Safety evaluation of rabbit eyes on scleral collagen cross-linking by riboflavin and ultraviolet A.

Background: To evaluate the safety of the scleral collagen cross-linking (CXL) transferred from corneal CXL in rabbit eyes using histology and electroretinography (ERG).
Methods: Stress-strain measurement was performed five rabbits 1 week after scleral CXL. Dark-adapted ERG was repeatedly applied on bilateral eyes of 10 rabbits before, and 1 week, 1 month and 3 months after the CXL operation. Histological analysis, terminal deoxynucleotidyl transferase dUTP nick-end labeling, the measurement of outer nuclear layer thickness and transmission electron microscopy were performed onto 15 rabbits at corresponding time points postoperatively.
Results: The mechanical and biochemical stability of rabbit scleral tissues was statistically increased after the scleral CXL (P = .00). However, the dark-adapted ERG amplitudes were statistically reduced 1 week, 1 month and 3 months postoperatively (P < 0.05). Compared with the control eyes, apoptotic cells and ultrastructural changes can be found in the retinal layers of scleral cross-linked eyes.
Conclusions: According to the electrophysiological and histopathological results, the current scleral CXL laboratory technique is not safe enough for the postoperative visual function of rabbit eyes.
(© 2014 Royal Australian and New Zealand College of Ophthalmologists.)