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Du Y, Di Y, Yang S, Mo F, Cui G, Chen D, Li Y. Association of myopia and astigmatism with postoperative ocular high order aberration after small incision lenticule extraction. BMC Ophthalmol 2024; 24:211. [PMID: 38741093 DOI: 10.1186/s12886-024-03475-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024] Open
Abstract
OBJECTIVE To investigate the correlation between higher-order aberrations (HOA) after small incision lenticule extraction (SMILE) and the severity of myopia and astigmatism, along with the relevant factors. These findings will provide valuable insights for decreasing the occurrence of HOA after SMILE and enhancing visual quality. METHODS A total of 75 patients (150 eyes) with myopia and astigmatism who underwent SMILE were categorized into four groups based on the severity of myopia and astigmatism: Myopia Group 1 (Group M1, spherical diopter ranged from -1.00 D to -4.00 D), Myopia Group 2 (Group M2, spherical diopter ranged from -4.10 D to -10.00 D), Astigmatism Group 1 (Group A1, cylindrical diopter ranged from 0 D to -1.00 D), and Astigmatism Group 2 (Group A2, cylindrical diopter ranged from -1.10 D to -3.00 D). A comprehensive assessment was performed to examine the association between HOA and various relevant factors, including a detailed analysis of the subgroups. RESULTS Group M1 had significantly lower levels of total eye coma aberration (CA), corneal total HOA (tHOA), internal tHOA, and vertical CA ( Z 3 - 1 ) after SMILE than Group M2 (P < 0.05). Similarly, Group A1 had significantly lower levels of total eye tHOA, CA, trefoil aberration (TA), corneal tHOA, TA, and vertical TA ( Z 3 - 3 ) after SMILE than Group A2 (P < 0.05). Pearson correlation analysis indicated a statistically significant positive relationship between the severity of myopia/astigmatism and most HOA (P < 0.05). Subgroup evaluations demonstrated a notable increase in postoperative HOA associated with myopia and astigmatism in Groups M2 and A2 compared with the control group. Lenticule thickness, postoperative central corneal thickness (CCT), postoperative uncorrected distance visual acuity (UDVA), and postoperative corneal Km and Cyl were strongly correlated with most HOA. Age, eyes, and postoperative intraocular pressure (IOP) were only associated with specific HOA. CONCLUSION HOA positively correlated with the severity of myopia and astigmatism after SMILE. However, this relationship was not linear. HOA after SMILE was influenced by various factors, and additional specialized investigations are required to establish its clinical importance.
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Affiliation(s)
- Yifan Du
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Yu Di
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Shan Yang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Fei Mo
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Ge Cui
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Di Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China
| | - Ying Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, People's Republic of China.
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Du Y, Di Y, Yang S, Mo F, Cui G, Chen D, Li Y. Differences in ocular high order aberrations before and after small incision lenticule extraction for correction of myopia: a systematic review and meta-analysis. Front Med (Lausanne) 2024; 11:1274101. [PMID: 38601117 PMCID: PMC11004322 DOI: 10.3389/fmed.2024.1274101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 03/13/2024] [Indexed: 04/12/2024] Open
Abstract
Objective To examine the causes and factors that lead to high order aberration (HOA) during the treatment of myopia using small incision lenticule extraction (SMILE), as well as the differences between SMILE and other corneal refractive surgeries through a systematic review and meta-analysis. Methods A systematic search was conducted from January 2015 to February 2023 in Pubmed, Embase, Web of Science, and Google Scholar databases to gather relevant studies on SMILE and HOA. Studies meeting specific criteria were chosen, and clinical data was retrieved for analysis. Results This meta-analysis resulted in the inclusion of 19 studies involving 1,503 eyes. Pooled results showed significant induction of total HOA (tHOA, d = -0.21, p < 0.001), spherical aberration (SA, d = -0.11, p < 0.001) and coma aberration (CA, d = -0.18, p < 0.001) after SMILE compared to pre-SMILE, while no significant change in trefoil aberration (TA) was observed (d = -0.00, p = 0.91). There was a significantly lower induction of tHOA after SMILE compared to femtosecond laser-assisted in situ keratomileusis (FS-LASIK, d = 0.04, p < 0.001), and no significant difference was observed compared to wavefront aberration-guided (WFG) refractive surgery (d = 0.00, p = 0.75). There was also a significant association between different levels of myopia and astigmatism, duration of follow-up, lenticule thickness, and preoperative central corneal thickness (CCT) on the induction of tHOA after SMILE (p < 0.05), while the higher preoperative myopia group (sphere > -5D), lower preoperative astigmatism group (cylinder ≤ -1D), larger lenticule thickness group (lenticule thickness > 100 μm), shorter follow-up group (follow-up 1 month postoperatively) and the thicker CCT group (CCT > 550 μm) brought a significant induction of tHOA compared to the opposite comparison group (p < 0.001). Conclusion While SMILE can induce HOA significantly, it induces less HOA than FS-LASIK. Postoperative HOA following SMILE can be affected by factors such as myopia, astigmatism, lenticule thickness, CCT, and duration of follow-up. Future research should continue to explore techniques to decrease the induction of HOA by using this methodology. Systematic review registration https://www.crd.york.ac.uk/prospero/.
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Affiliation(s)
| | | | | | | | | | | | - Ying Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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Zhu L, Ji Y, Yang X, Lu X, Wu Q, Wang Q, Xia J, Li M, Hu K, Wan W. Corneal morphological changes after small incision lenticule extraction for myopic anisometropia. Front Med (Lausanne) 2022; 9:977586. [PMID: 36091674 PMCID: PMC9449128 DOI: 10.3389/fmed.2022.977586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeThis research aims to study the corneal morphological changes in adult patients with myopic anisometropia after small incision lenticule extraction (SMILE) and the safety, efficacy, and predictability of clinical outcomes.MethodsThis was a prospective cohort study. Patients with myopic anisometropia [refractive difference >2.0 diopters (D)] were included in this study who underwent SMILE at our hospital from September 2019 to March 2021. For the two eyes of each patient, the one with higher myopia was defined as group A, and the fellow eye was group B. The follow-up time points were set as 1 week, 1 month, 3 months, and 6 months after the surgery. The data collected were uncorrected and best-corrected distance visual acuity (UDVA and CDVA), spherical equivalent (SE), efficacy and safety indexes, posterior corneal elevation (PCE), anterior and posterior corneal radius of curvature in the 3 mm area at the center of the thinnest point of the cornea (ARC and PRC), and higher-order aberrations (HOAs).ResultsThe study included 36 patients (72 eyes), and the mean age was 25.2 ± 6.4 years. The preoperative SEs were −6.45 ± 1.25 D in group A and −3.76 ± 1.29 D in group B. Six months after surgery, the SEs in groups A and B were −0.09 ± 0.50 D and 0.07 ± 0.47 (P = 0.059), respectively. The efficacy indexes were 1.06 ± 0.16 in group A and 1.07 ± 0.14 in group B (P = 0.750). The safety indexes were 1.08 ± 0.14 in group A and 1.12 ± 0.15 in group B (P = 0.173). The PCE was significantly reduced at 6 months after surgery in pagebreak both groups (P < 0.05). The ARC was significantly higher than before the surgery (P < 0.05) in the two groups. The two groups showed significant increases in total HOAs, coma 90°, and spherical aberrations (P < 0.05).ConclusionSMILE is predictable, effective, and safe in correcting myopic anisometropia. The postoperative changes in HOAs are characteristic.
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Song Y, Fang L, Liu Q, Gong J, Guo B. Wavefront aberrations caused by biomechanical effects after Small Incision Lenticule Extraction (SMILE) based on finite element analysis. Comput Methods Biomech Biomed Engin 2022; 26:755-763. [PMID: 35723594 DOI: 10.1080/10255842.2022.2088232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To examine wavefront aberrations induced by biomechanical effects after Small Incision Lenticule Extraction (SMILE) surgery. The three-dimensional (3D) finite element models of the human eye were established. By loading the intraocular pressure (IOP), the displacement of the anterior and posterior surface of the cornea was calculated. Then the displacement was converted into the wavefront aberrations by wave-surface fitting. The results showed that the induced wavefront aberrations were noticeable from biomechanical effects after SMILE surgery. The induced higher-order aberrations from the anterior corneal surface included spherical aberration, y-Trefoil, and x-Tetrafoil. Spherical aberration was positively correlated with corrected diopter (D), but x-Tetrafoil and y-Trefoil remained stable. The induced wavefront aberrations from the posterior corneal surface were smaller than those from the anterior corneal surface, and some of the aberrations compensated each other. With IOP increased, defocus and x-Tetrafoil from the anterior corneal surface increased, while y-Trefoil and spherical aberration decreased. The IOP only affected defocus from the posterior corneal surface. In addition, the incision size also had a distinct impact on primary x-astigmatism and x-Trefoil from the anterior corneal surface, and it had a smaller effect on the aberrations from the posterior corneal surface. Therefore, the biomechanical effects increased residual wavefront aberrations after SMILE refractive surgery.
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Affiliation(s)
- Yinyu Song
- Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, China
| | - Lihua Fang
- Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, China
| | - Qianwei Liu
- Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, China
| | - Jiahui Gong
- Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, China
| | - Binhui Guo
- Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, China
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Wu Y, Sun S, Liu Z, Wang S, Wang G, Zhao S, Wei R, Huang Y. Changes in asphericity of anterior and posterior corneal surfaces for mild–moderate and high myopia after topography-guided FS-LASIK. Int Ophthalmol 2022; 42:3555-3565. [DOI: 10.1007/s10792-022-02356-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 04/18/2022] [Indexed: 10/18/2022]
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Wang C, Li X, Guo Y, He R, Guo H, Chen W. Effects of Laser In Situ Keratomileusis and Small-Incision Lenticule Extraction on Corneal Biomechanical Behavior: A Finite Element Analysis. Front Bioeng Biotechnol 2022; 10:855367. [PMID: 35480973 PMCID: PMC9035518 DOI: 10.3389/fbioe.2022.855367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Myopia, which is the result of the uncoordinated development of the eyeball, has become a major public health focus worldwide. Laser in situ keratomileusis (LASIK) and small-incision lenticule extraction (SMILE) have been successfully used in modern corneal refractive surgery. However, there are still controversies about postoperative results of LASIK and SMILE. In this study, a three-dimensional finite element model of the cornea was constructed based on the elevation and pachymetry data of a female volunteer. Surgical parameters, magnitudes of myopic correction, and intraocular pressure (IOP) were varied. Furthermore, an iterative algorithm was applied to retrieve the free-stress state of the intact corneal model, LASIK model, and SMILE model. To better evaluate the differences between LASIK and SMILE procedures, the displacement and Von Mises stress on the anterior and posterior corneal surface along the x- and y-axes were analyzed. Results for the zero-pressure model showed larger displacement compared to the image-based corneal model, suggesting that the initial corneal pre-stress stiffens the response of the cornea, both in the intact cornea and under refractive surgery. In addition, the displacement on the corneal surface in LASIK (both zero-pressure and image-based model) was obviously higher than that of the SMILE model. In contrast, SMILE increased Von Mises stress in the corneal cap and reduced Von Mises stress in the residual stromal bed compared with the LASIK model. However, the maximum Von Mises stress in the SMILE model was still smaller than that of the LASIK model. Moreover, the displacement and Von Mises stress on the residual stromal bed increased linearly with IOP. Overall, LASIK and SMILE refractive surgery could change biomechanical behaviors of the cornea. Compared to LASIK refractive surgery, SMILE may present a lower risk of ectasia. Creating a corneal cap rather than a corneal flap may have an advantage in improving corneal biomechanical stability.
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Affiliation(s)
- Chenyan Wang
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Xiaona Li
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
- *Correspondence: Xiaona Li, ; Weiyi Chen,
| | - Yuan Guo
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Rui He
- Department of Excimer Laser, Shanxi Eye Hospital, Taiyuan, China
| | - Hongmei Guo
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Weiyi Chen
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
- *Correspondence: Xiaona Li, ; Weiyi Chen,
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Shan M, Dong Y, Chen J, Su Q, Wang Y. Global Tendency and Frontiers of Research on Myopia From 1900 to 2020: A Bibliometrics Analysis. Front Public Health 2022; 10:846601. [PMID: 35359777 PMCID: PMC8960427 DOI: 10.3389/fpubh.2022.846601] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 02/10/2022] [Indexed: 01/29/2023] Open
Abstract
Background:Myopia is one of the most common causes of vision impairment in children and adults and has become a public health priority with its growing prevalence worldwide. This study aims to identify and evaluate the global trends in myopia research of the past century and visualize the frontiers using bibliometric analysis.MethodsThe literature search was conducted on the Web of Science for myopia studies published between 1900 and 2020. Retrieved publications were analyzed in-depth by the annual publication number, prolific countries and institutions, core author and journal, and the number of citations through descriptive statistics. Collaboration networks and keywords burst were visualized by VOSviewer and CiteSpace. Myopia citation network was visualized using CitNetExplorer.ResultsIn total, 11,172 publications on myopia were retrieved from 1900 to 2020, with most published by the United States. Saw SM, from the National University of Singapore, contributed the most publications and citations. Investigative Ophthalmology & Visual Science was the journal with highest number of citations. Journal of Cataract and Refractive Surgery with the maximum number of publications. The top 10 cited papers mainly focused on the epidemiology of myopia. Previous research emphasized myopia-associated experimental animal models, while recent keywords include “SMILE” and “myopia control” with the stronger burst, indicating a shift of concern from etiology to therapy and coincided with the global increment of incidence. Document citation network was clustered into six groups: “prevalence and risk factors of myopia,” “surgical control of myopia,” “pathogenesis of myopia,” “optical interventions of myopia,” “myopia and glaucoma,” and “pathological myopia.”ConclusionsBibliometrics analysis in this study could help scholars comprehend global trends of myopia research frontiers better. Hundred years of myopia research were clustered into six groups, among which “prevalence and risk factors of myopia” and “surgical control of myopia” were the largest groups. With the increasing prevalence of myopia, interventions of myopia control are a potential research hotspot and pressing public health issue.
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Affiliation(s)
- Mengyuan Shan
- School of Medicine, Nankai University, Tianjin, China
| | - Yi Dong
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Jingyi Chen
- School of Medicine, Nankai University, Tianjin, China
| | - Qing Su
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yan Wang
- School of Medicine, Nankai University, Tianjin, China
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin Eye Hospital, Nankai University Affiliated Eye Hospital, Tianjin, China
- *Correspondence: Yan Wang
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Comparison of visual outcomes between 120-µm and 140-µm cap thicknesses 12 months after small incision lenticule extraction. Lasers Med Sci 2022; 37:2667-2673. [PMID: 35217941 DOI: 10.1007/s10103-022-03534-y] [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: 08/03/2021] [Accepted: 02/21/2022] [Indexed: 10/19/2022]
Abstract
To compare visual and refractive outcomes as well as changes in high-order aberrations in patients with 120- versus 140-µm cap thicknesses 12 months after small incision lenticule extraction. Ninety-four patients were randomized to receive small incision lenticule extraction with either a 120-µm cap thickness (n = 47) or a 140-µm cap thickness (n = 47) to treat myopia or myopic astigmatism, if not both. In an analysis of right eyes only during the 12-month follow-up period, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive outcomes, and high-order aberrations were evaluated. The distribution of patients by age and sex between the groups did not differ significantly (P = .803 and P = .680, respectively). CDVA, spherical and cylindrical refraction, and changes in total high-order aberration, spherical aberration, coma, and trefoil were similar between the groups at 6 and 12 months, postoperatively. However, UDVA was statistically significantly higher in patients with 140-μm cap thicknesses than with 120-μm cap thicknesses at 6 and 12 months postoperatively (P < .001 and P < .001, respectively). Patients with 140-µm cap thickness showed greater improvement in UDVA than ones with 120-µm cap thickness at 12-month follow-up (P = .005). Both 120- and 140-μm cap thicknesses in small incision lenticule extraction were safe and effective thicknesses for correcting myopia or myopic astigmatism. The patients with 140-μm cap thickness had better improvement in UDVA after 12-month follow-up compared to patients with 120-μm cap thickness.
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Chang JY, Lin PY, Hsu CC, Liu CJL. Comparison of clinical outcomes of LASIK, Trans-PRK, and SMILE for correction of myopia. J Chin Med Assoc 2022; 85:145-151. [PMID: 34861667 DOI: 10.1097/jcma.0000000000000674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Transepithelial photorefractive keratectomy (Trans-PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) are three mainstay refractive surgeries worldwide. The applicability, efficacy, safety, and predictability of these different techniques are quite similar. Trans-PRK has the strongest biostability, earliest return to normal corneal sensitivity but the longest recovery time, most uncomfortable postoperative experience, and possibility of corneal haze. LASIK possesses the fastest visual rehabilitation but the slowest corneal nerve reinnervation, and flap displacement is possibly lifelong. SMILE incurs no flap-related complications and has intermediate vision recovery time and biomechanics compared with Trans-PRK and LASIK. However, it lacks the cyclotorsion-compensation system, eye-tracking system, and customized treatment profile for high astigmatism or irregular corneal surface. This review aims to introduce the mechanisms, pros, and cons of these three types of refractive surgery. With full understanding, practitioners could advise patients on the most suitable treatment of choice.
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Affiliation(s)
- Jin-Yu Chang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
| | - Pei-Yu Lin
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Chih-Chien Hsu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Catherine Jui-Ling Liu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
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Kwak JJ, Jun I, Kim EK, Seo KY, Kim TI. Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations. KOREAN JOURNAL OF OPHTHALMOLOGY 2021; 34:76-84. [PMID: 32037752 PMCID: PMC7010474 DOI: 10.3341/kjo.2019.0109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/05/2019] [Accepted: 10/17/2019] [Indexed: 01/30/2023] Open
Abstract
PURPOSE To investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parameters and corneal aberrations in myopic patients. METHODS This retrospective, observational case series included 57 eyes (29 patients) that received treatment for myopia using SMILE. Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry, corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at 1 and 3 months after surgery. We analyzed the safety, efficacy, vector parameters, and corneal aberrations at 3 months after surgery. RESULTS Preoperatively, mean manifest refraction spherical equivalent refraction was -4.94 ± 1.94 D (range, -8.25 to 0 diopters [D]), and the cylinder was -1.14 ± 0.82 D (range, -3 to 0 D). Mean manifest refraction spherical equivalent improved to -0.10 ± 0.23 D at 3 months postoperatively, when uncorrected distance visual acuity was 20 / 20 or better in 55 (96%) eyes. The linear regression model of target induced astigmatism vector versus surgically induced astigmatism vector exhibited slopes and coefficients (R²) of 0.9618 and 0.9748, respectively (y = 0.9618x + 0.0006, R² = 0.9748). While total corneal root mean square higher order aberrations, coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significant change after SMILE. CONCLUSIONS SMILE has proven to be effective and safe for correcting myopia and astigmatism. We showed that SMILE did not induce spherical aberrations. A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil.
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Affiliation(s)
- Jay Jiyong Kwak
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Ikhyun Jun
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Eung Kweon Kim
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.,Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, and Brain Korea 21 Project for Medical Science, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Kyoung Yul Seo
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Tae Im Kim
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.,Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, and Brain Korea 21 Project for Medical Science, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
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Zhang R, Wei H, Jhanji V, Sun L, Li J, Jiang J, Zhuang S, Zhang M. Comparison of corneal aberrations and refractive outcomes after small-incision lenticule extraction and femtosecond-assisted laser-assisted in situ keratomileusis. Int Ophthalmol 2021; 41:2521-2531. [PMID: 33783676 DOI: 10.1007/s10792-021-01810-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 03/10/2021] [Indexed: 11/30/2022]
Abstract
PURPOSES To retrospectively compare the short-term refractive outcomes and corneal aberrations after small-incision lenticule extraction (SMILE) and femtosecond-assisted laser-assisted in situ keratomileusis (FS-LASIK) combined with smart pulse technology (SPT) in patients with compound myopic astigmatism. METHODS A total of 91 eyes (91 patients) were included, 43eyes in FS-LASIK group and 48 eyes in the SMILE group. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refractive results and corneal topography were evaluated 1 and 3 months postoperatively. Corneal aberrations of anterior corneal surface were calculated from the topography data over 6 mm-diameter. RESULTS There was no significant difference in UCVA, BCVA, and refractive results between the two groups. There were no statistical difference in TIA (target induced astigmatism), SIA (surgery induced astigmatism), DV (difference vector), ME (magnitude of error), AE (angle of error), AE (absolute value) and CI (correction index) between both groups at 1 and 3 months. Coma and spherical aberration improved in all the patients in both groups at 1 and 3 months postoperatively. The amount of induced spherical aberrations was higher in FS-LASIK group compared to SMILE group. CONCLUSIONS Both FS-LASIK and SMILE achieved similar refractive outcomes in patients with myopia and compound myopic astigmatism. FS-LASIK combined with SPT resulted in higher spherical aberration than SMILE in early postoperative period.
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Affiliation(s)
- Riping Zhang
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China.
| | - Heng Wei
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
| | - Vishal Jhanji
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Lixia Sun
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
| | - Jinyu Li
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
| | - Jingjing Jiang
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
| | - Suoqing Zhuang
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
| | - Mingzhi Zhang
- Joint Shantou International Eye Center of Shantou University, The Chinese University of Hong Kong, Shantou, 515041, China
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Hamilton DR, Chen AC, Khorrami R, Nutkiewicz M, Nejad M. Comparison of early visual outcomes after low-energy SMILE, high-energy SMILE, and LASIK for myopia and myopic astigmatism in the United States. J Cataract Refract Surg 2021; 47:18-26. [PMID: 32769749 DOI: 10.1097/j.jcrs.0000000000000368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/21/2020] [Indexed: 12/29/2022]
Abstract
PURPOSE To compare uncorrected distance visual acuities (UDVAs) and induced higher-order aberrations (HOAs) in the early postoperative period between low-energy (LE) small-incision lenticule extraction (SMILE), high-energy (HE) SMILE, and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) procedures. SETTING University based refractive surgery center. STUDY DESIGN Retrospective cohort study. METHODS Records of patients who underwent SMILE or FS-LASIK were retrospectively reviewed. SMILE patients were separated into 2 groups: HE settings (125 nJ, 3.0 μm spot spacing) and LE settings (125-130 nJ, 4.5 μm spot spacing). UDVA was measured at postoperative day (POD) 1. Corneal HOAs and UDVA were measured at postoperative month (POM) 1. Induced spherical aberration, vertical coma, horizontal coma, total coma, and total HOAs were calculated. RESULTS The study included 147 eyes of 106 patients, 49 in each group. For SMILE patients, the difference in mean UDVA at POD1 was highly statistically significant in favor of the LE group (-0.003 vs 0.141, P < .0001). No significant difference in mean UDVA at POD1 was noted between the LE group and FS-LASIK group (-0.003 vs -0.011, P = .498). Induced change in spherical aberration was less in LE SMILE than that in FS-LASIK (0.136 vs 0.186 μm, P = .02) at POM1. No significant differences in POM1 mean UDVA (-0.033 vs -0.036) or induced change in all other HOAs were noted between LE SMILE and FS-LASIK. CONCLUSIONS LE settings were associated with significantly improved POD1 UDVA. POD1 and POM1 UDVA were comparable with those of FS-LASIK. Spherical aberration induction was less with LE SMILE than that with FS-LASIK, whereas all other induced HOAs were comparable with FS-LASIK.
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Affiliation(s)
- D Rex Hamilton
- From the Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles (Chen, Khorrami, Nejad), Los Angeles, and Hamilton Eye Institute (Hamilton, Nutkiewicz), Los Angeles, California, USA
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13
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Xia F, Qin B, Shang J, Chen Z, Zhou X, Zhao J, Wang X, Zhou X. Four-Year Outcomes of Small Incision Lenticule Extraction for Extreme High Myopia and Myopic Astigmatism. Front Med (Lausanne) 2020; 7:575779. [PMID: 33313044 PMCID: PMC7703695 DOI: 10.3389/fmed.2020.575779] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 09/21/2020] [Indexed: 11/13/2022] Open
Abstract
Purpose: To evaluate the long-term safety, efficacy, predictability, and stability of small incision lenticule extraction (SMILE) for the treatment of high myopia and myopic astigmatism >−10.0 D. Methods: This was a prospective study that incorporated 35 consecutive patients (35 eyes) undergoing SMILE from September 2015 to March 2016. These patients had a mean preoperative spherical equivalent refraction of −10.06 ± 0.64 D. Patients were followed over a 4-year period and assessed for outcomes including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and corneal topography. Results: At 4 years post-SMILE, respective efficacy and safety indices were 1.01 ± 0.19 and 1.07 ± 0.15. In total, 97% of operated eyes achieved an UDVA of 20/25 or better. ≥1 line was gained for 9 eyes (26%), with 25 eyes (71%) remaining stable. Twenty-four (69%) and 33 (94%) eyes, respectively, were within ±0.50 D and ±1.0 D of target refraction. From 3 months to 4 years postoperatively, a mean refractive regression of −0.22 D (−0.06 D per year) was detected, whereas no significant changes in mean corneal back curvature or posterior central elevation were detected (P = 0.617 and 0.754, respectively). We detected significant increases in higher-order aberrations (HOAs) of the anterior and total cornea (all P < 0.001), with spherical aberrations and vertical coma being particularly common, whereas posterior corneal HOA remained fairly stable (all P < 0.05). Conclusion: SMILE is a safe, effective, predictable, and stable means of correcting high myopia and myopic astigmatism over a 4-year postoperative period.
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Affiliation(s)
- Fei Xia
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Bing Qin
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Jianmin Shang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Zhuoyi Chen
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xueyi Zhou
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Jing Zhao
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xiaoying Wang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Zhang X, Ma JH, Xi X, Guan L. Characteristics of corneal high-order aberrations in adolescents with mild to moderate myopia. BMC Ophthalmol 2020; 20:465. [PMID: 33243174 PMCID: PMC7690177 DOI: 10.1186/s12886-020-01727-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 11/09/2020] [Indexed: 01/16/2023] Open
Abstract
Background This study investigated the characteristics of corneal higher-order aberrations (HOAs) of the anterior surface, posterior surface, and total cornea in adolescents with mild to moderate myopia. Methods A total of 183 patients with myopia (183 eyes) aged 8 to 18 years were enrolled in this study. The axial length (AL) of the eyes was measured by an IOL-Master, and corneal curvatures (K-values) and HOAs were measured by a Pentacam anterior segment diagnostic analyzer. Results Results of this study showed that the anterior, posterior and total corneal horizontal coma Z31 were − 0.1249 ± 0.105 μm, 0.0009 ± 0.001 μm, and − 0.1331 ± 0.116 μm, respectively; the anterior, posterior and total corneal vertical coma Z3− 1 were − 0.0212 ± 0.164 μm, 0.0003 ± 0.043 μm, and − 0.0216 ± 0.168 μm, respectively; and spherical aberration (SA) Z40 values were 0.2244 ± 0.091 μm, 0.1437 ± 0.029 um, and 0.1889 ± 0.090 μm, respectively. Total corneal Z31 was statistically correlated with posterior corneal astigmatism (K2b − K1b) (p = 0.038). Total corneal Z3− 1 was correlated with anterior corneal astigmatism (K2f − K1f) (p = 0.027). Anterior, posterior, and total corneal Z40 were correlated with anterior and posterior corneal curvature (K1f, K2f, K1b, K2b) (p = 0.001). Posterior corneal Z40b was also significantly correlated with AL. Conclusions In adolescents with mild to moderate myopia, the posterior corneal surface shape may play a compensatory role in the balance of corneal aberrations, and the posterior corneal SA tended to become less negative as the AL increased. The corneal coma may also play a compensatory role in posterior corneal surface astigmatism, which was valuable for the treatment for improving visual quality. This conclusion still needs to be verified.
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Affiliation(s)
- Xu Zhang
- Baoding Yinghua Eye Hospital, Baoding, 071000, China
| | - Jin-Hui Ma
- Department of endocrinology, Affiliated Hospital of Hebei University, Baoding, 071000, China
| | - Xin Xi
- Central Laboratory, Affiliated Hospital of Hebei University, No 212. Yuhuadong Road, Lianchi District, Baoding, 071000, China.
| | - Lin Guan
- Department of mathematics, Hebei Agricultural University, Baoding, 071000, China
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Park SH, Che CY, Kim SI, Park CY, Lee JH, Kim YH, Jung JW, Lee JS, Lee JE. Comparison of clinical outcomes after femtosecond laser in situ keratomileusis in eyes with low or high myopia. Int J Ophthalmol 2020; 13:1780-1787. [PMID: 33215010 DOI: 10.18240/ijo.2020.11.15] [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: 09/27/2019] [Accepted: 03/23/2020] [Indexed: 11/23/2022] Open
Abstract
AIM To compare the clinical results of femtosecond (FS) laser in situ keratomileusis (LASIK) in high myopic patients and low myopic patients. METHODS This study included 212 myopic eyes undergoing LASIK using a VisuMax 500kHz FS laser. All treated eyes were assigned to one of two groups according to preoperative manifest spherical refraction: low myopia group (A, >-4.0 D) and high myopia group (B, ≤-4.0 D). Uncorrected and corrected distance visual acuity (UDVA, CDVA), refractive errors, and higher-order aberrations (HOAs) were measured preoperatively and 1wk, 1, 3 and 6mo postoperatively. RESULTS At 6mo of follow-up, 92% and 76% had a UDVA of 20/20 or better in group A and B, respectively (P=0.037) and UDVA was significantly different between two groups (P=0.042). Six and seven percentage lost one line of CDVA in group A and B, respectively (P=0.572) and no eyes in both groups lost more than two lines. Each group had 87% and 76% of treated eyes within ±0.5 D of the intended correction (P=0.186), and 13% and 43% with a change of >0.50 D in spherical equivalent from 1wk to 6mo postoperatively (P=0.005). In terms of postoperative astigmatism, each group had 89.1% and 76.6% within ±0.50 D, respectively and there was significant difference (P=0.006). Group A tends to induce smaller HOAs than group B. CONCLUSION FS LASIK is effective and safe for correcting high myopia as well as low myopia. However, high myopic eyes showed more postoperative astigmatism and HOAs which affect visual acuity.
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Affiliation(s)
- Su Hwan Park
- Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 50612, Gyeongnam Province, Republic of Korea.,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Gyeongnam Province, Republic of Korea
| | - Cheng-Ye Che
- Department of Ophthalmology, the Affiliated Hospital of Medical College, Qingdao University, Qingdao 266003, Shandong Province, China
| | - Sung Il Kim
- Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 50612, Gyeongnam Province, Republic of Korea.,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Gyeongnam Province, Republic of Korea
| | - Choul Yong Park
- Department of Ophthalmology, Dongguk University Ilsan Hospital, Dongguk University College of Medicine, Goyang 10326, Gyeonggi Province, Republic of Korea
| | - Jong Heon Lee
- Busan Medical Center, Busan 47527, Republic of Korea
| | - Young Hee Kim
- BalGunNun Eye Hospital, Busan 47195, Republic of Korea
| | - Ji Won Jung
- BalGunNun Eye Hospital, Busan 47195, Republic of Korea
| | - Jong Soo Lee
- Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 50612, Gyeongnam Province, Republic of Korea
| | - Ji Eun Lee
- Department of Ophthalmology, School of Medicine, Pusan National University, Yangsan 50612, Gyeongnam Province, Republic of Korea.,Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan 50612, Gyeongnam Province, Republic of Korea
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Li M, Yang D, Zhao Y, Yang W, Shang J, Zhou X, Yao P, Yang D, Lin X, Zhou X. Impact of ablation ratio on 5-year postoperative posterior corneal stability after refractive surgery: SMILE and FS-LASIK. EYE AND VISION 2020; 7:53. [PMID: 33292814 PMCID: PMC7654178 DOI: 10.1186/s40662-020-00218-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 10/20/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND To investigate the impact of the ablation ratio on 5-year postoperative posterior corneal stability in myopic eyes after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery. METHODS A prospective, nonrandomized, cohort study: 80 eyes of 43 patients underwent SMILE surgery and 63 eyes of 32 patients underwent FS-LASIK surgery at the EYE & ENT Hospital, Fudan University. Ablation ratio was defined as lenticule thickness (SMILE cases) or ablation depth (FS-LASIK cases) divided by central corneal thickness (CCT). Posterior corneal elevation changes were recorded as posterior central elevation (PCE), posterior corneal surface at thinnest point (PTE) and posterior corneal mean elevation (PME). Patients were followed up at 6-month and 5-year interval to investigate the impact of the ablation ratio on posterior corneal elevation after SMILE and FS-LASIK surgery. RESULTS PCE dropped at the 6-month follow-up for both SMILE (decreased by -1.11 ± 2.93 μm, P < 0.05) and FS-LASIK groups (decreased by -0.46 ± 3.72 μm, P < 0.05). PTE also dropped in SMILE (reduced by -2.04 ± 3.02 μm, P < 0.05) and FS-LASIK group (reduced by -1.28 ± 4.21 μm, P < 0.05) at the 6-month follow-up. Stable PCE (elevation change: SMILE -0.28 ± 4.03 μm; FS-LASIK 0.79 ± 4.13 μm, P > 0.05) and PTE (elevation change: SMILE -0.08 ± 4.28 μm; FS-LASIK 1.42 ± 3.85 μm, P > 0.05) for both groups were recorded at the 5-year follow-up compared to the 6-month visit. Ablation ratio was strongly correlated with 5-year postoperative PCE (β = 2.68 ± 1.05, P < 0.01) and PTE (β = 2.35 ± 1.17, P < 0.05). Cut-off value for 5-year postoperative raised PCE and PTE was 27.3 and 27.1%, respectively. CONCLUSIONS Ablation ratio was strongly correlated with postoperative posterior corneal elevation in a 5-year follow-up in both SMILE and FS-LASIK groups. PCE and PTE underwent slight backward displacement 6-month postoperatively and remain stable at the 5-year follow-up. Threshold of the ablation ratio for resisting forward displacement of posterior corneal surface was 27.3 and 27.1% for SMILE and FS-LASIK groups, respectively.
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Affiliation(s)
- Meiyan Li
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Danjuan Yang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yu Zhao
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Weiming Yang
- Department of Ophthalmology and Optometry, Children's Hospital of Fudan University, Shanghai, China
| | - Jianmin Shang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xueyi Zhou
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Peijun Yao
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Dong Yang
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xue Lin
- Department of Ophthalmology, Dalian Municipal Women and Children's Medical Center, Dalian, China.
| | - Xingtao Zhou
- Department of Ophthalmology, EYE & ENT Hospital, Fudan University, Shanghai, China. .,NHC Key Laboratory of Myopia (Fudan University), Shanghai, China. .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China. .,Department of Ophthalmology and Optometry, Children's Hospital of Fudan University, Shanghai, China.
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Accuracy of the posterior corneal elevation values of Pentacam HR from different reference surfaces in early ectasia diagnosis. Int Ophthalmol 2020; 41:629-638. [PMID: 33095345 DOI: 10.1007/s10792-020-01618-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE Detecting the accuracy of various posterior elevation (PE) indices of Pentacam HR, and correlating them with some possibly related factors or parameters, in a cohort with early keratoconus (KC). METHODS A cross sectional study that was conducted at Eye World Hospital, Egypt. One hundred and two corneas were enrolled, including two groups; group 1 (50 corneas) having forme fruste or early KC, and group 2 (52 corneas) for healthy controls. Corneas were scanned using Pentacam HR (Oculus, Wetzlar, Germany). The investigated PE parameters were: PE from best fit sphere (BFS), PE from best fit toric ellipsoid (BFTE), PE from exclusion map of Belin Ambrosio's display (BAD), and PE from difference map of BAD. The four PE values were correlated to age, thinnest corneal thickness "TCT," posterior aberrations, and posterior Q value. RESULTS All the investigated indices were significantly different in group 1 compared to group 2 (p < 0.001). Accuracy of PE parameters revealed the highest AUROC for PE from BFTE (AUROC = 0.989, and best cutoff > 4 um with sensitivity 96.00% and specificity 96.15%). PE from difference map was the least accurate. Correlation coefficients showed a significant correlation between all the studied PE parameters and some of the posterior aberrations (root mean square of higher order aberrations, vertical coma, and spherical aberrations), besides a significant correlation with posterior Q value. CONCLUSION PE indices are sensitive detectors of early ectasia. PE from BFTE had the highest deduced AUROC. Alterations in PE values can significantly alter many posterior corneal aberrations and the posterior Q.
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Fang L, Ma W, Wang Y, Dai Y, Fang Z. Theoretical Analysis of Wave-Front Aberrations Induced from Conventional Laser Refractive Surgery in a Biomechanical Finite Element Model. Invest Ophthalmol Vis Sci 2020; 61:34. [PMID: 32433759 PMCID: PMC7405709 DOI: 10.1167/iovs.61.5.34] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To examine the biomechanical effects-induced wave-front aberrations after conventional laser refractive surgery. Methods A finite element model of the human eye was established to simulate conventional laser refractive surgery with corrected refraction from –1 to –15 diopters (D). The deformation of the anterior and posterior corneal surfaces was obtained under the intraocular pressure (IOP). Then, the surface displacement was converted to wave-front aberrations. Results Following conventional refractive surgery, significant deformation of the anterior and posterior corneal surfaces occurred because of the corneal biomechanical effects, resulting in increased residual wave-front aberrations. Deformation of the anterior surface resulted in a hyperopic shift, which was significantly increased with the increasing refractive correction. The residual high-order aberrations consisted of spherical aberration, vertical coma, and y-trefoil. Spherical aberration was significantly positively correlated to enhanced refraction correction. The effect of posterior corneal surface on induced wave-front aberration was less than the anterior corneal surface. The IOP slightly affects the postoperative defocus, coma, and spherical aberration. When treatment decentration occurred during the procedure, the hyperopic shift decreased as the eccentricity increased. Treatment decentration had a significant impact on the spherical aberration and the coma. In addition, the ocular tissue elasticity played a key role in hyperopic shift, whereas it had little effect on the other aberrations. Conclusions Among the many factors that affect high-order aberrations after conventional laser refractive surgery, the alterations in corneal morphology caused by biomechanical effects must be considered, as they can lead to an increase in postoperative residual wave-front aberrations.
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Fang L, Wang Y, Yang R, Deng S, Deng J, Wan L. Effects of the LASIK flap thickness on corneal biomechanical behavior: a finite element analysis. BMC Ophthalmol 2020; 20:67. [PMID: 32093676 PMCID: PMC7038569 DOI: 10.1186/s12886-020-01338-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/07/2020] [Indexed: 12/04/2022] Open
Abstract
Background It is well known that the biomechanical properties change after LASIK refractive surgery. One reason is the impact of flap creation on the residual stroma. The results have revealed that the change is closely related with the flap thickness in several studies. However, the quantitative relationships between the distributions of displacement and stress on the corneal surface and flap thickness have not been studied. The aim of the study was to quantify evaluate the biomechanical change caused by the LASIK flap. Methods By building a finite element model of the cornea, the displacement, the stress and the strain on the corneal surface were analyzed. Results The results showed that the corneal flap could obviously cause the deformation of the anterior corneal surface. For example, the displacement of the corneal vertex achieved 15 μm more than that without corneal flap, when the thickness of corneal flap was 120 μm thick. This displacement was enough to cause the change of aberrations in the human eyes. In the central part of the cornea, the stress on the anterior corneal surface increased with flap thickness. But the change in the stress on the posterior corneal surface was significantly less than that on the anterior surface. In addition, the stress in the central part of the anterior corneal surface increased significantly as the intra-ocular pressure (IOP) increase. Furthermore the increase of IOP had a clearly less effect on stress distribution at the edge of the cornea. Distributions of strain on the corneal surface were similar to those of stress. Conclusions The changes in the biomechanical properties of cornea after refractive surgery should not be ignored.
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Affiliation(s)
- Lihua Fang
- Key Laboratory of National Engineering Laboratory for Nondestructive Testing and Optoelectric Sensing Technology and Application (Ministry of Education), Nanchang Hangkong University, Add: No 696. Fenghenan Rd, Donghu District, Nanchang city, Jiangxi Province, 330063, China.
| | - Yan Wang
- Tianjin Eye Hospital & Eye Institute, Ophthalmology and Visual Development Key Laboratory, Tianjin Medical University, Tianjin, 300020, China
| | - Ruizhi Yang
- Key Laboratory of National Engineering Laboratory for Nondestructive Testing and Optoelectric Sensing Technology and Application (Ministry of Education), Nanchang Hangkong University, Add: No 696. Fenghenan Rd, Donghu District, Nanchang city, Jiangxi Province, 330063, China
| | - Sijing Deng
- Key Laboratory of National Engineering Laboratory for Nondestructive Testing and Optoelectric Sensing Technology and Application (Ministry of Education), Nanchang Hangkong University, Add: No 696. Fenghenan Rd, Donghu District, Nanchang city, Jiangxi Province, 330063, China
| | - Jiahao Deng
- Key Laboratory of National Engineering Laboratory for Nondestructive Testing and Optoelectric Sensing Technology and Application (Ministry of Education), Nanchang Hangkong University, Add: No 696. Fenghenan Rd, Donghu District, Nanchang city, Jiangxi Province, 330063, China
| | - Linsun Wan
- Key Laboratory of National Engineering Laboratory for Nondestructive Testing and Optoelectric Sensing Technology and Application (Ministry of Education), Nanchang Hangkong University, Add: No 696. Fenghenan Rd, Donghu District, Nanchang city, Jiangxi Province, 330063, China
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Blum M, Kunert KS, Schulze M, Sekundo W. 10-Year Results of FLEx Refractive Surgery. J Refract Surg 2019; 35:707-711. [PMID: 31710372 DOI: 10.3928/1081597x-20191002-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 10/02/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the 10-year results of femtosecond lenticule extraction (FLEx) for treatment of myopia and myopic astigmatism. METHODS This long-term follow-up of a prospective clinical trial was conducted at HELIOS Klinikum Erfurt and Phillips University of Marburg, Germany. In 2006, 108 eyes underwent the FLEx procedure. All patients were invited for reexamination 10 years after FLEx treatment for myopia and astigmatism. Visual acuity, objective and manifest refraction, intraocular pressure, and slit-lamp examination and side effects were documented. Main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuity, objective and manifest refraction, and slit-lamp examination and side effects. RESULTS A total of 77 eyes of 40 patients of the original treatment group volunteered for a reexamination 10 years after surgery. The mean age of the patients was 45.9 years; 26 were women and 14 were men. UDVA was 0.09 ± 0.19 logMAR and CDVA was stable at -0.1 ± 0.09 logMAR. More than half of the eyes gained one or two Snellen lines, and none of the eyes lost two or more lines. Over the 10-year period, regression was 0.18 D. CONCLUSIONS FLEx has stable results 10 years after treatment for myopia and astigmatism. [J Refract Surg. 2019;35(11):707-711.].
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Ganesh S, Brar S, Sriprakash K. Post-small incision lenticule extraction phacoemulsification with multifocal IOL implantation: A case report. Indian J Ophthalmol 2019; 67:1353-1356. [PMID: 31332141 PMCID: PMC6677046 DOI: 10.4103/ijo.ijo_2069_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 54-year-old patient presented with cataract, 5 years after undergoing SMILE for high myopia in both eyes. He was motivated in achieving spectacle free vision and his post SMILE-induced aberrations were minimal, due to which he was found suitable for a trifocal IOL implant. Of the various methods considered, the IOL power predicted by a novel combined telecentric keratometry and swept source OCT-based method was finally selected. One month post-operatively, the patient achieved a binocular UDVA of 20/20p and near vision of N.6, suggesting that newer IOL formulae could be superior in providing satisfactory outcomes in post refractive patients.
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Affiliation(s)
- Sri Ganesh
- Nethradhama Superspecilaity Eye Hospital, Bangalore, India
| | - Sheetal Brar
- Nethradhama Superspecilaity Eye Hospital, Bangalore, India
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Fourier Analysis of Corneal Irregular Astigmatism After Small Incision Lenticule Extraction and Comparison to Femtosecond Laser-Assisted Laser In Situ Keratomileusis. Cornea 2019; 38:1536-1542. [DOI: 10.1097/ico.0000000000002029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Li M, Li M, Chen Y, Miao H, Yang D, Ni K, Zhou X. Five-year results of small incision lenticule extraction (SMILE) and femtosecond laser LASIK (FS-LASIK) for myopia. Acta Ophthalmol 2019; 97:e373-e380. [PMID: 30632671 DOI: 10.1111/aos.14017] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 10/26/2018] [Indexed: 11/27/2022]
Abstract
PURPOSE To compare visual outcomes and aberration outcomes in small incision lenticule extraction (SMILE) versus femtosecond laser LASIK (FS-LASIK). METHODS This prospective, comparative, nonrandomized clinical study included 68 eyes of 37 patients receiving SMILE and 55 eyes of 30 patients receiving FS-LASIK between December 2011 and January 2013 at the Fudan University Eye and ENT Hospital (Shanghai, People's Republic of China). Patients were followed up at 3, 6 months and 5 years after surgery. Main outcome measurements included uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, central corneal thickness (CCT), total corneal refractive power (TCRP) and wavefront aberrations. RESULTS About 98% (49/50) of treated eyes in the SMILE group and 95% (39/41) in the FS-LASIK group had a postoperative logMAR UDVA of 0 or better. Spherical equivalent (SE) after 5 years was -0.01 ± 0.35 D in the SMILE group and -0.23 ± 0.41 D in the FS-LASIK group. A regression of -0.02 ± 0.39 D in the SMILE group and -0.12 ± 0.32 D in the FS-LASIK group was observed between 6 months and 5 years postoperative time-points. TCRP increased by 0.39 ± 0.38 D in the SMILE group and 0.45 ± 0.49 D in the FS-LASIK group between 6-month and 5-year time-points. However, no statistically significant difference was found between the SMILE and FS-LASIK groups in terms of ∆SE, ∆CCT and ∆TCRP between 6 months and 5 years postoperative time-points. CONCLUSION Myopic regression was observed in terms of TCRP but not in subjective refraction. No statistically significant difference in stability was found between SMILE and FS-LASIK.
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Affiliation(s)
- Meiyan Li
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
| | - Meng Li
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
| | - Yingjun Chen
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
| | - Huamao Miao
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
| | - Dong Yang
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
| | - Katherine Ni
- Department of Medicine The Mount Sinai Hospital New York New York USA
| | - Xingtao Zhou
- Key Lab of Myopia, Ministry of Health Department of Ophthalmology EYE & ENT Hospital of Fudan University Shanghai China
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Yu M, Chen M, Liu W, Dai J. Comparative study of wave-front aberration and corneal Asphericity after SMILE and LASEK for myopia: a short and long term study. BMC Ophthalmol 2019; 19:80. [PMID: 30894159 PMCID: PMC6425702 DOI: 10.1186/s12886-019-1084-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 03/06/2019] [Indexed: 11/16/2022] Open
Abstract
Background The study compares the wave-front aberration and corneal asphericity from multiple perspectives after Small Incision Lenticule Extraction and Laser-assisted Subepithelial Keratomileusis for mild to moderate myopia in a short and long time period. Methods This prospective and comparative study included 32 eyes in the SMILE group, with a mean spherical equivalent (SE) of − 4.1 ± 0.9D and 32 eyes in the LASEK group, with a mean SE of − 3.7 ± 1.0D. Visual acuity, refractive error, wave-front aberration, corneal Q value and corneal refractive power were analyzed pre-, 3 months and 3 years post-operatively. Results There was no significant difference in refractive error, wave-front aberration, corneal Q value and corneal refractive power before treatment. Three months postoperative, Q value within 6 mm (SMILE: 0.46 ± 0.27, LASEK: 0.63 ± 0.28, p = 0.02), the relative peripheral corneal power (5-8 mm: p < 0.05), change of higher order aberration (SMILE: 0.10 ± 0.16, LASEK: 0.24 ± 0.20, p = 0.004) and spherical aberration (SA, SMILE: -0.07 ± 0.30, LASEK: -0.41 ± 0.40, p < 0.001) were significantly lower in the SMILE than in LASEK group. The visual acuity, refractive error, coma, peripheral Q value, central corneal power had no significant difference between the two groups. Three years post-operation, the corneal power distribution results and SA were similar to that of 3-month, while the Q value had no significant difference between the two groups. Conclusion In the early stage after SMILE, the HOAs was lower, the corneal refractive power from central to periphery was more uniform than after LASEK; and in the long-term run, SMILE still preceded LASEK in the corneal asphericity and aberration. Electronic supplementary material The online version of this article (10.1186/s12886-019-1084-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Manrong Yu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Minjie Chen
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Wangyuan Liu
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jinhui Dai
- Department of Ophthalmology, Eye and ENT Hospital, Fudan University, No. 83 Fenyang Road, Shanghai, 200031, China. .,NHC Key Laboratory of Myopia (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
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Jin HY, Wan T, Yu XN, Wu F, Yao K. Corneal higher-order aberrations of the anterior surface, posterior surface, and total cornea after small incision lenticule extraction (SMILE): high myopia versus mild to moderate myopia. BMC Ophthalmol 2018; 18:295. [PMID: 30419871 PMCID: PMC6233489 DOI: 10.1186/s12886-018-0965-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 10/30/2018] [Indexed: 11/23/2022] Open
Abstract
Background To investigate corneal higher-order aberrations (HOAs) of the anterior surface, posterior surface, and total cornea after small incision lenticule extraction (SMILE) in high myopic and mild to moderate myopic patients. Methods This retrospective study included 197 eyes (101 patients) undergoing SMILE surgery. According to the preoperative spherical equivalent (SE), treated eyes were divided into two groups: a high myopic group (more than − 6.0 D, Group H) and a mild to moderate myopic group (less than − 6.0 D, Group M). Corneal HOAs of the anterior surface, posterior surface, and total cornea were measured using a Scheimpflug camera preoperatively and 3 months postoperatively. Pearson’s correlation analysis was conducted to determine relationships between corneal aberrations and the SE. Results There were no significant differences in third-order to eight-order aberrations (RMS HOAs) of the anterior surface, posterior surface, and total corneal between the two groups before SMILE surgery. However, after SMILE, anterior and total corneal HOAs, especially vertical coma and spherical aberrations, significantly increased in both groups (p < 0.0167), whereas posterior corneal HOAs remained relatively stable (p > 0.0167). The induction of HOAs was significantly greater in Group H than Group M postoperatively (p < 0.0167). Changes in anterior surface and total corneal HOAs, especially vertical coma and spherical aberrations, were related to the SE (p < 0.05). Conclusions Anterior and total corneal HOAs, particularly vertical coma and spherical aberrations, significantly increased after SMILE in both groups, whereas posterior corneal HOAs remained stable. Aberration changes were related to SE. Trial registration Retrospectively registered. ChiCTR-ORC-17011040. Registered 1 April 2017. Name of registry: The observation of clinical results after corneal refractive surgery. Data of enrolment of the first participant to the trial: 15 December 2016.
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Affiliation(s)
- Hong-Ying Jin
- Eye Center, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
| | - Ting Wan
- Eye Center, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Xiao-Ning Yu
- Eye Center, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Fang Wu
- Eye Center, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Ke Yao
- Eye Center, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
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Zhang L, Wang Y, Zhao W, Cheng W, Cui T. Corneal remodeling and spatial profiles following small incision lenticule extraction. Int Ophthalmol 2018; 39:1827-1836. [PMID: 30171445 DOI: 10.1007/s10792-018-1010-3] [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: 10/03/2017] [Accepted: 08/27/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To evaluate the three-dimensional corneal spatial profiles following small incision lenticule extraction (SMILE) based on corneal asphericity, thickness, and volume. MATERIALS AND METHODS Eighty-three eyes in 83 patients who underwent SMILE were examined before and 1 and 6 months after surgery. The asphericity of the anterior and posterior corneal surfaces was analyzed. Corneal volume (CV) was measured in corneal regions measuring 3.0 mm, 5.0 mm, and 7.0 mm in diameter. Mean corneal thickness (CT) values were acquired at the apex (0.0 mm) and in four concentric radial zones from the apex (with diameters of 2.0, 4.0, 6.0, and 8.0 mm). RESULTS The mean anterior Q value increased from - 0.32 preoperatively to 0.67 at 1 month and 0.62 at 6 months postoperatively. The mean posterior Q value decreased from - 0.30 preoperatively to - 0.26 at 1 month and to - 0.25 at 6 months postoperatively. The CV increased by 0.05 ± 0.06 mm3 (1.40%), 0.06 ± 0.11 mm3 (0.83%), and 0.09 ± 0.17 mm3 (0.73%) along the radial zones with respective diameters of 3.0 mm, 5.0 mm, and 7.0 mm. The CT increased by 6.02 ± 6.48 µm (1.36%) at the apex and then decreased with increasing distance from the center, i.e., to 5.52 ± 6.31 µm (1.20%) at 2.0 mm, 4.72 ± 6.55 µm (0.92%) at 4.0 mm, 4.47 ± 7.86 µm (0.75%) at 6.0 mm, and 4.86 ± 10.31 µm (0.70%) at 8.0 mm. No correlations were observed between changes in CV and CT and refractive fluctuation between 1 month and 6 months postoperatively. CONCLUSIONS The corneal profile displayed a less oblate shift on the anterior surface; however, the posterior surface showed a slight backward shift during the postoperative period. The CV and CT steadily increased after surgery and mainly within the operative zones. Refraction remained stable postoperatively and was not affected by the corneal remodeling.
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Affiliation(s)
- Lin Zhang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yan Wang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China. .,Tianjin Eye Hospital and Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Clinical College of Ophthalmology, Tianjin Medical University, No 4. Gansu Road, Heping District, Tianjin, 300020, China.
| | - Wei Zhao
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Wenbo Cheng
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Tong Cui
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
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Functional Optical Zone After Small-Incision Lenticule Extraction as Stratified by Attempted Correction and Optical Zone. Cornea 2018; 37:1110-1117. [PMID: 29927753 DOI: 10.1097/ico.0000000000001669] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare the functional optical zone (OZ) with different levels of myopia and different OZ groups after small-incision lenticule extraction. METHODS This retrospective study included 249 patients (120 men) after small-incision lenticule extraction correction. We grouped participants according to attempted correction [low: spherical equivalent (SE) > -3.0 D; moderate: -6.0 D ≥ SE ≥ -3.0 D; high: SE ≥ -6.0 D] and planned functional optical zone (PFOZ) (OZ-1: PFOZ ≤ 6.3 mm; OZ-2: 6.3 mm < PFOZ ≤ 6.5; OZ-3: PFOZ > 6.5 mm), and we compared the achieved functional optical zone (AFOZ) and total corneal aberration, using Scheimpflug imaging, 1 month postoperatively. Correlations between corneal aberration and AFOZ were analyzed. RESULTS The AFOZ was smaller than the PFOZ in all 3 refraction groups (reduction: low, 0.78 ± 0.72 mm; moderate, 1.22 ± 0.60 mm; and high: 1.49 ± 0.58 mm, P < 0.001). There was no difference in the AFOZ among the 3 OZ groups. Total corneal aberration increased more in the high myopia group (total higher-order aberration, coma, and spherical aberration, P < 0.001), which also correlated with the AFOZ. CONCLUSIONS The discrepancy between the AFOZ and PFOZ increased with greater attempted correction. Attempted correction and AFOZ influence corneal aberration.
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Vector Analysis of the Effects of FS-LASIK and Toric ICL for Moderate to High Astigmatism Correction. J Ophthalmol 2018; 2018:6952710. [PMID: 30147948 PMCID: PMC6083598 DOI: 10.1155/2018/6952710] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/28/2018] [Accepted: 06/24/2018] [Indexed: 12/26/2022] Open
Abstract
Purpose To estimate the treatment effectiveness of femtosecond-assisted laser in situ keratomileusis (FS-LASIK) and Toric implantable collamer lens (Toric ICL) for moderate and high astigmatism via vector analysis. Materials and Methods The study involved 44 eyes from 44 patients who had a preoperative refractive cylinder ≥1.0 diopters (D) and underwent bilateral FS-LASIK or Toric ICL surgery. The examinations included corrected distance visual acuity measurement and subjective refraction before and 3 months after surgery. The astigmatic changes were estimated using vector analysis. Results No statistically significant differences were found in cylindrical refraction and percentage of spherical equivalent within 0 D, ±0.50 D, ±1.00 D, and ±1.50 D between the FS-LASIK and Toric ICL groups at 3 months after surgery. The parameters of the vector analysis included intended refractive correction, surgically induced refractive correction, error vector, correction ratio, error ratio, error of magnitude, and error of angle, with no significant differences between the groups. However, error ratio the of the off-axis correction in the FS-LASIK and Toric ICL groups was 4.11 ± 3.02 and 8.11 ± 3.82, respectively, and the difference was significant (t = −2.46, p=0.02). Conclusion Both FS-LASIK and Toric ICL were effective for correcting moderate and high astigmatism, although Toric ICL might produce a larger error of angle than FS-LASIK when an off-axis correction occurs.
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Comparing corneal higher-order aberrations in corneal wavefront-guided transepithelial photorefractive keratectomy versus small-incision lenticule extraction. J Cataract Refract Surg 2018; 44:725-733. [PMID: 29789156 DOI: 10.1016/j.jcrs.2018.03.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/02/2018] [Accepted: 03/25/2018] [Indexed: 11/23/2022]
Abstract
PURPOSE To evaluate the changes in corneal higher-order aberrations (HOAs) after corneal wavefront-guided transepithelial photorefractive keratectomy (PRK) and small-incision lenticule extraction (SMILE). SETTING Yonsei University College of Medicine and Eyereum Eye Clinic, South Korea. DESIGN Retrospective case series. METHODS Medical records of patients having either corneal wavefront-guided transepithelial PRK or small-incision lenticule extraction were examined. The root-mean-square total HOAs, 3rd-order coma aberration, and 4th-order spherical aberration were measured preoperatively and 6 months postoperatively. Independent t tests and analysis of covariance were used to compare changes in corneal HOAs between the 2 groups. RESULTS The study comprised 77 eyes having corneal wavefront-guided transepithelial PRK and 81 eyes having small-incision lenticule extraction. The total HOAs and spherical aberration increased after transepithelial PRK (all P < .001), whereas coma aberration was stable after transepithelial PRK. The total HOAs, spherical aberration, and coma aberration increased after small-incision lenticule extraction (P < .001 for total HOAs, spherical aberration; P = .004 for coma). At 6 months postoperatively, total HOAs and spherical aberration were significantly larger in the transepithelial PRK group than in the small-incision lenticule extraction group. Coma aberration was larger in the small-incision lenticule extraction group than in the transepithelial PRK group. Spherical aberration induction was significantly smaller in the small-incision lenticule extraction group than in the transepithelial PRK group (P < .001), and coma aberration induction was larger in the small-incision lenticule extraction group than in the transepithelial PRK group (P = .011). CONCLUSIONS Small-incision lenticule extraction demonstrated that the induction of total HOAs was comparable to corneal wavefront-guided transepithelial PRK, accompanied by smaller spherical aberration induction and larger coma aberration induction. During small-incision lenticule extraction, surgeons should aim to obtain optimum centration for smaller induction of corneal HOAs.
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Khalifa MA, Ghoneim A, Shafik Shaheen M, Aly MG, Piñero DP. Comparative Analysis of the Clinical Outcomes of SMILE and Wavefront-Guided LASIK in Low and Moderate Myopia. J Refract Surg 2018; 33:298-304. [PMID: 28486720 DOI: 10.3928/1081597x-20170222-01] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 01/25/2017] [Indexed: 01/12/2023]
Abstract
PURPOSE To compare the clinical outcomes of small incision lenticule extraction (SMILE) and wavefront-guided LASIK (WFG LASIK) in eyes with low and moderate myopia. METHODS This was a prospective, comparative study enrolling 110 eyes with low and moderate myopia (spherical equivalent ≤ 6.00 diopters [D]). Two groups were differentiated according to the surgical technique used: the WFG LASIK group included 51 eyes (51 patients) undergoing WFG LASIK using the STAR S4IR excimer laser and the iDesign aberrometer (Abbott Medical Optics, Abbott Park, IL) and the SMILE group included 59 eyes (59 patients) undergoing SMILE with the VisuMax platform (Carl Zeiss Meditec, Jena, Germany). Visual, refractive, aberrometric, and contrast sensitivity outcomes were evaluated during a 6-month follow-up. RESULTS Mean efficacy index was 0.92 ± 0.11 and 1.12 ± 0.17 in the SMILE and WFG LASIK groups, respectively (P < .001). Postoperative spherical equivalent was within ±0.50 D in 81.54% and 98% of eyes in the SMILE and WFG LASIK groups (P < .001), and postoperative cylinder was 0.50 or below in 84.7% and 100% of eyes, respectively (P = .038). Mean safety index was 0.98 ± 0.08 and 1.20 ± 0.14 in the SMILE and WFG LASIK groups (P < .001), with losses of lines of corrected distance visual acuity in 6.8% and 0.0% of eyes, respectively. Higher increase in higher order (P < .001) and coma (P < .001) root mean square and higher decrease in contrast sensitivity for 6, 12, and 18 cycles/degree (P ≤ .001) were observed after SMILE. CONCLUSIONS SMILE and WFG LASIK are efficacious and safe procedures for the correction of low and moderate myopia, but WFG LASIK allows a more predictable outcome and better aberrometric control. [J Refract Surg. 2017;33(5):298-304.].
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Qin B, Li M, Chen X, Sekundo W, Zhou X. Early visual outcomes and optical quality after femtosecond laser small-incision lenticule extraction for myopia and myopic astigmatism correction of over -10 dioptres. Acta Ophthalmol 2018; 96:e341-e346. [PMID: 29251814 DOI: 10.1111/aos.13609] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 09/02/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate early visual and refractive outcomes, corneal stability and optical quality after femtosecond laser small-incision lenticule extraction (SMILE) for treating myopia and myopic astigmatism over -10 D. METHODS Thirty eyes (30 patients) with myopia and myopic astigmatism of over -10 D were treated with VisuMax® femtosecond laser (version 3.0; Carl Zeiss Meditec AG, Jena, Germany). Six months postoperative safety, efficacy and predictability were evaluated. Corneal Scheimpflug topography was measured preoperatively, 1 day, 3 months and 6 months postoperatively. Wavefront aberrations were measured preoperatively, 3 months and 6 months postoperatively. RESULTS Six months postoperatively, LogMAR uncorrected and corrected distance visual acuity (CDVA) were -0.013 ± 0.086 and -0.073 ± 0.069, respectively. 73% (97%) of eyes were within 0.5 (1) D of target refraction. No eyes lost CDVA, 43% (13 eyes) gained one line and 7% (two eyes) gained two lines. Mean corneal back curvature (KMB) and posterior central elevation (PCE) did not change significantly comparing preoperative and 6 months postoperative data (p = 0.91 and 0.77, respectively). Comparing 1 day with 6 months postoperative data, central corneal thickness (CCT), mean corneal front curvature (KMF), KMB and PCE did not change significantly (p = 0.27, 0.07, 0.52, 0.71, respectively). Total higher-order aberration (HOA), spherical aberration and coma increased significantly (p < 0.01) but trefoil remained stable (p = 0.49). CONCLUSION Our results indicate that SMILE can correct myopia and myopic astigmatism of over -10 D predictably. No early ectasia was observed. Long-term changes in visual quality and corneal stability require further investigation.
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Affiliation(s)
- Bing Qin
- Department of Ophthalmology; Myopia Key Laboratory of the Health Ministry; Eye and ENT Hospital of Fudan University; Shanghai China
| | - Meiyan Li
- Department of Ophthalmology; Myopia Key Laboratory of the Health Ministry; Eye and ENT Hospital of Fudan University; Shanghai China
| | - Xun Chen
- Department of Ophthalmology; Myopia Key Laboratory of the Health Ministry; Eye and ENT Hospital of Fudan University; Shanghai China
| | - Walter Sekundo
- Department of Ophthalmology; Philipps University of Marburg; Marburg Germany
| | - Xingtao Zhou
- Department of Ophthalmology; Myopia Key Laboratory of the Health Ministry; Eye and ENT Hospital of Fudan University; Shanghai China
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Corneal Irregular Astigmatism and Curvature Changes After Small Incision Lenticule Extraction: Three-Year Follow-Up. Cornea 2018; 37:875-880. [DOI: 10.1097/ico.0000000000001532] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fu D, Wang L, Zhou XT, Yu ZQ. Cap morphology after small-incision lenticule extraction and its effects on intraocular scattering. Int J Ophthalmol 2018; 11:456-461. [PMID: 29600180 DOI: 10.18240/ijo.2018.03.16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 10/14/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate cap morphology after small-incision lenticule extraction (SMILE) and its effects on intraocular scattering. METHODS Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at 1d, 1wk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System (OQAS) values, and objective scattering index (OSI), were evaluated using OQAS™. RESULTS Cap thickness decreased from 1d to 1wk (P<0.001), but remained higher than intended thickness of 120 µm after 3mo (P<0.001). Cap thickness in central area was thinner than that of in the paracentral and peripheral areas (P<0.0001). Total number of microdistortions decreased from 1d to 3mo (P<0.0001). Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at 1d and 1mo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at 1d and 1moafter surgery. CONCLUSION The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.
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Affiliation(s)
- Dan Fu
- Eye and ENT Hospital of Fudan University, Shanghai 200031, China
| | - Lin Wang
- Eye and ENT Hospital of Fudan University, Shanghai 200031, China
| | - Xing-Tao Zhou
- Eye and ENT Hospital of Fudan University, Shanghai 200031, China.,Myopia Key Laboratory of the Health Ministry, Shanghai 200031, China
| | - Zhi-Qiang Yu
- Eye and ENT Hospital of Fudan University, Shanghai 200031, China.,Myopia Key Laboratory of the Health Ministry, Shanghai 200031, China
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Xu M, Simmons B, Lerner AL, Yoon G. Controlled elevation of intraocular pressure and its impact on ocular aberrations in healthy eyes. Exp Eye Res 2018; 171:68-75. [PMID: 29501880 DOI: 10.1016/j.exer.2018.02.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/30/2018] [Accepted: 02/28/2018] [Indexed: 11/30/2022]
Affiliation(s)
- Mengchen Xu
- Department of Mechanical Engineering, University of Rochester, Rochester, NY, United States.
| | - Brittany Simmons
- Flaum Eye Institute, Department of Ophthalmology, University of Rochester, Rochester, NY, United States.
| | - Amy L Lerner
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States; Department of Mechanical Engineering, University of Rochester, Rochester, NY, United States.
| | - Geunyoung Yoon
- Flaum Eye Institute, Department of Ophthalmology, University of Rochester, Rochester, NY, United States; Department of Biomedical Engineering, University of Rochester, Rochester, NY, United States.
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Yan H, Gong LY, Huang W, Peng YL. Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis. Int J Ophthalmol 2017; 10:1436-1445. [PMID: 28944205 DOI: 10.18240/ijo.2017.09.17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/07/2017] [Indexed: 12/31/2022] Open
Abstract
AIM To evaluate the possible differences in visual quality between small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK) for myopia. METHODS A Meta-analysis was performed. Patients were from previously reported comparative studies treated with SMILE versus FS-LASIK. The PubMed, EMBASE, Cochrane, Web of Science and Chinese databases (i.e. WANFANG and CNKI) were searched in Nov. of 2016 using RevMan 5.1 version software. The differences in visual acuity, aberration and biomechanical effects within six months postoperatively were showed. Twenty-seven studies including 4223 eyes were included. RESULTS No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery (P=0.14), the proportion of eyes achieving an uncorrected distance visual acuity of 20/20 or better (P=0.43), the final refractive spherical equivalent (P=0.89), the refractive spherical equivalent within ±1.00 diopter of the target values (P=0.80), vertical coma (P=0.45) and horizontal coma (P=0.06). Compared with the FS-LASIK group, total higher-order aberration (P<0.001) and spherical aberration (P<0.001) were higher and the decrease in corneal hysteresis (P=0.0005) and corneal resistance factor (P=0.02) were lower in the SMILE group. CONCLUSION SMILE and FS-LASIK are comparable in efficacy, safety and predictability for correcting myopia. However, the aberration in the SMILE group is superior to that in the FS-LASIK group, and the loss of biomechanical effects may occur less frequently after SMILE than after FS-LASIK.
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Affiliation(s)
- Huan Yan
- Department of Ophthalmology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing 400010, China
| | - Li-Yan Gong
- Department of Ophthalmology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing 400010, China
| | - Wei Huang
- Department of Ophthalmology, the Second Affiliated Hospital of Chongqing Medical University, Chongqing Medical University, Chongqing 400010, China
| | - Yan-Li Peng
- Department of Ophthalmology, Chongqing Aier-Mega Eye Hospital, Aier Eye Hospital Group, Chongqing 400060, China.,Aier School of Ophthalmology, Central South University, Changsha 410000, Hunan Province, China
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Jin HY, Wan T, Wu F, Yao K. Comparison of visual results and higher-order aberrations after small incision lenticule extraction (SMILE): high myopia vs. mild to moderate myopia. BMC Ophthalmol 2017; 17:118. [PMID: 28683793 PMCID: PMC5501544 DOI: 10.1186/s12886-017-0507-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 06/22/2017] [Indexed: 11/21/2022] Open
Abstract
Background To compare the refractive results and higher-order aberrations (HOAs) after small incision lenticule extraction (SMILE) in high myopia and mild to moderate myopia patients. Methods This prospective study included 165 eyes (86 patients) undergoing SMILE. According to the preoperative spherical equivalent (SE), treated eyes were divided into two groups: the high myopia group (more than -6.0 D, group-H) and the mild to moderate group (less than -6.0 D, group-M). Follow-up intervals were at 1 day, 10 days, 1 month and 3 months postoperatively. We obtained the following parameters: uncorrected (UDVA) and corrected distance visual acuity (CDVA), SE, efficacy and safety index, and HOAs. Results Preoperative SE was -7.16 ± 0.93 D in group-H and -4.34 ± 0.97 D in group-M. At 3 months postoperatively, the SE in group-H and group-M was -0.20 ± 0.37 D and 0.01 ± 0.19 D (t = - 4.11, P<0.05), respectively. It was found that 77% and 98% had an UDVA of 20/20, 98% and 99% had a CDVA of 20/20 in group-H and group-M, respectively, while 87% and 95% had a SE within ±0.5 D and ±1.0 D in group-H, and 98% and 100% in group-M. The efficacy indexes were 0.98 ± 0.18 in group-H and 1.05 ± 0.10 in group-M (t = - 3.084, p < 0.05). The safety indexes were 1.06 ± 0.09 and 1.06 ± 0.09 (t = 0.153, p > 0.05), respectively. There were significant increases in total HOAs, 3rd-order coma, and 4th-order spherical aberrations. Conclusions SMILE is an effective and safe surgery for correcting myopia. But the target correction amount in high myopia patients should be adjusted to avoid undercorrection and acquired more satisfaction. SMILE induced increases of HOAs. Trial registration ChiTrial registration number: ChiCTR-OON-16009164. Retrospectively registered: 06.September.2016
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Affiliation(s)
- Hong-Ying Jin
- Eye Center, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Ting Wan
- Eye Center, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Fang Wu
- Eye Center, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Ke Yao
- Eye Center, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310009, China.
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Ji YW, Kim M, Kang DSY, Reinstein DZ, Archer TJ, Choi JY, Kim EK, Lee HK, Seo KY, Kim TI. Lower Laser Energy Levels Lead to Better Visual Recovery After Small-Incision Lenticule Extraction: Prospective Randomized Clinical Trial. Am J Ophthalmol 2017; 179:159-170. [PMID: 28499707 DOI: 10.1016/j.ajo.2017.05.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 04/27/2017] [Accepted: 05/01/2017] [Indexed: 11/24/2022]
Abstract
PURPOSE To determine the effect of lowering laser energy on clinical outcomes in small-incision lenticule extraction (SMILE). DESIGN Prospective randomized clinical trial. METHODS A total of 151 patients (151 eyes) with moderate myopia scheduled for SMILE were included: 58 eyes received SMILE with low energy (100, 105, and 110 nJ; L-SMILE group) and 93 with conventional energy (115-150 nJ; C-SMILE group). Patients received complete ophthalmic examinations preoperatively and over 3 months postoperatively. RESULTS Uncorrected distance visual acuity (logMAR UDVA) 1 day and 1 week postoperatively was significantly better in L-SMILE than in C-SMILE (P < .001 and P = .005, respectively). There was no significant difference between the groups at 1 and 3 months. L-SMILE induced significantly fewer corneal aberrations compared with C-SMILE at 1 week and 1 month postoperatively (both P < .01), but there were no significant differences at 3 months. Though there was no difference in logMAR UDVA over the postoperative period between the 100, 105, and 110 nJ subgroups, there was a significant difference in logMAR UDVA on postoperative day 1 between L-SMILE and each subgroup in which an energy level of 115 nJ or higher was used. Furthermore, logMAR UDVA on postoperative day 1 showed a significant correlation with laser energy (r = 0.451, P < .001) and multiple linear regression analysis revealed that energy level was the only independent factor associated with logMAR UDVA on postoperative day 1 (P < .001). CONCLUSIONS SMILE using femtosecond energy of less than 115 nJ facilitates better visual acuity with less induction of corneal aberrations in the early postoperative period.
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Khalifa MA, Ghoneim AM, Shaheen MS, Piñero DP. Vector analysis of astigmatic changes after small-incision lenticule extraction and wavefront-guided laser in situ keratomileusis. J Cataract Refract Surg 2017; 43:819-824. [DOI: 10.1016/j.jcrs.2017.03.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 03/07/2017] [Accepted: 03/11/2017] [Indexed: 11/30/2022]
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Impact of Treatment Decentration on Higher-Order Aberrations after SMILE. J Ophthalmol 2017; 2017:9575723. [PMID: 28396804 PMCID: PMC5370520 DOI: 10.1155/2017/9575723] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/31/2017] [Indexed: 11/17/2022] Open
Abstract
Purpose. To evaluate decentration following femtosecond laser small incision lenticule extraction (SMILE) and sub-Bowman keratomileusis (SBK) and its impact on higher-order aberrations (HOAs). Methods. Prospective, nonrandom, and comparison study. There were 96 eyes of 52 patients who received SMILE and 96 eyes of 49 patients who received SBK in this study. Decentration was calculated 6 months after surgery with Pentacam. HOAs and visual acuity after the surgery were examined for patients in both groups before and 6 months after surgery. Results. The mean decentration displacement in SMILE group was significantly less than SBK group (P = 0.020). 89 eyes were decentered within 0.50 mm after SMILE and SBK. The association between vertical decentration and the induced spherical aberration was insignificant in SMILE group (P = 0.035). There was an association between decentration and safety index, efficacy index, vertical coma, spherical aberration, and HOAs in root mean square (RMS, μm) after SBK (all P < 0.05). No difference was found in uncorrected and corrected distance visual acuity, safety index, efficacy index, and wavefront aberrations between the two subgroups at any delimited value after SMILE (all P > 0.05). Decentration exceeding 0.37 mm affected vertical coma and RMSh of SBK eyes (P = 0.002, 0.005). Conclusion. SMILE surgery achieved more accurate centration than SBK surgery. Vertical decentration is associated with the induced spherical aberration in SMILE.
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