Effect of Topical Phenylephrine 2.5% on EVP in Normal Human Eyes
Status:
Completed
Trial end date:
2018-10-01
Target enrollment:
Participant gender:
Summary
Phenylephrine hydrochloride ophthalmic solution is an alpha-1 adrenergic receptor agonist
commonly used topically for dilation prior to ocular fundus examination. In the eye,
phenylephrine acts locally as a potent vasoconstrictor and mydriatic by constricting
ophthalmic blood vessels and the radial dilator muscle of the iris. Episcleral venous
pressure (EVP) is a determinant of intraocular pressure (IOP) and can be measured
non-invasively by venomanometry. Since phenylephrine is a vasoconstrictor, it may affect
episcleral venous tone, but the effect on EVP is unknown. Understanding the physiology of
episcleral veins helps us in better understanding of pathophysiology of glaucoma.