Dataset Information

Arginine as an Enhancer in Rose Bengal Photosensitized Corneal Crosslinking.

ABSTRACT: Purpose:Oxygen-independent cornea crosslinking (CXL) using rose bengal (RB) and green light may have unique clinical applications. These studies were designed to gain insight into the arginine (arg)-enhanced anaerobic crosslinking process, to maximize crosslinking efficiency, and to test a clinically feasible method for oxygen-free CXL. Methods:Rabbit corneas were treated ex vivo using 1 mM RB and 532 nm light. RB photodecomposition, monitored by absorption spectrophotometry, was used to optimize arg concentration and to develop an irradiation and re-dying protocol. The minimal effective green light fluence was identified by linear tensile strength measurements. RB penetration into the stroma was determined by fluorescence microscopy. To favor the anaerobic pathway, a contact lens was used to minimize stromal oxygen level during irradiation. Stromal cell toxicity was evaluated by a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Results:RB photodecomposition reached 75% of its maximal effect at 200 mM arg and the optimal fluence increment was 32.7 J/cm2. The minimal effective fluence for cornea stiffening was 65.4 J/cm2. Placement of a contact lens promoted oxygen-independent cornea stiffening, similar to that obtained on isolated, oxygen-deprived cornea. RB penetration into the stroma with arg present was limited to ?120 µm, about 25% deeper than without arg. Stromal cell toxicity was limited to the depth of RB and arg penetration. Conclusions:An oxygen-independent pathway in cornea for RB-CXL was characterized and optimized, including a possible clinical protocol for its use. Translational Relevance:Oxygen-independent RB-CXL is an efficient and effective process that can be developed further for unique clinical applications.

SUBMITTER: Wertheimer CM

PROVIDER: S-EPMC7422776 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Arginine as an Enhancer in Rose Bengal Photosensitized Corneal Crosslinking.

Wertheimer Christian M CM Mendes Bryan B Pei Qing Q Brandt Katharina K Kochevar Irene E IE

Translational vision science & technology 20200714 8

<h4>Purpose</h4>Oxygen-independent cornea crosslinking (CXL) using rose bengal (RB) and green light may have unique clinical applications. These studies were designed to gain insight into the arginine (arg)-enhanced anaerobic crosslinking process, to maximize crosslinking efficiency, and to test a clinically feasible method for oxygen-free CXL.<h4>Methods</h4>Rabbit corneas were treated ex vivo using 1 mM RB and 532 nm light. RB photodecomposition, monitored by absorption spectrophotometry, was ...[more]

PMID: 32855871

Similar Datasets

Project description:PurposePreviously, we found norepinephrine (NE) could affect the corneal epithelial integrity, herein we investigated the feasibility and safety of NE serving as a chemical enhancer to promote corneal penetration of riboflavin during transepithelial corneal crosslinking (CXL).MethodsThe dosage of NE that could promote riboflavin diffusion through the healthy epithelial barrier without inducing epithelial damage in C57BL/6 mice was determined. The safety of NE treatment was confirmed by morphological and histological examinations of the whole cornea. The efficacy of NE in promoting riboflavin penetration was verified by slit lamp and scanning electron microscope (SEM), and corneal biomechanical measurement after CXL. To better fit the clinical scenario, increased NE dosage and shortened riboflavin infiltration time were further evaluated.ResultsThe lowest dosage of NE (1 mg/mL) that facilitated transepithelial riboflavin permeation was 2 µL. No visible corneal structure alteration was observed after NE treatment. SEM indicated dissociation of intercellular junctions among corneal epithelial cells. Homogenous distribution of riboflavin throughout corneal stroma was observed. NE-treated corneas reached comparable biomechanical properties after CXL, including stress-relaxation curve and elastic modulus, with corneas treated with the commercially available transepithelial drug Peschke TE. To better fit the clinical scenario, increasing NE up to 5.5 µL helped riboflavin infiltrate the corneal stroma within 30 minutes. After CXL with 9 mW/cm2 ultraviolet-A (UVA) for 2.5 minutes, the cornea showed significantly enhanced corneal biomechanical properties with undisturbed corneal endothelium.ConclusionsNE serves as an effective enhancer in increasing riboflavin diffusion with limited impairment on corneal epithelium and has great potential for clinical application.Translation relevanceNE serves as an effective enhancer for riboflavin penetration and clinical transepithelial CXL.

Dataset Information

Arginine as an Enhancer in Rose Bengal Photosensitized Corneal Crosslinking.

Publications

Arginine as an Enhancer in Rose Bengal Photosensitized Corneal Crosslinking.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets