Is the RPE derived from the outer or inner layer of the optic cup?

Is the RPE derived from the outer or inner layer of the optic cup?

• A. Outer layer
• B. Inner layer
• C. Both
• D. Neither

Answer: (A)

RPE comes from the outer layer of the optic cup. During early eye development, the optic vesicle invaginates to form a bilaminar optic cup with an inner neural retina layer and an outer retinal pigment epithelium layer. The inner layer differentiates into the neural retina, while the outer layer becomes the pigmented retinal epithelium that sits adjacent to the choroid and supports the neural retina. The pigmentation, phagocytic activity for photoreceptor outer segments, and vitamin A cycle of the RPE all reflect its origin from that outer layer. So the outer layer is the source of the RPE.

RPE comes from the outer layer of the optic cup. During early eye development, the optic vesicle invaginates to form a bilaminar optic cup with an inner neural retina layer and an outer retinal pigment epithelium layer. The inner layer differentiates into the neural retina, while the outer layer becomes the pigmented retinal epithelium that sits adjacent to the choroid and supports the neural retina. The pigmentation, phagocytic activity for photoreceptor outer segments, and vitamin A cycle of the RPE all reflect its origin from that outer layer. So the outer layer is the source of the RPE.