Femtosecond laser assisted in situ keratomileusis (FS-LASIK) yields better results than transepithelial photorefractive keratectomy (Trans-PRK) for correction of low to moderate grade myopia

2020 ◽  
pp. 112067212098034
Author(s):  
Assaf Gershoni ◽  
Olga Reitblat ◽  
Michael Mimouni ◽  
Eitan Livny ◽  
Yoav Nahum ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Outcome Data ◽  
Photorefractive Keratectomy ◽  
Efficacy And Safety ◽  
Safety Index ◽  
Cohort Study Design ◽  
Safety Parameters ◽  
Efficacy Index ◽  
In Trans

Introduction: The purpose of this study was to compare the outcomes of transepithelial photorefractive keratectomy (Trans-PRK) with femtosecond laser assisted in situ keratomileusis (FS-LASIK) for the correction of low to moderate myopia. Methods: A retrospective cohort study design was used. The study group included patients with myopia less than −6.0 D, with or without concomitant astigmatism under 2.0 D, who were treated with FS-LASIK or Trans-PRK in 2013 through 2014. Background, clinical and outcome data were collected from the patient files. A comparison between eyes treated with FS-LASIK or Trans-PRK was performed. Results: The Trans-PRK group was comprised of 1793 eyes and the FS-LASIK group of 666 eyes. Mean ± SD spherical equivalent (SE) refraction prior to surgery was −3.43 ± 1.27 D in the Trans-PRK group and −3.18 ± 1.34 D in the FS-LASIK group ( p < 0.001). Efficacy index values were 0.95 ± 0.14 in the Trans-PRK group and 0.98 ± 0.12 in the FS-LASIK group ( p < 0.001), and corresponding safety index values were 0.96 ± 0.13 and 0.99 ± 0.12 ( p < 0.001). Distance from target refraction was 0.45 ± 0.42 D in Trans-PRK group and 0.43 ± 0.38 D in the FS-LASIK group ( p = 0.537); 71.6% and 74.2% of eyes were within ±0.5 D of attempted correction, respectively ( p = 0.193) Conclusions: Both Trans-PRK and FS-LASIK demonstrated excellent results, mostly comparable with the current literature. FS-LASIK achieved better results than Trans-PRK surgery in the efficacy and safety parameters.

scholarly journals Photorefractive Keratectomy for Residual Myopia after Myopic Laser In Situ Keratomileusis

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Kamal A. M. Solaiman ◽  
Sameh M. Fouda ◽  
Ashraf Bor’i ◽  
Haitham Y. Al-Nashar
Keyword(s):  
Corneal Thickness ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Safety Index ◽  
Corneal Resistance Factor ◽  
Corrected Visual Acuity ◽  
High Predictability ◽  
Efficacy Index ◽  
The Mean

Purpose. To evaluate the safety, efficacy, and predictability of photorefractive keratectomy (PRK) on the corneal flap for correction of residual myopia following myopic laser in situ keratomileusis (LASIK).Patients and Methods. A retrospective study on eyes retreated by PRK on the corneal flap for residual myopia after LASIK. All eyes had no enough stroma after LASIK sufficient for LASIK enhancement. Data included spherical equivalent (SE), uncorrected and best corrected visual acuity (UCVA and BCVA), central pachymetry, corneal higher order aberrations (HOAs), corneal hysteresis (CH), corneal resistance factor (CRF), and corneal haze.Results. The study included 64 eyes. Before PRK, the mean central pachymetry was400.21±7.8 μm, the mean SE was −1.74±0.51 D, and the mean UCVA and BCVA were0.35±0.18and0.91±0.07, respectively. 12 months postoperatively, the mean central corneal thickness was382.41±2.61 μm, the mean SE was −0.18±0.32 D (P<0.01), and the mean UCVA and BCVA were0.78±0.14(P=0.01) and0.92±0.13(P>0.5), respectively. The safety index was 1.01 and the efficacy index was 0.86. No significant change was observed in corneal HOAs.Conclusions. Residual myopia less than 3 D after LASIK could be safely and effectively treated by PRK and mitomycin C with a high predictability. This prevents postoperative ectasia and avoids the flap related complications but has no significant effect on HOAs.

scholarly journals One-Year Results of Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Collagen Cross-Linking in Keratoconus Utilizing a Modern Ablation Software

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
A. M. Sherif ◽  
M. A. Ammar ◽  
Y. S. Mostafa ◽  
S. A. Gamal Eldin ◽  
A. A. Osman
Keyword(s):  
Photorefractive Keratectomy ◽  
Cross Linking ◽  
Safety Index ◽  
Interventional Study ◽  
Effective Option ◽  
Efficacy Index ◽  
One Year ◽  
Collagen Cross Linking ◽  
Corneal Collagen

Purpose.To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen cross-linking in mild and moderate keratoconus.Methods. Prospective nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided PRK using a Custom Ablation Transition Zone (CATz) profile with 0.02% MMC application immediately followed by standard 3 mw/cm2UVA collagen cross-linking. Maximum ablation depth did not exceed 58 μm. Follow-up period: 12 months.Results.Progressive statistically significant improvement of UCVA from0.83±0.37logMAR preoperative, reaching0.25±0.26logMAR at 12 months (P<0.001). Preoperative BCVA (0.27±0.31logMAR) showed a progressive improvement reaching0.08±0.12logMAR at 12 months (P=0.02). MeanKmax reduced from48.9±2.8to45.4±3.1 D at 12 months (P<0.001), meanKmin reduced from45.9±2.8 D to44.1±3.2 D at 12 months (P<0.003), mean keratometric asymmetry reduced from3.01±2.03 D to1.25±1.2 D at 12 months (P<0.001). The safety index was 1.39 at 12 months and efficacy index 0.97 at 12 months.Conclusion. Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and moderate keratoconus.Precis. To our knowledge, this is the first published study on the use of the CATz ablation system on the Nidek Quest excimer laser platform combined with conventional cross-linking in the management of mild keratoconus.

The surgery correction of presbyopia: the modern possibilities

2016 ◽  
Vol 22 (3) ◽  
pp. 146-152
Author(s):  
Kirill B. Pershin
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Radio Frequency ◽  
Surgical Correction ◽  
Intraocular Lenses ◽  
Photorefractive Keratectomy ◽  
Social Significance ◽  
Advantages And Disadvantages ◽  
Optical Zone

The article presents review of actual publications' data concerning surgical correction of presbyopia. The data is presented related to social significance of presbyopia alongside with other disorders of refraction. The techniques applying monovision include thermokeratoplasty and such its modification as laser and radio-frequency thermokeratoplasty. All of them have number of deficiencies. The exdmer-laser ablation of cornea in the form of Laser-Assisted in Situ Keratomileusis (LASIK) or Photorefractive keratectomy (PRK) are considered as kerato-refractional techniques of correction of presbyopia. The femtosecond laser intrastromal correction of presbyopia (INTRACOR) is also labeled as kerato-refractional technique of correction of presbyopia and it is based on making intrastromal concentric rings in the central optical zone of cornea. The deficiency of INTRACOR is a relatively high cost of procedure due to application of femtosecond laser. The implantation of inlays (artificial devices) into cornea permits correcting presbyopia with less financial expenses. However, there are number of contraindications for implementing. The Tornton and Schachar operations are referred to the group of sclerotic operations of correcting presbyopia. However, nowadays these interventions are practically out of application. The implantation of intraocular lenses, including accommodating, multi-focal and monofocal by the principle of monovision ones, can be considered as the most adequate mode of correction of presbyopia. The advantages and disadvantages of implantation of various types of intraocular lenses are considered in detail.

scholarly journals Effect of Transepithelial Photorefractive Keratectomy without Mitomycin C in the Treatment of Femtosecond Laser In Situ Keratomileusis Corneal Flap Complications

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Jing Wang ◽  
Weiqian Cao ◽  
Liming Tao
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Mitomycin C ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Haze Formation

Purpose. To assess the efficacy and safety of transepithelial photorefractive keratectomy (TPRK) without mitomycin C as treatment for femtosecond laser in situ keratomileusis (FS-LASIK) corneal flap complications. Methods. Eight patients with corneal flap complications that occurred after FS-LASIK (five with eccentric flaps, two with buttonhole flaps, and one with a thick flap) were included in the study. Patients were treated with TPRK without mitomycin C between two weeks and twelve months after surgery. The postoperative manifest refraction, uncorrected distance visual acuity, and haze formation were assessed during six months of follow-up. Results. The mean manifest refractive spherical and cylinder refraction was 0.16 ± 0.26 and −0.44 ± 0.33 diopters, respectively, at six months postoperatively. The uncorrected distance visual acuity was above 20/25 in all patients after six months of follow-up. No haze formation was detected. Conclusions. TPRK without mitomycin C appears to be a safe and effective treatment for FS-LASIK corneal flap complications.

scholarly journals Changes in Intraocular Pressure after Transepithelial Photorefractive Keratectomy and Femtosecond Laser In Situ Keratomileusis

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Chien-Chih Chou ◽  
Po-Jen Shih ◽  
Hung-Chou Lin ◽  
Jun-Peng Chen ◽  
Jia-Yush Yen ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Femtosecond Laser ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
Linear Regression Models ◽  
Postoperative Changes

Purpose. To investigate the changes in intraocular pressure (IOP) and biomechanically corrected IOP (bIOP) in patients undergoing transepithelial photorefractive keratectomy (TPRK) and femtosecond laser in situ keratomileusis (FS-LASIK) and to determine the effects of preoperative biomechanical factors on IOP and bIOP changes after FS-LASIK and TPRK. Design. A retrospective comparative study. Methods. We retrospectively investigated the IOP and corneal biomechanical changes in 93 eyes undergoing FS-LASIK and 104 eyes undergoing TPRK in a clinical setting. Preoperative and postoperative data on ophthalmic and Corvis ST examinations, in vivo Young’s modulus, and noncontact tonometry were analyzed. Marginal linear regression models with generalized estimating equations were used for intragroup and intergroup comparisons of IOP and bIOP changes. Results. In the univariate model, IOP reduction after FS-LASIK was 2.49 mmHg higher than that after TPRK. In addition, bIOP reduction after FS-LASIK was 1.85 mmHg higher than that after TPRK. In the multiple regression model, we revealed that IOP reduction after FS-LASIK was 1.75 mmHg higher than that after TPRK. Additionally, bIOP reduction after FS-LASIK was 1.64 mmHg higher than that after TPRK. Postoperative changes in bIOP were less than those in IOP. In addition, Young’s modulus and CBI had no significant effect on postoperative IOP and bIOP changes. We establish a biomechanically predictive model using the available data to predict postoperative IOP and bIOP changes after TPRK and FS-LASIK. Conclusions. Reductions in IOP and bIOP after FS-LASIK were 1.75 mmHg and 1.64 mmHg, respectively, more than those after TPRK, after adjustment for confounders. We revealed that the type of refractive surgery and peak distance (PD) were significant predictors of postoperative IOP and bIOP changes. By contrast, depth of ablation showed a significant effect on only IOP changes.

Comparison of efficacy and safety of laser in situ keratomileusis using 2 femtosecond laser platforms in contralateral eyes

2013 ◽  
Vol 39 (7) ◽  
pp. 1066-1073 ◽  
Author(s):  
Mohamad Rosman ◽  
Reece C. Hall ◽  
Cordelia Chan ◽  
Andy Ang ◽  
Jane Koh ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser In Situ Keratomileusis ◽  
Efficacy And Safety

scholarly journals Changes in custom biomechanical variables after femtosecond laser in situ keratomileusis and photorefractive keratectomy for myopia

2014 ◽  
Vol 40 (6) ◽  
pp. 918-928 ◽  
Author(s):  
Marcony R. Santhiago ◽  
Steven E. Wilson ◽  
Katie M. Hallahan ◽  
David Smadja ◽  
Michelle Lin ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy
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