Corneal biomechanical properties after laser-assisted in situ keratomileusis and small-incision lenticule extraction in myopic eyes

2020 ◽  
Vol 21 (3) ◽  
pp. 146
Author(s):  
HazemA Elbedewy ◽  
Basma ElShourbagy ◽  
AlaaA El Dorghamy ◽  
AhmedM Ghoneim
Keyword(s):  
Biomechanical Properties ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Corneal Biomechanical Properties

scholarly journals Review of Corneal Biomechanical Properties Following LASIK and SMILE for Myopia and Myopic Astigmatism

2018 ◽  
Vol 12 (1) ◽  
pp. 164-174 ◽  
Author(s):  
Iben Bach Damgaard ◽  
Mohamed Reffat ◽  
Jesper Hjortdal
Keyword(s):  
Femtosecond Laser ◽  
Ex Vivo ◽  
Biomechanical Properties ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Lenticule Extraction ◽  
A Minor ◽  
Corneal Biomechanical Properties

Worldwide, femtosecond Laser AssistedIn-situKeratomileusis (LASIK) is a well known and commonly used refractive technique, although Small Incision Lenticule Extraction (SMILE) has become increasingly popular since it was introduced in 2011. In LASIK, a corneal flap is cut with a microkeratome or femtosecond laser, followed by thinning of the stromal bed with excimer laser ablation. In SMILE, a minor intrastromal lenticule is cut with a femtosecond laser and subsequently removed through a small incision, leaving the anterior and strongest part of the cornea almost intact. Both LASIK and SMILE require cutting of corneal lamellae that may reduce the biomechanical stability of the cornea, with the potential risk of corneal iatrogenic ectasia as a severe complication. However, SMILE preserves the anterior corneal integrity and may, in theory, better preserve the corneal biomechanical strength than LASIK after surgery.A review aimed to examine the current literature that describes and compares the corneal biomechanical properties after Laser AssistedIn-situKeratomileusis (LASIK) and Small Incision Lenticule Extraction (SMILE). A comprehensive search was performed in Pubmed.gov using the following search queries: Corneal biomechanical properties, corneal biomechanics, ocular response analyser, ocular response analyzer, ORA,ex vivo, in vitro, Corvis, Corvis ST, LASIK, and SMILE.

scholarly journals Evaluation of Corneal Biomechanical Properties Modification after Small Incision Lenticule Extraction Using Scheimpflug-Based Noncontact Tonometer

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Leonardo Mastropasqua ◽  
Roberta Calienno ◽  
Manuela Lanzini ◽  
Martina Colasante ◽  
Alessandra Mastropasqua ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Biomechanical Properties ◽  
Corneal Biomechanics ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Lenticule Extraction ◽  
Noncontact Tonometer ◽  
Corneal Biomechanical Properties

Purpose.To quantify the effect of small incision lenticule extraction (SMILE) on the corneal biomechanics using Scheimpflug noncontact tonometer (Corvis ST).Methods.Twenty eyes of twenty patients, evaluated as eligible for surgery, with high myopia and/or moderate myopic astigmatism, underwent small incision lenticule extraction (SMILE). All patients underwent Corvis ST preoperatively and postoperatively after 1 week, and 1 and 3 months to observe alterations of corneal biomechanical properties. The main outcome measures were Deformation Amplitude, 1st-AT, and 2nd-AT. The relationship between the amount of stroma removed and the percentage variation of the measured parameters from baseline was evaluated with generalized linear model from each time point. For completeness also intraocular pressure (IOP), central corneal thickness (CCT), and their variations after surgery were evaluated.Results.The ratio between the amount of removed refractive error and, respectively, changes of Deformation Amplitude, 1st-AT, and 2nd-AT were significantly modified at the 1st week after surgery(P=0.005; P=0.001; P=0.024). At 1 and 3 months these values did not show statistically significant alterations. Intraocular pressure and central corneal thickness showed statistically significant changes during follow-up.Conclusions.No significant modifications in biomechanical properties were observed after SMILE so this procedure could induce only minimal transient alterations of corneal biomechanics.

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.

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