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

NCT07181668 | Completed DMC

• 1 other identifier: Grigore T. Popa n.54/29.07.24
• Study Type: interventional
• Target: 61
• Locations: 1 country
• Sites: 1

Brief Summary

This study evaluates the role of perioperative low-level light therapy (LLLT) in reducing dry eye disease (DED) symptoms after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK). DED is one of the most frequent complications following Femto-LASIK, potentially affecting both visual recovery and patient satisfaction. In this prospective, multicenter, randomized, double-masked, sham-controlled trial, adult patients undergoing Femto-LASIK were assigned to receive either periocular LLLT (Eye-light® )or sham treatment before and after surgery. Tear film parameters and ocular surface symptoms were assessed at baseline, 1 week, 1 month, and 3 months postoperatively. Results showed that patients treated with LLLT maintained stable tear volume and reported fewer ocular discomfort symptoms compared with controls, who experienced significant declines. No adverse events related to LLLT were observed. These findings suggest that perioperative LLLT is a safe and well-tolerated approach that may help preserve tear film stability and improve postoperative comfort in Femto-LASIK patients.

Conditions

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

Keywords

Dry eye disease; LLLT; Photobiomodulation

Outcome Measures

Primary Outcomes (1)

• Ocular Surface Preservation after Femto-LASIK with LLLT

  The Dry Eye Questionnaire-5 (DEQ-5) is a validated 5-item instrument used to assess the severity of subjective dry eye symptoms. The total score ranges from 0 to 22, with higher scores indicating greater symptom severity. The primary outcome is the change in total DEQ-5 score from baseline to 3 months after surgery, comparing the LLLT group to the control group.

  Baseline (1 week preoperatively, T0) to 3 months postoperatively (T3)

Secondary Outcomes (4)

• Non-Invasive Tear Break-Up Time (NIBUT)

  Baseline (T0, 1 week preoperatively), 1 week postoperatively (T1), 1 month postoperatively (T2), 3 months postoperatively (T3)

• Tear Lipid Layer Thickness (Interferometry)

  Baseline (T0, 1 week preoperatively), 1 week postoperatively (T1), 1 month postoperatively (T2), 3 months postoperatively (T3)

• Tear Meniscus Height (TMH)

  Baseline (T0, 1 week preoperatively), 1 week postoperatively (T1), 1 month postoperatively (T2), 3 months postoperatively (T3)

• Schirmer Test (without anesthesia)

  Baseline (T0, 1 week preoperatively), 1 week postoperatively (T1), 1 month postoperatively (T2), 3 months postoperatively (T3)

Study Arms (2)

LLLT Group

EXPERIMENTAL

Participants in the LLLT group received periocular low-level light therapy (LLLT) using the Eye-light® device (Espansione Marketing S.p.A., Italy) for 15 minutes per session, one week before and one week after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK). The device delivers red light at 633 ± 10 nm through closed eyelids, targeting the periocular region and meibomian glands to support tear film stability and reduce ocular discomfort. All participants underwent standard Femto-LASIK surgery and received identical postoperative care, including topical antibiotics, corticosteroids, and preservative-free artificial tears. Of the 31 patients initially assigned to the LLLT group, 6 were lost to follow-up, leaving 23 patients (46 eyes) for the final analysis.

Device: Low-Level Light Therapy

Sham Group

SHAM COMPARATOR

Participants in the Control group underwent a sham treatment using the same Eye-light® device with minimal energy (\<30% of the full therapeutic dose) for 15 minutes per session, also one week before and one week after surgery. This procedure mimicked LLLT without providing therapeutic light exposure. Postoperative care and clinical assessments were identical to the LLLT group. Of the 30 patients initially assigned to the Control group, 13 were lost at the follow up leaving 17 patients (34 eyes) for the final analysis.

Device: Sham (No Treatment)

Interventions

Low-Level Light Therapy DEVICE

The intervention consists of non-invasive periocular photobiomodulation using the Eye-light® device (Espansione Marketing S.p.A., Italy), which delivers low-level monochromatic red light (633 ± 10 nm) through a specially designed mask. Participants receive two 15-minute sessions, one 7 days before and one 7 days after femtosecond laser-assisted in situ keratomileusis (Femto-LASIK). The treatment is designed to stimulate meibomian gland activity, improve tear film stability, and reduce ocular surface inflammation. This protocol is unique compared to standard post-refractive surgery care 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.

LLLT Group

Sham (No Treatment) DEVICE

Participants in the Control group underwent the same procedural setup as the LLLT group, using the Eye-light® device (Espansione Marketing S.p.A., Italy). Instead of delivering therapeutic light energy, the device operated in demo mode, emitting less than 30% of the full treatment power. This configuration mimicked the visual and sensory aspects of a low-level light therapy session without producing biologically effective photobiomodulation. Sham treatment consisted of two 15-minute sessions, one 7 days before and one 7 days after Femto-LASIK. This design ensured masking of participants and investigators while preventing active therapeutic exposure in the control group.

Sham Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged ≥18 years.
• Scheduled for bilateral Femto-LASIK surgery for refractive error correction.
• Willing and able to provide written informed consent.
• Ability and willingness to comply with all study procedures and follow-up visits.
• Baseline ocular surface within normal limits (no pre-existing dry eye or ocular surface disease)

You may not qualify if:

• Prior diagnosis of ocular surface disease (OSD) or dry eye disease (DED).
• History of ocular surgery in either eye.
• Presence of ocular comorbidities such as glaucoma, corneal dystrophies, or active ocular infections.
• Current or regular use of topical ocular treatments, including lubricants, corticosteroids, cyclosporine, or other drugs for DED or OSD.
• Use of instrumental therapies for ocular surface or tear film optimization (e.g., thermal pulsation, IPL).
• Systemic treatments known to influence tear production (e.g., diuretics, antihistamines, antidepressants, hormone replacement therapy).
• Autoimmune diseases affecting the eyes, including Sjögren's syndrome or rheumatoid arthritis.
• Any intraoperative or postoperative complications that could interfere with ocular surface assessment.

Sponsors & Collaborators

• Grigore T. Popa University of Medicine and Pharmacy: lead

Study Sites (1)

University of Medicine and Pharmacy "Grigore T. Popa" Iași,

Iași, Romania

Location

MeSH Terms

Conditions

Dry Eye Syndromes; Meibomian Gland Dysfunction

Interventions

Low-Level Light Therapy

Condition Hierarchy (Ancestors)

Lacrimal Apparatus Diseases; Eye Diseases; Eyelid Diseases

Intervention Hierarchy (Ancestors)

Laser Therapy; Therapeutics; Phototherapy

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal investigator

Model Details: This is a randomized, controlled, double-masked, parallel-group trial. Eligible participants undergoing femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) are randomly assigned in a 1:1 ratio to receive either low-level light therapy (LLLT) or a sham treatment. Interventions are administered perioperatively (1 week before and 1 week after surgery), and all clinical outcomes are assessed at baseline, 1 week, 1 month, and 3 months postoperatively. Participants remain in their assigned group for the duration of the study, with no crossover between groups.

Study Record Dates

• First Submitted: September 5, 2025
• First Posted: September 18, 2025
• Study Start: August 10, 2024
• Primary Completion: June 11, 2025
• Study Completion: July 30, 2025
• Last Updated: September 25, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR

Locations

RO (1)