What does typical hard drusen replace in the retinal pigment epithelium?

Typical hard drusen form as a result of accumulated materials between the retinal pigment epithelium (RPE) and Bruch's membrane, specifically in the region of the RPE basement membrane. They are composed mainly of lipid and protein deposits, which can lead to alterations or damage in the RPE's structural integrity and function.

When these drusen develop, they can displace and replace the RPE basement membrane substance due to the accumulation of these deposits. This replacement can disrupt normal RPE function and contribute to the pathophysiology of age-related macular degeneration (AMD) and other retinal diseases. Understanding that hard drusen affect the RPE basement membrane helps clarify their role in disease progression and highlights the importance of monitoring these changes in patients with AMD.