The Effect of Hinge Location on Corneal Sensation and Dry Eye After LASIK: A Systematic Review and Meta-analysis

Study Overview
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Brief Summary
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The purpose of this study is to investigate the possible effect of hinge location on corneal sensation and dry eye syndrome after laser in situ keratomileusis (LASIK).

Detailed Description
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Dry eye symptoms are a frequent postoperative complication of laser in situ keratomileusis (LASIK). Although estimates of the incidence of dry eye syndrome vary widely, from 3% to 59%, almost all patients will have transient dry eye during the immediate postoperative period.Because of the variability in corneal innervation patterns, altering flap characteristics in LASIK may affect postoperative corneal sensation and dry-eye disease. Some studies have reported that postoperative corneal sensation may be higher and recovery faster in eyes with horizontal flaps (nasal- or temporal-hinge) than in eyes with vertical flaps (superior- hinge). However, some other studies have not established an association between corneal sensation and hinge position. This study reviewed the published literature and performed a meta-analysis aimed to investigate the effects of hinge location on corneal sensation and dry-eye symptoms after LASIK.

Official Title
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The Effect of Hinge Location on Corneal Sensation and Dry Eye After LASIK: A Systematic Review and Meta-analysis

Conditions
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Dry Eye

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: each trial should be a prospective randomized controlled clinical trial (RCT), the age of patient population should be over 18 years Exclusion Criteria: non-randomized controlled trials patients who had had a previous ophthalmic surgery or ocular surface disorders the raw data was not completed

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| horizontal flap<br>patients were scheduled to undergo LASIK and with horizontal flaps(nasal- or temporal-hinge) | |
| vertical flap<br>patients were scheduled to undergo LASIK and with vertical flaps(superior- hinge) | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal sensitivity | Change of corneal sensitivity by using the Cochet-Bonnet esthesiometer,we chose to analyze results at 1 week and 1-, 3-, 6-month postoperatively. | 6 months | 
| Tear break-up time | Change of tear break-up time at 1 week and 1-, 3-, 6-month postoperatively | 6 months | 
| Schirmer's I test | Change of Schirmer's I score at 1 week and 1-, 3-, 6-month postoperatively | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal fluorescein staining |  | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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hinge position, dry eye