Collagen cross-linking treatment effects on corneal dynamic biomechanical properties

2015 ◽  
Vol 135 ◽  
pp. 88-92 ◽  
Author(s):  
Hamed Hatami-Marbini ◽  
Abdolrasol Rahimi
Keyword(s):  
Treatment Effects ◽  
Biomechanical Properties ◽  
Cross Linking ◽  
Collagen Cross Linking

Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female athletes

2013 ◽  
Vol 114 (8) ◽  
pp. 998-1008 ◽  
Author(s):  
Mette Hansen ◽  
Christian Couppe ◽  
Christina S. E. Hansen ◽  
Dorthe Skovgaard ◽  
Vuokko Kovanen ◽  
...  
Keyword(s):  
Patellar Tendon ◽  
Female Athletes ◽  
Maximum Voluntary Contraction ◽  
Biomechanical Properties ◽  
Cross Sectional Area ◽  
Cross Linking ◽  
Sectional Area ◽  
Cross Sectional ◽  
Collagen Cross Linking

Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and length were measured from MRI images, and tendon biopsies were obtained for analysis of tendon fibril characteristics and collagen cross-linking. Overall, no difference in tendon biomechanical properties, tendon fibril characteristics, or collagen cross-linking was observed between the OC users and nonusers, or between the different phases of the menstrual cycle. In athletes, tendon cross-sectional area in the preferred jumping leg tended to be larger than that in the contralateral leg ( P = 0.09), and a greater absolute ( P = 0.01) and normalized tendon stiffness ( P = 0.02), as well as a lower strain ( P = 0.04), were observed in the jumping leg compared with the contralateral leg. The results indicate that long-term OC use or menstrual phases does not influence structure or mechanical properties of the patellar tendon in female team handball athletes.

scholarly journals Technology of the Local Cross-linking (Part 1): Keratotensotopography and Vacuum-compression Topographic Test—New Diagnostic Possibilities for Studying the Local Biomechanical Properties of Cornea

2017 ◽  
Vol 6 (1) ◽  
pp. 14-16 ◽  
Author(s):  
SY Anisimova ◽  
AS Mistryukov ◽  
NS Anisimova ◽  
SI Anisimov
Keyword(s):  
Intraocular Pressure ◽  
Clinical Significance ◽  
Uv Irradiation ◽  
Compression Test ◽  
Biomechanical Properties ◽  
Cross Linking ◽  
Peripheral Part ◽  
Special Software ◽  
Collagen Cross Linking ◽  
Corneal Collagen

ABSTRACT Aim The aim of this study is the development and evaluation of clinical significance methodology for determining mech­anical stress (MS) and elasticity of the cornea comparable to its topographic settings. Materials and methods Combining the data of optical pachymeter, keratotopography, and pneumotonometry through our special software allows us to get Lokolink MS distribution in the cornea in the form of maps, which we propose to call keratotensotopogram (KTT). Results Normal KTT has the form of concentric, uniform, and symmetrical zones. In keratoconus (KC), the corneal center is more tense than peripheral part of cornea. The focus zone of KC may coincide with the region of maximum MS or may be out of this area. In the process of vacuum-compression test, the reaction of profile of the cornea was markedly different in patients with healthy corneas and in patients with KC. In all cases of healthy cornea, the curvature increased in the center. In KC, the cornea became more flat in the center under high intraocular pressure (in 100% of cases). Conclusion The KTT ineyes with the cornea without pathology differs from KTT in the different cases of KC. The KTT can be used for the diagnosis and prediction of cornea's state to perform the plan of UV irradiation areas for corneal collagen cross-linking. How to cite this article Anisimov SI, Anisimova SY, Mistryukov AS, Anisimova NS. Technology of the Local Cross-linking (Part 1): Keratotensotopography and Vacuum-compression Topographic Test—New Diagnostic Possibilities for Studying the Local Biomechanical Properties of Cornea. Int J Kerat Ect Cor Dis 2017;6(1):14-16.

scholarly journals Assessment of the changes in corneal biomechanical properties after collagen cross-linking in patients with keratoconus

2019 ◽  
Vol 31 (3) ◽  
pp. 262-267 ◽  
Author(s):  
Ramin Salouti ◽  
Mohammad Reza Khalili ◽  
Mohammad Zamani ◽  
Maryam Ghoreyshi ◽  
M. Hossein Nowroozzadeh
Keyword(s):  
Biomechanical Properties ◽  
Cross Linking ◽  
Corneal Biomechanical Properties ◽  
Collagen Cross Linking

scholarly journals Simultaneous topography-guided photorefractive keratectomy with accelerated collagen cross-linking in the treatment of stage I keratoconus

2019 ◽  
Vol 12 (4) ◽  
pp. 28-34
Author(s):  
A. V. Ivanova ◽  
A. S. Sklyarova ◽  
K. B. Letnikova ◽  
A. T. Khandzhyan ◽  
N. V. Khodzhabekyan
Keyword(s):  
Visual Acuity ◽  
Combined Treatment ◽  
Functional Results ◽  
Biomechanical Properties ◽  
Stage I ◽  
Photorefractive Keratectomy ◽  
Cross Linking ◽  
Uncorrected Visual Acuity ◽  
Corneal Collagen Crosslinking ◽  
Collagen Cross Linking

Purpose: to evaluate the efficiency of simultaneous topography-guided photorefractive keratectomy (PRK) with accelerated collagen cross-linking in the treatment of stage I keratoconus.Material and methods. 38 patients (49 eyes) aged 18 to 44 with stage I keratoconus were treated with simultaneous topography-guided PRK combined with accelerated corneal collagen crosslinking. Along with standard ophthalmological testing, patients underwent aberrometry, confocal microscopy, optical coherence tomography of the cornea, imaging of the anterior eye section on a Scheimpflug analyzer, and examination of the biomechanical properties of the cornea. The follow-up period was 2 years.Results. Two years after surgery, uncorrected visual acuity which originally was 0.23 ± 0.03 showed a statistically significant increase and reached 0.72 ± 0.02; best corrected visual acuity improved from 0.44 ± 0.03 to 0.89 ± 0.02; the refractive power of the cornea fell from 45.03 ± 0.28 to 42.55 ± 0.31 D; the spherical component of refraction reduced from -2.00 ± 0.19 to -0.73 ± 0.09 D; the cylinder component reduced from 2.46 ± 0.14 to 0.79 ± 0.07 mm, the thinnest point of the cornea reduced from 486.30 ± 4.78 to 406.80 ± 6.51 μm. The highest order aberrations showed the following results: Coma index reduced from 0.27 ± 0.12 to 0.08 ± 0.07, Tilt reduced from 0.53 ± 0.11 to 0.10 ± 0,09, and Trefoil reduced from 0.13 ± 0.04 to 0.05 ± 0.02.Conclusion. The analysis of clinical and functional results, biomechanical properties and structures of the cornea confirmed the efficacy and safety of the combined treatment of patients with stage I keratoconus.

scholarly journals A copper sulfate and hydroxylysine treatment regimen for enhancing collagen cross‐linking and biomechanical properties in engineered neocartilage

2013 ◽  
Vol 27 (6) ◽  
pp. 2421-2430 ◽  
Author(s):  
Eleftherios A. Makris ◽  
Regina F. MacBarb ◽  
Donald J. Responte ◽  
Jerry C. Hu ◽  
Kyriacos A. Athanasiou
Keyword(s):  
Treatment Regimen ◽  
Copper Sulfate ◽  
Biomechanical Properties ◽  
Cross Linking ◽  
Collagen Cross Linking

Corneal Collagen Cross-linking in Keratectasia

2009 ◽  
Vol 03 (01) ◽  
pp. 57
Author(s):  
Farhad Hafezi ◽  
Keyword(s):  
Biomechanical Properties ◽  
Cross Linking ◽  
Ultraviolet A ◽  
Comprehensive Overview ◽  
Basic Principles ◽  
Safety Issues ◽  
Current State ◽  
Biochemical Resistance ◽  
Collagen Cross Linking ◽  
Corneal Collagen

In recent years, increased attention has been paid to the biomechanical properties of the cornea. Corneal biomechanics are altered not only in inherited and acquired corneal conditions, such as ectatic disorders or melting processes, but also by refractive surgical procedures. Therefore, a therapeutic approach to increase the biomechanical and biochemical resistance of the cornea would address important issues in a variety of corneal disorders. Corneal collagen cross-linking (CXL) with riboflavin and ultraviolet A (UVA) is an innovative clinical technique that fulfils these criteria. To assist researchers and clinicians interested in the field, this article provides a comprehensive overview of the current state of CXL, its basic principles, the technique and clinical indications, but also safety issues and potential complications.

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