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

Author(s):  
Leopoldo Spadea ◽  
Francesca Verboschi ◽  
Stefano Valente ◽  
Enzo Maria Vingolo

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.

2021 ◽  
Author(s):  
Junjie Piao ◽  
Shen Wang ◽  
Ye Tao ◽  
Yue Hua Zhou ◽  
Ying Li

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.


2014 ◽  
Vol 40 (10) ◽  
pp. 1591-1596 ◽  
Author(s):  
Aydin Yildirim ◽  
Hanefi Cakir ◽  
Necip Kara ◽  
Hasim Uslu ◽  
Bulent Gurler ◽  
...  

Author(s):  
B.E. Malugin ◽  
◽  
E.G. Solodkova ◽  
S.V. Balalin ◽  
V.S. Kulikov ◽  
...  

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.


2021 ◽  
Vol 18 (4) ◽  
pp. 840-844
Author(s):  
E. Yu. Markova ◽  
G. V. Avakyants ◽  
E. V. Kechin

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


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