Collagen Cross-Linking Using Rose Bengal and Green Light to Increase Corneal Stiffness
| Autor: | Irene E. Kochevar, Francis J. Doyle, E. Eri Verter, Samir A. Melki, Thomas E. Gisel, Seok Hyun Yun, Robert W. Redmond, Giuliano Scarcelli, Daniel G Cherfan |
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| Rok vydání: | 2013 |
| Předmět: |
Keratoconus
medicine.medical_specialty genetic structures Light Corneal Stroma Corneal collagen cross-linking Cell Count Corneal Keratocytes Lasers Solid-State chemistry.chemical_compound Tensile Strength Cornea Ophthalmology Microscopy medicine Fluorescence microscope Rose bengal Animals Irradiation Rose Bengal Frozen section procedure Photosensitizing Agents Chemistry Articles Anatomy medicine.disease Elasticity eye diseases Cross-Linking Reagents medicine.anatomical_structure Microscopy Fluorescence Collagen Rabbits sense organs |
| Zdroj: | Investigative Opthalmology & Visual Science. 54:3426 |
| ISSN: | 1552-5783 |
| DOI: | 10.1167/iovs.12-11509 |
| Popis: | Purpose Photochemical cross-linking of corneal collagen is an evolving treatment for keratoconus and other ectatic disorders. We evaluated collagen cross-linking by rose bengal plus green light (RGX) in rabbit eyes and investigated factors important for clinical application. Methods Rose bengal (RB, 0.1%) was applied to deepithelialized corneas of enucleated rabbit eyes for 2 minutes. The diffusion distance of RB into the stroma was measured by fluorescence microscopy on frozen sections. RB-stained corneas were exposed to green (532-nm) light for 3.3 to 9.9 minutes (50-150 J/cm(2)). Changes in the absorption spectrum during the irradiation were recorded. Corneal stiffness was measured by uniaxial tensiometry. The spatial distribution of the stromal elastic modulus was assessed by Brillouin microscopy. Viable keratocytes were counted on H&E-stained sections 24 hours posttreatment. Results RB penetrated approximately 100 μm into the corneal stroma and absorbed >90% of the incident green light. RGX (150 J/cm(2)) increased stromal stiffness by 3.8-fold. The elastic modulus increased in the anterior approximately 120 μm of stroma. RB was partially photobleached during the 2-minute irradiation, but reapplication of RB blocked light transmission by >70%. Spectral measurements suggested that RGX initiated cross-linking by an oxygen-dependent mechanism. RGX did not decrease keratocyte viability. Conclusions RGX significantly increases cornea stiffness in a rapid treatment (≅12 minutes total time), does not cause toxicity to keratocytes and may be used to stiffen corneas thinner than 400 μm. Thus, RGX may provide an attractive approach to inhibit progression of keratoconus and other ectatic disorders. |
| Databáze: | OpenAIRE |
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