Episcleral Venous Pressure

Episcleral venous pressure (EVP) is the pressure within the episcleral veins, which are part of the eye’s vascular system and play a crucial role in regulating intraocular pressure (IOP). EVP represents the resistance against which aqueous humor must flow as it exits the eye through conventional outflow pathways. It is a physiological parameter that reflects hemodynamic conditions in ocular venous drainage. Normal EVP values typically range from 8 to 10 mmHg in humans. Elevated EVP can result from obstruction/compression along orbital/systemic venous drainage pathways or idiopathic causes. Chronic elevation leads to impaired aqueous outflow, sustained high IOP, and potential glaucomatous optic nerve damage.