Effects of photobiomodulation with red and infrared low-level laser diodes in individuals undergoing rhinoplasty at a single centre in Sao Paulo, Brazil: protocol for a randomised, double-blind, controlled clinical trial

Introduction Oedema and ecchymosis are common after rhinoplasty and may delay recovery. Photobiomodulation (PBM) has been shown to have analgesic, anti-inflammatory and regenerative effects; however, its role in rhinoplasty remains underexplored.

This study aims to evaluate the effectiveness of PBM in reducing periorbital oedema in patients undergoing rhinoplasty. Methods and analysis This is a single-centre, randomised, controlled, double-blind clinical trial that will include 60 participants allocated into two groups: a control group (n=30), receiving sham PBM before surgery, and an intervention group (n=30), receiving preoperative PBM followed by rhinoplasty.

PBM will be delivered using a cluster device containing three red low-level laser diodes (660 nm, 150 mW each) and three infrared low-level laser diodes (808 nm, 150 mW each), applying 12 J per point for 80 s at three standardised facial sites. The intervention (PBM or sham) will be applied 1 hour before the surgical procedure.

The primary outcome will be periorbital oedema on postoperative day 3, assessed using the Hoffmann clinical scale. Standardised photographic analysis using ImageJ software will be employed as a complementary measure.