Effect of Low-Level Light Therapy on Ocular Surface Parameters in Patients Undergoing Cataract Surgery

This randomized, controlled clinical trial investigates the perioperative use of low-level light therapy (LLLT) to prevent or reduce signs and symptoms of dry eye disease (DED) in patients undergoing cataract surgery. DED is a prevalent postoperative complication associated with ocular surface inflammation, meibomian gland dysfunction, and tear film instability, which can compromise visual outcomes and patient satisfaction. The study enrolled adult patients scheduled for phacoemulsification, with baseline evidence of mild-to-moderate ocular surface disease. Participants were randomly assigned to receive either LLLT via a polychromatic light-emitting mask (Eye-light® ) or a sham device, administered one week before and one week after surgery. The LLLT protocol is designed to photobiomodulate eyelid and periocular tissues to enhance meibomian gland function and reduce subclinical inflammation. Clinical assessments were conducted at baseline, one week, and six months postoperatively. The primary endpoint was the change in Ocular Surface Disease Index (OSDI) score at one and six months. Secondary endpoints included tear film stability (TBUT), Schirmer I test, corneal staining, tear osmolarity, and tear inflammatory and reparative biomarkers. The study also evaluated the safety and tolerability of the LLLT intervention. This is the first prospective study assessing the role of perioperative LLLT in mitigating post-cataract ocular surface disease in consecutive patients. The findings may support the integration of LLLT in perioperative ocular surface management protocols.