Histopathological changes on the ocular surface of New Zealand white rabbits after instillation of a fixed combination of 0.09 % xanthan gum and 0.1 % chondroitin sulfate.

The aim of this study was to evaluate the histopathological changes in a model of New Zealand white rabbits after the ocular instillation of a fixed combination containing 0.09 % xanthan gum and 0.1 % chondroitin sulfate for 15 days. This was a preclinical study which compared the previously described combination with placebo on an animal model of sixteen New Zealand white rabbits. The intervention consisted of the instillation of one drop of a fixed combination containing 0.09 % xanthan gum and 0.1 % chondroitin sulfate on the right eye of each rabbit 6 times per day (every 2 h) in a 12-hour period for 15 days. The left eyes were used as control. Assessments on the anterior and posterior segment, ocular signs, and specific ocular surface characteristics were conducted at days 0, 1, 2, 4, 7, 10, and 15. Histopathological studies of the corneal and conjunctival epithelium were performed at the end of the intervention. No significant changes were observed during the assessments of the anterior and posterior segments. No differences in the number of goblet cells between groups were reported. The histopathological study of the corneal basement membrane's thickness, stromal, and conjunctival epithelium did not show significant changes between groups. The use of a fixed-dose combination containing 0.09 % xanthan gum and 0.1 % chondroitin sulfate on the ocular surface of New Zealand white rabbits every 2 h for 15 days causes no histopathological changes in anterior/posterior segments, nor a decrease in the number of goblet cells compared with placebo.