The Efficacy of Quantitative Sensory Test (QST) in Assessing Corneal Nerve Functions in Patients With Ocular Surface Diseases
Overview
- Phase
- Not Applicable
- Intervention
- Quantitative Sensory Test
- Conditions
- Corneal Disease
- Sponsor
- Tufts Medical Center
- Enrollment
- 108
- Locations
- 1
- Primary Endpoint
- Thermal stimulus response to QST on site of trigeminal nerve first branch, as assessed by cold detection threshold (CDT) and hot detection threshold (HDT)
- Status
- Suspended
- Last Updated
- 3 months ago
Overview
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.
Detailed 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.
Investigators
Eligibility Criteria
Inclusion Criteria
- •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
Exclusion Criteria
- •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
- •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
Arms & Interventions
Stage I Neurotrophic Keratopathy
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.
Intervention: Quantitative Sensory Test
Stage II Neurotrophic Keratopathy
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.
Intervention: Quantitative Sensory Test
Dry Eye Disease
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.
Intervention: Quantitative Sensory Test
Healthy Individuals
Absence of any ocular symptoms, absence of surface findings (including corneal or conjunctival staining, corneal scar or surgical wound), and normal corneal sensation.
Intervention: Quantitative Sensory Test
Outcomes
Primary Outcomes
Thermal stimulus response to QST on site of trigeminal nerve first branch, as assessed by cold detection threshold (CDT) and hot detection threshold (HDT)
Time Frame: From visit 1 up to 4 weeks
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.
Differences in mechanical stimulus pain threshold across the 4 study arms
Time Frame: From visit 1 up to 4 weeks
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
Mechanical stimulus response to QST on site of trigeminal nerve first branch, as assessed by vibration detection threshold (VDT)
Time Frame: From visit 1 up to 4 weeks
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.
Differences in thermal stimulus pain threshold across the 4 study arms
Time Frame: From visit 1 up to 4 weeks
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
Secondary Outcomes
- To compare QST response differences between trigeminal nerve first branch and forearm in patients.(From visit 1 up to 4 weeks)
- 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)