Which structure forms the innermost boundary of the retina facing the vitreous?

Which structure forms the innermost boundary of the retina facing the vitreous?

• A. Internal Limiting Membrane
• B. External Limiting Membrane
• C. Retinal Pigment Epithelium
• D. Outer Limiting Membrane

Answer: (A)

The boundary that directly faces the vitreous is formed by the internal limiting membrane. This thin layer is the basement membrane produced by the endfeet of Müller glial cells that line the inner retina, creating the innermost surface in contact with the vitreous cavity. It acts as the retinal boundary against the vitreous and is the surface where epiretinal membranes and posterior hyaloid interactions occur.

The other membranes sit deeper within the retina: the external limiting membrane lies farther out in the retinal structure, separating parts of the photoreceptor and Müller cell junctions in the outer retina, while the outer limiting membrane is likewise a deeper retinal boundary. The retinal pigment epithelium forms the outermost layer facing the choroid, not the vitreous.