Angioid streaks result from damage to which Bruch's membrane layer?

• A. Elastic Layer
• B. Outer Collagenous Layer
• C. Inner Collagenous Layer
• D. Basement Membrane of choriocapillaris

Answer: (A)

Angioid streaks occur when Bruch’s membrane develops linear breaks, and this most often happens in the elastic layer that sits between the two collagenous layers. Bruch’s membrane has five layers: the RPE basement membrane, the outer collagenous layer, the elastic layer, the inner collagenous layer, and the basement membrane of the choriocapillaris. The elastic layer provides the elastic support between the collagenous layers, and it is the part most prone to weakening, calcification, and rupture in conditions that affect Bruch’s membrane. When the elastic layer fractures, it creates the visible, radiating streaks characteristic of angioid streaks. The other layers—the collagenous layers and the basement membranes—are not the typical sites for these ruptures, which is why the elastic layer is the correct focus.