Effect of Alphagan and Xalatan Eye Drops on Corneal Temperature

Study Overview
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Brief Summary
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It is already known that the local treatment with Alphagan eye drops (a drug commonly used by glaucoma patients) reduces ocular blood flow. In-vitro studies suggest that the vasoconstrictive effect of Alphagan is more pronounced when this drug is combined with a prostaglandin analogue (eg. Xalatan eye drops). The investigators also question whether this effect is more pronounced in subjects suffering from a primary vascular dysregulation (PVD). To test for the effect of these drugs on PVD and non-PVD subjects the investigators will take measurements of corneal temperature as surrogate for ocular blood flow.

Detailed Description
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The investigators would like to investigate the effect of Alphagan eye drops, Xalatan eye drops and their combination (both Alphagan and Xalatan) on corneal temperature in healthy subjects with and without a primary vascular dysregulation (PVD). The investigators would like to answer the following questions: Do the individual drugs influence the circulation to the eye as quantified indirectly via corneal temperature? Does the combination of Alphagan and Xalatan give an additive or even potentiated effect? Is the sequence of application of drugs of relevance (Alphagan applied first, Xalatan second, or vice versa)? Do PVD and non-PVD subjects respond differently to these drugs? 20 healthy non-PVD subjects and 20 healthy PVD subjects in the age range from 20-40 years will be recruited. Recruited subjects will have all measurements: corneal temperature, intraocular pressure (IOP), ear temperature, blood-pressure. Both prior to and after instillation of eye drops (Xalatan, Alphagan and placebo).

Official Title
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Effect of Alphagan and Xalatan Eye Drops on Corneal Temperature

Conditions
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Primary Vascular Dysregulation

Intervention / Treatment
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* Drug: Brimonidine
* Drug: Latanoprost
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: healthy age 18-48 years normal findings on ophthalmological examination Exclusion Criteria: history of ocular or systemic disease chronic or current systemic or topical medication drug or alcohol abuse art. hypertension

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 48 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: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: healthy subjects without PVD<br>healthy subjects without primary vascular dysregulation Intervention: Brimonidine, Latanoprost and Placebo | Drug: Brimonidine<br>* Week1, day2: 1 eyedrop/right eye Week2, day1: 1 eyedrop/left eye Week2, day2: 1 eyedrop/left eye<br>* Other names: Alphagan;Drug: Latanoprost<br>* Week1, day1: 1 eyedrop/right eye Week1, day2: 1 eyedrop/right eye Week2, day2: 1 eyedrop/left eye<br>* Other names: Xalatan;Drug: Placebo<br>* Week1, day1: 1 eyedrop/left eye Week1, day2: 2 eyedrops/left eye Week2, day1: 1 eyedrop/right eye Week2, day2: 2 eyedrops/right eye<br>* Other names: Fermavisc;|
| Active Comparator: healthy subjects with PVD<br>healthy subjects with primary vascular dysregulation Intervention: Brimonidine, Latanoprost and Placebo | Drug: Brimonidine<br>* Week1, day2: 1 eyedrop/right eye Week2, day1: 1 eyedrop/left eye Week2, day2: 1 eyedrop/left eye<br>* Other names: Alphagan;Drug: Latanoprost<br>* Week1, day1: 1 eyedrop/right eye Week1, day2: 1 eyedrop/right eye Week2, day2: 1 eyedrop/left eye<br>* Other names: Xalatan;Drug: Placebo<br>* Week1, day1: 1 eyedrop/left eye Week1, day2: 2 eyedrops/left eye Week2, day1: 1 eyedrop/right eye Week2, day2: 2 eyedrops/right eye<br>* Other names: Fermavisc;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Corneal temperature |  | Week 1: day 1 and 2 before eyedrops and after. Week 2: day 1 and 2 before eyedrops and after. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intraocular pressure |  | Week 1: day 1 and 2 before eyedrops and after. Week 2: day 1 and 2 before eyedrops and after. | 
| Ear temperature |  | Week 1: day 1 and 2 before eyedrops and after. Week 2: day 1 and 2 before eyedrops and after. | 
| Blood pressure |  | Week 1: day 1 and 2 before eyedrops and after. Week 2: day 1 and 2 before eyedrops and after. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Alphagan, Xalatan, corneal temperature, primary vascular dysregulation