Purpose: To study the retinal alterations in rabbit eyes after intravitreal injection of 0.5, 1.0 and 2.0% lidocaine through histopathological analysis with light and transmission electron microscopy. Methods: Forty eyes of 20 New Zeland albino rabbits were submitted to intravitreal injection of 0.5 (group II), 1.0 (group III) and 2.0 % (group IV) lidocaine in the right eyes and saline solution in the left eyes (group I - control) after general anesthesia. Bilateral indirect ophthalmoscopy was performed before the intravitreal injection, during the procedure, one hour postoperative and on days 1, 3, 7 and 15. On the same days one eye of group II, two eyes of group III and one eye of group IV were enucleated and examined under light and transmission electron microscopy. Results: No alterations were found under bilateral indirect ophthalmoscopy before and during the intravitreal injection, but on days 1, 3, 7 and 15 after the procedure the retina showed a whitish aspect, an elevation of the vitreous-retinal interface, retinal edema and virtual condensation ring in all groups. No alterations were found using light and transmission electron microscopy analysis. Conclusion: Intravitreal injection of 0.5, 1.0 and 2.0% lidocaine morphologically showed no toxicity to New Zeland albino rabbit retina, based on light and transmission electron microscopy analysis.
Rabbits; Lidocaine; Injections; Local anesthetics; Vitreous body; Retina; Electron microscopy; Scanning transmission electron microscopy; Animals
