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Ying J, Zhang J, Wang B, Pan F, Yang S. Comprehensive Assessment of Posterior Corneal Asphericity Change Calculated by Tangential Radius of Curvature After FS-LASIK and SMILE. J Refract Surg 2024; 40:e133-e141. [PMID: 38466766 DOI: 10.3928/1081597x-20240205-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
PURPOSE To evaluate changes in posterior corneal asphericity (ΔQ) using the tangential radius of curvature after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) procedures. METHODS One hundred twenty right eyes of myopic patients who underwent either FS-LASIK or SMILE procedures were analyzed using Sirius 3D corneal topography for assessment. The tangential radius was employed to calculate both preoperative and postoperative posterior corneal Q-values across each semimeridian. After both surgical interventions, the ΔQ value variations across the 360° semimeridional regions of the posterior corneal surface were compared. RESULTS A marked postoperative increase in the posterior corneal Q-value was documented. No significant differences were noted between the postoperative Q-values or ΔQ-values of the two surgical approaches. Among patients with moderate myopia, postoperative Q-value exhibited considerably lower increases and ΔQ-value significantly smaller than their counterparts with high myopia. Moreover, the fluctuation in ΔQ across semimeridional regions was less evident in patients with moderate myopia than in those with high myopia. Notably, the degree of ΔQ fluctuation across semimeridional regions was similar between both surgical categories. These data offer insights into variations in the posterior corneal surface after refractive surgeries depending on the degree of myopia, illuminating their clinical relevance. CONCLUSIONS Both FS-LASIK and SMILE introduce notable changes to posterior corneal asphericity among patients with different myopia intensities. Furthermore, the influence on the asphericity across the entire posterior surface is similarly distributed between FS-LASIK and SMILE techniques. [J Refract Surg. 2024;40(3):e133-e141.].
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Li ZJ, Yang C, Liu SH, Guo J, Duan YH. Changes in corneal biomechanics and posterior corneal surface elevation after FS-LASIK. Int J Ophthalmol 2023; 16:1832-1837. [PMID: 38028510 PMCID: PMC10626345 DOI: 10.18240/ijo.2023.11.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/05/2023] [Indexed: 12/01/2023] Open
Abstract
AIM To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS Totally 197 eyes of 100 patients who underwent the FS-LASIK from April 2022 to November 2022 were included. They were divided into three groups according to the ratio of residual corneal stroma thickness/corneal thickness (RCST/CT): Group I (50%≤RCST/CT<55%, 63 eyes of 32 patients), Group II (55%≤RCST/CT<60%, 67 eyes of 34 patients), and Group III (RCST/CT≥60%, 67 eyes of 34 patients). The intraocular pressure (IOP), corneal compensated IOP (IOPcc), corneal hysteresis (CH) and corneal resistance factor (CRF) were measured immediately, 1, and 3mo postoperatively by ocular response analyzer (ORA) and the posterior elevation difference (PED) was measured by Pentacam. RESULTS After operation, IOP, CH, CRF, and PED were statistically different among the three groups (F=12.99, 31.148, 23.998, all P<0.0001). There was no statistically significant difference in IOPcc among the three groups (F=0.603, P>0.05). The IOP, IOPcc, CH, and CRF were statistical changed after surgery (F=699.635, 104.125, 308.474, 640.145, all P<0.0001). The PED of Group I was significantly higher than that of Group II (P<0.05), and Group II was significantly higher than that of Group III (P<0.05). The PED value of 3mo after surgery decreased in each group compared with 1mo after surgery, but there was no statistical difference (Group I: t=0.82, P=0.41; Group II: t=0.17, P=0.87; Group III: t=1.35, P=0.18). The correlation analysis of corneal biomechanical parameter changes with PED at 1mo and 3mo after surgery showed that ΔIOP, ΔIOPcc, ΔCH, and ΔCRF were not correlated with PED value in three groups (P>0.05). CONCLUSION The smaller the RCST/CT, the greater effect on corneal biomechanics and posterior surface elevation. There is no correlation between changes in corneal biomechanics and posterior corneal surface elevation in the range of RCST/CT≥50%.
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Affiliation(s)
- Zhong-Ji Li
- Department of Ophthalmology, Xi'an Gaoxin Hospital, Xi'an 710075, Shaanxi Province, China
| | - Chen Yang
- Department of Ophthalmology, Xi'an Gaoxin Hospital, Xi'an 710075, Shaanxi Province, China
| | - Su-Han Liu
- Department of Ophthalmology, Xi'an Gaoxin Hospital, Xi'an 710075, Shaanxi Province, China
| | - Jiao Guo
- Department of Ophthalmology, Xi'an Gaoxin Hospital, Xi'an 710075, Shaanxi Province, China
| | - Yu-Hui Duan
- Department of Ophthalmology, Xi'an Gaoxin Hospital, Xi'an 710075, Shaanxi Province, China
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Liu S, Yu L, Zhao Y, Zhou X. Changes in the posterior corneal surface after femtosecond laser-assisted lenticule intrastromal keratoplasty (LIKE) performed into a pocket (SMI-LIKE) or under a flap (FS-LIKE). Eye Vis (Lond) 2023; 10:23. [PMID: 37122005 PMCID: PMC10150533 DOI: 10.1186/s40662-023-00337-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 03/16/2023] [Indexed: 05/02/2023]
Abstract
BACKGROUND To compare the changes in posterior corneal surface after small-incision lenticule intrastromal keratoplasty (SMI-LIKE) and femtosecond laser-assisted lenticule intrastromal keratoplasty (FS-LIKE) for hyperopia correction. METHODS In this prospective comparative randomized study, 23 eyes with hyperopia were recruited. Eyes were categorized into two groups-SMI-LIKE group (11 eyes) and FS-LIKE group (12 eyes). Lenticules from myopia small incision lenticule extraction were implanted into a pocket (SMI-LIKE group) or at a depth of 100 µm under a flap (FS-LIKE group). Posterior corneal elevations in the center, mid-periphery, and periphery, as well as mean keratometry of the posterior corneal surface (Kmb) were measured using a Pentacam over a three-month follow-up. RESULTS All surgeries were completed successfully and no complications occurred. At one day postoperatively, there was a slight backward change with SMI-LIKE and a forward change with FS-LIKE in the central region of the posterior corneal elevation. Conversely, the peripheral area showed forward displacement in SMI-LIKE and an apparent backward change in FS-LIKE. The mid-peripheral regions manifested a backward change after the procedure throughout the entire follow-up in both groups. Kmb exhibited flattening at one month postoperatively and subsequently returned to its original level at three months after SMI-LIKE while in FS-LIKE, Kmb steepened after lenticule implantation with a significant change noted at one day postoperatively (P = 0.001). CONCLUSIONS Posterior corneal surface after SMI-LIKE and FS-LIKE exhibited different change patterns in various corneal regions, with the most prominent change occurring at one day postoperatively during the three-month follow-up. TRIAL REGISTRATION Chinese Clinical Trial Registry: ChiCTR-ONC-16008300. Registered on Apr 18th, 2016. http://www.chictr.org.cn/edit.aspx?pid=14090&htm=4.
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Affiliation(s)
- Shengtao Liu
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Lanhui Yu
- Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Yu Zhao
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China.
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital of Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Fudan University, Shanghai, China.
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, China.
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Li H, Zhang J, Shao T, Wang H, Liu S, Long K. Two-year stability of posterior corneal surface after transepithelial photorefractive keratectomy with a residual stromal thickness less than 350 μm. Graefes Arch Clin Exp Ophthalmol 2023; 261:857-865. [PMID: 36138148 DOI: 10.1007/s00417-022-05814-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/16/2022] [Accepted: 08/19/2022] [Indexed: 11/04/2022] Open
Abstract
PURPOSE This study aimed to investigate the stability of posterior corneal surface 2 years after transepithelial photorefractive keratectomy (TPRK) in patients with a residual stromal thickness less than 350 μm. METHODS In total, 408 eyes of 212 patients (160 women, 52 men) who underwent TPRK were enrolled in this retrospective study. All surgeries were performed in the Amaris 750S excimer laser platform with smart pulse technology. The posterior corneal elevation, anterior chamber depth, Q value, and curvature were measured using Pentacam preoperatively and postoperatively. All patients were followed up for 2 years. The relationship between percent tissue altered (PTA), age, and changes in posterior corneal surface was analyzed. RESULTS The mean preoperative spherical equivalent was - 6.80 ± 1.18 D (range: - 9.00 to - 2.63 D). The mean residual stromal thickness was 336.46 ± 7.25 μm (range: 310-348 μm). The mean PTA was 30.93 ± 2.03% (range: 24.29-35.28%). At 2 years after surgery, the elevation of six points in the central area decreased by 1.91 ± 2.97 μm, 2.98 ± 3.23 μm, 1.17 ± 3.85 μm, 1.70 ± 2.88 μm, 1.36 ± 3.19 μm, and 1.65 ± 3.18 μm, compared with the preoperative value (P < 0.05). The elevation of three points in the peripheral area increased by 1.87 ± 6.34 μm, 0.68 ± 6.00 μm, and 0.95 ± 5.50 μm (P < 0.05). There was no significant linear relationship between PTA, age, and changes in posterior corneal surface, anterior chamber depth, and K2 (all P > 0.05). CONCLUSION Within 2 years after TPRK, the posterior corneal surface remained stable in patients with a residual stromal thickness between 310 and 350 μm. There was no sign of iatrogenic ectasia during the follow-up period.
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Affiliation(s)
- Hua Li
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China
| | - Jiafan Zhang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China
| | - Ting Shao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China
| | - Huifeng Wang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China
| | - Sai Liu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China
| | - Keli Long
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Qingdao Eye Hospital of Shandong First Medical University, Eye Institute of Shandong First Medical University, Qingdao, 266071, Shandong Province, China.
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Li N, Chen T, Tian G, Lin Y, Meng Y, Gao H, Liu M. Changes in aberrations and biomechanics after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) in eyes with high astigmatism: a retrospective case control study. BMC Ophthalmol 2023; 23:62. [PMID: 36782180 PMCID: PMC9923895 DOI: 10.1186/s12886-023-02809-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/06/2023] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND To compare the 6-month changes in aberration and biomechanics after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for high astigmatism. METHODS In this retrospective case control study, 47 eyes with high astigmatism (≥ 2.5 D, HA group) and 47 eyes with low astigmatism (≤ 1.0 D, LA group) underwent FS-LASIK. Preoperative and follow-up examinations included visual outcomes, higher order aberrations (HOAs) and biomechanics. Biomechanical parameters include a deformation amplitude ratio of 2 mm (DA ratio 2 mm), integrated inverse radius (IIR), stiffness parameter at first applanation (SP-A1), and ambrosio relational thickness through the horizontal meridian (ARTh). RESULTS Six months postoperatively, there was no significant difference in the efficacy and safety index (both P > 0.05) between the two groups, but the cylinder was higher in the HA group. The HOAs increased significantly after surgery in both groups (all P < 0.05). Six months postoperatively, the changes in spherical aberration and HOAs were larger in the HA group (both P < 0.005), but there was no significant difference between the changes in coma (P > 0.05). Significant decreases in SP-A1 and ARTh and significant increases in the IIR and DA ratio of 2 mm (all P < 0.05) were observed after surgery in both groups. The changes in the DA ratio 2 mm, IIR, SP-A1, and ARTh were not significantly different between the groups. CONCLUSION FS-LASIK had relative comparable efficacy and safety in correcting high and low myopic astigmatism, with higher astigmatic under-correction in eyes with high astigmatism. High astigmatism in eyes after FS-LASIK could introduce larger corneal aberrations, but the impact on corneal stiffness was the same as that in eyes with low astigmatism.
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Affiliation(s)
- Na Li
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Tong Chen
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Ge Tian
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Yue Lin
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Yuan Meng
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Hua Gao
- grid.490473.dEye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021 Jinan, China ,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021 Jinan, China ,grid.410638.80000 0000 8910 6733School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021 Jinan, China
| | - Mingna Liu
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), 372 Jingsi Road, 250021, Jinan, China. .,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, 372 Jingsi Road, 250021, Jinan, China. .,School of Ophthalmology, Shandong First Medical University, 372 Jingsi Road, 250021, Jinan, China.
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Yang L, Liu S, Zhou X, Zhao Y. Correlation between the ablation ratio and posterior corneal stability after small incision lenticule extraction for high myopia. Graefes Arch Clin Exp Ophthalmol 2023:10.1007/s00417-023-05979-5. [PMID: 36662234 DOI: 10.1007/s00417-023-05979-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/06/2022] [Accepted: 01/09/2023] [Indexed: 01/21/2023] Open
Abstract
PURPOSE The aim of this study is to investigate changes in posterior corneal elevation and their correlations with the ablation ratio 3 years after small incision lenticule extraction (SMILE) for high myopia. METHODS Eighty eyes underwent SMILE were enrolled in this study. Eyes were classified into two groups based on the ablation ratio (AR, lenticule thickness from SMILE machine/thinnest corneal thickness): group A (< 25%, 40 eyes) and group B (≥ 25%, 40 eyes). Pentacam was used to measure the posterior corneal elevation at the central point, thinnest point, and posterior maximum elevation (PME) and the mean posterior elevation in the central 2-mm area (MPE-2 mm), 4-mm area, and 6-mm area at the 3-year follow-up. RESULTS More than 85% of the eyes had an AR of less than 27%, and no cases of iatrogenic keratectasia developed. In both groups, for central region, posterior elevation decreased implying backward displacement; for peripheral region, it increased indicating forward trend. There was no significant difference in changes in all determined parameters between the two groups (P ≥ 0.07). Moreover, no significant correlation was noted between AR and posterior elevation changes. In group A, decreasing changes in PME (r = - 0.42, P = 0.01) and MPE-2 mm (r = 0.40, P = 0.01) demonstrated negative correlations with residual bed thickness. CONCLUSION Region-dependent changes were demonstrated in the eyes that underwent SMILE. The central area showed a subtly declining posterior elevation, and the peripheral area showed a slightly increasing elevation. The limited ablation ratio had no impact on the changes in posterior corneal elevation.
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Affiliation(s)
- Liyuan Yang
- Department of Ophthalmology, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Shengtao Liu
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, 83 Fenyang Road, Shanghai, 200031, People's Republic of China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, 83 Fenyang Road, Shanghai, 200031, People's Republic of China. .,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China. .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
| | - Yu Zhao
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, 83 Fenyang Road, Shanghai, 200031, People's Republic of China. .,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China. .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China.
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Cao H, Zhang L, Liang S, Chen X, Jhanji V, Wang Y. Predictive factors of posterior corneal shift after small incision lenticule extraction: a 5-year follow-up study. Acta Ophthalmol 2022; 100:e1431-e1438. [PMID: 35488809 DOI: 10.1111/aos.15166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 04/01/2022] [Accepted: 04/18/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE The aim of this study was to determine risk factors affecting changes in posterior corneal elevation (PCE) and predict the 5-year stability after small incision lenticule extraction (SMILE). METHODS This retrospective, longitudinal study enrolled 161 patients post-SMILE. The PCE values were measured at the apex, thinnest, maximal and 24 other prespecified preoperative points and at 6 months, 1 year and 5 years postoperatively. RESULTS Posterior corneas exhibited time-dependent, region-dependent and angle-dependent changes. For every dioptre increase in the absolute preoperative spherical equivalent (SE), 10-μm decrease in the central corneal thickness (CCT), 10-μm increase in the maximum lenticule thickness (MLT), 10-μm decrease in the residual bed thickness (RBT), 10% increase in the percentage ablation depth (PAD, MLT divided by CCT) and 10% decrease in the percentage stromal bed thickness (PSBT, RBT divided by CCT), PCE exhibited average forward displacements of 0.2-0.4, 0.2-0.7, 0.1-0.2, 0.1-0.3, 0.6-1.0 and 0.5-1.1 μm, respectively (p < 0.05). PSBT was the variable with the highest accuracy in predicting 5-year stability of posterior corneas (area under curve = 0.75). The cut-off values of SE, CCT, MLT, RBT, PAD and PSBT for increased PCE were -8.00 to -8.31 D, 481.0-498.5 μm, 139.5-144.5 μm, 255.5-263.5 μm, 26.9-28.3% and 48.9-52.6%, respectively. CONCLUSION Eyes with thinner corneas, higher myopia requiring greater MLT and lower RBT exhibited greater predispositions towards posterior protrusion. The thresholds for preventing forward posterior corneal displacement were 26.9-28.3% for PAD and 48.9-52.6% for PSBT. Prediction of posterior corneal stability is useful for assessing surgical risks post-SMILE.
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Affiliation(s)
- Huazheng Cao
- Clinical College of Ophthalmology Tianjin Medical University Tianjin China
| | - Lin Zhang
- Clinical College of Ophthalmology Tianjin Medical University Tianjin China
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute Nankai University Affiliated Eye Hospital Tianjin China
| | - Shuang Liang
- Clinical College of Ophthalmology Tianjin Medical University Tianjin China
| | - Xuan Chen
- Clinical College of Ophthalmology Tianjin Medical University Tianjin China
| | - Vishal Jhanji
- Department of Ophthalmology University of Pittsburgh School of Medicine Pittsburgh PA USA
| | - Yan Wang
- Clinical College of Ophthalmology Tianjin Medical University Tianjin China
- Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute Nankai University Affiliated Eye Hospital Tianjin China
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