Published in:
01-08-2014 | Basic Science
In vitro extraction of intra-corneal iron using reverse iontophoresis and vitamin C
Published in: Graefe's Archive for Clinical and Experimental Ophthalmology | Issue 8/2014
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Purpose
The aim of this study was to optimize reverse iontophoretic (RI) extraction of ferric/ferrous ions from the cornea.
Methods
Group I consisted of the right eye corneas from 20 normal rabbits. Corneal blood staining was induced in 60 right eyes. The corneal depths from the endothelium to the epithelium layers were divided into three groups by slit-lamp examination: Group II, one-third corneal thickness; Group III, one-half corneal thickness; Group IV, full corneal thickness. RI was performed using vertical diffusion cells. The lower chamber was loaded with glutathione bicarbonate Ringer’s buffer (GBR; pH 7.0) or vitamin C (12.5 mg/mL) and GBR (pH 7.0), while the upper chamber was filled with 1 mL GBR. Progress of corneal blood staining removal was evaluated.
Results
Application of 1.5 mA to the cornea increased flux by 1.72- and 2.19-fold in Groups III and IV, respectively, but not in Groups I or II, compared to the control. When vitamin C was included, we observed significant flux increases in the controls (1.5-, 2.06-, 2.60-, and 4.59-fold) for Groups I, II, III, and IV, and under RI conditions for Groups III and IV. Following RI, the corneal endothelia appeared similar to corneas from untreated control rabbits, while Draize scores were zero.
Conclusions
These results suggested that extracellular ferric/ferrous ions could be extracted from the cornea in vitro by RI, and that vitamin C reduced Fe3+ to Fe2+ in the cornea and altered its permselectivity, thus increasing the RI contribution to iron extraction.