scholarly journals Corneal Epithelial Remodeling After Femtosecond Laser-Assisted in Situ Keratomileusis Combined with Intraoperative Accelerated Corneal Collagen Crosslinking for Myopia: A Retrospective Study

2021 ◽  
Author(s):  
Junjie Piao ◽  
Shen Wang ◽  
Ye Tao ◽  
Yue Hua Zhou ◽  
Ying Li
Keyword(s):  
Retrospective Study ◽  
Femtosecond Laser ◽  
Corneal Thickness ◽  
Corneal Epithelial ◽  
Collagen Crosslinking ◽  
Visual Outcomes ◽  
Corneal Collagen Crosslinking ◽  
Corneal Epithelial Thickness ◽  
Corneal Collagen

Abstract Background This study analyzed regional corneal thickness remodeling, biomechanical properties, and visual outcomes after femtosecond laser-assisted in situ keratomileusis combined with intraoperative accelerated corneal collagen crosslinking (LASIK Xtra) for myopia. Methods This retrospective study comprised 21 consecutive patients (18 women and 3 men; 42 eyes) who were treated with LASIK Xtra. All treatments were performed with ultraviolet-A (energy, 2.7 J/cm2; irradiance, 30 mW/cm2), using continuous (90 s) illumination. Postoperative values of corneal biometrics and visual outcomes were compared with preoperative values. Corneal thickness changes were evaluated using anterior segment optical coherence tomography. All patients were followed up for 12 months postoperatively. Preoperative and postoperative data were compared statistically using the paired t-test for normally distributed parameters and the Wilcoxon rank-sum test and Friedman analysis of variance with Bonferroni correction for non-normally distributed data. Results Uncorrected distance visual acuity (UDVA) significantly improved at 6 months after surgery (P < 0.001). The central and inner regional corneal epithelial thickness significantly increased after LASIK Xtra (P < 0.05 for all), while peripheral corneal epithelial thickness remained stable at 12 months after surgery. There was also a statistically significant decreased in the stromal thickness at most locations (P < 0.05 for all), except in the outer superior and outer superior-temporal regions. Conclusion LASIK Xtra provided predictable postoperative UDVA, corneal curvature, and corneal biomechanical stability. Since the retrospective study results depended on the cohort members’ past information, it is inferred and confirmed that regular corneal thickness remodeling occurred after treatment.

scholarly journals Corneal Collagen Crosslinking for Keratectasia after Laser in situ Keratomileusis: A Review of the Literature

2013 ◽  
Vol 2 (3) ◽  
pp. 113-120
Author(s):  
Leopoldo Spadea ◽  
Francesca Verboschi ◽  
Stefano Valente ◽  
Enzo Maria Vingolo
Keyword(s):  
Corneal Thickness ◽  
Laser In Situ Keratomileusis ◽  
Lamellar Keratoplasty ◽  
Review Of The Literature ◽  
Covalent Bonds ◽  
Collagen Crosslinking ◽  
Corneal Ectasia ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

ABSTRACT Corneal ectasia is a serious vision-threatening complication of laser in situ keratomileusis (LASIK). It is associated with progressive corneal steepening, an increase in myopia and astigmatism, and decrease in uncorrected visual acuity. Before LASIK presence of risk factors (corneal thickness, refractive error, presence of clinical and subclinical corneal pathologies) should be studied so patients should be risk-stratified. Forme fruste keratoconus or marginal pellucid degeneration should be investigated before LASIK in order to inform the patients of the possibility to develop a corneal complication. Management of post-LASIK ectasia enlists crosslinking, INTACTS, contact lenses and, in the most serious cases, lamellar keratoplasty and corneal transplantation. Crosslinking is a technique to treat and even prevent post-LASIK corneal ectasia. LASIK is a technique that reduces the corneal strength and stability. Crosslinking increases the number of collagen interfibrillar covalent bonds, using ultraviolet A and riboflavin. This result increases stability in corneal strength, reducing the risk to develop corneal ectasia (if performed simultaneously with LASIK) or it treats ectasia (if performed after LASIK keratectasia). How to cite this article Spadea L, Verboschi F, Valente S, Vingolo EM. Corneal Collagen Crosslinking for Keratectasia after Laser in situ Keratomileusis: A Review of the Literature. J Kerat Ect Cor Dis 2013;2(3):113-120.

Evaluation of changes in corneal biomechanics in eyes with keratectasia

2021 ◽  
pp. 179-187
Author(s):  
B.E. Malugin ◽  
◽  
E.G. Solodkova ◽  
S.V. Balalin ◽  
V.S. Kulikov ◽  
...  
Keyword(s):  
Corneal Thickness ◽  
Corneal Biomechanics ◽  
Corvis St ◽  
Collagen Crosslinking ◽  
The Third ◽  
Corneal Rigidity ◽  
Corneal Collagen Crosslinking ◽  
Early Features ◽  
Healthy Persons ◽  
Corneal Collagen

Purpose. To make a comparative analysis of topographic, tomographic and biomechanical values, measured by Pentacam HR and Corvis ST, in healthy multirefractive cohort versus patients with keratectasia of various severity. Material and methods. The prospective study comprised 237 patients aged from 18 to 47 years, subdivided into three groups. The first group included 174 healthy persons with various refraction (174 eyes). The second and the third group embraced 63 patients with keratoconus: 36 patients (36 eyes) with keratoconus of the I degree and 27 eyes with keratoconus of the II and III degrees. Besides the conventional comprehensive ocular examination the following studies were performed in all the patients: evaluation of topographic, tomographic and biomechanical corneal properties with application of Pentacam HR and Corvis ST (OCULUS Optikgerate GmbH; Wetzlar, Germany). Results. It was revealed that the following biomechanical values, assessed by means of Pentacam HR and Corvis ST, exhibited statistically significant changes (p<0,001) in all degrees of ketatoconus: a relative corneal thickness by Ambrosio, inverted radius of applanation curvature (IntRadius), DA Ratio Coefficient, values of corneal rigidity – SP-A 1 and SSI. Conclusion. The detected parameters may be applied as indicators, allowing to evaluate corneal biomechanics, to define early features of ectatic process, to assess effectiveness of the performed corneal collagen crosslinking and intralamellar keratoplasty with implantation of corneal segments. Key words: keratoconus, corneal biomechanics, pachymetry, index of pachymetric progression, corneal viscoelasticity.

scholarly journals Keratoconus in Children. Мodern Treatment Options

2021 ◽  
Vol 18 (4) ◽  
pp. 840-844
Author(s):  
E. Yu. Markova ◽  
G. V. Avakyants ◽  
E. V. Kechin
Keyword(s):  
Visual Acuity ◽  
Treatment Options ◽  
Corneal Thickness ◽  
High Tech ◽  
Cross Linking ◽  
Posterior Surface ◽  
Collagen Crosslinking ◽  
Optical Correction ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

Objective: to evaluate the results of corneal collagen crosslinking in children with keratoconus.Patients and methods. Since 2017, 125 children aged 4 to 17 years have been under observation, who have applied to the Eye Microsurgery named after Academician S.N. Fedorov with complaints of reduced visual acuity and, in some cases, the inability to select optical correction. All patients were examined, including using high-tech methods (Sheimpflug camera, OCT). Based on the anamnesis and the data obtained, the diagnosis of keratoconus stage I–III was made. Corneal collagen crosslinking was performed in 30 patients with stage II–III.Results. The study included 30 eyes of 30 patients (21 (68 %) boys, 9 (32 %) girls) with a median age — 16 (15; 17) years (12 to 17 years), who underwent accelerated “epi-off” crosslinking. No intra-and postoperative complications were observed. 12 months after CXL, there was a slowdown in the progression of keratoconus in children (minimum corneal thickness before surgery 460.00 (445.00; 477.00), after surgery 457.00 (441.00; 477.00), p = 0.112; K1 before surgery 44.60 (43.20; 46.90), after surgery 44.60 (42.90; 46.50), p = 0.481; K2 before surgery 48.30 (47.30; 51.25), after surgery 48.20 (47.21; 49.20), p = 0.779; elevation of the posterior surface before surgery 25.00 (18.00; 42.00), after surgery 26.00 (21.00; 42.00), p = 0.074, and increased visual acuity (NCOZ from 0.30 (0.05; 0.40) to 0.30 (0.20; 0.40) (p = 0.039) and MCOZ from 0.60 (0.40; 0.80) to 0.60 (0.50; 1.00) (p = 0.010)).Conclusion. 1. Keratoconus is also found in the child population. 2. Timely cross-linking of corneal collagen can slow the progression of keratoconus in children

scholarly journals Compressional Optical Coherence Elastography of the Cornea

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 111
Author(s):  
Manmohan Singh ◽  
Achuth Nair ◽  
Salavat R. Aglyamov ◽  
Kirill V. Larin
Keyword(s):  
Rabbit Model ◽  
Biomechanical Properties ◽  
Clinical Applications ◽  
Optical Coherence ◽  
Collagen Crosslinking ◽  
Corneal Collagen Crosslinking ◽  
Corneal Biomechanical Properties ◽  
Corneal Collagen

Assessing the biomechanical properties of the cornea is crucial for detecting the onset and progression of eye diseases. In this work, we demonstrate the application of compression-based optical coherence elastography (OCE) to measure the biomechanical properties of the cornea under various conditions, including validation in an in situ rabbit model and a demonstration of feasibility for in vivo measurements. Our results show a stark increase in the stiffness of the corneas as IOP was increased. Moreover, UV-A/riboflavin corneal collagen crosslinking (CXL) also dramatically increased the stiffness of the corneas. The results were consistent across 4 different scenarios (whole CXL in situ, partial CXL in situ, whole CXL in vivo, and partial CXL in vivo), emphasizing the reliability of compression OCE to measure corneal biomechanical properties and its potential for clinical applications.

scholarly journals Impact of COVID-19 on keratoconus patients waiting for corneal cross linking

2021 ◽  
pp. 112067212110013
Author(s):  
Haider Shah ◽  
Luca Pagano ◽  
Anuj Vakharia ◽  
Giulia Coco ◽  
Kunal A Gadhvi ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Observational Study ◽  
Corneal Thickness ◽  
Treatment Delay ◽  
Cross Linking ◽  
Corneal Surface ◽  
Collagen Crosslinking ◽  
Time Period ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

Purpose: Royal College of Ophthalmologist recent guidance recommended delaying cross-linking services during the COVID-19 pandemic. This study investigates the effects of such delays in the delivery of cross-linking services in patients with keratoconus progression. Methods: Retrospective observational study of 46 patients with keratoconus progression, whose cross-linking was delayed due to the COVID-19 pandemic. Demographic and clinical details were obtained from assessments on the day of listing, and subsequent review on the day of the procedure. Topographic indices included keratometry of the posterior and anterior corneal surface, maximum keratometry ( Kmax), thinnest corneal thickness, ABCD progression and progression based on standard criteria recommendations (1.5 D Kmax & 20 microns thinning). Results: A total of 46 eyes were analysed with an average time between being listed for CXL and having the procedure done was 182 ± 65 days. The delay due to COVID-19 was of 3 months. In this time period they had a significant worsening of all keratometric indices and lost almost one line of visual acuity (0.19 ± 0.19 to 0.26 ± 0.18 LogMAR, p: 0.03). Thirty two eyes (70%) demonstrated progression in accordance with the ABCD progression criteria, while 18 eyes (39%) showed either an increase in Kmax of more than 1.5D or a thinning in corneal thickness of at least 20 μm. Conclusions: The treatment delay for the keratoconus patients caused further progression and vision worsening. We recommend that corneal collagen crosslinking needs to be considered as a high priority intervention.

scholarly journals Silicone Hydrogel Miniscleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia

2014 ◽  
Vol 3 (3) ◽  
pp. 127-129
Author(s):  
Boris Severinsky
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Visual Outcome ◽  
Visual Rehabilitation ◽  
Collagen Crosslinking ◽  
Silicone Hydrogel ◽  
Corneal Collagen Crosslinking ◽  
Corneal Collagen

ABSTRACT Purpose To report successful visual rehabilitation of post refractive surgery keratoectasia shortly after corneal collage crosslinking (CXL) procedure achieved with silicone hydrogel mini-scleral (SHmS) contact lens. Materials and methods A 29-year-old woman attended to our clinic with complaints on decreased vision in her left eye. Twelve years earlier she underwent bilateral laser-assisted in situ keratomileusis (LASIK) procedure for myopia correction. Corneal topography revealed bilateral central keratoectasia with maximal keratometry values of 55.4 Diopter (D) for her right eye and 59.7 D for the left, corneal thicknesses were 422 and 443 respectively. The patient underwent an uneventful CXL procedure in her left eye and was fitted with SHmS lens 5 weeks later. The lens was designed to rest over the patients’ sclera and perilimbal cornea and vault the central cornea with minimal support over it. Results SHmS lens fitting resulted in significant subjective improvement in visual acuity (from 20/200, unaided to 20/25, contact lens corrected). The patient was able to wear the lens upto 10 hours a day with stable contact lens corrected vision. No contact lens related complications, such as edema or neovascularization were observed during 3 months follow-up period. As a result of successful restoration of vision in the CXL-treated eye, the patient was scheduled for the procedure in her other eye. Conclusion SHmS contact lens should be considered as an option for the visual rehabilitation of corneas shortly after collagen corneal crosslinking procedure. This novel contact lens modality made from flexible and highly gas permeable material minimizes contact lens influence on corneal recovery after CXL and provides an excellent visual outcome. How to cite this article Severinsky B. Silicone Hydrogel Mini-scleral Contact Lenses after Corneal Collagen Crosslinking for Post-LASIK Keratoectasia. Int J Kerat Ect Cor Dis 2014;3(3):127-129.

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