scholarly journals Corneal densitometry after photorefractive keratectomy, laser-assisted in situ keratomileusis, and small-incision lenticule extraction

Eye ◽  
2017 ◽  
Vol 31 (12) ◽  
pp. 1647-1654 ◽  
Author(s):  
F Poyales ◽  
N Garzón ◽  
J Mendicute ◽  
I Illarramendi ◽  
P Caro ◽  
...  
Keyword(s):  
Photorefractive Keratectomy ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Corneal Densitometry ◽  
Lenticule Extraction

Refractive ophthalmology

2018 ◽  
pp. 925-1009
Keyword(s):  
Refractive Error ◽  
Contact Lens ◽  
Refractive Surgery ◽  
Photorefractive Keratectomy ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Lenticule Extraction

‘Refractive ophthalmology’ provides the reader with an introduction to the causes and treatment of refractive error. This chapter covers the use of spectacles, contact lens, and refractive surgery, including laser stromal in situ keratomileusis (LASIK), laser-assisted subepithelial keratomileusis (LASEK), photorefractive keratectomy (PRK), small-incision lenticule extraction (SMILE), incisional refractive surgery, collagen shrinkage procedures, and lens-based techniques.

scholarly journals Corneal Clarity and Visual Outcomes after Small-Incision Lenticule Extraction and Comparison to Femtosecond Laser-Assisted In Situ Keratomileusis

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Apostolos Lazaridis ◽  
Konstantinos Droutsas ◽  
Walter Sekundo ◽  
Michael Petrak ◽  
Stephan Schulze
Keyword(s):  
Femtosecond Laser ◽  
Ablation Depth ◽  
Negative Association ◽  
Small Incision Lenticule Extraction ◽  
Visual Outcomes ◽  
Small Incision ◽  
Corneal Densitometry ◽  
Corrected Distance Visual Acuity ◽  
Lenticule Extraction

Purpose. To evaluate corneal clarity and visual outcomes after small-incision lenticule extraction (SMILE) and compare them to femtosecond laser-assisted in situ keratomileusis (FS-LASIK).Materials and Methods. Fifty-eight myopic eyes of 33 patients who underwent SMILE were compared to 58 eyes of 33 patients treated with FS-LASIK. All procedures were performed using VisuMax® femtosecond laser and MEL 80® excimer laser (Carl Zeiss Meditec AG, Germany). Pentacam™ (Oculus, Germany) was used for pre- and 3-month postoperative corneal densitometry (CD) analysis. CD was evaluated at 3 optically relevant, concentric radial zones (0–2 mm, 2–6 mm, and 0–6 mm annulus) around the corneal apex and at 3 different anatomical corneal layers (anterior, central, and posterior). Associations of postoperative CD values with the lenticule thickness and ablation depth were examined. Preoperative and postoperative corrected distance visual acuity (CDVA) values were also compared.Results. After SMILE, the total CD (all corneal layers) at 0–6 mm annulus showed no significant change compared to preoperative values (P=0.259). After FS-LASIK, the total CD was significantly reduced (P=0.033). Three-month postoperative CD showed no significant differences between the 2 groups for all examined annuli (0–2 mm:P=0.569; 2–6 mm:P=0.055; and 0–6 mm:P=0.686). Total CD after SMILE at 0–6 mm annulus displayed a weak negative association with the lenticule thickness (P=0.079,R2=0.0532) and after FS-LASIK displayed a weak negative association with the ablation depth (P=0.731,R2=0.0015). Postoperative CDVA was similar for both groups (P=0.517).Conclusion. Quantification of corneal clarity using the Scheimpflug CD showed similar results before and 3 months after SMILE. Compared to FS-LASIK, no significant differences of corneal clarity and CDVA were found 3 months postoperatively.

Corneal Densitometry after Femtosecond Laser-Assisted In Situ Keratomileusis (Fs-LASIK) and Small Incision Lenticule Extraction (SMILE)

2018 ◽  
Vol 43 (5) ◽  
pp. 605-610 ◽  
Author(s):  
Mehdi Shajari ◽  
Emanuel Wanner ◽  
Vladimir Rusev ◽  
Shervin Mir Mohi Sefat ◽  
Wolfgang J Mayer ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Small Incision Lenticule Extraction ◽  
Small Incision ◽  
Corneal Densitometry ◽  
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 Corneal Safety and Stability in Cases of Small Incision Lenticule Extraction with Collagen Cross-Linking (SMILE Xtra)

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Ihab Mohamed Osman ◽  
Hany Ahmed Helaly ◽  
Mohsen Abou Shousha ◽  
Amir AbouSamra ◽  
Islam Ahmed
Keyword(s):  
Visual Acuity ◽  
Cross Linking ◽  
Small Incision Lenticule Extraction ◽  
Distance Visual Acuity ◽  
Small Incision ◽  
Corneal Densitometry ◽  
Lenticule Extraction ◽  
Safety And Stability ◽  
Collagen Cross Linking

Purpose. To assess the safety and stability in cases of small incision lenticule extraction with collagen cross-linking (SMILE Xtra). Methods. This study was a retrospective interventional comparative study that included 60 eyes of 30 patients divided equally into two groups: SMILE Xtra and SMILE alone. The inclusion criteria were patients >18 years of age, myopic error >6 D, thinner cornea <520 microns, and abnormal corneal topography. Outcome data were recorded including uncorrected distance visual acuity and corrected distance visual acuity (UDVA and CDVA), manifest refraction spherical equivalent (MRSE), central corneal thickness, average keratometry, endothelial cell density, corneal resistance factor (CRF), and corneal densitometry. The follow-up period was 24 months. Results. There was a significant difference between the 2 groups regarding UDVA, CDVA, and MRSE at 1 month. In the SMILE Xtra group, 90% of eyes had postoperative UDVA of 20/20 and 97% had UDVA of 20/30 at 24 months. At 24 months, 26 eyes (87%) vs. 25 eyes (84%) were within ±0.50 D of attempted correction in SMILE Xtra and SMILE groups, respectively. Regarding stability, both groups showed improvement of MRSE at 1st month postoperatively and remained stable along the 24 months of follow-up. CRF and corneal densitometry were higher in the SMILE Xtra group along the whole follow-up period (p=0.001). Conclusion. Combining corneal cross-linking with SMILE procedure (SMILE Xtra) is a promising tool to prevent ectasia in high-risk patients. It is a safe and simple procedure that can be offered to patients undergoing SMILE with risk for ectasia. Trial registration no: PACTR201810577524718.

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