scholarly journals Functional optical zone after wavefront-optimized versus wavefront-guided laser in situ keratomileusis

2021 ◽  
Vol 10 (3) ◽  
pp. 129-137
Author(s):  
Mariam A Elshawarby ◽  
Ali Saad ◽  
Thanaa Helmy ◽  
Mouamen M. Seleet ◽  
Tamer Elraggal
Keyword(s):  
Visual Acuity ◽  
Refractive Error ◽  
Ablation Depth ◽  
Laser In Situ Keratomileusis ◽  
Treatment Modalities ◽  
Significant Difference ◽  
Corneal Asphericity ◽  
Optical Zone ◽  
The Mean

Background: Many studies have used functional optical zone (FOZ) as a measure to compare different refractive laser treatment modalities. However, to our knowledge, no study has compared wavefrontoptimized (WFO) and wavefront-guided (WFG) laser in situ keratomileusis (LASIK) using FOZ. We compared the FOZ after WFO versus WFG LASIK in patients with myopia and myopic astigmatism.Methods: In this prospective comparative study, we included 100 myopic eyes of 50 patients with or without astigmatism. They were divided into two groups according to the platform used: WFO or WFG femtosecond LASIK. Using Holladay’s equivalent keratometry reading (EKR) report of Pentacam HR, FOZ was defined as a zone centered on the pupil center with a standard deviation (SD) of 0.5 D, around the mean EKR. The differences in FOZ between the two platforms were analyzed at 3 months postoperatively. Visual acuity, refractive error, corneal asphericity (Q-value), and root mean square of higher-order aberrations (RMS for HOAs) were evaluated and compared.Results: The mean ± SD of patient age was 26.64 ± 5.67 years. The preoperative characteristics of the two groups were comparable (all P > 0.05). The intended optical zone (IOZ) was 6 mm in both groups. The mean laser ablation depth was significantly greater in the WFG group (18 ?m per D) than in the WFO group (16 ?m per D) (P = 0.035). At 3 months postoperatively, the mean ± SD of FOZ diameter was 4.32 ± 0.94 mm (71.99 ± 15.68% of intended optical zone) in the WFO group and 4.16 ± 1.13 mm (69.33 ± 18.78% of intended optical zone) in the WFG group, with no significant difference between the two groups (P = 0.622). The change in corneal asphericity was greater in the WFG group than in the WFO group (P = 0.034). Postoperative mean corrected and uncorrected distance visual acuity, manifest refraction, and RMS for HOAs showed no significant difference between the two groups (all P > 0.05).Conclusions: We found that WFG LASIK resulted in greater ablation depth and change in corneal asphericity than WFO LASIK at 3 months postoperatively. However, there was no significant difference in FOZ diameter, refractive error, and RMS for HOAs between the two groups. Further research is needed to confirm these findings.

A quality of life assessment of military recruits after refractive surgery

2020 ◽  
Vol 1 (1) ◽  
pp. 42-46
Author(s):  
Jian-He Xiao ◽  
◽  
Shi-Yang Li ◽  
Xing Xing ◽  
Ai-Hong Zhao ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Refractive Error ◽  
High Myopia ◽  
Refractive Surgery ◽  
Laser In Situ Keratomileusis ◽  
Significant Difference ◽  
Lenticule Extraction ◽  
Postoperative Interval

AIM: To evaluate the quality of life of recruits after refractive surgery. METHODS: Population-based, cross-sectional study. Using the Quality of Life Impact of Refractive Correction (QIRC) questionnaire, the quality of life in 615 recruits underwent refractive surgery was evaluated. The overall score and each question score of QIRC were compared between subgroups of different strength of preoperative refractive error, postoperative interval, type of surgical procedure and postoperative recovery. RESULTS: The mean overall QIRC score of recruits underwent refractive surgery was 49.15±7.89. Significant difference was found for strength of preoperative refractive error (F=4.16, P<0.05), with the low myopia group (50.67±7.59) had significantly better scores than those with high myopia (47.57±7.52, F=4.16, P<0.05). Recruits after a postoperative interval no more than 6mo (49.18±7.86) scored equally to those of more than 6mo (49.18±8.03). Recruits underwent surface ablation surgery scored lowest (46.68±6.09), but showed no significant difference when compared with all underwent refractive surgery (t=1.99, P>0.05). Scores of recruits underwent mechanical microkeratome laser in situ keratomileusis (MK-LASIK), Sub-Bowman’s keratomileusis (SBK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), femtosecond lenticule extraction (ReLEx flex) or small-incision lenticule extraction (ReLEx SMILE) procedure showed no significant difference too. Recruits had adverse complaints postoperatively (45.85±6.66) scored lower when compared with all underwent refractive surgery (t=5.28, P<0.01). CONCLUSION: The quality of life of recruits after refractive surgery was good except those with postoperative complications. Preoperative low myopia recruits had better quality of life than medium and high myopia ones.

scholarly journals The assessment of the stability of the corneal structure after LASIK correction of myopia by different optical zone diameters

2016 ◽  
Vol 73 (6) ◽  
pp. 572-576 ◽  
Author(s):  
Milorad Milivojevic ◽  
Vladimir Petrovic ◽  
Miroslav Vukosavljevic ◽  
Ivan Marjanovic ◽  
Mirko Resan
Keyword(s):  
Structural Parameters ◽  
Preoperative Assessment ◽  
Laser In Situ Keratomileusis ◽  
Group I ◽  
Significant Difference ◽  
Optical Zone ◽  
Corneal Structure ◽  
The Stability ◽  
Corneal Thinning

Background/Aim. Enlargement of optical zone (OZ) diameter during laser in situ keratomileusis (LASIK) correction of myopia postoperatively improves the optical outcome, however, it also leads to the increased stroma tissue consumption - progressive corneal thinning. The aim of this investigation was to present the possibility of safe OZ enlargement without impairing the structural stability of the cornea, while obtaining an improved optical outcome with LASIK treatment of shortsightedness. Methods. Preoperative assessment of the cornea structure and prediction of the ablated stroma tissue consumption was conducted in 37 patients (74 eyes) treated for shortsightedness by means of the LASIK method. With the eyes that, according to their cornea structure, had the capacity for OZ diameter enlargement of 0.5 mm, LASIK treatment was performed within the wider OZ diameter of 7.0 mm compared to the standard 6.5 mm. The following two groups were formed, depending on the diameter of the utilized OZ: the group I (the eyes treated with the OZ 6.5 mm, n = 37) and the group II (the eyes treated with the OZ 7.0 mm, n = 37). Results. No significant difference in the observed structural parameters of the cornea was detected between the groups of patients treated with different OZ diameters. The values of all the parameters were significantly bellow the threshold values for the development of postoperative ectasia. Conclusion. Diameter enlargement of the treated OZ, if there is a preoperative cornea capacity for such enlargement, will not impair the postoperative stability of the cornea structure, and will significantly improve the optical outcome.

Stability of corneal topography and aberrometry after hyperopic laser in situ keratomileusis with a 500-Hz excimer laser platform: A 3-year follow-up study

2019 ◽  
Vol 30 (6) ◽  
pp. 1238-1245
Author(s):  
Ana B Plaza-Puche ◽  
Verónica Vargas ◽  
Pilar Yébana ◽  
Samuel Arba ◽  
Jorge L Alio
Keyword(s):  
Excimer Laser ◽  
Spherical Aberration ◽  
Case Series ◽  
Corneal Topography ◽  
Laser In Situ Keratomileusis ◽  
Case Series Study ◽  
Significant Difference ◽  
Optical Zone

Purpose: The aim of this study is to analyze the long-term stability of the corneal topography, the functional optical zone, and the refractive stability throughout 3 years following laser in situ keratomileusis surgery for hyperopia using a 500-Hz excimer laser system. Methods: This retrospective consecutive observational case series study comprised 66 eyes that underwent laser in situ keratomileusis to correct hyperopia with a postoperative follow-up of 3 years. Laser in situ keratomileusis procedures were performed using the SCHWIND Amaris 500-Hz excimer laser. Main outcomes measured were stability of the functional optical zone at corneal topography and corneal aberrometry. Results: Statistically significant differences were found in simulated keratometry (K2 (steep meridian) and Km (mean keratometry)) between 3 and 36 months postoperatively ( p ⩽ 0.01); these differences disappeared at 12 and 36 months ( p ⩾ 0.18). No statistically significant changes were observed in the horizontal and vertical diameter of the functional optical zone throughout the whole follow-up ( p ⩾ 0.07). A statistically significant difference was found in the spherical aberration between 3 and 36 months ( p = 0.02); this difference disappeared when compared between 12 and 36 months ( p = 0.72). Statistically significant correlations were detected between the vertical functional optical zone and coma root mean square ( r = –0.510, p < 0.01) and between the vertical functional optical zone and spherical aberration ( r = 0.441, p = 0.02) 36 months after surgery. Conclusion: Following 3 years of hyperopic laser in situ keratomileusis with a 500-Hz Amaris excimer laser, keratometry, functional optical zone, and corneal aberrations remain stable from 1 year after surgery. Topographical regression is not observed in hyperopic laser in situ keratomileusis with this excimer laser technology from 1 year after surgery.

scholarly journals Traumatic displacement of laser in situ keratomileusis flaps: an integrated clinical case presentation and literature review

2021 ◽  
Author(s):  
Lu-Yang Shih ◽  
Kai-Ling Peng ◽  
Jiunn-Liang Chen
Keyword(s):  
Visual Acuity ◽  
Case Series ◽  
Laser In Situ Keratomileusis ◽  
Ocular Surface Disease Index ◽  
Retrospective Case ◽  
Corneal Sensation ◽  
Replacement Surgery ◽  
Traumatic Dislocation ◽  
The Mean

Abstract Background Traumatic dislocation of laser-assisted in situ keratomileusis (LASIK) corneal flaps is an uncommon postoperative complication that could occur any time after LASIK, and could be visually devastating. We evaluated the visual outcomes, corneal sensation, tear function, and dry eye questionnaire results of patients with traumatic dislocation of LASIK flaps, including one LASIK flap amputation. Methods This is a retrospective case series. Twelve patients were diagnosed with traumatic displacement of the LASIK flap between August 2014 and January 2019. Of these, seven who underwent flap replacement surgery were included. Patient’s visual acuity, refraction, corneal sensitivity, non-invasive tear breakup time (NIBUT), tear meniscus height (TMH), and ocular surface disease index (OSDI) results were evaluated. Results The patients’ mean age was 35.86 ± 5.84 years, and 42.9% (3/7) were male. The mean duration from LASIK to trauma was 8.86 ± 2.48 years.The mean preoperative and postoperative six-month best-corrected visual acuity were 0.55 ± 0.34 and 0.02 ± 0.03, respectively. Vision improvement was significant (P = 0.018). The mean spherical equivalent and astigmatism at six months postoperatively was − 1.0 ± 0.95 D and − 0.5 ± 0.25 D, respectively. The corneal flap was clear and well-positioned at the final follow-up (mean: 28.57 ± 6.9 months). 85.71% (6/7) of the patients showed worse corneal sensation in the injured eye. Interocular OSDI discrepancy was significantly less (P = 0.048) in those whose last visit was more than 30 months after the trauma. Conclusions Postoperative vision at six months was significantly improved, and the refractive data also showed some improvement. The corneal nerve and tear function recovery peaked before 30 months, while the OSDI continued to improve beyond 30 months.

scholarly journals Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking

2016 ◽  
Vol 5 (3) ◽  
pp. 93-98 ◽  
Author(s):  
Rafael J Pérez-Cambrodí ◽  
Pedro Ruiz-Fortes ◽  
Alberto Artola
Keyword(s):  
Visual Acuity ◽  
Clinical Outcomes ◽  
Statistical Significance ◽  
Cross Linking ◽  
Corneal Ectasia ◽  
Significant Difference ◽  
Corrected Distance Visual Acuity ◽  
The Mean

ABSTRACT Objective To assess the clinical outcomes in ectatic corneas following accelerated transepithelial cross-linking (CXL) over 1 year of follow-up. Materials and methods Twenty-one eyes diagnosed with progressive corneal ectasia (19 keratoconus, 2 post-laser in situ keratomileusis ectasias) in 14 patients aged between 26 and 69 years were enrolled. All cases were treated with accelerated transepithelial CXL using the Avedro KXL® system (Waltham, MA, United States). Changes at visual, refractive, corneal topographic, and corneal aberrometric level were evaluated over a 12-month follow-up period. The demarcation was also determined using optical coherence tomography (OCT). Results The mean depth of the demarcation line measured by OCT was 202.72 µm, varying between 153 and 230 µm. One month postsurgery, a change was noted at the limit of statistical significance in sphere (p = 0.05) and in spherical equivalent (p = 0.05). Likewise, a statistically significant difference was observed in corrected distance visual acuity (CDVA) (p = 0.01). There were no significant changes in either visual acuity or refraction between 1 and 6 months (p ≥ 0.35). Although changes in trend were observed in corneal topographic and aberrometric parameters after surgery, none reached statistical significance (p ≥ 0.08). A significant change was observed only in astigmatism of the posterior surface between 1 and 12 months (p = 0.02). Conclusion Accelerated transepithelial CXL may be a useful technique for the management of progressive corneal ectasia, as it is able to maintain the topographic and aberrometric profile of the cornea with no significant changes. Longer-term studies are required to confirm this finding How to cite this article Piñero DP, Artola A, Ruiz-Fortes P, Soto-Negro R, Pérez-Cambrodi RJ. Clinical Outcomes at 1 Year following Corneal Ectasia Treatment with Accelerated Transepithelial Cross-linking. Int J Kerat Ect Cor Dis 2016;5(3):93-98.

scholarly journals Higher-order aberrations following wavefront-guided photorefractive keratectomy and laser in situ keratomileusis

2021 ◽  
Vol 1 (2) ◽  
pp. 100-104
Author(s):  
Esra Vural ◽  
Deniz Kilic ◽  
Ayse Cicek ◽  
M. Rasit Sirem ◽  
Necati Duru ◽  
...  
Keyword(s):  
Higher Order ◽  
Laser In Situ Keratomileusis ◽  
Photorefractive Keratectomy ◽  
City Hospital ◽  
Higher Order Aberrations ◽  
Significant Difference ◽  
Manifest Refraction ◽  
Group A ◽  
The Mean

Background: We aimed to evaluate higher-order aberrations (HOAs) following wavefront-guided photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with myopia and myopic astigmatism. Methods: This retrospective observational case-control study included patients who underwent wavefront-guided PRK (40 eyes of 20 patients) or LASIK (40 eyes of 20 patients) between August 2018 and November 2018 at the refractive surgery unit of Kayseri City Hospital Eye Clinic, Turkey. The corrected distance visual acuity (CDVA), manifest refraction, corneal topography, and HOAs were evaluated preoperatively and 3 months postoperatively in all patients. Results: The mean age ± standard deviation (SD) was 27.13 ± 5.54 years and 29.10 ± 4.38 years in the PRK and LASIK groups, respectively (P = 0.06). Both groups had a mean CDVA of 1.00. The mean ± SD of spherical and spherical equivalent values was -2.09 ± 1.56 diopter (D) and -3.03 ± 1.72 D in the PRK group and -2.23 ± 1.69 D and -3.35 ± 1.71 D in the LASIK group, respectively (P = 0.58). When the preoperative and postoperative HOAs and root mean square (RMS) values (for a 6-mm pupil diameter) were compared in the PRK group, a significant difference was found in vertical coma and total RMS values (P = 0.003 and P ˂ 0.001, respectively); in the LASIK group, there was a significant difference in preoperative and postoperative vertical coma and total RMS values (P = 0.0.001 and P ˂ 0.001, respectively). There was no significant difference in preoperative and postoperative vertical coma values between the two groups (P = 0.735 and P = 0.583, respectively). Conclusions: In terms of HOAs, total RMS values decreased significantly and vertical coma values increased significantly at 3 months postoperatively in both PRK and LASIK groups. However, there were no differences between the two groups.

scholarly journals Flap Sliding Technique for Managing Flap Striae following Laser In Situ Keratomileusis

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Khaled Abdelazeem ◽  
Mohamed A. Nassr ◽  
Hazem Abdelmotaal ◽  
Ehab Wasfi ◽  
Dalia Mohamed El-Sebaity
Keyword(s):  
Visual Acuity ◽  
Laser In Situ Keratomileusis ◽  
Distance Visual Acuity ◽  
Uncorrected Distance Visual Acuity ◽  
Corrected Distance Visual Acuity ◽  
Safe Technique ◽  
Optical Zone ◽  
Sliding Technique ◽  
Flap Elevation

Purpose. To assess the efficacy and safety of a simple, noninvasive, “flap-sliding” technique for managing flap striae following laser in situ keratomileusis (LASIK). Methods. This prospective, interventional study included eyes with post-LASIK flap striae. All eyes underwent flap sliding 1-2 days after surgery. Following flap edge epithelialisation, a cellulose sponge was used to gently slide the flap perpendicular to the striae direction. This technique allows for flap striae treatment without flap lifting, avoiding any associated lifting complications. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and refractive error were monitored one day after the flap-sliding procedure. Results. Fifteen eyes (15 patients) with post-LASIK flap striae were managed using the flap-sliding technique. The procedure did not successfully relocate the flap striae in 1 eye, and flap elevation and floating (using a balanced salt solution) were required. Therefore, 14 eyes were included in post-flap-sliding analyses. The UDVA improved in all patients the first day after the flap-sliding procedure was performed, with 11 of 14 eyes (78.57%) reaching an UDVA of 20/25 or better. Complications following flap sliding occurred in 2 eyes (14.29%). One eye had intraoperative epithelial abrasion, and 1 eye had residual postoperative striae outside of the optical zone. Conclusion. The flap-sliding technique is a simple, noninvasive, efficient, and safe technique for managing post-LASIK flap striae that develop after epithelial healing in the early post-LASIK period. This trial is registered with NCT04055337.

scholarly journals Optical and visual quality comparison of implantable collamer lens and femtosecond laser assisted laser in situ keratomileusis for high myopia correction

2021 ◽  
Vol 14 (5) ◽  
pp. 737-743
Author(s):  
Zheng Jiang ◽  
◽  
Dong-Qiang Luo ◽  
Jiao Chen ◽  
◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Clinical Outcomes ◽  
High Myopia ◽  
Cutoff Frequency ◽  
Laser In Situ Keratomileusis ◽  
Spherical Equivalent ◽  
Implantable Collamer Lens ◽  
Significant Difference

AIM: To compare clinical outcomes and refractive stability of implantable collamer lens (ICL) implantation and femtosecond laser assisted laser in situ keratomileusis (FS-LASIK) for high myopia correction. METHODS: The Optical Quality Analysis System (OQAS) was used to evaluate clinical outcomes objectively after operation for high myopia correction. We compared the two procedures in terms of 1-year changes in uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), safety index, efficacy index, spherical equivalent, modulation transfer function (MTF) cutoff frequency, strehl ratio (SR) and objective scatter index (OSI). RESULTS: At 1y postoperatively, the safety indices were 1.33±0.27 in ICL group, and 1.17±0.24 in FS-LASIK group. 39.58% in the ICL group and 27.59% in the FS-LASIK group gained CDVA in 2 lines or better than that in preoperative CDVA. The efficacy indices were 1.28±0.22 in ICL group, and 1.13±0.26 in FS-LASIK group. The changes of spherical equivalent from 1wk to 1y postoperatively was -0.12±0.37 D in ICL group, and -0.79±0.58 D in FS-LASIK group (P&#x003C;0.05). Spherical equivalent within ±0.50 D was achieved in 97.92% in ICL group and 68.97% in FS-LASIK group. MTF cutoff frequency were higher with ICL as compared to FS-LASIK (P&#x003C;0.05) at each postoperative follow-up stage; for postoperative 1mo later, SR was statistically significant difference between two groups (P&#x003C;0.05); with no statistically significant difference in OSI between two groups (P&#x003E;0.05) in postoperative 3mo later. CONCLUSION: ICL implantation and FS-LASIK procedures both provide good safety and predictability in high myopia correction. ICL implantation provides better clinical outcomes and refractive stability than FS-LASIK.

scholarly journals Correction of Myopia and Myopic Astigmatism by Femtosecond Laser in Situ Keratomileusis

2019 ◽  
Vol 75 (2) ◽  
pp. 65-71
Author(s):  
Tereza Řeháková ◽  
Věra Veliká ◽  
Naďa Jirásková
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
High Myopia ◽  
Laser In Situ Keratomileusis ◽  
Patient’S Satisfaction ◽  
The Mean ◽  
One Year ◽  
Myopic Astigmatism

Aim: We analysed one-year refractive results and the incidence of complications in patients with correction of low-to-high myopia or myopic astigmatism by femtosecond laser in situ keratomileusis (FS-LASIK) using femtosecond laser LenSx® (Alcon, Fort Worth, Texas, USA) a excimer laser Excimer Amaris 500 (Schwind eye-tech-solutions GmbH and Co KG, Kleinostheim, Germany). Methods: To the retrospective study were included 171 eyes of 87 patients (38 men, 49 women) who underwent correction of myopia and myopic astigmatism by FS-LASIK in the outpatient Department of Ophthalmology, University Hospital in Hradec Králové between 2013-2017. We assessed uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA), subjective refraction, central corneal thickness (CCT) in the thinnest point, patient’s satisfaction and the incidence of complications in the one-year follow-up period. Results: At the time of laser procedure the mean patient‘s age was 29,26 ± 6,47 years (range 18 to 46 years). In 21 eyes was corrected myopia (range -6,5 to -2,5 D sph) and in 150 eyes myopic astigmatism (range -8,75 to -0,25 D sph and -3,0 to -0,25 D cyl). The mean preoperative UCVA 0,06 ± 0,08 (range 0,02 to 0,8) got better to 1,12 ± 0,17 (range 0,8 to 1,5) at the end of follow-up period. There wasn’t statistically significant change in BCVA between preoperative and postoperative values. Preoperative mean value of subjective refraction was -4,14 ± 1,43 D sph (range -8,5 to -1 D sph) and -0,57 ± 0,58 D cyl (range -3 to 0 D cyl) and after 12 months -0,02 ± 0,16 D sph (range -0,1 to 0,75 D sph) and -0,01 ± 0,1 D cyl (range -0,5 to 0,5 D cyl). The initial mean CCT was 554,76 ± 30,07 μm (range 485 to 660 μm), after 6 months 494,06 ± 34,99 μm (range 421 to 594 μm) and after 12 months 492,92 ± 34,55 μm (range 411 to 592 μm). We observed peroperative complications in 3 eyes. The suction loss of femtosecond laser occurred during flap creation due to sudden eye movement. Postoperatively in one case we enrolled flap pucker first postoperative day. In other case flap dislocation occurred after abdonimal surgery under general anesthesia which was performed 3 months after refractive procedure and we had to indicate flap reposition. The mean grade of patient’s satisfaction was at the end of follow-up period 1,04. The most often complaints were the sensation of dry eye (10 patients) and blurry vision during computer working, inadequate lighting and fatique (6 pacients). Conclusions: According to our experience correction of low-to-high myopia or myopic astigmatism by using FS-LASIK is an effective, relatively safe and predictable method. The basic assumption of good postoperative results and patient’s satisfaction is thorough and comprehensive preoperative examination with respect to indication criteria.

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