Optical Coherence Tomography (OCT) C Fundamentals Practice Test

Drusen form at the boundary between the retinal pigment epithelium (RPE) and Bruch's membrane, specifically in the sub-RPE space. These extracellular deposits accumulate at this interface (the RPE basal lamina–Bruch's membrane region) with aging and in age-related macular degeneration, and they appear as elevations of the RPE on imaging because the material sits just beneath the RPE. The other suggested interfaces are not where drusen develop: the space between photoreceptors and the RPE is the subretinal area, not where drusen form; the outer nuclear layer is a retinal neuronal layer containing photoreceptor nuclei; and the inner limiting membrane is the innermost boundary of the retina facing the vitreous.