Cornea collagen crosslinking

PURPOSE: We recently showed that in situ-forming collagen gels crosslinked through multifunctional polyethylene glycol (PEG) supported corneal epithelialization 7 days after treatment of lamellar keratectomy wounds. In this study, we aimed to evaluate the longer-term regenerative effects of this gel in animals. METHOD: Corneal wound healing was assessed 60 days after lamellar keratectomy and gel treatment using slitlamp examination, optical coherence tomography (OCT), pachymetry, corneal topography, an ocular response analyzer, and tonometry...

The Boston Keratoprosthesis type I (B-KPro) is widely used in the world, but the lack of donor corneas limits its application. This study aims to prepare the acellular porcine cornea (APC) crosslinked with ultraviolet A (UVA)/riboflavin instead of donor corneas as the scaffold for B-KPro. Decellularization of freeze-thaw combined with biological enzymes resulted in approximately 5 ng/mg DNA residue, the a-Gal removal rate of 99%, and glycosaminoglycans retention at a high level of 46.66 ± 2...

PURPOSE: To evaluate the clinical and functional outcomes of bandage therapeutic-optical keratoplasty (BTOK) surgery in patients with keratoconus (KC) and significant changes in corneal thickness. MATERIAL AND METHODS: Surgical treatment was performed in 15 patients (15 eyes) with stage IV KC aged from 22 to 51 years (mean age - 32.61±7.94 years). The follow-up period lasted 3 years. All patients underwent BTOK surgery using an interlamellar graft with a thickness of 320 to 350 µm...

The cornea is responsible for most of the refractive power in the eye and acts as a protective layer for internal contents of the eye. The cornea requires mechanical strength for maintaining its precise shape and for withstanding external and internal forces. Corneal collagen crosslinking (CXL) is a treatment option to improve corneal mechanical properties. The primary objective of this study was to characterize CXL effects on viscoelastic shear properties of the porcine cornea as a function of compressive strain...

PURPOSE: The relevance of corneal biomechanics and the importance of including it in the clinical assessment of corneal ectasias are being increasingly recognized. The connection between corneal ultrastructure, biomechanical properties, and optical function is exemplified by a condition like keratoconus. Biomechanical instability is seen as the underlying basis for the secondary morphological changes in the cornea. Asymmetric biomechanical weakening is believed to drive progressive corneal steepening and thinning...

The present work focuses on the computational study of the structural micro-organization of hydrogels based on collagen-like peptides (CLPs) in complex with Rose Bengal (RB). In previous studies, these hydrogels computationally and experimentally demonstrated that when RB was activated by green light, it could generate forms of stable crosslinked structures capable of regenerating biological tissues such as the skin and cornea. Here, we focus on the structural and atomic interactions of two collagen-like peptides (collagen-like peptide I (CLPI), and collagen-like peptide II, (CLPII)) in the presence and absence of RB, highlighting the acquired three-dimensional organization and going deep into the stabilization effect caused by the dye...

Purpose: To assess the change in corneal pachymetry after a novel epithelium-on (EpiSmart® ) corneal crosslinking procedure (CXL). Methods: Eyes treated as part of the open-label, non-controlled arm of the study "Collagen Crosslinking with Ultraviolet-A in Asymmetric Corneas" (NCT01097447) were examined at baseline, 3-, 6- and 12-months post-CXL. Thinnest pachymetry readings based on Pentacam (OCULUS GmbH, Wetzlar, Germany) were recorded. Results: A total of 101 eyes met the study inclusion criteria...

Development of an artificial cornea can potentially fulfil the demand of donor corneas for transplantation as the number of donors is far less than needed to treat corneal blindness. Collagen-based artificial corneas stand out as a regenerative option, having promising clinical outcomes. Collagen crosslinked with chemical crosslinkers which modify the parent functional groups of collagen. However, crosslinkers are usually cytotoxic, so crosslinkers need to be removed from implants completely before application in humans...

Corneal collagen crosslinking (CXL) is a commonly used minimally invasive surgical technique to prevent the progression of corneal ectasias, such as keratoconus. Unfortunately, riboflavin/UV-A light-based CXL procedures have not been successfully applied to all patients, and result in frequent complications, such as corneal haze and endothelial damage. We propose a new method for corneal crosslinking by using a Ruthenium (Ru) based water-soluble photoinitiator and visible light (430 nm). Tris(bipyridine)ruthenium(II) ([Ru(bpy)3 ]2+ ) and sodium persulfate (SPS) mixture covalently crosslinks free tyrosine, histidine, and lysine groups under visible light (400-450 nm), which prevents UV-A light-induced cytotoxicity in an efficient and time saving collagen crosslinking procedure...

Scleral photocrosslinking is increasingly investigated for treatment of myopia and glaucoma. In this study a computational model was developed to predict crosslinking efficiency of visible/near infrared photosensitizers in the sclera. Photocrosslinking was validated against riboflavin corneal crosslinking experimental studies and subsequently modeled for the sensitizer, methylene blue, administered by retrobulbar injection to the posterior sclera and irradiated with a transpupillary light beam. Optimal ranges were determined for treatment parameters including light intensity, methylene blue concentration, injection volume, and inspired oxygen concentration...

Purpose: To assess Photo Activated Chromophore for Infective Keratitis-Cross Linking (PACK-CXL) and its efficacy as a treatment modality in managing microbial keratitis. Methods: Single Centre prospective interventional study in infectious keratitis. A total of eleven patients were taken who had corneal thickness (CT) more than 400μm. PACK-CXL was performed according to Dresden's protocol. The response was assessed by slit lamp examination, BCVA and AS-OCT at the time of complete healing...

The biomechanical properties of the cornea have a profound influence on the health, structural integrity, and function of the eye. Understanding these properties may be critical for diagnosis and identifying disease pathogenesis. This work demonstrates how two different elastography techniques can be combined for a multimodal approach to measuring corneal biomechanical properties. Heartbeat optical coherence elastography (Hb-OCE) and compression OCE were performed simultaneously to measure the stiffness of the cornea in an in vivo rabbit model...

Corneal collagen cross-linking has established itself as the only known treatment with a proven ability to arrest the progression of keratoconus. The efficacy and safety of the procedure have been entirely due to meticulous preparation by the innovators of this technique, before clinical application was confidently advocated. The article by Spoerl et al, entitled "Safety of UVA riboflavin crosslinking of the cornea," one of the most frequently cited articles in the journal " Cornea ," explains the logic behind the formulation of the "Dresdon protocol" that remains the gold standard in the treatment of keratoconus by collagen cross-linking...

The aim of this study was to assess the effect of the standard crosslinking (CXL) procedure on corneal properties and subsequent changes in collagen bonds formation using optical coherence tomography (OCT) corneal speckle statistics and vibrational spectroscopy. Porcine eyes with intact corneal epithelium were randomly selected to one of the four study groups: (1) untreated eyes moistened with phosphate-buffered saline (PBS); (2) eyes after the epithelial debridement and riboflavin application; (3) eyes after CXL procedure according to the Dresden protocol; and (4) eyes after corneal epithelial debridement, regularly moistened with PBS...

A 26-year-old female presented to us with complaints of progressive loss of vision in right eye (RE) since past 6 months. Patient was a known case of generalized systemic sclerosis with hypothyroidism for the past 2 years and was under treatment with a rheumatologist Physical features of scleroderma seen in her included diffuse skin tightness, hyper pigmentation of skin of face, abdomen, thighs, legs and arms, with ulcers on fingers. Her best corrected visual acuity was 20/320 in the RE and 20/20 in the left eye (LE)...

Keratoconus is the most common primary corneal ectasia characterized by progressive focal thinning. Patients experience increased irregular astigmatism, decreased visual acuity and corneal sensitivity. Corneal collagen crosslinking (CXL), a minimally invasive procedure, is effective in halting disease progression. Historically, keratoconus research was confined to ex vivo settings. In vivo confocal microscopy (IVCM) has been used to examine the corneal microstructure clinically. In this review, we discuss keratoconus cellular changes evaluated by IVCM before and after CXL...

Purpose: The multicenter studies reviewed were designed to evaluate the safety and efficacy of corneal collagen crosslinking (CXL) for the treatment of progressive keratoconus and corneal ectasia after laser refractive surgery. The results of these studies led to approval by the United States Food and Drug Agency for both conditions in 2016. This paper reviews these studies, as well as single-center substudies investigating other aspects of crosslinking outcomes. Methods: As part of prospective, randomized, controlled clinical trials, the treatment group received standard CXL, and the sham control group received only riboflavin ophthalmic solution...

Fungal keratitis is a serious clinical infection on the cornea caused by fungi and is one of the leading causes of blindness in Asian countries. The treatment options are currently limited to a few antifungal agents. With the increasing incidence of drug-resistant infections, many patients fail to respond to antibiotics. Riboflavin-mediated corneal crosslinking (similar to photodynamic therapy (PDT)) for corneal ectasia was approved in the US in the early 2000s. Current evidence suggests that PDT could have the potential to inhibit fungal biofilm formation and overcome drug resistance by using riboflavin and rose bengal as photosensitizers...

BACKGROUND: Keratoconus is a non-inflammatory disease characterized by progressive corneal steepening, which leads to decreased visual acuity secondary to high irregular astigmatism. OBJECTIVES: To compare the one-year outcomes of accelerated vs. standard collagen crosslinking (CXL) in the treatment of keratoconus. METHODS: A database search of patients who underwent CXL from 2009 to 2017 was conducted at the cornea clinic at Sheba Medical Center...

Purpose: To investigate the potential predictive factors of the visual change achieved with accelerated epi-on and epi-off corneal collagen crosslinking (CXL) in keratoconus. Methods: This retrospective comparative study analyzed 67 eyes treated with an accelerated epithelium-on (epi-on group) and epithelium-off (epi-off group) CXL. The clinical outcomes were evaluated and compared during a 1-year follow-up. Likewise, the relationship of the change achieved with both CXL techniques in the corrected distance visual acuity (CDVA) with different preoperative data was investigated...