The safety of intraocular ketorolac in rabbits.
OBJECTIVE
To assess the safety of a possible substitute treatment for intraocular steroid injections, intraocular injections of ketorolac tromethamine, one of the nonsteroidal anti-inflammatory drugs, were performed in rabbits.


METHODS
Either 0.5% or 0.25% preservative-free ketorolac tromethamine ophthalmic solution (0.1 mL) was injected into the vitreous of the right eye of 15 rabbits. Physiologic saline solution (BSS; Alcon, Ft. Worth, TX) was injected into the left eye of each rabbit as a control. A standard electroretinogram and intraocular pressure measurements were obtained before injection, and repeated 1 day and 1, 2, 3, and 4 weeks after injection. After 4 weeks, the rabbits were euthanatized and the retinas examined by light and electron microscopy. Differences in the electroretinograms, intraocular pressure, and histopathology between the two eyes were recorded. Further, the elimination half-life of the drug in the vitreous was assessed.


RESULTS
There were no statistically significant differences in electroretinograms, or intraocular pressure measurements obtained between the ketorolac-injected eyes and the control eyes. The half life of the drug was measured to be 2.3 hours. No histopathologic changes were observed in study eyes compared with control eyes.


CONCLUSIONS
Preservative-free ketorolac tromethamine is nontoxic to the retinas of rabbits when injected intravitreally and could be considered as an alternative to intraocular steroid injections.
Margalit
Eyal
E
Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha 68198-5540, USA. emargalit@unmc.edu
Kugler
Lance J
LJ
Brumm
Matthew V
MV
Meza
Jane L
JL
Kompella
Uday B
UB
Escobar
Edith R
ER
Christensen
Gerald R
GR
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity*; D004596:Electroretinography / Q000187:drug effects; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D020911:Ketorolac Tromethamine / Q000633:toxicity*; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000648:ultrastructure; D014822:Vitreous Body
D000894:Anti-Inflammatory Agents, Non-Steroidal; D020911:Ketorolac Tromethamine