Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07546617

In Vivo Imaging of the Olfactory Epithelium Using Confocal Laser Endomicroscopy

This research is being done to better characterize the part of the nose that helps us smell. Currently, the only ways to study smell loss mostly rely on how people report it, rather than being able to see the underlying structures directly. In this study, we will use a special microscope (Confocal Laser Endomicroscopy (CLE)), originally developed for brain tissue, to look at the part of the nose that helps to detects smell. We hope to identify the tiny structures in that area and see how they might be different in people who have smell loss compared to those who do not.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Conditions

Endonasal Surgery Anosmia Endoscopic Sinus Surgery Nervous System Diseases Neurologic Manifestations Olfaction Disorders Olfactory Dysfunction Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Dartmouth-Hitchcock Medical Center

Lebanon, New Hampshire, 03755, United States

Location contact

Ryan E Little, MD

CONTACT

[email protected]

603-650-8123

Ryan E Little, MD

PRINCIPAL_INVESTIGATOR

About this study

Aim 1: Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.

We will obtain preoperative Sniffin' Sticks threshold-discrimination-identification (TDI) scores and questionnaires in 36 surgical patients recruited from NH and VT, followed by intraoperative CLE imaging after intravenous fluorescein. CLE images will be assessed for epithelial features such as neuronal loss, epithelial thinning, basement membrane irregularity, and inflammatory changes.

Aim 2: Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers. When routine surgery includes removal of superior turbinate tissue, CLE images will be paired with histopathology to assess concordance in features such as neuronal density, sustentacular cell integrity, and inflammation.

Who can participate

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged ≥18 years
  • Undergoing endoscopic sinus or endonasal skull base surgery while under - general anesthesia where the nasal turbinate is accessible
  • Able to complete study questionnaires and psychophysical smell testing
  • Able to provide informed consent.

Exclusion criteria

  • Known allergy or hypersensitivity to fluorescein
  • Pregnancy
  • Medical instability precluding participation
  • Severe anatomic obstruction preventing safe access to the olfactory cleft and nasal turbinate
  • Any other safety concern identified by the investigator

Treatment and study plan

CONVIVO system

Device

Approximately 2-5 minutes following administration of FNa in situ imaging will be performed by the participating surgeon ensuring proper technique. Prior to entering the surgical field, the probe will be covered in a disposable sterile sheath that is manufactured with quality assurance for this purpose. The probe will gently be held against the tissue interface while imaging occurs. Following image acquisition, a pathologist present in the operating room, will review and capture each image.

Conventional histologic evaluation

Other

Following image acquisition, if clinically indicated, the tissue region imaged with the CONVIVO system will then be biopsied. This will be passed immediately off the surgical field as a research specimen and provided to a member of the research team to be prepared for conventional histologic evaluation. The specimen will be labeled with the deidentified subject and sample number. This sequence will then be repeated for each successive sample.

Fluorescein injection, USP 10%

Drug

Sodium fluorescein will be administered intravenously or topically (applied directly to nasal mucosa) at doses of 5-10 mg/kg (not exceeding 20 mg/kg cumulative). Administration will be performed by the anesthesia team in the operating room.

Other names: AK-FLUOR, FNa

Primary outcomes

  1. Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.

    Time frame: On day of Surgery, Day 0

    (1) High feasibility (≥85% interpretable images); (2) identifiable CLE signatures associated with OD severity; (3) significant correlations between CLE features, TDI scores, and symptom burden.

Secondary outcomes

  1. Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers.

    Time frame: On day of Surgery, Day 0

    When routine surgery includes removal of superior turbinate tissue, CLE images will be paired with histopathology to assess concordance in features such as neuronal density, sustentacular cell integrity, and inflammation.

    Expected Outcomes: Identification of CLE features corresponding to gold-standard histopathology, generating preliminary in vivo imaging biomarkers.

Study contacts

Contact information is provided by the study sponsor or research team.

Michaela M Geffert, MS

CONTACT

[email protected]

603-650-2054

Ryan E Little, MD

CONTACT

[email protected]

603-650-8123

Sponsors and collaborators

Lead sponsor

Dartmouth-Hitchcock Medical Center

Other

Collaborators

  • National Center for Advancing Translational Sciences (NCATS)

Registry information

Official study title

In Vivo Imaging of Olfactory Epithelium in Humans With Olfactory Impairment Using Confocal Laser Endomicroscopy

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Apr 23, 2026
Registry last updated
Apr 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.