Purpose:
To evaluate corneal nerve regeneration in normal rabbit eyes after collagen cross-linking (CXL) treatment.
Methods:
The right eyes of 12 New Zealand male rabbits were treated with CXL. The left eyes were control eyes. Corneal sensitivity was measured with a Cochet-Bonnet esthesiometer preoperatively and at postoperative day 1, 7, 14, 30, 60, and 120. After sensitivity measurements, in vivo confocal microscopy was performed on both eyes. After confocal microscopy, corneas from 2 rabbits were excised and processed for histology at each time point.
Results:
Corneal sensitivity was significantly lower comparing before and after treatment (day 1, 7, 14, 30, and 60) and went back to preoperative level after 120 days (P = 0.25). A trend of regeneration was observed comparing different time point (Figure 1). Corneal nerve regeneration was visible in parallel with sensitivity alterations. Confocal microscopy showed that corneal nerve was absent until postoperative day 30. Corneal nerve was significantly regenerating at 60 days and was fully regenerated at 120 days. Histology showed that corneal nerve was starting to regenerate at day 14 and was fully regenerated at 120 days (Figure 2).
Conclusions:
Corneal sensitivity was reduced and recovered after collagen cross-linking treatment in rabbit eyes. Corneal nerve damage and subsequent regeneration was observed in parallel with sensitivity alterations.
Keywords: wound healing • cornea: basic science • regeneration