Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Diameter and Spherical Aberration Induction

2017 ◽  
Vol 33 (6) ◽  
pp. 370-376 ◽  
Author(s):  
Dan Z. Reinstein ◽  
Kishore R. Pradhan ◽  
Glenn I. Carp ◽  
Timothy J. Archer ◽  
Marine Gobbe ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Small Incision Lenticule Extraction ◽  
Zone Diameter ◽  
Small Incision ◽  
Optical Zone ◽  
Lenticule Extraction

scholarly journals SMILE and Wavefront-Guided LASIK Out-Compete Other Refractive Surgeries in Ameliorating the Induction of High-Order Aberrations in Anterior Corneal Surface

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Min-jie Ye ◽  
Cai-yuan Liu ◽  
Rong-feng Liao ◽  
Zheng-yu Gu ◽  
Bing-ying Zhao ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Laser In Situ Keratomileusis ◽  
Small Incision Lenticule Extraction ◽  
Corneal Surface ◽  
Small Incision ◽  
Significant Difference ◽  
Lenticule Extraction ◽  
A Prospective Study ◽  
High Order Aberrations

Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE).Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes underwent FS-LASIK, and 170 eyes underwent SMILE surgery. HOAs were measured with Pentacam device preoperatively and 6 months after surgery. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs, spherical aberration (SA), horizontal coma, and vertical coma over 6 mm diameter central corneal zone.Results. Six months postoperatively, all procedures result in increase of anterior corneal total HOAs and SA. There were no significant differences in the induced HOAs between LASIK and FS-LASIK, while SMILE induced fewer total HOAs and SA compared with LASIK and FS-LASIK. Similarly, WF-LASIK also induced less total HOAs than LASIK and FS-LASIK, but only fewer SA than FS-LASIK (P<0.05). No significant difference could be detected in the induced total HOAs and SA between SMILE and WF-LASIK, whereas SMILE induced more horizontal coma and vertical coma compared with WF-LASIK (P<0.05).Conclusion. FS-LASIK and LASIK induced comparable anterior corneal HOAs. Compared to LASIK and FS-LASIK, both SMILE and WF-LASIK showed advantages in inducing less total HOAs. In addition, SMILE also possesses better ability to reduce the induction of SA in comparison with LASIK and FS-LASIK. However, SMILE induced more horizontal coma and vertical coma compared with WF-LASIK, indicating that the centration of SMILE procedure is probably less precise than WF-LASIK.

scholarly journals Small Incision Lenticule Extraction (SMILE) for Moderate and High Myopia: Seven-Year Outcomes of Refraction, Corneal tomography and Wavefront Aberrations

2019 ◽  
Author(s):  
Fei Xia ◽  
Yang Shen ◽  
Tian Han ◽  
Jing Zhao ◽  
Hai-Peng Xu ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Spherical Aberration ◽  
Case Series ◽  
Final Visit ◽  
Small Incision Lenticule Extraction ◽  
Wavefront Aberrations ◽  
Distance Visual Acuity ◽  
Small Incision ◽  
Uncorrected Distance Visual Acuity ◽  
Lenticule Extraction

Abstract Background To investigate the long-term corneal stability and wavefront aberrations after small incision lenticule extraction (SMILE) for moderate and high myopia.Methods Prospective, non-consecutive case series. A total of 26 patients (42 eyes) who underwent SMILE from May 2010 to March 2013 at the Fudan University Eye and ENT Hospital (Shanghai, China) were enrolled. The periods of follow-up were 1 month, 1 year, 5 years and 7 years after surgery. The routine eye examinations included uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), manifest refraction and corneal topography.Results All surgeries were executed without any complications. At the final visit, a UDVA of 20/20 or better was achieved in 42 eyes (100%), 21 eyes (50%) exhibited no change in CDVA. 15 eyes (36%) gained one line, 6 eyes (14%) gained two lines, and no eyes lost CDVA lines. 93% and 100% of eyes were within ±0.5 D and ±1.00 D of the target refraction, respectively. A mean refractive regression of -0.17 D was observed between 1 month and 7 years postoperatively. Mean corneal front curvature (KMF) were significantly increased between pre- and post-SMILE surgery (P<0.0001). Higher-order aberrations (HOAs) and vertical coma were significantly increased after SMILE compared to those measured before surgery (all P<0.001). There were no significant differences in horizontal coma, trefoil and spherical aberration between pre- and post-SMILE surgery (all P>0.05).Conclusions SMILE is an effective, safe and stable procedure for myopia correction, with relatively constant corneal stability and wavefront aberrations.

scholarly journals Early visual quality outcomes after small-incision lenticule extraction surgery for correcting high myopic astigmatism

2020 ◽  
Author(s):  
Xiangtao Hou ◽  
Xiaoying Wu ◽  
Kaixuan Du ◽  
Dan Wen ◽  
Shengfa Hu ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Optical Quality ◽  
Small Incision Lenticule Extraction ◽  
Quality Outcomes ◽  
Vector Method ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Axis Rotation ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Abstract Background: To evaluate early optical quality outcomes after small-incision lenticule extraction (SMILE) surgery for correcting high myopic astigmatism.Methods: This retrospective study enrolled 55 eyes from 37 patients who had preoperative myopic astigmatism of ≥2.00 diopters (D) who had been treated with SMILE surgery. Preoperatively, the mean cylinder was -2.41 ± 0.54 D (range, -2.00 D to -4.50 D). The preoperative and postoperative visual outcomes, refraction, and higher-order aberration (HOA) at 1 and 3 months were compared. Refractive astigmatism changes were analyzed by the Alpins vector method.Results: Three months after SMILE surgery, the average cylinder was -0.14 ± 0.31 D, and the average astigmatism vector was -0.09 D × 6.34°. The angle of error (AofE) was limited to within ±10°, and the magnitude of error was limited to within ±1.0 D in all patients. The correction index (CI) was 0.98 ± 0.07, the index of success (IOS) was 0.08 ± 0.13, and the flattening index (FI) was 0.97 ± 0.07. Significant positive correlations were found between IOS and |AofE| (P = 0.000); negative correlations were found between FI and |AofE| (P = 0.000). The postoperative total HOA, spherical aberration, vertical coma aberration, and trefoil 30° were increased significantly compared with preoperative measurements, and the increase in HOA was closely related to preoperative astigmatism (P < 0.05).Conclusions: SMILE has preferable outcomes for correcting high myopic astigmatism. Axis rotation during the surgery might influence the undercorrection of astigmatism. The increase of HOA after surgery is related to preoperative astigmatism.

scholarly journals Early visual quality outcomes after small-incision lenticule extraction surgery for correcting high myopic astigmatism

2021 ◽  
Author(s):  
Xiangtao Hou ◽  
Kaixuan Du ◽  
Dan Wen ◽  
Shengfa Hu ◽  
Tu Hu ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Optical Quality ◽  
Small Incision Lenticule Extraction ◽  
Quality Outcomes ◽  
Vector Method ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Axis Rotation ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Abstract Background: To evaluate early optical quality outcomes after small-incision lenticule extraction (SMILE) surgery for correcting high myopic astigmatism.Methods: This retrospective study enrolled 55 eyes from 37 patients who had preoperative myopic astigmatism of ≥2.00 diopters (D) who had been treated with SMILE surgery. Preoperatively, the mean cylinder was -2.41 ± 0.54 D (range, -2.00 D to -4.50 D). The preoperative and postoperative visual outcomes, refraction, and higher-order aberration (HOA) at 1 and 3 months were compared. Refractive astigmatism changes were analyzed by the Alpins vector method.Results: Three months after SMILE surgery, the average cylinder was -0.14 ± 0.31 D, and the average astigmatism vector was -0.09 D × 6.34°. The angle of error (AofE) was limited to within ±10°, and the magnitude of error was limited to within ±1.0 D in all patients. The correction index (CI) was 0.98 ± 0.07, the index of success (IOS) was 0.08 ± 0.13, and the flattening index (FI) was 0.97 ± 0.07. Significant positive correlations were found between IOS and |AofE| (P = 0.000); negative correlations were found between FI and |AofE| (P = 0.000). The postoperative total HOA, spherical aberration, vertical coma aberration, and trefoil 30° were increased significantly compared with preoperative measurements, and the increase in HOA was closely related to preoperative astigmatism (P < 0.05).Conclusions: SMILE has preferable outcomes for correcting high myopic astigmatism. Axis rotation during the surgery might influence the undercorrection of astigmatism. The increase of HOA after surgery is related to preoperative astigmatism.

scholarly journals Clinical outcomes after small incision lenticule extraction versus femtosecond laser-assisted LASIK for high myopia: a Meta-analysis.

2020 ◽  
Author(s):  
Yanyan Fu ◽  
Yewei Yin ◽  
Yang Zhao ◽  
Aiqun Xiang ◽  
Ying Lu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Clinical Outcomes ◽  
High Myopia ◽  
Spherical Aberration ◽  
Meta Analysis ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Significant Difference ◽  
Lenticule Extraction

Abstract Background To compare postoperative clinical outcomes of high myopia after being treated by Small incision lenticule extraction (SMILE) and femtosecond laser in situ keratomileusis (FS-LASIK).Methods Comprehensive studies were conducted on the PubMed, MEDLINE, EMBASE, the Cochrane Library, and Chinese databases.Trials meeting the selection criteria were quality appraised, and the data were extracted by 2 independent authors, and the RevMan 5.3 version software were used in analyzing.Result Ten studies involving 637 patients (1093 eyes;575 eyes in the SMILE group and 518 eyes in the FS-LASIK group) were included in this meta-analysis. Pooled result revealed no significant differences in the following outcomes: the logMAR values of postoperative UDVA(WMD = -0.01, 95% CI: -0.02,0.00, I²=0%, P = 0.10 at postoperative 1mo; WMD =-0.01, 95% CI: -0.00 to 0.01, I²=0%,P = 0.35 at postoperative 3mo; WMD = -0.01, 95% CI:-0.02 to 0.01, I²=17%,P = 0.26 at long term), the logMAR values of postoperative CDVA(WMD = -0.02, 95% CI, -0.04 to 0.00, I²=0%, P = 0.11),and the postoperative mean refractive SE (WMD =0.02, 95% CI:0.04 to 0.08, I²=29%, P=0.60) . In the long-term observation, postoperative tHOA (WMD =-0.10, 95% CI:-0.13 to -0.07, I²=15%, P<0.00001)and postoperative spherical aberration (WMD =-0.13, 95% CI:--0.17 to -0.09, I²=38%, P<0.00001) were found to be less in the SMILE group compared with the FS-LASIK group, but no significant difference was found in postoperative coma (WMD =-0.02, 95% CI:-0.04 to 0.00, I²=98%, P=0.40).We also found greater PCE change post FS-LASIK than SMILE at long term follow-ups(WMD =-0.69, 95% CI:-1.36 to -0.01, I²=0%, P<0.05, however, there was no significant difference between the two groups at 3- or 6- months.(WMD =-0.19, 95% CI:-0.41 to 0.03, I²=31%, P=0.09;WMD =-0.20, 95% CI:-0.50 to 0.10, I²=17%, P=0.20)Conclusion For patients with high myopia, both SMILE and FS-LASIK are safe and efficacious. However, SMILE induced less tHOA and spherical aberration compared with FS-LASIK. Besides, FS-LASIK showed a greater increase in PCE than SMILE only at long term follow-ups. It remains to be seen whether the patients can get a better visual quality after SMILE and more comparative studies focused on high myopia is necessary.

scholarly journals Long-term Visual Quality after Small Incision Lenticule Extraction (SMILE) and Laser Epithelial Keratomileusis (LASEK) for Low Myopia

2021 ◽  
Author(s):  
Mengjun Fu ◽  
Meiyan Li ◽  
Ruoyan Wei ◽  
Chuanwei Zhang ◽  
Yangyi Huang ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Visual Quality ◽  
Small Incision Lenticule Extraction ◽  
Wavefront Aberrations ◽  
Small Incision ◽  
Patient Reported ◽  
Manifest Refraction ◽  
Lenticule Extraction ◽  
Efficacy Index

Abstract Background: Few studies have reported the visual outcomes of small-incision lenticule extraction (SMILE) and laser-assisted epithelial keratomileusis (LASEK) for myopia correction. This study aims to compare the visual quality and corneal wavefront aberrations after SMILE and LASEK for low-myopia correction.Methods: In this prospective study, we included 29 eyes of 29 patients who received SMILE, and 23 eyes of 23 patients who received LASEK between June 2018 and January 2019. The following measurements were assessed: uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, corneal wavefront aberrations, and subjective visual quality. All patients were followed up for two years.Results: All procedures were uneventful. An efficacy index of 1.19 ± 0.17 was established in the SMILE group and 1.23 ± 0.20 in the LASEK group. No eyes lost more than two lines of CDVA. We found that 93% (27/29) of the treated eyes in the SMILE group and 91% (21/23) in the LASEK group had spherical equivalent (SE) within ± 0.25D. The increases in the total corneal spherical aberration and the corneal front spherical aberration were lower in the SMILE group than in the LASEK group (P < 0.01). In contrast, the increases in the total corneal vertical coma and the corneal front vertical coma in the SMILE group were greater than those in the LASEK group (P < 0.01).Conclusion: Both SMILE and LASEK have good safety, stability, and patient-reported satisfaction for low myopia. SMILE induced less corneal spherical aberration but greater vertical coma than LASEK.

scholarly journals Early visual quality outcomes after small-incision lenticule extraction surgery for correcting high myopic astigmatism

2020 ◽  
Author(s):  
Xiangtao Hou ◽  
Dan Wen ◽  
Kaixuan Du ◽  
Shengfa Hu ◽  
Tu Hu ◽  
...  
Keyword(s):  
Spherical Aberration ◽  
Optical Quality ◽  
Small Incision Lenticule Extraction ◽  
Quality Outcomes ◽  
Vector Method ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Axis Rotation ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Abstract Background: To evaluate early optical quality outcomes after small-incision lenticule extraction (SMILE) surgery for correcting high myopic astigmatism.Methods: This retrospective study enrolled 55 eyes from 37 patients who had preoperative myopic astigmatism of ≥2.00 diopters (D) who had been treated with SMILE surgery. Preoperatively, the mean cylinder was -2.41 ± 0.54 D (range, -2.00 D to -4.50 D). The preoperative and postoperative visual outcomes, refraction, and higher-order aberration (HOA) at 1 and 3 months were compared. Refractive astigmatism changes were analyzed by the Alpins vector method.Results: Three months after SMILE surgery, the average cylinder was -0.14 ± 0.31 D, and the average astigmatism vector was -0.09 D × 6.34°. The angle of error (AofE) was limited to within ±10°, and the magnitude of error was limited to within ±1.0 D in all patients. The correction index (CI) was 0.98 ± 0.07, the index of success (IOS) was 0.08 ± 0.13, and the flattening index (FI) was 0.97 ± 0.07. Significant positive correlations were found between IOS and |AofE| (P = 0.000); negative correlations were found between FI and |AofE| (P = 0.000). The postoperative total HOA, spherical aberration, vertical coma aberration, and trefoil 30° were increased significantly compared with preoperative measurements, and the increase in HOA was closely related to preoperative astigmatism (P < 0.05).Conclusions: SMILE has preferable outcomes for correcting high myopic astigmatism. Axis rotation during the surgery might influence the undercorrection of astigmatism. The increase of HOA after surgery is related to preoperative astigmatism.

scholarly journals Impact of Unintended Initial Dissection of the Posterior Plane on Surgery Time During Small Incision Lenticule Extraction Surgery

2021 ◽  
Author(s):  
Ke Zheng ◽  
Yinan Han ◽  
Jing Wang ◽  
Tian Han ◽  
Xingtao Zhou
Keyword(s):  
Early Detection ◽  
Demographic Data ◽  
Preoperative Evaluation ◽  
Operation Time ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Optical Zone ◽  
Lenticule Extraction ◽  
The Impact ◽  
Late Detection

Abstract Background: To study the impact of unintended initial dissection of the posterior plane (UIDPP) on operation time and surgical outcomes during small incision lenticule extraction (SMILE) surgery.Methods: Based on the SMILE procedure video, the operating eyes were assigned to the normal and UIDPP groups according to the presence or absence of UIDPP signals during surgery. The UIDPP group was further separated into early and late detection. Patient's demographic data, preoperative evaluation data, operation time and postoperative outcomes were collected.Results: Sixty-six patients who underwent SMILE were included, with 24 patients with UIDPP (13 in the early detection group and 11 in the late group). The optical zone was smaller (median 6.5 vs. 6.6, P=0.007), and the operation time was longer (median, 189.5 vs. 91.0 s, P<0.001) in the UIDPP group compared with controls. There were significant differences in operation time between the late detection group and early detection group (median, 489.0 vs. 139.0 s, P<0.05) and between the late detection group and normal group (489.0 vs. 91.0 s, P<0.05), while the optical zone was different only between the late detection and normal groups (median, 6.6 vs. 6.5, P<0.05). Conclusion: The occurrence of UIDPP will increase the surgery time of SMILE. Detecting IUDPP earlier could help shorten the operation time.

scholarly journals Comparison of early visual quality in patients with moderate myopia using different optical zones in small incision lenticule extraction (SMILE)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yan Wu ◽  
Zhenping Huang
Keyword(s):  
Visual Acuity ◽  
Night Vision ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Spatial Frequencies ◽  
Significant Difference ◽  
Group A ◽  
Optical Zone ◽  
Lenticule Extraction ◽  
Group B

Abstract Background The early visual qualities of patients with moderate myopia were evaluated after small incision lenticule extraction (SMILE) using different optical zones. Methods In this retrospective case study, 27 cases (51 eyes) were selected, including 10 cases in Group A (19 eyes), 6.6–6.8 mm in the optical zone, 10 cases in Group B (19 eyes), 6.4–6.5 mm in the optical zone, and 7 cases in Group C (13 eyes),6.1–6.3 mm in the optical zone. The following items were examined preoperatively and 1 month postoperatively: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical, cylinder, central corneal thickness (CCT), corneal mean curvature (CMC), total ocular aberrations (TA), total low order aberrations (tLOAs), defocus, astigmatism and total high order aberrations (tHOAs), spherical, coma, trefoil, modulation transfer function (MTF), MTFcutoff, SR, objective scatter index (OSI), point scatter function at 50 and 10% (PSF50%, PSF10%), and contrast visual acuity of 100, 20, and 9% (VA100%, VA20%, and VA9%). We compared the three groups by Kruskal-Wallis test. Wilcoxon signed ranks test was used for each group before and 1 month after surgeries. P< 0.05 was considered statistically significant. Results There was no significant difference in UCVA, BCVA, CCT, cylinder, and CMC in three groups preoperatively and 1 month postoperatively (P> 0.05). Comparison of the aberrations of the three groups showed statistically significant difference only in TA, tLOA, defocus, astigmatism and SA preoperatively, and trefoil 1 month postoperatively(P< 0.05). The postoperative TA, tLOAs, defocus, astigmatism and trefoil of the three groups were lower than those before surgeries (P< 0.05). The postoperative tHOAs of Group B and C was lower than those before surgeries (P< 0.05). The MTF results showed that before surgeries, there were significant differences in three groups (P< 0.05) in spatial frequencies 5~15 cycles per degree (cpd), and no differences in 20~30 cpd(P> 0.05), while no difference were observed in all spatial frequencies postoperatively (P> 0.05). Comparing the preoperative and postoperative MTF values for each group, the results showed that there was a significant difference in Group C at 5~20 cpd after surgeries(P< 0.05). There was no significant difference in MTFcutoff, SR, OSI, PSF50%, PSF10%, VA100%, VA20%, and VA9% in the three groups preoperatively (P> 0.05). One month after surgeries, higher VA9% values were measured for Group C compared to Group A and B (P < 0.05). There was no significant difference in each group before and after surgeries (P> 0.05). Conclusion SMILE could improve the visual qualities of patients with moderate myopia. Reducing the surgical optical zone will only affect night vision slightly.

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