Which specific layer marks the boundary between retina and vitreous, and which cells form it?

• A. Internal Limiting Membrane (ILM) formed by Müller cell endfeet
• B. External Limiting Membrane
• C. Henle's fiber layer
• D. Plexiform Layer

Answer: (A)

The boundary between the retina and the vitreous is marked by the inner limiting membrane, which is the basement membrane on the retina’s inner surface. It is formed by the endfeet of Müller glial cells that extend to the inner retina and lay down this basal membrane. This creates the vitreoretinal interface—the boundary where the retina meets the vitreous.

The other structures mentioned aren’t at this boundary: the external limiting membrane lies in the outer retina and is formed by adherens junctions between photoreceptors and Müller cells; Henle’s fiber layer and the plexiform layers are specific retinal layers involved in photoreceptor alignment and synaptic connections, not the boundary with the vitreous.