Bruch's membrane

Bruch's membrane is a thin (2–4 μm), acellular, five-layered extracellular matrix located between the retinal pigment epithelium (RPE) and the choriocapillaris within the eye. It serves as a semi-permeable barrier that regulates the exchange of nutrients, oxygen, metabolic waste products, lipids, vitamins, signaling molecules, and other factors essential for photoreceptor function between the retina/RPE complex and general circulation. The structure consists of five layers—two basement membranes on either side sandwiching collagenous zones with a central elastic fiber band. With age or disease states such as age-related macular degeneration or inherited disorders like pseudoxanthoma elasticum or Alport syndrome, Bruch’s membrane can thicken or accumulate lipid-rich deposits ("drusen"), impairing its transport functions. This dysfunction contributes to vision loss through mechanisms such as neovascularization or detachment of retinal layers. While crucial in ocular physiology and pathology—especially in diseases like AMD—Bruch’s membrane itself is not considered a direct therapeutic target like receptors or enzymes but rather an anatomical substrate involved in disease processes.[1][3][5]

Other names

Lamina vitreaVitreous laminaMembrane vitriaeLamina basalis choroideae (Latin)