Influence of Silicone Hydrogel Extended Contact Lens Wear on Corneal Sensitivity

Study Overview
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Brief Summary
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Soft contact lens wear reduces the amount of oxygen reaching the eye, which may have an influence on corneal sensitivity. The aim of this study is to measure corneal sensitivity with means of liquid jet esthesiometry at baseline and after 6 days of continuous, extended contact lens wear.

Detailed Description
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Contact lens wear may have an influence on corneal sensitivity, by three mechanisms: hypoxic, mechanical and inflammatory. Extended silicone hydrogel contact lens wear increases the risk of infections. A change in corneal sensitivity may be considered as an indicator for change in corneal physiology. It is there the aim of this study is to measure corneal sensitivity with means of liquid jet esthesiometry at baseline and after 6 days of continuous, extended contact lens wear.

Official Title
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Influence of Silicone Hydrogel Extended Contact Lens Wear on Corneal Sensitivity

Conditions
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Cornea

Intervention / Treatment
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* Device: silicone hydrogel contact lens


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: no contact lens wear three days before first visit corneal radius between 7.4 and 8.0; if corneal radius >8.0, corneal diameter must be at least 12 mm; if corneal radius < 7.4, corneal diameter must be < 12.0 OSDI score no higher than 13 points Exclusion Criteria: systemic disease that may have an influence ocular healtjh active ocular disease and no history of ocular surgery

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: extended contact lens wear<br>subjects wear silicone hydrogel contact lenses continuously for 7+/- 1 days - corneal sensitivity will be measured and compared at baseline versus after extended contact lens wear | Device: silicone hydrogel contact lens<br>* silicone hydrogel contact lens<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| difference in corneal sensitivity threshold baseline and after 7 days of extended contact lens wear | The difference in corneal sensitivity threshold baseline versus after 7 days of extended contact lens wear will be determined. Corneal sensitivity measurement will take place with the Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity (SLACS) and will be recorded in mbar. | 7+/-1 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| correlation between corneal sensitvity threshold and subjective symptoms | correlation between corneal sensitvity threshold and subjective symptoms after 7 days of extended contact lens wear: corneal sensitivity threshold will be determinded with the Swiss Liquid Jet Aesthesiometer for Corneal Sensitivity (SLACS) and will be recorded in mbar. Subjective Symptoms will be recorded with the CLEDQ8 questionnaire (specifically designed to assess contact lens comfort) | 7+/-1 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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silicone hydrogel contact lens, extended contact lens wear, corneal sensitivity, esthesiometry