Assessing the Efficacy of Photodynamic Therapy for Preventing Surgical Site Infections (LIGHT)

June 10, 2026 updated by: Guy's and St Thomas' NHS Foundation Trust

Leveraging Photodynamic Therapy to Inhibit Microorganisms - Assessing the Efficacy of Photodynamic Therapy for Preventing Surgical Site Infections in Nasal Surgery Patients: A Pilot Study

This is a randomised, unblinded interventional device proof of concept pilot trial in which patients undergoing nasal surgery will be selected for either photodisinfection therapy (PDT) with the Steriwave™ ND System, or control with nares swabbed with 'photosensitizer formulation' preoperatively.

This trial will primarily assess the safety and efficacy of nasal photodisinfection treatment in decreasing post-operative events in patients undergoing nasal surgery. After signing informed consent, and before surgery, participants will receive a baseline culture of the anterior nares to determine nasal bacterial colonization and will have a flexible nasendoscopy to determine their Lund-Kennedy (LK) endoscopic score. Subjects will then be randomised to nasal PDT (which includes two applications of 'photosensitizer formulation' [0.01% methylene blue with 0.25% chlorhexidine solution], two minutes apart), along with light therapy, or control with nares swabbed twice with 'photosensitizer formulation' with two minutes in between (no light therapy). Following treatment, participants will be re-cultured (2 weeks after the surgery ± 7 days) and reviewed for antibiotic use and surgical site infection (SSI) using LK endoscopic scoring. At 30 days, all participants will be followed up by telephone to review if they received antibiotics for presumed postoperative infection. Standard post-operative care will be provided according to the type of surgery performed. Any required interventions post-operatively will be documented.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Preoperative nasal decolonisation has been shown to achieve significant reductions in surgical site infections at sites remote from the nasal cavity. It would therefore seem to have great potential in reducing the risk of post-operative infections after sinonasal surgery, and therefore reduce antibiotic usage. If surgeons have confidence in the treatment, those that routinely prescribe prophylactic antibiotics may also be pursued to change their practice.

The aim of this study is to assess the efficacy and safety of photodisinfection therapy versus control with nares swabbed with 'photosensitizer formulation' (0.01% methylene blue with 0.25% chlorhexidine solution) to reduce the antibiotics usage for presumed SSI inpatients undergoing nasal surgery. The investigators hypothesise that preoperative photodisinfection will demonstrate greater efficacy compared to control with nares swabbed with 'photosensitizer formulation' (0.01% methylene blue with 0.25% chlorhexidine solution) in reducing the usage of antibiotics for presumed surgical site infection (SSI) among patients undergoing nasal surgery.

The investigators will also further evaluate the effectiveness of nasal decolonisation in eliminating colonization of the anterior nares with S. aureus and other potentially pathogenic microbes. The anterior nares are often considered the primary reservoir of S. aureus and other pathogens on the body (36). Therefore, this product could play an important role in helping to eliminate the anterior nares as a pathogen reservoir in surgical patients.

This study is meant to provide further safety, efficacy, and methodological data, but is not intended to establish definitive statistical significance. If required, this study will support a subsequent larger study that would establish statistical significance for the reduction of surgical site infections, but which is currently not the subject of this protocol.

Study Type

Interventional

Enrollment (Estimated)

80

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United Kingdom
    • London
      • London, London, United Kingdom, SE1 9RT
        • Recruiting
        • Guy's Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Nora Haloob
        • Sub-Investigator:
          • Pavol Surda

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients ≥ 16 years

  • Patients scheduled to undergo elective:

    • Endoscopic Sinus Surgery (ESS) with or without adjunctive Septoplasty and/or Turbinoplasty
    • Septoplasty with or without adjunctive Turbinoplasty
    • Closed Septoplasty with or without adjunctive Turbinoplasty
  • Judged by the Investigator as suitable for participation in the study without safety concerns based on medical history and physical examination
  • Willing and able to provide written informed consent prior to participation in the clinical investigation
  • Willing and able to comply with all study related procedures

Exclusion Criteria:

-• Patients undergoing open septorhinoplasty, anterior or septal biopsies, or post cautery

  • Congenital or acquired immunodeficiency, bone marrow disease, diabetes, autoimmune conditions requiring immunosuppressive treatment, any immunosuppressive medication at the time of consent or within the last 4 weeks before randomisation
  • Primary or secondary ciliary dyskinesia, cystic fibrosis
  • Patients who have received antibiotics within a week before randomisation
  • Patients who receive prophylactic antibiotics or antibiotics prior to discharge
  • Systemic steroid treatment less than 4 weeks before randomisation
  • History of frequent nose bleeds, or a condition that increases the risk of excessive bleeding
  • Undergoing active cancer treatment at time of consent/ or planning to start cancer treatment within trial period or completed cancer treatment within the last 4 weeks
  • Any disease, condition (medical or surgical), or drug or alcohol abuse, which, in the opinion of the investigator, might compromise the study results, or would place the patient at increased risk of infection
  • Previously treated with radiation on the face, head, or neck regions
  • Female patients who are pregnant or breastfeeding at the time of consent
  • Received a study drug in a clinical trial for an investigational drug within the previous 30 days from consent, or 5 half-lives, whichever is longer
  • Used antimicrobial wash or wipes within 7 days of randomisation or during the study period
  • Patients with allergies / hypersensitivity to methylene blue, polymethyl methacrylate (PMMA), or to chlorhexidine gluconate (CHG)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Photodisinfection
The photodisinfection product consists of a CE-marked light source (SW4000), a disposable single-use nasal light diffuser, and a single-use photosensitiser applicator that can be used in hospital settings.
Device: Nasal PDT
Two two-minute cycles will be provided by a member of the research team in the pre-operative area on the day of surgery. A saturated swab containing 0.01% methylene blue and 0.25% chlorhexidine gluconate will be applied to nares, which is then activated by light.
Other Names:
  • Steriwave (SW4000)
Other: Standard follow-up
All patients will receive standard post-operative wound follow up. This might include being advised to contact the GP or the hospital if there are any wound problems and, or, being invited to an out-patient clinic appointment.
Diagnostic test: Nasal culture
Nasal swab cultures will be obtained before Nasal PDT or control swabbing and converted to colony-forming units to measure bacterial burden at baseline, and after treatment (2 weeks +/- 7 days).
Other: In-person review
On Week 2 (±7 days), the participant will undergo an in-person review conducted in the ENT Outpatient department, 2nd floor Southwark wing, Guy's Hospital by the CI, PI or Co-investigator. During this appointment, concomitant medications and use of post-operative antibiotics will be reviewed.
Other: Telephone Follow-up

On day 30, the research nurse will telephone participants from the ENT research office.

  • Review of adverse events/adverse device effects
  • Review of concomitant medications
  • Signs and symptoms post-surgery
  • Nasal washout
  • Record any use of post-operative antibiotics, both local and systemic
Diagnostic test: Flexible nasendoscopy
Sinonasal mucosal inflammation using the Flexible Nasendoscopy Endoscopic Lund-Kennedy (LK) Score will also be obtained before Nasal PDT or control swabbing and at 2 weeks (+/-7 days).
Active Comparator: Control
The control group will have nares swabbed with 'photosensitizer formulation' (0.01% methylene blue with 0.25% chlorhexidine solution) prior to surgery.
Other: Standard follow-up
All patients will receive standard post-operative wound follow up. This might include being advised to contact the GP or the hospital if there are any wound problems and, or, being invited to an out-patient clinic appointment.
Diagnostic test: Nasal culture
Nasal swab cultures will be obtained before Nasal PDT or control swabbing and converted to colony-forming units to measure bacterial burden at baseline, and after treatment (2 weeks +/- 7 days).
Other: In-person review
On Week 2 (±7 days), the participant will undergo an in-person review conducted in the ENT Outpatient department, 2nd floor Southwark wing, Guy's Hospital by the CI, PI or Co-investigator. During this appointment, concomitant medications and use of post-operative antibiotics will be reviewed.
Other: Telephone Follow-up

On day 30, the research nurse will telephone participants from the ENT research office.

  • Review of adverse events/adverse device effects
  • Review of concomitant medications
  • Signs and symptoms post-surgery
  • Nasal washout
  • Record any use of post-operative antibiotics, both local and systemic
Combination product: Photosensitizer formulation only
Nares will be swabbed with Photosensitizer formulation (0.01% methylene blue with 0.25% chlorhexidine solution). Nasal swab cultures will be obtained before control swabbing and converted to colony-forming units to measure bacterial burden at baseline, and after treatment (2 weeks +/- 7 days). Sinonasal mucosal inflammation using the Flexible Nasendoscopy Endoscopic LK Score will also be obtained before treatment at 2 weeks (+/-7 days).
Diagnostic test: Flexible nasendoscopy
Sinonasal mucosal inflammation using the Flexible Nasendoscopy Endoscopic Lund-Kennedy (LK) Score will also be obtained before Nasal PDT or control swabbing and at 2 weeks (+/-7 days).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Antibiotic usage in number and percentages
Time Frame: 30 days
The proportion of patients requiring antibiotic therapy for presumed surgical site infections (SSIs) within 30 days after undergoing nasal surgery. Specifically, the intention is to compare those who received preoperative PDT with those in the control group.
30 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of surgical site infection
Time Frame: 30 days
The proportion of patients developing a postoperative infection within 30 days of surgery, defined by the presence of sinus purulence (Lund-Kennedy score of 2: 'Thick and purulent discharge') on nasal endoscopy and requiring antibiotic treatment.
30 days
Bacterial Nasal Culture Rates
Time Frame: 30 days
The percentage of patients with positive bacterial cultures (S. aureus and Group A Streptococcus) from nasal swabs during the study period, comparing the PDT group with the control group.
30 days
Lund-Kennedy Score Assessment
Time Frame: 30 days

The change in Lund-Kenned (LK) scores from baseline during the study period, as measured by flexible nasendoscopy, in patients who received preoperative PDT compared to those in the control group.

Each side is graded on an ordinal scale from 0-2, with higher scores indicating worse disease.
30 days

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Safety of PDT
Time Frame: 30 days
The incidence of adverse events or complications (e.g., nasal irritation, bleeding, discomfort) associated with the nasal photodisinfection procedure, as reported by patients and assessed by clinical examination during the study period.
30 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Guy's and St Thomas' NHS Foundation Trust

Investigators

  • Principal Investigator: Claire Hopkins, Guy's and St Thomas' NHS Foundation Trust

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 4, 2025

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2026

Study Registration Dates

First Submitted

December 11, 2024

First Submitted That Met QC Criteria

December 11, 2024

First Posted (Actual)

December 13, 2024

Study Record Updates

Last Update Posted (Actual)

June 11, 2026

Last Update Submitted That Met QC Criteria

June 10, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRAS345142

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The trial will be conducted in accordance with the Data Protection Act 2018. The chief investigator will ensure that participant's anonymity is maintained throughout the study and following completion of the study.

Pseudonymised data will be shared with the study Statistician who is an employee of the Trust and member of the study team. It will be extracted from REDCap and sent via encrypted email in a locked Excel document. After the analysis the data will be archived in Iron Mountain.

No data will be shared outside of GSTT during the course of the study.

Data will not be shared with the device manufacturer.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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