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Riboflavin osmolar modification for transepithelial corneal cross-linking
Frederik Raiskup1, Roberto Pinelli, Eberhard Spoerl
1Department of Ophthalmology, Carl Gustav Carus University Hospital, Fetscherstrasse 74, Dresden, Germany. frederik.raiskup@uniklinikum-dresden.de
Current Eye Research
|February 17, 2012
Summary
Optimizing riboflavin solutions for corneal cross-linking involves adjusting osmolarity. Adding 0.01% benzalkonium chloride (BAC) and 0.44% sodium chloride (NaCl) enhances riboflavin permeability through the epithelium.
Area of Science:
- Ophthalmology
- Corneal Cross-linking
- Biomaterials
Background:
- Corneal cross-linking (CXL) is a procedure to strengthen the cornea.
- Riboflavin is a key photosensitizer used in CXL.
- Optimizing riboflavin delivery is crucial for CXL efficacy.
Purpose of the Study:
- To determine how osmolarity affects transepithelial riboflavin permeability.
- To identify optimal concentrations of sodium chloride (NaCl) and benzalkonium chloride (BAC) in riboflavin solutions for CXL.
Main Methods:
- Rabbit eyes were treated with riboflavin 0.1% solutions containing varying NaCl and BAC concentrations.
- Absorption coefficients were measured to quantify riboflavin penetration.
- Control groups included epithelium-off and epithelium-on corneas.
Main Results:
- Lowering NaCl concentration to 0.44% significantly increased riboflavin penetration compared to 0.9% NaCl (P=0.004).
- Benzalkonium chloride (BAC) at 0.01% or 0.02% in 0.44% NaCl solution enhanced penetration.
- These optimized solutions achieved 33-37% of the penetration seen in epithelium-off controls.
Conclusions:
- Riboflavin solutions for CXL should exclude dextran.
- A formulation of 0.01% BAC and 0.44% NaCl in riboflavin solution promotes epithelial permeability.
- This enhances riboflavin concentration in the corneal stroma for effective cross-linking.
