scholarly journals Vector Analysis of High Astigmatism (≥2.0 Diopters) Correction after Small-Incision Lenticule Extraction with Stringent Head Positioning and Femtosecond Laser-Assisted Laser in Situ Keratomileusis with Compensation of Cyclotorsion

2021 ◽  
Author(s):  
Jihong Zhou ◽  
Wei Gu ◽  
Yan Gao ◽  
Guoli He ◽  
Fengju Zhang
Keyword(s):  
Vector Analysis ◽  
Laser In Situ Keratomileusis ◽  
Small Incision Lenticule Extraction ◽  
Head Positioning ◽  
Significant Difference ◽  
Induced Astigmatism ◽  
Lenticule Extraction ◽  
Myopic Astigmatism ◽  
High Myopic Astigmatism

Abstract PURPOSE： To compare the astigmatic correction by vector analysis in the high myopic astigmatism between femtosecond laser-assisted laser in situ keratomileusis with compensation of cyclotorsion (FS-LASIK) and small-incision lenticule extraction(SMILE) with stringent head positioning.SETTING: Beijing Aier-Intech Eye Hospital, Beijing, China.DESIGN: Retrospective case series. METHOD: Patients who had correction of myopic astigmatism of 2 diopters (D) or more had either FS-LASIK with compensation of cyclotorsion or SMILE with stringently control the head position were included. Results of vision and refraction were analyzed and compared between groups with the right eye.RESULT: The study enrolled 94 patients (41eye in the FS-LASIK with compensation of cyclotorsion and 53 eyes in SMILE with stringently control the head position). The mean preoperative manifest cylinder was -2.65±0.77D in FS-LASIK and 2.51±0.56D in SMILE group. (P=0.302). At 12-month, there was no significant difference between the two groups in uncorrected distance visual acuity (UDVA, P = 0.274) and postoperative spherical equivalent (P=0.107). 46.3% and 24.5% of eyes were within 0.25D post-op cylinder, 78% and 66% of eyes were within 0.5 D post-op cylinder for FS-LASIK group and SMILE group, respectively (P=0.027, P = 0.202). Vector analysis showed comparable target-induced astigmatism (TIA, P=0.114), surgically induced astigmatism vector (SIA, P=0.057), difference vector (DV, P=0.069) and the angle of error (AE, P=0 .213) between groups. Index of success (IOS) was 0.18 in the FS-LASIK and 0.24 in the SMILE (P=0.024), and significant difference for two groups.CONCLUSION: FS-LASIK with compensation of cyclotorsion had favorable correction in high myopic astigmatism (≥2.0 diopters) compared to SMILE with stringent head positioning at 12-month.

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.

Vector analysis of small incision lenticule extraction and toric implantable collamer lens implantation for astigmatism correction

2020 ◽  
pp. 112067212093060
Author(s):  
Ting Wan ◽  
Houfa Yin ◽  
Zhiyi Wu ◽  
Yabo Yang
Keyword(s):  
Vector Analysis ◽  
Small Incision Lenticule Extraction ◽  
Implantable Collamer Lens ◽  
Small Incision ◽  
Astigmatism Correction ◽  
Induced Astigmatism ◽  
Lenticule Extraction ◽  
The Difference ◽  
Surgically Induced ◽  
Myopic Astigmatism

Objectives: To compare the efficacy of small incision lenticule extraction (SMILE) and toric implantable collamer lens (TICL) implantation for myopic astigmatism correction using vector analysis. Methods: In this retrospective study, 171 eyes of 171 patients with cylinder ⩾1.0 diopters (D) were recruited, with 97 eyes underwent SMILE and 74 eyes underwent TICL implantation. Preoperative and 3-months postoperative visual and refractive results were examined. The astigmatism correction, graded by the degree of preoperative cylinder was compared between two groups using vector analysis. Results: At 3-months postoperatively, the residual cylinder was −0.10 ± 0.21 D in the SMILE group and −0.30 ± 0.32 D in the TCL group ( p < 0.05). Furthermore, 98% and 85% of eyes had the cylinder within ±0.5 D in the SMILE and TICL group, respectively. The vector analysis revealed similar target induced astigmatism vector in two groups. However, the difference vector, magnitude of error, angle of error, and index of success were significantly higher (0.30 ± 0.32 D, −0.19 ± 0.25, −2° ± 4.35°, and 0.16 ± 0.17 D, respectively) in the TICL group than the values in the SMILE group (0.10 ± 0.21 D, −0.05 ± 0.20, −0.03° ± 2.13°, and 0.05 ± 0.12, respectively), regardless of the degree of preoperative cylinder (all p < 0.05). For preoperative cylinder < 2.0 D, surgically induced astigmatism vector and correction index in the SMILE group were higher than those in the TICL group ( p < 0.05). Conclusion: Both SMILE and TICL implantation are effective techniques for myopic astigmatism correction. However, the accuracy of correction in the magnitude and axis of astigmatism with SMILE was better than that achieved with TICL implantation.

scholarly journals Comparison of clinical outcomes of implantable collamer lens versus femtosecondlaser in situ keratomileusis and small incision lenticule extraction for moderate-to-high myopia and myopic astigmatism correction

2021 ◽  
Vol 17 (4) ◽  
pp. 400-415
Author(s):  
Yen Hai Tran ◽  
Huy Dinh Minh Tran ◽  
Ly Thi-Hai Tran ◽  
Dung Thi Mong Nguyen ◽  
Chuong Nguyen Thao Le ◽  
...  
Keyword(s):  
High Myopia ◽  
Linear Models ◽  
Laser In Situ Keratomileusis ◽  
Small Incision Lenticule Extraction ◽  
Implantable Collamer Lens ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Safety Indices ◽  
Myopic Astigmatism

Purpose: To compare safety, efficacy, stability, and predictability of implantable collamer lens (ICL) with femtosecond-laser in situ keratomileusis (FS-LASIK) or small incision lenticule extraction (SMILE) for the correction of moderate-to-high myopia/myopic astigmatism. Study design: We retrospectively collected data from patients with moderate-to-high myopia/myopic astigmatism (spherical equivalent [SE] ≥ −3.00 diopters [D]) who underwent ICL (48 eyes), FS-LASIK (36 eyes), or SMILE (86 eyes) at Hai Yen Eye Center from October 2016 to February 2018. Materials and methods: The Wilcoxon Mann-Whitney U test was used to compare pre- and postoperative patients’ characteristics of ICL with SMILE or FS-LASIK. Generalized linear models with unstructured correlation matrix and robust standard errors were used to analyze efficacy and safety indices; logistic regression was used for cylinder predictability. Results: After controlling for age, preoperative SE, and preoperative corrected distance visual acuity (pCDVA), SMILE had significantly lower safety indices (Coefficient = −0.04, 95% CI = −0.07–−0.01) and efficacy indices (Coefficient = −0.10, 95% CI = −0.20–−0.01) than did ICL, while FS-LASIK was not significantly different from ICL (Coefficient = −0.02, 95% CI = −0.06–0.02 and Coefficient = −0.01, 95% CI= −0.10–0.09, respectively). ICL SEswere stable over 12 months after surgery. However, in FS-LASIK and SMILE, SEs significantly decreased at 12 months compared with 6 months after surgery. The percentage of eyes that underwent FS-LASIK and had target SEs within ±0.5 D at 12 months was significantly lower than those that underwent ICL (OR = 0.14, 95% CI = 0.02–0.85), after controlling for age, preoperative SE, and pCDVA. Conclusion: For the correction of moderate-to-high myopia/myopic astigmatism, ICL seems to perform better than SMILE and FS-LASIK.

scholarly journals Three-year outcomes of small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia and myopic astigmatism

2018 ◽  
Vol 103 (4) ◽  
pp. 565-568 ◽  
Author(s):  
Tian Han ◽  
Ye Xu ◽  
Xiao Han ◽  
Li Zeng ◽  
Jianmin Shang ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Laser In Situ Keratomileusis ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Myopic Astigmatism

AimsTo compare long-term clinical outcomes following small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) for myopia and myopic astigmatism correction.MethodsIn this retrospective study, we enrolled a total of 101 patients (101 eyes) who underwent SMILE or FS-LASIK 3 years prior. Measured parameters included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction and corneal wavefront aberrations.ResultsNo significant differences in patient characteristics were found between the two groups. At the 3-year follow-up, UDVA was better than or equal to 20/20 in 90% and 85% (p=0.540) of the eyes; the efficacy indexes were 1.05±0.19 and 1.01±0.21 in the SMILE and FS-LASIK groups, respectively (p=0.352). Safety indexes were 1.19±0.17 and 1.15±0.20 in the SMILE and FS-LASIK groups, respectively (p=0.307). Eighty per cent and 65% of eyes were within ±0.50 D of the attempted spherical equivalent correction after SMILE and FS-LASIK, respectively (p=0.164). Vector analysis revealed no significant differences in astigmatic correction between the two groups (p>0.05). Surgically induced spherical aberration was higher in the FS-LASIK group than in the SMILE group (p<0.001).ConclusionLong-term follow-up analysis suggested that both SMILE and FS-LASIK were safe and equally effective for myopic and astigmatic correction.

Comparison between Small Incision Lenticule Extraction and Wavefront-Guided Femtosecond Laser-Assisted In Situ Keratomileusis in Correction of Myopic Astigmatism

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Khaled M Al-Boraie ◽  
Tamer M. El Mekkawy ◽  
Mohammad G Metwally ◽  
Ashraf H Soliman
Keyword(s):  
Visual Acuity ◽  
Higher Order ◽  
Small Incision Lenticule Extraction ◽  
Higher Order Aberrations ◽  
Significant Difference ◽  
Manifest Refraction ◽  
Lenticule Extraction ◽  
The Mean ◽  
Myopic Astigmatism

Abstract Aim of the Work To compare visual acuity, refractive and topographic outcome between small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG FS-LASIK) in patients with myopic astigmatism. Patients and methods This prospective, non-randomized, comparative clinical study included 60 eyes of 30 patients with simple or compound myopic astigmatism presenting for refractive error correction. Femtosecond assisted LASIK group included 30 eyes and SMILE group included 30 eyes. The following tests were done for all patients preoperatively and at 3 months postoperatively: full ophthalmological examination, manifest refraction, UDVA, CDVA, corneal topography using combined schimflug and placcido disc imaging namely Pentacam. (Oculus Inc.) and wavefront analysis using ATLAS 9000 (Carl Zeiss Meditec) Main Outcome Measures: Uncorrected distance visual acuity (UDVA), corrected disctance visual acuity (CDVA), manifest refraction, Efficacy, safety, predictability, corneal higher order aberrations. Results At 3 months, the mean manifest refractive spherical equivalent (MRSE) in SMILE group was -0.33 ± 0.34 D and the mean MRSE in FS- LASIK group was 0.23 ± 0.35 D and there was a statistically significant difference between both groups (P &lt; 0.05). mean postoperative cylinder was -0.56 ± 0.28 D in SMILE group and -0.53 ± 0.38D in FS-LASIK with statistically significant difference ( P = 0.254 ) 93% and 93% of eyes in the SMILE and FS-LASIK groups were within ± 0.5 D; 96.67% and 100% of eyes in the SMILE and FS-LASIK groups, respectively, were within ± 1 D. There were 86.66% of treated eyes in the SMILE group, and 93.33% treated eyes in the FS-LASIK group that had 20/25 or better UDVA. Regarding safety, the CDVA in the SMILE group, 20 eyes (66.67%) showed no change, 8 eyes (27%) gained 1 line, 2 eyes (7%) lost 1 line, and no eyes lost more than 1 line. whereas in the FS-LASIK group, 27 eyes (90%) exhibited no change, 2 eyes (6.66%) gained 1 line, 1 eye (3.33%) lost 1 line, and no eyes lost more than 1 line and There was no statistically significant difference between both groups (P = 0. 554 ). Regarding corneal asphericity, both procedures increased Q-value with no statistically significant difference between both groups (P = 0. 052). Regarding corneal higher order aberrations, both procedures significantly increased total corneal aberrations but there was no statistically significant difference in the change in RMS of total corneal higher order aberration (P = 0.434) .but SMILE increased RMS of coma aberration significantly more than FS-LASIK (P = 0. 029). Conclusion both SMILE and FS-LASIK procedures have shown excellent efficacy, safety, and predictability for the correction of myopia and myopic astigmatism. SMILE was closer to emmetropia regarding sphere and spherical equivalent, However, astigmatic undercorrection was noted after both surgeries with increased astigmatism. Both procedures increased the total corneal higher order aberrations with no statistically significant difference between both groups. A higher vertical coma was found in SMILE than WFG FS-LASIK.

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