Which statement best describes Bruch's membrane?

Which statement best describes Bruch's membrane?

• A. It lies between the choroid and the retinal pigment epithelium and provides structural support
• B. It is the innermost layer of the retina
• C. It is part of the sensory retina
• D. It is the outermost layer of the cornea

Answer: (A)

Bruch's membrane is a thin extracellular layer that sits between the retinal pigment epithelium and the choroid. Its main roles are to provide structural support for the RPE and to serve as a barrier and conduit for metabolite exchange between the vascular choroid and the outer retina. That placement—between the choroid and the RPE—along with its supportive function, is what makes the statement describing its position and role the best description. It isn’t part of the inner retina, it isn’t a component of the sensory retina, and it isn’t related to the cornea, so those options don’t fit.

Bruch's membrane is a thin extracellular layer that sits between the retinal pigment epithelium and the choroid. Its main roles are to provide structural support for the RPE and to serve as a barrier and conduit for metabolite exchange between the vascular choroid and the outer retina. That placement—between the choroid and the RPE—along with its supportive function, is what makes the statement describing its position and role the best description. It isn’t part of the inner retina, it isn’t a component of the sensory retina, and it isn’t related to the cornea, so those options don’t fit.