Cystoid macular edema (CME) is one of the major problems in diabetes patients after cataract surgery, which leads to fluid accumulation within the macular region. This clinical study aims to evaluate the effect of topical nepafenac 0.1% in preventing macular edema. The prospective interventional clinical study was conducted in the Department of Ophthalmology of a tertiary care hospital at Salem for a period of six months from Jan 2024 to June 2024. Investigations include random blood sugar (RBS), visual acuity, macular thickness and intraocular pressure (IOP) done on patients. 50 patients received sterile ophthalmic suspensions of 0.1% nepafenac and 50 patients received 0.5% carboxy methyl cellulose as placebo, both used thrice in a day before and after cataract surgery. Optical coherence tomography (OCT) was performed both pre-operatively before cataract surgery and up to 90 days after post-operative. The outcome of this study shows a gradual decrease in macular thickness and, an increase in visual acuity. This study negotiates that nepafenac 0.1% was effective in preventing macular edema. It is considered to be safe and no complications were developed in patients subjected to nepafenac after cataract surgery in diabetes patients. © 2025 Elsevier B.V., All rights reserved.