Changes of Clinical Characteristics and Tear Film Biomarkers Following FS-LASIK

Study Overview
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Brief Summary
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to analyze the clinical and tear molecular profile up to 6 months after FS-LASIK surgery

Detailed Description
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FS-LASIK is a refractive surgery technique widely used in China. To explore the role of inflammation and nerve in the occurrence and development of dry eyes after FS-LASIK by dynamically observing the ocular surface characteristics and the levels of inflammatory factors and neurotransmitters in the early and late stage after FS-LASIK.

Official Title
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Changes of Clinical Characteristics and Tear Film Biomarkers Following FS-LASIK

Conditions
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Dry Eye

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who preparing for FS-LASIK with age between 18 and 45 years old Any gender Provision of written informed consent. Exclusion Criteria: active ocular infection, ocular inflammation, active ocular allergy, severe blepharitis or obvious inflammation of the eyelid margin. Pregnant and lactating women, or those planning a pregnancy over the course of the study Uncontrolled systemic disease Suffer from diseases that may affect corneal nerves, such as keratoconus, trigeminal neuralgia, allergic conjunctivitis, etc.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ocular surface disease index (OSDI) | OSDI is one of the most frequently used questionnaires for evaluation of dry eye disease (DED). This includes 12 questions which measure the frequency of symptoms over the recent week, and the scores range from 0 to 100. | from Pre-surgery to 6 months after surgery | 
| Tear break-up time (TBUT)(s) | BUT is the time from normal blinking to the first appearance of a break in the tear film. | from Pre-surgery to 6 months after surgery | 
| Corneal fluorescein staining (CFS) | The degree of fluorescein staining of the cornea was evaluated using the National Eye Institute (NEI) scale of five corneal regions (central, superior, temporal, nasal, and inferior). The scores range from 0 to 15. | from Pre-surgery to 6 months after surgery | 
| Schirmer Ⅰ test (SⅠt) (mm/5 minutes) | The Schirmer I test is performed using sterile strips without anesthesia. The strips are placed in the lateral part of the inferior fornix of the eye for 5min and the extent of tear flow down was measured in millimeters. | from Pre-surgery to 6 months after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the concentration of Interleukin-1β（IL-1β) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IL-1β levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of Interleukin-6 (IL-6) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IL-6 levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of Interleukin-10 (IL-10) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IL-10 levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of Interleukin-23 (IL-23) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IL-23 levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of Interleukin-17A (IL-17A) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IL-17A levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of tumor necrosis factor-α (TNF-α)(pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. TNF-α levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of interferon-γ (IFN-γ)(pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. IFN-γ levels will be quantified by Luminex immunoassay | from Pre-surgery to 6 months after surgery | 
| the concentration of granulocyte-macrophage colony-stimulating factor (GM-CSF)(pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this inflammatory cytokine. GM-CSF levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of substance P (SP)(pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this neuropeptide. SP levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of alpha-melanocyte-stimulating hormone (α-MSH) (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this neuropeptide. α-MSH levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of β-endorphin (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this neuropeptide. β-endorphin levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of neurotensin (pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this neuropeptide. β-endorphin levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| the concentration of oxytocin(pg/ml) | basal tears will be collected from the inferior meniscus of each subject to test this neuropeptide. oxytocin levels will be quantified by Luminex immunoassay. | from Pre-surgery to 6 months after surgery | 
| Lissamine green staining | To grade the temporal zone, the subject looks nasally; to grade the nasal zone the subject looks temporally. The upper and lower conjunctiva can also be graded. | from Pre-surgery to 6 months after surgery | 
| meibomian gland dropout rate | grade 0: no gland atrophy; grade 1: ≤1/3 gland atrophy; grade 2: 1/3 to 2/3 gland atrophy；grade 3: >2/3 gland atrophy. | from Pre-surgery to 6 months after surgery | 
| corneal sensitivity (range, 60-0 mm) | Corneal sensitivity will be measured in the right eye only using the Cochet-Bonnet aesthesiometer and the ascending method of limits to determine the threshold of stimulus detection. | from Pre-surgery to 6 months after surgery | 
| sub-basal corneal nerve density (mm/mm2) | Sub-basal corneal nerve plexus image will be acquired using a laser scanning confocal microscope. | from Pre-surgery to 6 months after surgery | 
| numerical rating scale (NRS) | The NRS was used to evaluate ocular pain and consists of a numbered line from 0 to 10 scores that measures pain intensity: 0-1: no pain; 2-4: mild pain; 5-7: moderate pain; and 8-10: severe pain. | from Pre-surgery to 6 months after surgery | 
| NPSI-Eye (range 0-100 score) | Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-Eye) (range 0-100 over a 24-hour recall period) | from Pre-surgery to 6 months after surgery |