अमूर्त

Drusen and pigmentary abnormality: Two ways leading to AMD progression.

Shoji Notomi

Drusen are known to be the hallmark that predicts progression of Age-related Macular Degeneration (AMD). It is well studied that large drusen over 125 μm, pigmentary abnormality, and medium drusen 63-125 μm provide an increased risk of AMD progression toward late AMD, namely neovascular AMD and geographic atrophy, especially in Western populations. There are several racial and ethnic differences well recognized in AMD. The prevalences of drusen are lower in Asia than those in Western countries. In contrast, neovascular AMD is more frequently seen rather than atrophic dry AMD in Asians. Here we review the current understanding and epidemiology of drusen and other retinal/choroidal features predicting their progression to late AMD and also summarize our recent study. Thick choroid may be a unique feature of part of AMD, which is often found in Asians. To be noted, pigmentary abnormality rather than soft drusen was more associated with “pachychoroid”, which is accompanied by the dilated choroidal vessels and their hyperpermeability, leading to the formation of PCV, a special type of macular neovascularization commonly seen in Asians.