Which cells compose the endfeet that form the Internal Limiting Membrane?

• A. Müller cell endfeet
• B. Retinal photoreceptors
• C. Bipolar cells
• D. Ganglion cells

Answer: (A)

The inner limiting membrane is formed by the endfeet of Müller glial cells. These glial cells span the retina, and their foot processes converge at the inner surface to lay down a basement membrane that becomes the ILM, the boundary between the retina and the vitreous. This glial endfoot layer provides structural support and helps organize the vitreoretinal interface. Photoreceptors are located in the outer retina and do not contribute to the ILM; bipolar cells and ganglion cells have their own distinct layers and processes but do not form the endfeet that create the ILM.