Pharmacokinetics of the Brimonidine Tartrate Posterior Segment Delivery System in Patients Undergoing Pars Plana Vitrectomy

Study Overview
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Brief Summary
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This study will evaluate the pharmacokinetics of brimonidine following a single intravitreal administration of the 200 ug or 400 ug Brimonidine Tartrate Posterior Segment Drug Delivery System in patients 2, 4 or 8 weeks prior to undergoing a pars plana vitrectomy.

Conditions
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Vitrectomy

Intervention / Treatment
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* Drug: 400 µg Brimonidine Tartrate Implant
* Drug: 200 µg Brimonidine Tartrate Implant


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Plan on having a pars plana vitrectomy for repair of a posterior segment condition (eg, epiretinal membrane, macular hole, vitreomacular traction) Visual acuity in the non-study eye better than 20/200 Exclusion Criteria: History of pars plana vitrectomy or retinal detachment surgery in the study eye Surgery or laser treatment in the study eye within 3 months Use of brimonidine, apraclonidine or other topical alpha-2-agonist in either eye within 2 weeks Intraocular infection or inflammation

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 400 µg Brimonidine Tartrate Implant<br>400 µg brimonidine tartrate implant in the study eye on Day 1 (2, 4 or 8 weeks prior to undergoing a pars plana vitrectomy). | Drug: 400 µg Brimonidine Tartrate Implant<br>* 400 µg brimonidine tartrate implant in the study eye on Day 1 (2, 4 or 8 weeks prior to undergoing a pars plana vitrectomy).<br>* Other names: Brimonidine Tartrate PS DDS®;|
| Experimental: 200 µg Brimonidine Tartrate Implant<br>200 µg brimonidine tartrate implant in the study eye on Day 1 (2, 4 or 8 weeks prior to undergoing a pars plana vitrectomy). | Drug: 200 µg Brimonidine Tartrate Implant<br>* 200 µg brimonidine tartrate implant in the study eye on Day 1 (2, 4 or 8 weeks prior to undergoing a pars plana vitrectomy).<br>* Other names: Brimonidine Tartrate PS DDS®;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Highest Vitreous Humor Level of Brimonidine in the Study Eye | The highest level of brimonidine measured in the vitreous humor of the study eye in any patient is reported for each treatment arm. The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye. | 60 Days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Highest Aqueous Humor Level of Brimonidine in the Study Eye | The highest level of brimonidine measured in the aqueous humor of the study eye in any patient is reported for each treatment arm. The aqueous humor is the clear fluid in the chamber of the eye between the cornea and the lens. | 60 Days | 
| Percentage of Patient Samples With Plasma Levels of Brimonidine Below the Limit of Quantitation (BLQ) | Percentage of patient samples with plasma levels of brimonidine reported as BLQ (i.e., too low to be determined using standard methods). Plasma is the fluid portion of the blood. | 60 Days |