Which of the following is NOT a type of drusen?

Drusen are small yellow-white deposits that form under the retina and are commonly associated with age-related macular degeneration (AMD). They are classified primarily into two types: hard drusen and soft drusen.

Hard drusen are smaller, well-defined, and have a distinct border, often appearing as tiny yellowish spots. In contrast, soft drusen are larger, less organized, and have a more indistinct border. They can vary in size and are often associated with a higher risk of progression to advanced AMD.

Fluffy drusen, however, is not an established or recognized classification of drusen in ophthalmology. This term may evoke a visual image but lacks scientific backing as a defined category of drusen. The recognition of only hard and soft drusen in clinical practice highlights the established understanding of their types and characteristics, thereby making the option of fluffy drusen clearly incorrect in this context.

Thus, recognizing that hard and soft are the only accepted types of drusen allows for an accurate understanding of their role in ocular health, particularly in conditions such as AMD.