Which of the following is NOT true regarding the pressure gradients of the eye?

The statement regarding the pressure gradients of the eye that is not true is the assertion that intraocular pressure (IOP) must be higher than the pressure of the retinal arteries to facilitate the transmission of nutrients from the choriocapillaris to the retinal pigment epithelium (RPE). In fact, nutrient exchange from the choriocapillaris to the RPE occurs primarily due to diffusion and not directly because of a pressure gradient created by IOP relative to the retinal artery pressure. The choroidal blood flow is responsible for supplying nutrients to the RPE, and this process does not depend on IOP being higher than that of the retinal arteries.

In contrast, other statements regarding pressure gradients are accurate and reflect essential physiological principles. For instance, IOP indeed needs to exceed episcleral venous pressure to ensure proper drainage of aqueous humor through the trabecular meshwork, facilitating appropriate outflow to maintain eye health. Additionally, for adequate axoplasmic flow within the optic nerve, a higher IOP must exist compared to intracranial pressure (ICP) to prevent the obstruction of axonal transport. Lastly, the protein content being higher in the choroid compared to the retina is consistent with the richness of the