QST for Corneal Nerve Function

Tufts University

Status: Suspended

Conditions: Corneal Disease; Dry Eye Disease; Neurotrophic Keratitis; Neuropathy

Treatments: Device: Quantitative Sensory Test

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT05758753

STUDY00002510

Details and patient eligibility

About

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.

Full description

Quantitative Sensory Test (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 for the purpose of characterizing somatosensory function or dysfunction.

In this study, we propose to evaluate corneal nerve functions in patients with corneal nerve abnormalities by QST and correlate the nerve functions with symptoms, clinical signs and nerve morphology detected by In-Vivo Confocal Microscopy (IVCM). Identification of corneal nerve functions and correlations with other findings may help us to understand underlying pathological mechanisms of the disease and may guide us toward new treatment targets.

We hypothesize that, QST may provide us detailed information about corneal nerve function alterations and may correlate with morphological nerve changes detected by IVCM.

Enrollment: 108 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

Group 1: Stage I Neurotrophic Keratopathy (NK)

1. Clinical findings of Stage I NK
2. Decreased nerve density by IVCM
3. Decreased corneal sensation

Group 2: Stage II NK

1. Clinical findings of Stage II NK
2. Decreased nerve density by IVCM
3. Decreased corneal sensation

Group 3: Dry Eye Disease (DED)

1. Symptoms of DED at least 3 months
2. 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
3. Normal or mildly effected corneal sensation

Group 4: Healthy Individuals

1. Absence of any ocular surface symptoms
2. Absence of ocular surface findings
3. Transparent and clear cornea
4. Normal corneal sensation

Group 5: NCP

1. Presence of neuropathic symptoms AND
2. Symptoms out of proportion to clinical findings AND
3. Nerve abnormalities detected by in vivo confocal microscopy

Exclusion criteria

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

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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108 participants in 4 patient groups

Stage I Neurotrophic Keratopathy

Experimental group

Description:

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.

Treatment:

Device: Quantitative Sensory Test

Stage II Neurotrophic Keratopathy

Experimental group

Description:

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.

Treatment:

Device: Quantitative Sensory Test

Dry Eye Disease

Experimental group

Description:

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.

Treatment:

Device: Quantitative Sensory Test

Healthy Individuals

Experimental group

Description:

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

Treatment:

Device: Quantitative Sensory Test