The Influence of Atropine on Choroidal Thickness

Study Overview
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Brief Summary
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Atropine eye drops are increasingly prescribed for the management of progressive myopia or short-sightedness. A previous study suggested that the back of the eye or choroid may be a part of the mechanism by which it induces its effects. The aim of this study is to characterize the effects of atropine on choroidal thickness and the influence of time of administration (am vs pm). It is hypothesized that the atropine's effect on choroidal thickness will vary with baseline thickness related to diurnal rhythm, where thicker baseline thickness will show a reduced choroidal response.

Detailed Description
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Atropine eye drops are increasingly prescribed for the management of progressive myopia or short-sightedness. A previous study suggested that the back of the eye or choroid may be a part of the mechanism by which it induces its effects. The choroid shows diurnal variation and the efficacy of atropine on myopia control in relationship to the patient's baseline choroidal thickness is unknown. Thus, the objective of this study is to provide data to characterize the influence of atropine on choroid thickness. The study aims are to: Determine the effect of am or pm atropine application on choroid thickness Determine the effect of atropine on choroid thickness in relationship to baseline thickness Participants will be asked to attend a screening session and 13 study visits. Following the screening visit, participants will be scheduled to return for 4 visits across 12 hours (4 hour intervals starting from 8am) in a single day where eye shape measurements will be taken to characterize diurnal variations in eye shape. Subjects will then be randomized to receive a drop of 1% atropine eye drops in both eyes in the morning or a night. Measurements of the shape of the front and back of the eye will be taken after approximately 1, 12, 24 and 96 hours after drop instillation. After a 2 week washout period, 1% atropine eye drops will be administered either in the morning or at night (the visit that was not previously scheduled) and measurements of the shape of the front and back of the eye will be taken after approximately 1, 12, 24 and 96 hours after drop instillation.

Official Title
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The Influence of Atropine on Choroidal Thickness

Conditions
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Myopia

Intervention / Treatment
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* Drug: Atropine Sulfate 1% Oph Soln


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Good general and ocular health Soft contact lens wearers to cease lens wear for at least 24 hours No previous rigid gas permeable lens wear Exclusion Criteria: History of ocular surgery, including refractive surgery Amblyopia Use of ocular medications Known allergies or sensitivity to atropine Pregnant, plan to become pregnant, or are breastfeeding Taking monoamine oxidase inhibitors (MAOIs)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 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: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Atropine group<br>One drop of Atropine Sulfate 1% Oph Soln will be administered either in the morning or at night in each eye. Study measurements will be taken approximately after 1, 12, 24 and 96 hours after drop instillation. After a 2 week wash out period with no eye drops, another drop of 1% atropine sulfate ophthalmic eye drops will be administered either in the morning or night (the visit that was not taken before) and study measurements will be scheduled approximately after 1, 12 24 and 96 hours after drop instillation | Drug: Atropine Sulfate 1% Oph Soln<br>* Atropine sulphate 1% ophthalmic solution is both a mydriatic and cycloplegic<br>* Other names: 1% atropine eye drops;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Choroidal thickness | Change in choroidal thickness after atropine | Baseline, then after approximately 1, 12, 24 and 96 hours after atropine instillation |