The etiology of choroidal folds. A biomechanical explanation.

Folding of the choroid, Bruch's membrane, and the overlying retina occurs in a variety of ocular and orbital diseases and after certain surgical procedures. The etiology of the folding is explained, using the principles of deformation of materials and by considering the biomechanical properties of the choroid and sclera. Choroidal folds are likely to develop in association with any intra- or extraocular process that induces sufficient compressive stress within the choroid, Bruch's membrane, and retina to force these tissues to buckle. A detailed explanation of the pathogenesis of folding is presented in various clinical settings.