reticular pseudodrusen can be detected very precisely. As shown previously in studies using SD-OCT, reticular pseudodrusen are collections of granular hyperreflective material above the RPE and are primarily located between the RPE and the boundary between the inner and outer segments of the photoreceptors [23, 24]. In histological studies, corresponding aggregations containing typical drusen-associated components were found in the subretinal space, too [24, 25]. Therefore, several authors now prefer the term “subretinal drusenoid deposits” instead of “reticular pseudodrusen” [22, 24]. While the association between reticular pseudodrusen and AMD has been previously proposed [26], a significant relationship between this type of drusen and late AMD has been recently shown in a case-control study using SD-OCT [27]. Furthermore, the multicenter, prospective GAP study revealed a prevalence of reticular pseudodrusen in almost two-thirds of 458 study participants with geographic atrophy. Therefore, suitable imaging techniques using various cSLO recording modes were systematically applied [28].

Spontaneous dynamic changes of drusen (see overview “Possible spontaneous modifications of drusen”) include the following:

•Hard drusen may enlarge and progress to soft drusen (“drusen softening”) [29].

•Soft drusen may enlarge and become confluent, leading to detachment of the pigmented epithelium of the retina.

•Calcifications within drusen material show up as refractile, crystalline structures on ophthalmoscopy (usually cholesterol crystals).

•While drusen usually increase in number and density with age, spontaneous regression is also possible (Fig. 6.6). Apparently, drusen material is then phagocytosed, degraded, and cleared from the subpigment epithelial space. Disappearance of drusen can also be induced by low-energy perifoveal laser photocoagulation.

Peripheral drusen outside the macular area can

also occur with age. In contrast to drusen at the posterior pole, peripheral drusen usually have a pigmented halo around the yellowish center. There is no evidence to suggest that drusen of this type are associated with an increased risk that late-stage AMD with visual loss will develop. The term “reticular pigmentary degeneration” has been used to describe clusters of peripheral drusen with lacy linear hyperpigmentation.

6.2.3Fluorescence Angiography and Optical Coherence Tomography

Fluorescence angiography may allow better visualization of drusen than conventional ophthalmoscopy. Hypofluorescent drusen are distinguished from hyperfluorescent drusen by their biochemical composition and, thus, their affinity to the hydrophilic fluorescein dye [30]. In particular, soft drusen may