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QST for Corneal Nerve Function

Title The Efficacy of Quantitative Sensory Test (QST) in Assessing Corneal Nerve Functions in Patients with Ocular Surface Diseases
Therapeutic Area Corneal Disorders, Dry Eye
Principal Investigator Pedram Hamrah, MD
Min Age 18 Years
Gender Any
Contact Nancy Gee
More Information


The cornea (window in the front of your eye) is made up of many nerves with important regions that allow you to feel sensations like, heat, cold, pressure and vibration. It is well known that many ocular surface disorders, such as dry eye disease (DED), neurotrophic keratitis and post-herpetic neuralgia, affect corneal nerve structure, which can be detected by a special type of eye imaging called ‘In-vivo Confocal Microscopy (IVCM)’. However, the relationship between eye symptoms, signs and abnormal corneal nerve functions are not yet well understood. The quantitative sensory motor test (QST) is a non-invasive method which evaluates nerve function with different stimuli such as cold, heat and vibration. Therefore, people with different corneal conditions who undergo QST may show varying pain responses to each sensation, and may characterize their pain in unique ways. This goal of this study is to find out which types of stimuli have the most impact on ocular discomfort among those with different types of corneal conditions, and compare QST results between ocular surface patients and those without any ocular surface conditions. Most procedures are standard of care which means they are typically performed during a routine eye exam and therefore during your routine clinical visit.

Study Details

Inclusion Criteria

Group I (Healthy Controls) 1) Absence of ocular surface abnormalities or symptoms (including dry eye disease, Stage I or II Neurotrophic Keratitis) 2) TBUT 7 seconds or higher 3) No corneal or conjunctival staining Group II (Ocular Surface Abnormalities) 1) Diagnosis of Dry eye disease (DED), Stage I Neurotrophic Keratitis or Stage II Neurotrophic Keratitis 2) Ability to consent 3) Ability to speak English  

Exclusion Criteria

1)History of ocular surgery , corneal infection, or corneal injury within the last 3 months 2) Systemic regular anti-inflammatory and/or steroid and/or immune-modulatory therapy in the last 3 months 3) Active ocular allergies

Study Requirements

All prospective participants will be invited to complete the QST following completion of their routine scheduled ophthalmology visit. Information generated from their routine eye examination will be used for study data. Participants will also be given the option to return at a later date for the QST testing, at which time they will sign the consent form and complete the QST. All necessary data will already exist from their routine clinc visit.