Experimental intravitreal application of ciprofloxacin in rabbits.
BACKGROUND
Ciprofloxacin (CFLX) is a fluoroquinolone antibiotic with a broad antimicrobial spectrum. This study was performed to examine the retinal toxicity of free and liposome-incorporated CFLX in rabbit eyes after intravitreal injection.


METHODS
Free CFLX in doses of 100, 250, 500, 1,000 and 2,000 microg was injected into the midvitreous of rabbit eyes (n = 28). To prolong the intravitreal antibacterial level, CFLX was incorporated into multilamellar liposomes: 0.1 ml of this suspension ( wedge 273.6 microg CFLX) was injected into the midvitreous of a second group of rabbit eyes (n = 6). The other eye served as a control and received normal saline solution or empty liposomes, respectively. Before injection and at the end of follow-up an electroretinogram (ERG) was obtained. After a follow-up of 1, 14 and 28 days the animals were perfused with glutaraldehyde and the eyes were examined by light and transmission electron microscopy.


RESULTS
Significant reduction of the ERG was observed after 2,000 microg free CFLX in 4 out of 6 eyes after 14 days. Fourteen days after injection of 2,000 microg CFLX the central retina showed pigmentary changes in 4 out of 6 eyes. In the second group the ERG as well as the histologic studies did not reveal any pathologic changes after injection of liposome-incorporated CFLX compared to the control eyes.


CONCLUSIONS
In therapeutic doses of 100-500 microg, free CFLX does not have retinal toxicity in rabbit eyes. No retinal toxicity was observed after intravitreal injection of liposome-incorporated CFLX.
Wiechens
B
B
Department of Ophthalmology, Christian Albrechts University, Kiel, Germany.bwiechens@ophthalmol.uni-kiel.de
Grammer
J B
JB
Johannsen
U
U
Pleyer
U
U
Hedderich
J
J
Duncker
G I
GI
D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000633:toxicity; D002939:Ciprofloxacin / Q000008:administration & dosage* / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004337:Drug Carriers; D004596:Electroretinography / Q000187:drug effects; D005500:Follow-Up Studies; D008081:Liposomes; D008297:Male; D010865:Pilot Projects; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D014822:Vitreous Body / Q000187:drug effects* / Q000648:ultrastructure
D000890:Anti-Infective Agents; D004337:Drug Carriers; D008081:Liposomes; D002939:Ciprofloxacin