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

Summary

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.

Conditions

• Dry Eye
• Meibomian Gland Dysfunction (Disorder)
• Ocular Surface Disease

Interventions

DEVICE

Low-Level Light Therapy

The intervention consists of non-invasive periocular photobiomodulation using the Eye-light® device (Espansione Group, Italy), which delivers low-level polychromatic red and near-infrared light (600-1200 nm) through a specially designed mask. Participants receive two 15-minute sessions, one 7 days before and one 7 days after cataract surgery. The treatment is designed to stimulate meibomian gland activity, improve tear film stability, reduce ocular surface inflammation. This protocol is unique compared to standard treatments for dry eye because it targets cellular mitochondrial activity to enhance tissue repair and anti-inflammatory effects. It is non-pharmacological, non-contact, and well-tolerated, making it suitable for perioperative application. The light is delivered through closed eyelids, ensuring safety and comfort, and the device used is CE-marked for ophthalmic applications.

DEVICE

Sham (No Treatment)

Sham-treated controls underwent the same procedural setup as the active treatment group, using the Eye-light® device (Espansione Group, Italy). However, instead of delivering therapeutic levels of light energy, the device operated in demo light mode, emitting less than 30% of the full treatment power. This setting simulated the visual and sensory experience of a low-level light therapy (LLLT) session without delivering biologically effective photobiomodulation. The sham intervention included two 15-minute sessions: one administered 7 days before cataract surgery and one 7 days after. This approach allowed for masking of participants and investigators to minimize bias, while ensuring that patients in the control group received no active therapeutic exposure.

Sponsors & Collaborators

• Grigore T. Popa University of Medicine and Pharmacy

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-01-08

Primary Completion

2025-09-11

Completion

2025-09-11

Countries

• Romania

Study Locations