achieved. There was a loss of one or more lines at 3 months of follow-up in 1.6%. The safety index was 1.03 and efficacy index was 1.02. No significant difference between the right and left eyes was found. CONCLUSIONS The 3-month follow-up data show that SmartSight treatment for correction of myopia and myopic astigmatism with the SCHWIND ATOS is a safe, efficient, and accurate procedure. It provided excellent results in terms of visual recovery, predictability, and higher order aberrations. [J Refract Surg. 2024;40(1):e30-e41.].
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Xu W, Jia F, Liu J, Li J, Zhao J, Lin S, Jia Y, Li Y. Digital Pupillometry and Centroid Shift Changes in Dominant and Nondominant Eyes. Klin Monbl Augenheilkd 2023. [PMID: 37774740 DOI: 10.1055/a-2184-4260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
PURPOSE To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes. METHODS A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed. RESULTS Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12 weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively. CONCLUSIONS This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.
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Affiliation(s)
- Wenhao Xu
- Ophthalmology, Fuyang People's Hospital of Anhui Medical University, Fuyang, China
- Ophthalmology, Enshi Huiyi Ophthalmology Hospital, Enshi, China
- Ophthalmology, Yanbian University Hospital, Yanji, China
| | - Fali Jia
- Ophthalmology, Yanbian University Hospital, Yanji, China
| | - Jingting Liu
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Jiahao Li
- Ophthalmology, Fuyang People's Hospital of Anhui Medical University, Fuyang, China
| | - Jian Zhao
- Ophthalmology, Yanbian University Hospital, Yanji, China
| | - Shuhua Lin
- Ophthalmology, Ningde Municipal Hospital of Ningde Normal University, Ningde, China
| | - Yujie Jia
- Ophthalmology, Zaozhuang Municipal Hospital, Zaozhuang, China
| | - Yingjun Li
- Ophthalmology, Fuyang People's Hospital of Anhui Medical University, Fuyang, China
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de Ortueta D, von Rüden D, Arba Mosquera S. Symmetric offset versus asymmetric offset ablation with transepithelial refractive keratectomy. BMC Ophthalmol 2023; 23:219. [PMID: 37198622 DOI: 10.1186/s12886-023-02971-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 05/09/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND In eyes with hyperopia, astigmatism, and mixed astigmatism Transepithelial photorefractive keratectomy (TransPRK) is a modality of surface ablation surgery. We center on the corneal vertex for all our treatments (all have an offset to the center of the pupil) and wanted to compare the visual results of symmetrical profile treatments versus asymmetrical profile treatments (the center of the treatment on the vertex and the boundaries with the pupil center) using TransPRK as corneal refractive surgery. METHODS We retrospectively analyzed two consecutive groups of eyes treated with TransPRK in the Aurelios Augenlaserzentrum Recklinghausen: 47 eyes treated with symmetrical offset and 51 eyes treated with asymmetrical offset. The intergroup comparisons were assessed using unpaired Student's T-tests, whereas preoperative to postoperative changes were assessed using paired Student's T-tests. RESULTS Refractive outcomes were good for both groups. 83 and 88% of eyes were within the spherical equivalent of 0.5 D from the target in the symmetric and asymmetric offset groups, respectively. 85 and 84% of eyes had a postoperative astigmatism of 0.5 D or lower in the symmetric and asymmetric offset groups, respectively. CONCLUSION We have not found a significant difference in the refractive outcomes between the symmetric group and the asymmetric group of eyes treated both with TransPRK for preoperatively hyperopic or mixed astigmatism.
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Affiliation(s)
- Diego de Ortueta
- Aurelios Augenlaserzentrum Recklinghausen, Erlbruch 34-36, 45657, Recklinghausen, Germany.
| | - Dennis von Rüden
- Aurelios Augenlaserzentrum Recklinghausen, Erlbruch 34-36, 45657, Recklinghausen, Germany
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Comparative study of refractive and visual quality after wavefront-optimized FS-LASIK for angle kappa adjustment in dominant and nondominant eyes. J Cataract Refract Surg 2023; 49:184-189. [PMID: 36026702 DOI: 10.1097/j.jcrs.0000000000001050] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 08/18/2022] [Indexed: 02/02/2023]
Abstract
PURPOSE To investigate the differences between dominant and nondominant eyes in femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) with 50% angle kappa compensation on diopter and visual quality. SETTING University hospital. DESIGN Retrospective clinical study. METHODS 109 patients (218 eyes, 100%) with myopia who underwent FS-LASIK were randomly selected. The preoperative pupil size, center position, and offset between the coaxially sighted corneal light reflex ( P-Dist ) of the patients was recorded. In preoperative and postoperative 6 months, an iTrace wavefront aberrometer was used to measure the corneal, internal optics, and total aberrations. RESULTS The 6 months postoperatively for corneal coma of the dominant eyes were 0.141 ± 0.055 μm and the nondominant eyes were 0.157 ± 0.033 μm, which was significantly greater than the dominant eyes ( P = .028). The postoperative corneal coma aberration changes were positively correlated with preoperative P-Dist , the dominant eyes ( r = 0.221, P = .023), and the nondominant eyes ( r = 0.251, P = .009). CONCLUSIONS Adjusting the angle kappa percentage in the nondominant eyes to be higher than that of the dominant eyes in individualized corneal refractive surgery may help find the ablation center closest to the visual axis.
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Reliability and agreement of apparent chord mu measurements between static and dynamic evaluations. J Cataract Refract Surg 2023; 49:21-28. [PMID: 36573762 DOI: 10.1097/j.jcrs.0000000000001036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 07/26/2022] [Indexed: 12/28/2022]
Abstract
PURPOSE To assess the repeatability and agreement of Cartesian coordinates and the length of apparent chord mu and pupil diameter measurements during static (Galilei G4) and dynamic (Topolyzer Vario) evaluations. SETTING IOBA-Eye Institute, Valladolid, Spain. DESIGN Case series. METHODS 3 consecutive measurements per scenario (Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions) were performed by the same clinician. The intrasession repeatability was assessed using the within-subject SD (Sw), the precision, the coefficient of variation, and the intraclass correlation coefficient (ICC). The agreement was analyzed using repeated-measures analysis of variance and the Bland-Altman method. RESULTS Thirty-seven healthy participants were recruited. The Sw values for chord mu parameters and pupil diameter ranged from 0.01 to 0.03 and 0.08 to 0.21, respectively. The ICC was ≥0.89 for all parameters. Galilei G4 and Topolyzer Vario under low mesopic and photopic conditions provided significantly different measures of apparent chord mu length (0.23 ± 0.11 mm, 0.30 ± 0.10 mm, and 0.25 ± 0.11 mm, respectively, P ≤ .02), X-coordinate (-0.18 ± 0.12 mm, -0.27 ± 0.11 mm, and -0.21 ± 0.12 mm, respectively, P < .001), and pupil diameter (3.38 ± 0.50 mm, 6.29 ± 0.60 mm, and 3.04 ± 0.41 mm, respectively, P < .001). Y-coordinate values obtained by Galilei G4 and Topolyzer Vario under low mesopic conditions were significantly different (0.06 ± 0.13 mm vs 0.03 ± 0.11 mm, respectively, P = .02), in contrast to Galilei G4 and Topolyzer Vario under photopic conditions (0.05 ± 0.13 mm, P = .82) and both illumination conditions of Topolyzer Vario (P ≥ .23). CONCLUSIONS Galilei G4 and Topolyzer Vario provide consistent measurements of apparent chord mu Cartesian coordinates and length, as well as pupil diameter; however, the measurements are not interchangeable. Ophthalmic surgeons should consider these findings when planning customized intraocular lens implantation and refractive surgery procedures.
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Pradhan KR, Arba Mosquera S. Twelve-month outcomes of a new refractive lenticular extraction procedure. JOURNAL OF OPTOMETRY 2023; 16:30-41. [PMID: 34949535 PMCID: PMC9811368 DOI: 10.1016/j.optom.2021.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 11/02/2021] [Accepted: 11/11/2021] [Indexed: 06/07/2023]
Abstract
BACKGROUND To evaluate the 12-month refractive and visual outcomes of Small Incision Guided Human-cornea Treatment (SmartSight®, SCHWIND eye-tech-solutions, Kleinostheim, Germany) in the treatment of myopia corrections with low to moderate astigmatism with the use of a new femtosecond laser system. METHODS 221 eyes of 114 patients consecutively treated with SmartSight lenticule extraction were assessed. The mean age of the patients was 28±6 years at the time of treatment with a mean spherical equivalent refraction of -6.26±2.17D and mean astigmatism of 0.92±0.68D. Monocular corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA) were assessed pre- and post-operatively. Refractive changes have been determined in terms of changes in refraction, as well as changes in keratometric readings. The changes in central epithelial thickness have been determined. RESULTS At twelve months post-operatively, mean UDVA was 20/21±2. Spherical equivalent showed a residual refraction of +0.48±0.31D with refractive astigmatism of 0.13±0.18D postoperatively. There was a slight decrease of -0.1 Snellen lines at 12-months follow-up. The same correction was determined using changes in refraction, as well as changes in keratometric readings. The central epithelial thickness increased by +3±2µm. Spherical equivalent correction within ±0.50D was achieved in 199 eyes (90%), and cylindrical correction in 221 (100%). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 213 eyes (96%), and postoperative uncorrected (UDVA) was 20/20 or better in 205 eyes (93%). No eye had lost two or more Snellen lines of CDVA. CONCLUSIONS Myopic astigmatism correction with SmartSight provided good results for efficacy, safety, predictability, and visual outcomes at the twelve months of follow up. The central epithelial thickness barely increased by 3±2µm.
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Affiliation(s)
- Kishore Raj Pradhan
- Matrika Eye Center, Dhunge Dhara Marg, Ward number 9, Kathmandu 44600, Nepal.
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Bang SP, Lyu J, Ng CJ, Yoon G. Visual Axis and Stiles-Crawford Effect Peak Show a Positional Correlation in Normal Eyes: A Cohort Study. Invest Ophthalmol Vis Sci 2022; 63:26. [PMID: 36306143 PMCID: PMC9624269 DOI: 10.1167/iovs.63.11.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to locate the visual axis and evaluate its correlation with the Stiles-Crawford effect (SCE) peak. Methods Ten young, healthy individuals (20 eyes) were enrolled. An optical system was developed to locate the visual axis and measure SCE. To locate the visual axis, 2 small laser spots at 450 nm and 680 nm were co-aligned and delivered to the retina. The participants were asked to move a translatable pinhole until these spots were perceived to overlap each other. The same system assessed SCE at 680 nm using a bipartite, 2-channel (reference and test) Maxwellian-view optical system. The peak positions were estimated using a two-dimensional Gaussian fitting function and correlated with the visual axis positions. Results Both the visual axis (x = 0.24 ± 0.35 mm, y = -0.16 ± 0.34 mm) and the SCE peak (x = 0.27 ± 0.35 mm, y = -0.15 ± 0.31 mm) showed intersubject variability among the cohort. The SCE peak positions were highly correlated in both the horizontal and vertical meridians to the visual axes (R2 = 0.98 and 0.96 for the x and y coordinates, respectively). Nine of the 10 participants demonstrated mirror symmetry for the coordinates of the visual axis and the SCE peak between the eyes (R2 = 0.71 for the visual axis and 0.76 for the SCE peak). Conclusions The visual axis and SCE peak locations varied among the participants; however, they were highly correlated with each other for each individual. These findings suggest a potential mechanism underlying the foveal cone photoreceptor alignment.
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Affiliation(s)
- Seung Pil Bang
- Department of Biomedical Engineering, University of Rochester, Rochester, New York, USA
| | - Jiakai Lyu
- Institute of Optics, University of Rochester, Rochester, New York, USA
| | - Cherlyn J. Ng
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Geunyoung Yoon
- College of Optometry, University of Houston, Houston, Texas, USA
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Deng WQ, Fang YH, Lin SH, Li YJ. Dynamic distribution and correlation analysis of the angle kappa in myopia patients undergoing femtosecond-assisted laser in situ keratomileusis. Medicine (Baltimore) 2022; 101:e29425. [PMID: 35713451 PMCID: PMC9276180 DOI: 10.1097/md.0000000000029425] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To explore the offset distribution of pupillary centres, the offset between the pupil centre and the coaxially sighted corneal light reflex (P-Dist) and their correlation in femtosecond laser combined with excimer laser in situ keratomileusis. METHODS Randomly selected 194 patients (398 eyes) who underwent femtosecond-assisted laser in situ keratomileusis with preoperative use of WaveLight Allegro Topolyzer Corneal Topography (WaveLight Laser Technologies AG, Erlangen, Germany) to measure the pupil size and centre position. The P-Dist of the patients was recorded by the X and Y axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system. RESULTS The P-Dist was 0.214 ± 0.092 mm in the right eyes and 0.228 ± 0.105 mm in the left eyes (P = .041). Under scotopic conditions, the pupil centre of left eye X-axis was -0.046 ± 0.091 mm, the right eye was -0.152 ± 0.084 mm, with significant differences (P = .015), and the Y-axis direction showed no significant changes (P = .062). The white to white was positively correlated with changes of pupil diameter (scotopic pupil diameter-photopic pupil diameter) (r = 0.270, P < .001). The equivalent spherical mirror and measured centroid shift were negatively correlated (r = -0.214, P = .002). CONCLUSION The angle kappa of the right eye is smaller than that of the left eye and from scotopic to photopic condition, the pupil centroid shift of both eyes to the nasal inferior side. If the cornea is too large, the low illumination environment should be maintained during the operation to improve the efficiency of pupil matching.
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Affiliation(s)
- Wen-Qing Deng
- Department of Ophthalmology, Fuyang People's Hospital of Anhui Medical University, Fuyang, Anhui, China
- Department of Ophthalmology, Affiliated Hospital of Yanbian University, Yanji, Jilin, China
| | - Yu-Hui Fang
- Department of Dermatology, Fuyang People's Hospital of Anhui Medical University, Fuyang, Anhui, China
| | - Shu-Hua Lin
- Department of Ophthalmology, Affiliated Hospital of Yanbian University, Yanji, Jilin, China
| | - Ying-Jun Li
- Department of Ophthalmology, Fuyang People's Hospital of Anhui Medical University, Fuyang, Anhui, China
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Langenbucher A, Szentmáry N, Cayless A, Weisensee J, Wendelstein J, Hoffmann P. Translation model for CW chord to angle Alpha derived from a Monte-Carlo simulation based on raytracing. PLoS One 2022; 17:e0267028. [PMID: 35576202 PMCID: PMC9109904 DOI: 10.1371/journal.pone.0267028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/31/2022] [Indexed: 11/18/2022] Open
Abstract
Background The Chang-Waring chord is provided by many ophthalmic instruments, but proper interpretation of this chord for use in centring refractive procedures at the cornea is not fully understood. The purpose of this study is to develop a strategy for translating the Chang-Waring chord (position of pupil centre relative to the Purkinje reflex PI) into angle Alpha using raytracing techniques. Methods The retrospective analysis was based on a large dataset of 8959 measurements of 8959 eyes from 1 clinical centre, using the Casia2 anterior segment tomographer. An optical model based on: corneal front and back surface radius Ra and Rp, asphericities Qa and Qp, corneal thickness CCT, anterior chamber depth ACD, and pupil centre position (X-Y position: PupX and PupY), was defined for each measurement. Using raytracing rays with an incident angle IX and IY the CW chord (CWX and CWY) was calculated. Using these data, a multivariable linear model was built up in terms of a Monte-Carlo simulation for a simple translation of incident ray angle to CW chord. Results Raytracing allows for calculation of the CW chord CWX/CWY from biometric measures and the incident ray angle IX/IY. In our dataset mean values of CWX = 0.32±0.30 mm and CWY = -0.10±0.26 mm were derived for a mean incident ray angle (angle Alpha) of IX = -5.02±1.77° and IY = 0.01±1.47°. The raytracing results could be modelled with a linear multivariable model, and the effect sizes for the prediction model for CWX are identified as Ra, Qa, Rp, CCT, ACD, PupX, PupY, IX, and for CWY they are Ra, Rp, PupY, and IY. Conclusion Today the CW chord can be directly measured with any biometer, topographer or tomographer. If biometric measures of Ra, Qa, Rp, CCT, ACD, PupX, PupY are available in addition to the CW chord components CWX and CWY, a prediction of angle Alpha is possible using a simple matrix operation.
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Affiliation(s)
- Achim Langenbucher
- Department of Experimental Ophthalmology, Universität des Saarlandes, Homburg/Saar, Germany
- * E-mail:
| | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Universität des Saarlandes, Homburg/Saar, Germany
- Department of Ophthalmology, Semmelweis-University, Budapest, Hungary
| | - Alan Cayless
- School of Physical Sciences, The Open University, Milton Keynes, United Kingdom
| | - Johannes Weisensee
- Department of Experimental Ophthalmology, Universität des Saarlandes, Homburg/Saar, Germany
| | - Jascha Wendelstein
- Department of Experimental Ophthalmology, Universität des Saarlandes, Homburg/Saar, Germany
- Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Peter Hoffmann
- Augen- und Laserklinik Castrop-Rauxel, Castrop-Rauxel, Germany
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Langenbucher A, Szentmáry N, Cayless A, Weisensee J, Wendelstein J, Hoffmann P. Prediction of CW chord as a measure for the eye's orientation axis after cataract surgery from preoperative IOLMaster 700 measurement data. Acta Ophthalmol 2021; 100:e1232-e1239. [PMID: 34850585 DOI: 10.1111/aos.15071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/28/2021] [Accepted: 11/19/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND The angles alpha and kappa are widely discussed for centring refractive procedures, but they cannot be determined with ophthalmic instruments. The purpose of this study is to investigate the Chang-Waring chord (position of the Purkinje reflex PI relative to the corneal centre) derived from an optical biometer before and after cataract surgery and to study the changes resulting from cataract surgery. METHODS The analysis was based on a large dataset of 1587 complete sets of preoperative and postoperative IOMaster 700 biometry measurements from two clinical centres, each containing: valid data for pupil and corneal centre position, the position of the Purkinje reflex PI originated from a coaxial fixation target, keratometry (K), axial length (AL), anterior chamber depth (ACD), lens thickness (LT), central corneal thickness CCT, and horizontal corneal diameter W2W. The Chang-Waring chord CW was derived from pupil centre and Purkinje reflex PI analysed preoperatively and postoperatively, and a multilinear regression model together with a feedforward neural network algorithm was set up to predict postoperative CW chord from preoperative CW chord, K and biometric distances of the eye. RESULTS The Y component of CW chord shows a slight shift in the inferior direction in both left and right eyes, before and after cataract surgery. The X component shows some shift in the temporal direction, which is more pronounced preoperatively and slightly reduced postoperatively but with a larger variation. The change in CW chord from preoperative to postoperative shows a slight shift in the superior and nasal directions. Our algorithms for prediction of postoperative CW chord using preoperative CW chord, keratometry and biometry as input data performed with a multilinear regression and a feedforward neural network approach were able to reduce the variance, but could not properly predict the postoperative CW chord X and Y components. CONCLUSION The CW chord as the position of the Purkinje reflex PI with respect to the pupil centre can be directly measured with any biometer, topographer or tomographer with a coaxial fixation light. The mean Y component does not differ between right and left eyes or preoperatively and postoperatively, but the mean temporal shift of the X component preoperatively is slightly reduced postoperatively, but with a larger scatter of the values.
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Affiliation(s)
- Achim Langenbucher
- Department of Experimental Ophthalmology Saarland University Homburg/Saar Germany
| | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research Saarland University Homburg/Saar Germany
- Department of Ophthalmology Semmelweis‐University Budapest Hungary
| | - Alan Cayless
- School of Physical Sciences The Open University Milton Keynes UK
| | - Johannes Weisensee
- Department of Experimental Ophthalmology Saarland University Homburg/Saar Germany
| | - Jascha Wendelstein
- Department of Ophthalmology Johannes Kepler University Linz Linz Austria
| | - Peter Hoffmann
- Augen‐ und Laserklinik Castrop‐Rauxel Castrop‐Rauxel Germany
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Tutchenko L, Patel S, Skovron M, Horak O, Voytsekhivskyy O. The relationship between angle kappa and astigmatism after phacoemulsification with implanting of spherical and aspheric intraocular lens. Indian J Ophthalmol 2021; 69:3503-3510. [PMID: 34826984 PMCID: PMC8837301 DOI: 10.4103/ijo.ijo_572_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Purpose: To determine the significance of any association between either change in angle kappa (K°) or the rectilinear displacement (L, mm) of the first Purkinje image relative to the pupil center and unexpected changes in astigmatism after phacoemulsification. Methods: Orbscan II (Bausch and Lomb) measurements were taken at 1, 2, and 3 months after unremarkable phacoemulsification in patients implanted with spherical (group 1, SA60AT, Alcon) or aspheric (group 2, SN60WF, Alcon) nontoric IOLs. The outputs were used to calculate L. Astigmatism, measured by autorefractometry and subjective refraction, was subjected to vector analysis (polar and cartesian formats) to determine the actual change induced over the periods 1–2 and 2–3 months postop. Results: Chief findings were that the mean (n, ±SD, 95%CI) values for L over each period were as follows: Group 1, 0.407 (38, ±0.340, 0.299–0.521), 0.315 (23, ±0.184, 0.335–0.485); Group 2, 0.442 (45, ±0.423, 0.308–0.577), 0.372 (26, ±0.244, 0.335–0.485). Differences between groups were not significant. There was a significant linear relationship between (A) the change in K (ΔK = value at 1 month-value at 2 months) and K at 1 month (x), where ΔK =0.668-3.794X (r = 0.812, n = 38, P = <0.001) in group 1 and ΔK = 0.263x -1.462 (r = 0.494, n = 45, P = 0.002) in group 2, (B) L and the J45 vector describing the actual change in astigmatism between 1 and 2 months in group 2, where J45 (by autorefractometry) =0.287L-0.160 (r = 0.487, n = 38, P = 0.001) and J45 (by subjective refraction) =0.281L-0.102 (r = 0.490, n = 38, P = 0.002), and (C) J45 and ΔK between 2 and 3 months in group 2, where J45 (by subjective refraction) =0.086ΔK-0.063 (r = 0.378, n = 26, P = 0.020). Conclusion: Changes in the location of the first Purkinje image relative to the pupil center after phacoemulsification contributes to changes in refractive astigmatism. However, the relationship between the induced change in astigmatism resulting from a change in L is not straightforward.
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Affiliation(s)
- Larysa Tutchenko
- Department of Ophthalmology, Kyiv City Clinical Ophthalmological Hospital, Eye Microsurgical Center, Kyiv, Ukraine
| | - Sudi Patel
- Department of Ophthalmology, Specialty Eye Hospital Svjetlost, Zagreb, Croatia
| | - Mykhailo Skovron
- Department of Ophthalmology, Kyiv City Clinical Ophthalmological Hospital, Eye Microsurgical Center, Kyiv, Ukraine
| | - Olha Horak
- Department of Ophthalmology, Kyiv City Clinical Ophthalmological Hospital, Eye Microsurgical Center, Kyiv, Ukraine
| | - Oleksiy Voytsekhivskyy
- Department of Ophthalmology, Kyiv City Clinical Ophthalmological Hospital, Eye Microsurgical Center, Kyiv, Ukraine
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Distribution of angle α and angle κ in a population with cataract in Shanghai. J Cataract Refract Surg 2021; 47:579-584. [PMID: 33181624 DOI: 10.1097/j.jcrs.0000000000000490] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/14/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe the distribution of angle α and angle κ in a population with cataract in Shanghai. SETTING Eye and Ear, Nose, Throat Hospital, Fudan University, Shanghai, China. DESIGN Hospital-based, cross-sectional study. METHODS Angle α, angle κ, and other ocular biometric parameters were determined by IOLMaster 700. The distributions of angle α and angle κ and their associations with systemic and ocular parameters were assessed. RESULTS This study included 15 127 eyes of 15 127 cataract patients. The mean angle α and angle κ values were 0.45 ± 0.21 mm and 0.30 ± 0.18 mm, respectively. Angle α and angle κ were both predominantly located temporal to the visual axis. A greater angle α or angle κ was associated with older age, lower corneal power, shorter white-to-white distance, and shallower anterior chamber depth (all P < .05). Angle α correlated positively with angle κ. With increasing axial length (AL), angle α gradually decreased in a nonlinear way and shifted to the nasal side of the visual axis, whereas angle κ decreased in eyes with AL less than 27.5 mm but increased again in eyes with longer AL. CONCLUSIONS Angle α and angle κ, both predominantly located temporal to the visual axis, were influenced by multiple anterior segment parameters. As AL increased, the changes in angle α and angle κ were nonlinear, and their locations gradually shifted from the temporal to the nasal side of the visual axis.
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Comparison of effective corneal refractive centration to the visual axis: LASIK vs. SMILE, a contralateral eye digitized comparison of the postoperative result. J Cataract Refract Surg 2021; 47:1511-1518. [PMID: 34074993 DOI: 10.1097/j.jcrs.0000000000000687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 04/24/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To define and compare the centration of the ablation effect in LASIK to the corresponding effect in SMILE, in myopic laser vision correction in order to possibly explain the refractive performance differences noted between the two procedures in a contralateral eye study. SETTING Private Ambulatory Eye Surgery Unit. DESIGN Prospective randomized contralateral eye study. METHODS In 22 consecutive patients (44 eyes), one eye was prospectively randomized to have myopic topography-guided LASIK treatment and the contralateral eye to have SMILE; Digital image analysis of the achieved centration to the aimed corneal vertex was assessed for both procedures on the perioperative Scheimpflug tangential curvature maps, using a proprietary digitized methodology. RESULTS The radial displacement between the attempted centration on the corneal vertex versus the center of the effective anterior corneal curvature flattening was on average 130 ± 62 μm in the LASIK group and 313 ± 144μm in the SMILE group (P<0.001). CONCLUSIONS In this contralateral eye study, topography-guided myopic LASIK was found to achieve significantly better effective centration compared to myopic SMILE, in regards digitally measured decentration of the effective refractive change achieved in the anterior corneal curvature from the corneal vertex. This may explain the previously reported superior visual outcomes in the LASIK group eyes when compared to the contralateral SMILE group eyes.
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Clinical outcomes of corneal refractive surgery comparing centration on the corneal vertex with the pupil center: a meta-analysis. Int Ophthalmol 2020; 40:3555-3563. [PMID: 32671600 DOI: 10.1007/s10792-020-01506-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/06/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare the visual and refractive outcomes between centration on the corneal vertex and the pupil center in corneal refractive surgery. METHODS A comprehensive literature search was conducted using PubMed, MEDLINE, EMBASE, and the Cochrane Library to identify relevant studies. The primary outcomes were the postoperative spherical equivalent (SE), effectiveness [uncorrected distance visual acuity (UDVA) ≥ 20/20, eyes within ± 0.50 diopter (D) of target refraction], and safety [loss ≥ 2 lines of corrected distance visual acuity (CDVA)]. Higher-order aberrations were considered secondary outcomes. RESULTS Seven studies describing a total of 1964 eyes were included in this meta-analysis. A statistical significance in postoperative SE was found between the two centration methods for the correction of myopia that favor the CV-centered method (p < 0.001). No significant differences were observed in the proportion of eyes with UDVA ≥ 20/20 or loss ≥ 2 lines of CDVA postoperatively. However, the proportion of eyes within ± 0.50 D was slightly higher (p = 0.02) and the coma aberration was much lower in the corneal vertex-centered method (p < 0.001). CONCLUSION Preferable visual and refractive outcomes could be achieved with either centering on the corneal vertex or pupil center in corneal refractive surgery; however, the corneal vertex-centered method has shown partial benefits in some clinical indices. In order to obtain higher quality of clinical evidences, more randomized controlled trials (RCTs) are required in further investigations.
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Liu Y, Wang Y. Optical quality comparison between laser ablated myopic eyes with centration on coaxially sighted corneal light reflex and on entrance pupil center. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:B103-B109. [PMID: 31044979 DOI: 10.1364/josaa.36.00b103] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/24/2019] [Indexed: 06/09/2023]
Abstract
This paper aims to compare the image quality between centration on the coaxially sighted corneal light reflex (CSCLR) and on the entrance pupil center (EPC). Myopic laser ablation was simulated on eye models, and the optical performances were compared. Centration on the EPC leads to higher wavefront aberrations and lower modulation transfer function. The two centration methods give nearly identical retinal images for angle kappa less than 5°. Because of less tissue removal, centration on the EPC is probably preferable for angle kappa less than 5°, but CSCLR centration may be preferable for angle kappa larger than 5°. The degree of tilt of the post-surgery anterior corneal surface explains the differences between the two methods.
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Arbelaez MC, Alpins N, Verma S, Stamatelatos G, Arbelaez JG, Arba-Mosquera S. Clinical outcomes of laser in situ keratomileusis with an aberration-neutral profile centered on the corneal vertex comparing vector planning with manifest refraction planning for the treatment of myopic astigmatism. J Cataract Refract Surg 2017; 43:1504-1514. [DOI: 10.1016/j.jcrs.2017.07.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/08/2017] [Accepted: 07/26/2017] [Indexed: 11/16/2022]
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