Abstract
Purpose :
To investigate the effect of repetitive magnetic stimulation (RMS) on corneal epithelial permeability in a short-term dry eye model in rabbits.
Methods :
Thirteen New Zealand white rabbits were used. One eye of each rabbit was treated with magnetic stimulation (Rapid2 stimulator, Magstim) at 40% output intensity and frequency of 20 Hz. The other untreated eye served as control. One hour later, rabbits were anesthetized and eyes were kept open for two hours to induce acute corneal desiccation. To evaluate corneal barrier, five microliters of sodium fluorescein (10%) were instilled on rabbit corneas. Extent of fluorescein corneal staining was evaluated using IMAGE J. Fluorescein penetration through the corneal barrier was assessed by determining fluorescein concentration in a 100 microliter sample withdrawn from the anterior chamber 1 hour following fluorescein installation. To determine duration of the therapeutic effect, five rabbits underwent acute corneal desiccation once a week for five weeks, and monitored for fluorescein corneal staining and penetration to the anterior chamber. Histopathology and optical coherence tomography (OCT) were used to evaluate the safety of RMS treatment.
Results :
Compared with untreated control eyes, RMS-treated eyes showed a significant decrease in fluorescein concentration in the anterior chamber (15.3 ng/ml [SE=4] vs 51.2 ng/ml [SE=7], p=0.0002) and in percentage of corneal surface stained with fluorescein (2% [SE=4.5] vs 17.4%[SE=3.4], p=0.001). Therapeutic effect was maintained for 5 weeks, with at least 2 fold lower fluorescein corneal staining in eyes treated with RMS. OCT and histopathology analysis revealed no pathological changes in the eyes.
Conclusions :
These findings demonstrate that RMS treatment decreases epithelial corneal permeability in an acute dry eye model in rabbits, with no indication for pathological changes in the eye. This study suggests that RMS may present a novel treatment for protection of corneal epithelium from desiccation in patients with dry eye.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.