Histological toxicity of grepafloxacin after intravitreal injection

To determine the intravitreal levels of grepafloxacin after intravitreal injection of 80 microg and to evaluate the retinal toxicity after intravitreal injection of different doses of grepafloxacin in rabbit eyes.

Fifteen female New Zealand white rabbits and 15 female pigmented 'Gigantes de España' rabbits were injected with 80 microg of grepafloxacin into the vitreous cavity. The grepafloxacin concentration was determined with HPLC after 2, 4, 8, 12 and 24 h. Eighteen female rabbits (9 New Zealand white rabbits and 9 pigmented 'Gigantes de España' rabbits) were used for a study of toxicity. The rabbits were divided into 6 treatment groups: group 1 (3 pigmented rabbits) received an intravitreal injection of 80 microg of grepafloxacin in 0.1 ml of saline solution, group 2 (3 white rabbits) 80 microg of grepafloxacin in 0.1 ml, group 3 (3 pigmented rabbits) 800 microg of grepafloxacin, group 4 (3 white rabbits) 800 microg of grepafloxacin, group 5 (3 pigmented rabbits) and group 6 (3 white rabbits) 0.1 ml of saline solution. Clinical examination was performed prior to injection and 24 h and 10 days after surgery. The animals were sacrificed 10 days after the injection, and the eyes were enucleated and fixed for histopathology. The specimens were stained with hematoxylin-eosin and toluidine blue.

No relevant complications were found during the clinical follow-up. All the eyes showed no abnormalities in the histologic evaluation.

Grepafloxacin can be considered as a safe alternative for intravitreal injection for the treatment of intraocular infections.