scholarly journals Impact of Treatment Decentration on Higher-Order Aberrations after SMILE

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ying Yu ◽  
Wenwen Zhang ◽  
Xinliang Cheng ◽  
Jianru Cai ◽  
Hui Chen

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.

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Banu Torun Acar ◽  
Suphi Acar

Purpose. To evaluate the effect of cap-lenticule diameter difference (CLDD) on the visual outcome and higher-order aberrations (HOAs) of small-incision lenticule extraction (SMILE). Methods. A total of 132 patients who had bilateral SMILE for myopia or myopic astigmatism were included. The CLDD was 0.4 mm in 54 patients (group 1) and 1.0 mm in 78 patients (group 2). The refractive parameters, uncorrected (UDVA) and corrected distance visual acuity (CDVA), and HOAs were determined preoperatively and during six months follow-up. Results. Group 1 had better CDVA (in logMAR) compared to group 2 at day 1 (−0.07 ± 0.07 versus 0.04 ± 0.07, resp.; p<0.001) and week 1 (−0.07 ± 0.07 versus –0.04 ± 0.07, resp.; p=0.001). The visual acuity improved more in group 1 than in group 2. The UDVA (in logMAR) was 0.07 ± 0.07 and 0.29 ± 0.09 at day 1 (p<0.001) and −0.08 ± 0.07 and −0.06 ± 0.06 at six months (p=0.038) in group 1 and group 2, respectively. Group 1 was associated with significantly less induction of HOAs (0.24 ± 0.08 μm and 0.32 ± 0.26 μm, resp.; p=0.002). Conclusions. In SMILE, 0.4 mm CLDD is associated with better visual outcome and less induction of HOAs than 1.0 mm. Narrow CLDD should be considered in SMILE to increase the visual acuity particularly in the early postoperative period.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Alex L. K. Ng ◽  
Tommy C. Y. Chan ◽  
George P. M. Cheng ◽  
Vishal Jhanji ◽  
Cong Ye ◽  
...  

Background. To compare the early outcome of combined SMILE and collagen crosslinking (SMILE Xtra) with SMILE.Method. Prospective, comparative interventional study of 21 eyes receiving SMILE Xtra using a low energy protocol and 32 control eyes receiving SMILE only. The outcomes were compared at 1, 3, and 6 months postoperatively.Results. Both groups had myopia with spherical equivalent refraction (SEQ) > 4.00 D. The SMILE Xtra group had thinner preoperative central corneal thickness and residual stromal bed thickness (p<0.021). At 6 months, no eyes lost more than 1 line in corrected distance visual acuity. The safety index was0.96±0.06and1.00±0.00in SMILE Xtra and control, respectively (p<0.001). 89% and 94% of eyes were within ±0.50 D of target refraction, respectively, with the mean error in SEQ correction being-0.17±0.26 D for SMILE Xtra and+0.03±0.25 D for control (p=0.021). The efficacy index was0.88±0.13and0.97±0.06, respectively (p=0.005).Conclusion. SMILE Xtra had good overall safety profile and predictability at 6 months. However, when compared with control, the safety index and efficacy index were statistically significantly lower in the early postoperative period.


2017 ◽  
Vol 102 (8) ◽  
pp. 1122-1126 ◽  
Author(s):  
Alex L K Ng ◽  
George P M Cheng ◽  
Victor C P Woo ◽  
Vishal Jhanji ◽  
Tommy C Y Chan

BackgroundWe described a modified ‘hydroexpression’ technique for the lenticule removal during small-incision lenticule extraction (SMILE) surgery and compared the results with conventional forceps method.MethodsThis was a retrospective, comparative study of 50 patients who underwent SMILE surgery by the same surgeon. We compared the 1-week and 3-months postoperative results after SMILE using the hydroexpression technique with the conventional forceps technique. Main outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, refractive accuracy, safety index and efficacy index.ResultsThe baseline characteristics were comparable between both groups. At postoperative 1 week, the safety index in forceps and hydroexpression group was 0.93±0.11 and 0.97±0.10, respectively (P=0.246). At 3 months, they were 1.00±0.06 and 0.99±0.09 (P=0.850). For efficacy indices, at 1 week they were 0.84±0.17 and 0.91±0.17 (P=0.158). At 3 months, they were 0.92±0.13 and 0.94±0.19 (P=0.624). All eyes aimed for a plano target. 96% in forceps group and 90% in hydroexpression group were within ±0.50 dioptre (D) in spherical equivalent refraction (SEQ) correction at postoperative 3 months (P=0.567). The mean errors of SEQ correction were −0.10±0.21 D in forceps group and −0.08±0.30 D in hydroexpression group (P=0.705).ConclusionHydroexpression was simple and safe and had early results comparable to the conventional forceps technique. This technique was particularly useful for cases with more adhesions between lenticule and anterior cap, thin lenticule cases and for the inexperienced SMILE surgeons.


QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Khaled M Al-Boraie ◽  
Tamer M. El Mekkawy ◽  
Mohammad G Metwally ◽  
Ashraf H Soliman

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mohammad Miraftab ◽  
Hassan Hashemi ◽  
Mohammadreza Aghamirsalim ◽  
Shiva Fayyaz ◽  
Soheila Asgari

Abstract Background The refractive surgeries induce corneal higher order aberrations (C-HOAs). In this study, change of C-HOAs after small-incision lenticule extraction (SMILE) compared to femtosecond assisted laser in situ keratomileusis (femto-LASIK), and to photorefractive keratectomy with mitomycin-C (PRK) under photopic and mesopic conditions. Methods In this prospective study, age, gender, and apical corneal thickness (ACT) matched cases with moderate myopia [spherical equivalent (SE) 3.00 to 6.00D) to high myopia (SE > 6.00D)] were enrolled. In addition to visual acuity and refraction, total C-HOA, coma, spherical aberration (SA), and trefoil in the 3- and 6-mm zones were measured before and 3 and 6 months after surgery. Results Overall, 372 moderate myopia cases (124 eyes of 124 individuals in each surgical group) and 171 high myopia cases (57 eyes of 57 individuals in each surgical group) were enrolled. At baseline, the differences in age, gender, ACT, uncorrected and corrected visual acuity, and SE were not statistically significant between subgroups of surgical methods within each myopia group (all P > 0.05). At 12 months, in the moderate myopia group, there was less increase in 6-mm zone total C-HOA, coma, and SA with SMILE compared to the other groups (all P < 0.05). In the high myopia group, there was greater increase in photopic total C-HOA and trefoil and less increase in mesopic SA with SMILE (all P < 0.05). Conclusions In correction of moderate myopia, SMILE has better results in mesopic condition. In high myopia correction, femto-LASIK and PRK have better results in photopic and SMILE in mesopic condition.


2007 ◽  
Vol 17 (4) ◽  
pp. 507-514 ◽  
Author(s):  
D. Wygledowska-Promienska ◽  
I. Zawojska

Purpose To assess efficacy, safety, and changes in higher order aberrations after wavefront-guided photorefractive keratectomy (PRK) in comparison with conventional PRK for low to moderate myopia with myopic astigmatism using a WASCA Workstation with the MEL 70 G-Scan excimer laser. Methods A total of 126 myopic or myopic-astigmatic eyes of 112 patients were included in this retrospective study. Patients were divided into two groups: Group 1, the study group; and Group 2, the control group. Group 1 consisted of 78 eyes treated with wavefront-guided PRK. Group 2 consisted of 48 eyes treated with spherocylindrical conventional PRK. Results Two years postoperatively, in Group 1, 5% of eyes achieved an uncorrected visual acuity (UCVA) of 0.05; 69% achieved a UCVA of 0.00; 18% of eyes experienced enhanced visual acuity of −0.18 and 8% of −0.30. In Group 2, 8% of eyes achieved a UCVA of 0.1; 25% achieved a UCVA of 0.05; and 67% achieved a UCVA of 0.00 according to logMAR calculation method. Total higher-order root-mean square increased by a factor 1.18 for Group 1 and 1.6 for Group 2. There was a significant increase of coma by a factor 1.74 in Group 2 and spherical aberration by a factor 2.09 in Group 1 and 3.56 in Group 2. Conclusions The data support the safety and effectiveness of the wavefront-guided PRK using a WASCA Workstation for correction of low to moderate refractive errors. This method reduced the number of higher order aberrations induced by excimer laser surgery and improved uncorrected and spectacle-corrected visual acuity when compared to conventional PRK.


2021 ◽  
Vol 10 (18) ◽  
pp. 4115
Author(s):  
Hiromitsu Onoe ◽  
Kazuyuki Hirooka ◽  
Hideaki Okumichi ◽  
Yumiko Murakami ◽  
Yoshiaki Kiuchi

We examined postoperative corneal higher-order aberrations (HOAs) present after combined phacoemulsification with either microhook ab interno trabeculotomy (μLOT-Phaco) or goniotomy, using the Kahook Dual Blade (KDB-Phaco). Retrospective study: A total of 45 eyes underwent μLOT-Phaco and KDB-Phaco (LOT-Phaco) procedures, with 21 eyes that underwent cataract surgery alone used as controls. Visual acuity and corneal HOAs, coma-like aberrations, and spherical-like aberrations were analyzed before and at 1, 2, and 3 months after the surgeries. Risk factors that could potentially influence HOAs were evaluated. No significant postoperative changes were noted for corneal HOAs, coma-like aberrations, and spherical-like aberrations after cataract surgery alone. The mean corneal HOAs, coma-like aberrations, and spherical-like aberrations were 0.222 ± 0.115 μm, 0.203 ± 0.113 μm, and 0.084 ± 0.043 μm at baseline and 0.326 ± 0.195 μm (p < 0.001), 0.302 ± 0.289 μm (p = 0.03), and 0.150 ± 0.115 μm (p < 0.001) at 3 months after LOT-Phaco, respectively. Results of the analysis for risk factors suggested that a longer incision in Schlemm’s canal could influence corneal HOAs, coma-like aberrations, and spherical-like aberrations after LOT-Phaco. Although no significant postoperative changes were observed in corneal HOAs and coma-like or spherical-like aberrations after cataract surgery alone, a significant increase in corneal HOAs and coma-like or spherical-like aberrations remained after the LOT-Phaco procedure.


2019 ◽  
Author(s):  
Fei Xia ◽  
Yang Shen ◽  
Tian Han ◽  
Jing Zhao ◽  
Hai-Peng Xu ◽  
...  

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.


2019 ◽  
Vol 30 (5) ◽  
pp. 978-984
Author(s):  
Meryem Altin Ekin ◽  
Seyda Karadeniz Ugurlu

Objective: To evaluate the changes of visual acuity, contrast sensitivity, astigmatism, and higher order aberrations after blepharoplasty in patients with dermatochalasis. Methods: Two hundred six eyelids of 103 patients with dermatochalasis were prospectively studied. Visual acuity, contrast sensitivity, corneal topography, astigmatism degree, and higher order aberrations were examined and recorded before and at 1 month after upper eyelid blepharoplasty. Change in contrast sensitivity and astigmatism values were determined according to margin reflex distance of patients, which were classified into three following groups: <2 mm, 2–3 mm, and ⩾ 4 mm. A Wilcoxon signed rank test was performed to compare the difference. Results: No significant differences were observed for visual acuity (p = 0.157). The contrast sensitivity of patients significantly increased at all spatial frequencies both under glare and nonglare conditions (p < 0.05). The mean refractive astigmatism significantly decreased from ‒1.01 ± 1.3 to ‒0.79 ± 0.71, postoperatively (p = 0.029). In patients with marginal reflex distance < 2 mm, mean contrast sensitivity was increased (p < 0.001) and mean astigmatism was decreased significantly (p < 0.001) compared with those with ⩾ 2 mm. Higher order aberrations decreased significantly from 0.62 ± 0.41 µm to 0.55 ± 0.38 µm (p = 0.038) after blepharoplasty. Root mean square of the vertical trefoil (p = 0.038), vertical coma (p = 0.002), horizontal trefoil (p = 0.027), third-order aberration (p = 0.005), secondary vertical stigmatism (p = 0.001), spherical aberration (p = 0.023), secondary horizontal astigmatism (p = 0.002), fourth-order aberration (p = 0.024), vertical pentafoil (p = 0.015), secondary horizontal coma (p = 0.035), secondary horizontal trefoil (p = 0.030), and horizontal pentafoil (p = 0.048) were decreased significantly. Conclusion: Upper eyelid blepharoplasty in patients with dermatochalasis has a significant improvement in visual function in terms of contrast sensitivity, astigmatism, and higher order aberrations.


2021 ◽  
Author(s):  
Mengjun Fu ◽  
Meiyan Li ◽  
Ruoyan Wei ◽  
Chuanwei Zhang ◽  
Yangyi Huang ◽  
...  

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.


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