The Effect of Brimonidine

Phase 4

Completed

Conditions: Intraocular Pressure

Interventions: Drug: Brimonidine
Drug: Tropicamide
Drug: Phenylephrine Ophthalmic Product

Registration Number: NCT03959176

Lead Sponsor: Wake Forest University Health Sciences

Brief Summary: This study will evaluate whether pre-treating patients with Brimonidine 0.2% before and/or after dilating the pupils will help to control the changes in intraocular pressure often seen when using dilating drops. The study will also evaluate the effects of different sequences of administering dilating drops along with Brimonidine on pupil size and reactivity.

Detailed Description: Intraocular pressure (IOP) can fluctuate due to various external factors such as exercise, medications, and eye movements. Although it is considered natural for IOP to fluctuate daily, prolonged increases in IOP can be harmful. Sustained elevated IOP has been linked to optic nerve damage and glaucoma. Mydriatic drops routinely given to dilate pupils in patients in need of an eye exam have been known to increase IOP. In practice, a combination of drugs are used to achieve pupil dilation needed for routine eye exams or in perioperative situations. The use of Tropicamide 1% and Phenylephrine 2.5% are known to be safe and effective options for dilating the pupils when used in conjunction with one another, but these drugs can increase IOP. Drugs such as Brimonidine, a selective alpha-2 agonist, are known to reduce IOP through several different methods. This study seeks to understand the effects of Brimonidine used along with Tropicamide and Phenylephrine to control IOP.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 13

Inclusion Criteria

Healthy individuals
Females of childbearing potential must agree to use a reliable method of birth control while participating in the study.

Exclusion Criteria

Diabetic
Have a history of glaucoma
Have a history of iris trauma
Have a history of eye surgery except for LASIK or PRK
Pregnant
Anisocoria (unequal pupils)

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group 1	Phenylephrine Ophthalmic Product	The right eye will receive a sham drop followed by 1 drop of Tropicamide 1%/Phenylephrine 2.5% five minutes after the sham drop is administered. A one minute wait will occur followed by a second drop of Tropicamide 1%/Phenylephrine 2.5%. The left eye will receive 2 drops of Brimonidine 0.2% followed by a five minute wait time. One drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a one minute wait time. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered.
Group 2	Phenylephrine Ophthalmic Product	The right eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered followed by a 15 second wait after which a sham drop will be administered. The left eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a 15 second wait after which 2 drops of Brimonidine will be administered.
Group 1	Brimonidine	The right eye will receive a sham drop followed by 1 drop of Tropicamide 1%/Phenylephrine 2.5% five minutes after the sham drop is administered. A one minute wait will occur followed by a second drop of Tropicamide 1%/Phenylephrine 2.5%. The left eye will receive 2 drops of Brimonidine 0.2% followed by a five minute wait time. One drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a one minute wait time. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered.
Group 1	Tropicamide	The right eye will receive a sham drop followed by 1 drop of Tropicamide 1%/Phenylephrine 2.5% five minutes after the sham drop is administered. A one minute wait will occur followed by a second drop of Tropicamide 1%/Phenylephrine 2.5%. The left eye will receive 2 drops of Brimonidine 0.2% followed by a five minute wait time. One drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a one minute wait time. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered.
Group 2	Brimonidine	The right eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered followed by a 15 second wait after which a sham drop will be administered. The left eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a 15 second wait after which 2 drops of Brimonidine will be administered.
Group 2	Tropicamide	The right eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will be administered followed by a 15 second wait after which a sham drop will be administered. The left eye will receive 1 drop of Tropicamide 1%/Phenylephrine 2.5% followed by a one minute wait. A second drop of Tropicamide 1%/Phenylephrine 2.5% will then be administered followed by a 15 second wait after which 2 drops of Brimonidine will be administered.

Primary Outcome Measures

Name	Time	Method
Intraocular Pressure	4 hour post drop administration	To observe how differing the sequence of administration of Tropicamide 1%/Phenylephrine 2.5% and Brimonidine 0.2% influences intraocular pressure.

Secondary Outcome Measures

Name	Time	Method
Pupil Reaction to Light	4 hours post drop administration	Pupil reaction to light will be measured as none (0), poor (1) or brisk (2).
Pupil Size	4 hours post drop administration	Pupil size measurement