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Systemic blood pressure and intraocular pressure relationship
T Gherezghiher1, J A Hey, M C Koss
1Department of Ophthalmology, Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City.
Journal of Ocular Pharmacology
|January 1, 1988
Summary
Intraocular pressure (IOP) is significantly affected by arterial blood pressure (BP) changes. Drug effects on IOP result from combined systemic blood pressure and direct ocular actions.
Area of Science:
- Ophthalmology
- Cardiovascular Physiology
- Pharmacology
Background:
- Intraocular pressure (IOP) regulation is complex.
- Understanding the interplay between systemic blood pressure (BP) and IOP is crucial for ocular health.
Purpose of the Study:
- To investigate the acute effects of pressor and depressor agents on IOP in anesthetized cats.
- To differentiate between systemic and direct ocular drug effects on IOP.
Main Methods:
- Anesthetized cats underwent measurements of IOP and BP.
- Pressor agents (norepinephrine, angiotensin II) and depressor agents (methacholine, isoproterenol) were administered intravenously.
- Carotid artery cannulation and direct ocular arterial injections were used to isolate drug effects.
Main Results:
- Systemic administration of pressor agents increased both BP and IOP; depressor agents decreased both.
- Methacholine exhibited a biphasic IOP response (initial decrease, then increase).
- Separating drug circulation revealed distinct systemic and direct ocular contributions to IOP changes.
Conclusions:
- Acute IOP is substantially influenced by systemic arterial blood pressure.
- The overall IOP response to drugs is an algebraic sum of their systemic BP and direct ocular effects.