QST for Corneal Nerve Function

NCT05758753 | Suspended

• 1 other identifier: STUDY00002510
• Study Type: interventional
• Target: 108
• Locations: 1 country
• Sites: 1

Brief Summary

This study is designed to learn more about the impact different types of stimuli, such as heat, cold and vibration, can have on ocular pain response. This is called quantitative sensory testing (QST). Most procedures being performed in this study, except the QST, are standard of care which means they are performed during the participant's routine eye examination.

Conditions

Corneal Disease; Neuropathy; Dry Eye Disease; Neurotrophic Keratitis

Keywords

Quantitative Sensory Test

Outcome Measures

Primary Outcomes (4)

• Thermal stimulus response to QST on site of trigeminal nerve first branch, as assessed by cold detection threshold (CDT) and hot detection threshold (HDT)

  Cold and heat sensation thresholds will be evaluated by placing a 16 mm x 16 mm probe over the skin on the site to be tested, and an average of 3 reading while be taken for each stimuli. Participants will receive successive ramps of gradually decreasing or increasing temperature, starting from a resting neutral temperature of 32°C. Participants will be instructed to press a response button when a thermal sensation (either cold or warm) is perceived.

  From visit 1 up to 4 weeks

• Mechanical stimulus response to QST on site of trigeminal nerve first branch, as assessed by vibration detection threshold (VDT)

  Vibration sensation threshold will be evaluated by placing a 16 mm x 16 mm probe over the skin on the site to be tested, and an average of 3 reading while be taken. Participants will receive successive ramps of gradually decreasing or increasing vibration, starting from. Participants will be instructed to press a response button when a mechanical sensation is perceived.

  From visit 1 up to 4 weeks

• Differences in thermal stimulus pain threshold across the 4 study arms

  Cold pain threshold (CPT) and heat pain threshold (HPT) will be measured by asking participants to press a response button when they first feel a pain or discomfort from probe on QST testing

  From visit 1 up to 4 weeks

• Differences in mechanical stimulus pain threshold across the 4 study arms

  Vibration pain threshold (VPT) will be measured by asking participants to press a response button when they first feel a pain or discomfort from vibration probe on QST testing

  From visit 1 up to 4 weeks

Secondary Outcomes (3)

• To correlate the QST responses with morphological changes of corneal nerves detected by IVCM

  From visit 1 up to 4 weeks

• To correlate symptom severity as assessed by the Ocular Surface Disease Index (OSDI), to stimulus response across the 4 interventional arms.

  From visit 1 up to 4 weeks

• To compare QST response differences between trigeminal nerve first branch and forearm in patients.

  From visit 1 up to 4 weeks

Study Arms (4)

Stage I Neurotrophic Keratopathy

EXPERIMENTAL

Clinical findings of corneal hyperplasia and irregularity, scattered small facets of dried epithelium, decreased nerve density as assessed by in vivo confocal microscopy (IVCM), and decreased corneal sensation.

Device: Quantitative Sensory Test

Stage II Neurotrophic Keratopathy

EXPERIMENTAL

Clinical findings of corneal epithelial defect with smooth and rolled edges, decreased nerve density as assessed by in vivo confocal microscopy (IVCM), and decreased corneal sensation.

Device: Quantitative Sensory Test

Dry Eye Disease

EXPERIMENTAL

Symptoms of dry eye disease for at least 3 months, supported by clinical finding of decreased tear film break-up time or ocular surface staining. Normal corneal sensation.

Device: Quantitative Sensory Test

Healthy Individuals

EXPERIMENTAL

Absence of any ocular symptoms, absence of surface findings (including corneal or conjunctival staining, corneal scar or surgical wound), and normal corneal sensation.

Device: Quantitative Sensory Test

Interventions

Quantitative Sensory Test DEVICE

Quantitative Sensory Test (Medoc Ltd, Israel), QST is a non-invasive neurophysiological method that refers to a group of procedures that assess the perceptual responses to systematically applied and quantifiable sensory stimuli (modalities including heat, cold and vibration) for the purpose of characterizing somatosensory function or dysfunction. For this test, subjects will be seated comfortably on a chair in a quiet room, or laying supine in a horizontal examination chair, with ambient temperature of 24-25◦ C. Medial upper eyelid; just below the supraorbital notch, nasolacrimal sac area; 4-5 mm medial to nasal cantus, and non-dominant forearm will be used as test sites. Patients will be instructed in detail of the nature of the test and the need to react attentively and promptly to change in temperatures.

Dry Eye Disease; Healthy Individuals; Stage I Neurotrophic Keratopathy; Stage II Neurotrophic Keratopathy

Eligibility Criteria

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

You may qualify if:

• Group 1: Stage I Neurotrophic Keratopathy (NK)
• Clinical findings of Stage I NK
• Decreased nerve density by IVCM
• Decreased corneal sensation
• Group 2: Stage II NK
• Clinical findings of Stage II NK
• Decreased nerve density by IVCM
• Decreased corneal sensation
• Group 3: Dry Eye Disease (DED)
• Symptoms of DED at least 3 months
• Presence of at least one of the following DED signs; tear film break-up time lower than 7, ocular surface staining more than +1 based on NIH scale
• Normal or mildly effected corneal sensation
• Group 4: Healthy Individuals
• Absence of any ocular surface symptoms
• Absence of ocular surface findings

You may not qualify if:

• History of diabetes
• History of ocular surgery, corneal infection, or corneal injury within the last 3 months
• Systemic regular anti-inflammatory and/or steroid and/or immune-modulatory therapy in the last 3 months
• Active ocular allergies
• Any major psychiatric illness including bipolar, psychosis, obsessive-compulsive disorder and major depression
• Pregnancy
• History of surgery within the last 3 months
• History of , sarcoidosis, GVHD or collagen vascular disease
• Allergic to benzalkonium chloride "BAK" (an eye-drop preservative)
• Concurrent enrollment in other studies that in the opinion of the investigator will interfere with the results of this study
• Non-English speakers

Sponsors & Collaborators

• Tufts Medical Center: lead
• Dompé Farmaceutici S.p.A: collaborator

Study Sites (1)

Tufts Medical Center

Boston, Massachusetts, 02111, United States

Location

MeSH Terms

Conditions

Corneal Diseases; Dry Eye Syndromes

Condition Hierarchy (Ancestors)

Eye Diseases; Lacrimal Apparatus Diseases

Study Officials

• Pedram Hamrah, MD

  Tufts Medical Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 6, 2022
• First Posted: March 7, 2023
• Study Start: May 16, 2023
• Primary Completion (Estimated): October 31, 2026
• Study Completion (Estimated): June 30, 2027
• Last Updated: January 8, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)