Abstract
Purpose: (1) To determine ketorolac concentrations in selected ocular tissues following the intracameral administration of phenylephrine and ketorolac injection 1%/0.3% (OMIDRIA®) delivered in irrigation solution during lens replacement surgery in beagle dogs. (2) To compare the ketorolac initial dose and resultant concentrations from the above study to those achieved in aqueous and vitreous by topical administration in patients undergoing cataract surgery or vitrectomy, respectively.Methods: Lens replacement surgery with phacoemulsification was performed in 20 female beagle dogs. A fixed combination of phenylephrine and ketorolac injection 1%/0.3% was diluted 125-fold into the balanced salt solution and delivered intracamerally during the phacoemulsification procedure. Ketorolac concentration was determined by liquid chromatography/mass spectrometry.Results: Concentrations of ketorolac when administered by the intracameral route in the dosing solution in dogs were found to be considerably higher in both aqueous and vitreous compared to what is achieved with topical dosing in patients.Conclusions: Adequate therapeutic concentrations of ketorolac in aqueous and vitreous humor were achieved even at 10 h postdose. Critical concentrations in the aqueous that envelopes the iris/ciliary body, which are sites of prostaglandin E2 synthesis, and the vitreous are not achieved by topical dosing in clinical studies after the surgery, but are by direct intracameral dosing as determined in this study. Based on these studies and clinical data, phenylephrine and ketorolac injection 1%/0.3% delivered during surgery as an irrigation solution may preclude the need for topically administered pre- and postoperative NSAIDs.
Highlights
While cataract surgery has made many technical advances over the past 20 years,[1,2,3] the administration of ophthalmic drugs accompanying the surgery remains reliant on topical drug delivery, which has changed little for several decades
The purpose of the present study was to compare the ketorolac total dose and concentrations in ocular tissues achieved utilizing an intracameral administration of phenylephrine (PE) and ketorolac (KE) injection 1%/0.3% diluted in buffer solution in a canine model of lens replacement surgery with those achieved by topical dosing in human cataract surgery and from patients undergoing vitrectomies
The summed total gives an estimate of the total dose delivered by a formulation of ketorolac (0.0024%) and phenylephrine (0.008%) as diluted in irrigation solution
Summary
While cataract surgery has made many technical advances over the past 20 years,[1,2,3] the administration of ophthalmic drugs accompanying the surgery remains reliant on topical drug delivery, which has changed little for several decades. Dosing topically multiple times before cataract surgery with nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids has become very commonplace.[4,5,6] The purpose of the present study was to compare the ketorolac total dose and concentrations in ocular tissues achieved utilizing an intracameral administration of phenylephrine (PE) and ketorolac (KE) injection 1%/0.3% diluted in buffer solution in a canine model of lens replacement surgery with those achieved by topical dosing in human cataract surgery and from patients undergoing vitrectomies. Phenylephrine concentrations were not determined in this study because comparable clinical samples were not available. While it is recognized that dog ocular pharmacokinetics may differ in significant ways to that of humans, this study does raise questions about the usefulness of topical dosing of NSAIDs before cataract surgery, when intraoperative administration is available
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
