Age-Related Macular Degeneration

Kiran Panesar, BPharmS (Hons), MRPharmS, RPh, CPh


US Pharmacist. 2015;40(6):22-26. 

In This Article


Drusen are focal deposits of extracellular debris that typically form between the basal lamina of the RPE and the inner collagenous layer of Bruch's membrane. They are generally round and yellowish in color. These lesions, which are considered the hallmark of ARMD and are characteristic of the aging eye and age-related maculopathy, can be detected through various assays.[23]

Drusen are classified as hard or soft, depending upon their borders and the level of risk they confer on progression of ARMD.[9]Soft drusen are more commonly found in the macula and pose a higher risk of ARMD development.[9,23]They are slightly larger than hard drusen and do not have well-defined margins.[7] Hard drusen tend to be smaller and well defined. The distinct features of the druse may give an indication of the stage of ARMD.[23] Furthermore, the content of drusen is important in understanding the formation process of the lesions that are specific to ARMD. Drusen are known to contain lipids, carbohydrates, zinc, and at least 129 different proteins, including extracellular matrix.[23] The molecules trapped in drusen have varying roles, including the processing of extracellular enzymes, the stigmata of formative processes (e.g., extrusion or secretion of cellular materials), and cellular invasion.[23]