title: Evaluation of Intrastromal Riboflavin Concentration in Human Corneas after Three Corneal Cross-Linking Imbibition Procedures: A Pilot Study.
abstract: Purpose. To compare stromal riboflavin concentration after three corneal cross-linking (CXL) imbibition procedures: standard (EpiOff), transepithelial corneal (EpiOn), and iontophoresis-assisted technique (Ionto) using 0.1% hypotonic riboflavin phosphate. Methods. Randomized open-label pilot clinical study. Twelve corneas/12 patients with advanced keratoconus were randomly divided into 4 groups for CXL (n = 3). The corneas underwent imbibition with standard riboflavin EpiOff and with enhanced riboflavin solution (RICROLIN+) EpiOff, EpiOn, and iontophoresis techniques. Thereafter, deep anterior lamellar keratectomy procedure was performed and the obtained debrided corneal tissues were frozen. The maximal intrastromal riboflavin concentration was measured by high-performance liquid chromatography/mass spectrometry (mcg/dg). Results. The mean stromal concentration of riboflavin was 2.02 ± 0.72 mcg/dg in EpiOff group, 4.33 ± 0.12 mcg/g in EpiOff-RICROLIN+ group, 0.63 ± 0.21 mcg/dg in EpiOn-RICROLIN+ group, and 1.15 ± 0.27 mcg/dg in iontophoresis RICROLIN+ group. A 7-fold decrease in intrastromal riboflavin concentration was observed comparing EpiOn-RICROLIN+ and EpiOff-RICROLIN+ groups. Conclusion. The present pilot study indicates that both transepithelial CXL techniques in combination with hypotonic enhanced riboflavin formulation (RICROLIN+) were still inferior to the standard CXL technique; however, larger clinical studies to further validate the results are needed and in progress.
authors: Department of Ophthalmology, SS Giovanni e Paolo Hospital, Sestiere Castello 6777, 30122 Venice, Italy.
authors: Antonella
authors: A
authors: Franch
authors: Department of Ophthalmology, SS Giovanni e Paolo Hospital, Sestiere Castello 6777, 30122 Venice, Italy.
authors: Federica
authors: F
authors: Birattari
authors: Department of Ophthalmology, SS Giovanni e Paolo Hospital, Sestiere Castello 6777, 30122 Venice, Italy.
authors: Gloria
authors: G
authors: Dal Mas
authors: Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama, Via Paccagnella 11, Zelarino, 30174 Venice, Italy; Eye Hospital, University Medical Centre, Grablovičeva Ulica 46, 1525 Ljubljana, Slovenia.
authors: Zala
authors: Z
authors: Lužnik
authors: Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama, Via Paccagnella 11, Zelarino, 30174 Venice, Italy.
authors: Mohit
authors: M
authors: Parekh
authors: Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama, Via Paccagnella 11, Zelarino, 30174 Venice, Italy.
authors: Stefano
authors: S
authors: Ferrari
authors: Fondazione Banca degli Occhi del Veneto, c/o Padiglione G. Rama, Via Paccagnella 11, Zelarino, 30174 Venice, Italy.
authors: Diego
authors: D
authors: Ponzin