the effect of prophylactic administration of ketorolac ophthalmic suspension on prevention of surgically induced miosis in patients undergoing cataract surgery

background: cataract extraction surgery remains the most commonly performed eye surgery by ophthalmologists. the maintenance of mydriasis is required throughout surgery to allow better visualization of the surgical field and a greater working space within the center of the eye. non-steroidal anti-inflammatory agents (nsaids) have their effect in maintaining mydriasis by their ability to inhibit prostaglandin synthesis. methods: this was a prospective, randomized clinical trial study in 84 patients undergoing phacoemulsification cataract surgery. patients were randomized to ketorolac tromethamine 0.5% (n=42) or the control group (n=42). patients in the ketorolac group received one drop of ketorolac every 15 min for a total of 4 drops from one hour before surgery. the horizontal diameters of the pupil were measured in millimeters with a caliper under the microscope at the following stages: before surgery, after intracameral epinephrine injection, after nuclear emulsification and at the end of surgery. results: the difference in pupillary diameter at the end of surgery was statistically significant between two groups (7.34 ± 1.0 mm and 8.01 ±0.67 mm in the control and the ketorolac groups, respectively; p=0.018). the difference in mean pupil size after intracameral epinephrine injection and after nuclear emulsification between the control group (0.51 ± 0.25 mm) and the ketorolac group (0.01 ± 0.20 mm) was statistically significant (p <0.001). moreover, the difference in mean pupil size after intracameral epinephrine injection and at the end of surgery between the control group (0.79 ± 0.44 mm) and the ketorolac group (0.19 ± 0.23 mm) was statistically significant (p <0.001). there was no difference in maintaining mydriasis between diabetic patients and non-diabetic patients. conclusion: topical ketorolac is an effective inhibitor of miosis during phacoemulsification cataract surgery, and provides a more stable mydriatic effect throughout the surgical procedure.