The effects of the intravitreal and anterior chamber ropivacaine injection on the intraocular tissues in rat model

Abstract

The purpose of this study is to investigate the histopathological changes of ropivacaine on intraocular tissues after intravitreal and anterior chamber injection. Methods: Thirty Wistar albino rats were randomly divided into three groups; each group consisted of 10 rats. Group 1 was injected intravitreal 0.05 mL (0.25 mg) ropivacaine. Group 2 was injected anterior chamber 0.02 mL (0.1 mg) ropivacaine. Group 3 was used as control five were injected intravitreal 0.05 mL balanced salt solutions (BSS(R)), and the other five rats were injected anterior chamber 0.02 mL BSS. On postinjection days 2, 5, 7, 10 and 15, the eyes were enucleated, and iris, ciliary body, and retina were processed for light microscopic examination. Histologic sections were stained with hematoxylin-eosin, periodic acid-Schiff, and Masson trichrome stains. In additional, the corneal thickness was measured with objective micrometer. Results: Histopathological examination revealed no abnormalities in all eyes after 2, 5, 7, 10, and 15 days in the study and control groups. Similar findings in the iris, ciliary body, and retina were observed. Histologic sections did not reveal inflammatory reaction, cell degeneration, and cell necrosis. Mean corneal thickness of group 2 was 249.5 +/- 36.5 mu m and group 3 (0.02 mL BSS injected anterior chamber, five rats) was 248.6 +/- 25.3 mu m. There was no statistically significant difference between groups for corneal thickness ( p > 0.05). Conclusion: Our findings have shown that ropivacaine appeared to be safe, with no histopathological abnormalities with intravitreal and anterior chamber injection.