Internal limiting membrane

Internal limiting membrane (ILM) is the innermost layer of the retina, which separates the vitreous body from the rest of the retina. It is a transparent, acellular structure that plays a crucial role in maintaining the structural and functional integrity of the retina.

Structure

The ILM is composed of two main components: the basement membrane of the Müller cells and the footplates of the astrocytes. The basement membrane of the Müller cells forms the bulk of the ILM, while the astrocytes provide additional support and stability.

Function

The primary function of the ILM is to provide a barrier between the vitreous body and the rest of the retina. This barrier prevents the migration of cells and molecules from the vitreous body into the retina, thereby maintaining the structural and functional integrity of the retina. The ILM also plays a role in the regulation of retinal blood flow and the transport of nutrients and waste products between the retina and the vitreous body.

Clinical significance

In certain pathological conditions, such as macular hole and epiretinal membrane, the ILM can become thickened or contracted, leading to visual impairment. Surgical removal of the ILM (ILM peeling) is a common treatment for these conditions. However, this procedure can be challenging due to the thin and transparent nature of the ILM.

See also

• Retina
• Müller cells
• Astrocytes
• Macular hole
• Epiretinal membrane