Aqueous and Vitreous Ketorolac Levels in Combined Cataract and Pars Plana Vitrectomy with Intracameral Ketorolac 0.3% Versus Topical Ketorolac 0.4.

INTRODUCTION

Ketorolac is well documented to reduce postoperative inflammation, pain, and the risk of cystoid macular edema (CME) during cataract surgery. The concentration of ketorolac in the vitreous humor following topical administration has been reported to be very low. As there is a lack of evidence on the vitreous levels of ketorolac following intracameral administration, this study aimed to evaluate the concentration of ketorolac in aqueous and vitreous humor samples during combined cataract surgery and pars plana vitrectomy in patients receiving preoperative topical ketorolac 0.4% or intracameral phenylephrine 1.0%/ketorolac 0.3% (OMIDRIA®, Rayner Surgical Inc., Bellevue, WA, USA).

METHODS

This prospective, randomized, controlled study recruited patients undergoing combined cataract surgery and pars plana vitrectomy and randomized in a 1:1 ratio to receive either intracameral phenylephrine 1.0%/ketorolac 0.3% (study arm) or preoperative topical ketorolac 0.4% (control arm). Aqueous samples were collected at the start of cataract surgery in the control arm and at the end of cataract surgery in the study arm. The vitreous samples were taken at the start of vitrectomy in all eyes. The samples were frozen and sent to an independent lab (Emery Pharma, Alameda, CA) for analysis. Ketorolac levels were determined using liquid chromatography-tandem mass spectrometry.

RESULTS

Five eyes of five patients received ketorolac intracamerally, and six eyes of six patients received it topically. The mean aqueous ketorolac concentration was significantly higher in the study eyes than in the control (20,868.2 ± 7342.4 ng/mL versus 635.1 ± 909.6 ng/mL, p < 0.0001). In the vitreous, the mean ketorolac concentration was significantly higher in the study eyes than in the control (2508.8 ± 4477.6 ng/mL versus 3.1 ± 7.7 ng/mL, p = 0.0004).

CONCLUSIONS

The intracameral administration of phenylephrine/ketorolac resulted in 33 times higher ketorolac concentration in the aqueous and 809 times higher in the vitreous humor than the topically administered ketorolac during combined cataract surgery and pars plana vitrectomy.

TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT06539637, date of registration 29 July 2024 (retrospectively registered).