Abstract
Purpose :
The cornea has the most dense nerve density in the human body. Considering previous reports showing that microcurrent stimulation to the damaged tissue accelerates the regeneration of epithelium and nerve tissue in brain and skin, we aimed to investigate whether weak electric current (WEC) facilitates corneal nerve regeneration (CNR) after superficial lamellar keratectomy (SLK) together with healing of corneal epithelial defect (CED) in new zealand white (NZW) rabbits.
Methods :
We made both CED and SLK models in NZW rabbit (male, 2-2.5 kg), respectively. Next, we classified to animal randomly into two groups for each model (control [C] and experimental [E] groups; n = 10, respectively). Group E was treated with WEC stimulation (7 mA, 20 Hz, 30 mins) once a day for 14 days. Immediately and 7 and 14 days after surgery, the extent of regeneration of CED was measured in CED model. In SLK model, the rabbits were sacrificed at 7 and 14 days after surgery (n = 5, respectively). Then, Immunofluorescent staining of β3 tubulin for the measurement of nerve density and western blot analysis of nerve regeneration factor CGRP were performed.
Results :
In CED model, the size of CED at day 7 was significantly smaller in Group E than that in Group C. In SLK model, the eyes of Group E (121.7 ± 7.0%) displayed significantly increased expression of β3 tubulin than that of Group C (100.0 ± 9.1%) in the cornea at day 7. In addition, western blot analysis also showed that protein level of CGRP was increased in Group E compared to that of Group C at day 7. A similar tendency of increased β3 tubulin density and CGRP level was found in Group E compared to Group C.
Conclusions :
Our results demonstrated the beneficial role of WEC stimulation in CNR process after SLK together with regeneration of corneal epithelium. CNR by WEC stimulation is a new alternative, combinative strategy that can be used to promote nerve regeneration in patients treated with refractive surgery. Further investigation is warranted to evaluate its efficacy and safety in clinical trials.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.