Where is Bruch's membrane located?

Where is Bruch's membrane located?

• A. Between the photoreceptors and the RPE
• B. Between the RPE and the choriocapillaris
• C. Inside the choriocapillaris
• D. Between the sclera and choroid

Answer: (B)

Bruch's membrane is the thin, acellular layer that sits at the retina–choroid boundary, located between the retinal pigment epithelium (RPE) and the choriocapillaris. It forms the interface through which nutrients and waste diffuse between the RPE/outer retina and the vascular choroid, and in imaging it appears as a distinct line just below the RPE, separating it from the choroidal vasculature. The other interfaces described do not match this location: it is not between the photoreceptors and the RPE (that region involves the outer retina and the contact with RPE microvilli), not inside the choriocapillaris (that would be within a blood vessel), and not between the sclera and choroid (that area lies posterior to Bruch's membrane). Therefore, the correct location is between the RPE and the choriocapillaris.

Bruch's membrane is the thin, acellular layer that sits at the retina–choroid boundary, located between the retinal pigment epithelium (RPE) and the choriocapillaris. It forms the interface through which nutrients and waste diffuse between the RPE/outer retina and the vascular choroid, and in imaging it appears as a distinct line just below the RPE, separating it from the choroidal vasculature. The other interfaces described do not match this location: it is not between the photoreceptors and the RPE (that region involves the outer retina and the contact with RPE microvilli), not inside the choriocapillaris (that would be within a blood vessel), and not between the sclera and choroid (that area lies posterior to Bruch's membrane). Therefore, the correct location is between the RPE and the choriocapillaris.