TY - BOOK AU - Rubinfeld, Roy S TI - Quantitative analysis of corneal stromal riboflavin concentration without epithelial removal SN - 0886-3350 PY - 2018/// KW - *Corneal Stroma/me [Metabolism] KW - *Epithelium, Corneal/su [Surgery] KW - *Photosensitizing Agents/pk [Pharmacokinetics] KW - *Riboflavin/pk [Pharmacokinetics] KW - Animals KW - Chromatography, Liquid KW - Cross-Linking Reagents/pk [Pharmacokinetics] KW - Debridement KW - Mass Spectrometry KW - Rabbits KW - MedStar Washington Hospital Center KW - Ophthalmology KW - Journal Article N1 - Available online through MWHC library: 1999 - 2010, Available in print through MWHC library:1999-2007 N2 - CONCLUSIONS: The system used in Group 1 produced corneal riboflavin concentrations that were theoretically adequate for effective transepithelial CXL (>=15 mug/g), while the system in Group 2 did not. Slitlamp grading successfully estimated the corneal riboflavin concentration and can be used to ensure an adequate concentration of riboflavin in the cornea for transepithelial CXL; Copyright (c) 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved; DESIGN: Experimental study; METHODS: The stromal riboflavin concentration of 2 transepithelial CXL systems was compared in rabbit eyes in vivo. The systems were the CXLO (Group 1) and Paracel/Vibex Xtra, containing TRIS and ethylenediaminetetraacetic acid and an isotonic solution of riboflavin 0.25%, (Group 2). Manufacturers' Instructions For Use were followed. The intensity of riboflavin fluorescence by slitlamp observation 10, 15, and 20 minutes after instillation was graded on a scale of 0 to 5. The animals were humanely killed and the corneal stromal samples analyzed with liquid chromatography and mass spectrometry; PURPOSE: To compare the corneal stromal riboflavin concentration and distribution using 2 transepithelial corneal crosslinking (CXL) systems; RESULTS: The mean riboflavin fluorescence intensity grades in Group 1 (4 eyes) were 3.8, 4.8, and 4.8 at 10, 15, and 20 minutes, respectively. The mean grades in Group 2 (3 eyes) were 2.0, 2.3, and 2.0, respectively. The riboflavin distribution was uniform in Group 1 but not in Group 2. The mean riboflavin concentration by liquid chromatography and mass spectrometry was 27.0 mug/g stromal tissue in Group 1 and 6.7 mug/g in Group 2. A stromal riboflavin concentration theoretically adequate for CXL, 15 mug/g, was achieved in all eyes in Group 1 and no eyes in Group 2. Slitlamp grading correlated well with liquid chromatography and mass spectrometry concentration (R2 = 0.940); SETTING: Absorption Systems, San Diego, California, USA UR - https://dx.doi.org/10.1016/j.jcrs.2018.01.010 ER -