Clinical manifestations of cuticular drusen in Korean patients

Abstract

Don-il Ham 2* Cuticular drusen show some similarities to and differences from soft drusen in age-related macular degeneration (AMD) and might thus be a unique AMD subtype. previous studies on cuticular drusen were performed mainly in white ethnic groups, but AMD shows ethnic differences. We investigated clinical manifestations of cuticular drusen in Korean patients to evaluate possible ethnic differences. clinical records of Korean patients with cuticular drusen were retrospectively reviewed. fundus distribution pattern, imaging features, and presence of large drusen, drusenoid pigment epithelial detachment (peD), and macular complications, including geographic atrophy (GA), choroidal neovascularization (cnV), and acquired vitelliform lesion (AVL), were assessed via multimodal imaging in 162 eyes with cuticular drusen (n = 81 patients; 67 females; mean age: 66.6 ± 9.1 years). Diffuse distribution was found in 61.7% and peripapillary involvement in 75.3% of eyes. Large drusen, drusenoid PED, GA, CNV, and AVL were observed in 59.3%, 26.5%, 18.5%, 3.7%, and 1.2% of eyes, respectively. The macular complication prevalence was similar between patients ≤ 60 and those > 60 years old. In Korean patients, cuticular drusen were less frequently associated with macular complications than in white patients, and the proportion of macular complications differed significantly, with AVL representing an uncommon complication. Cuticular drusen are multiple, small, round drusen that appear hyperfluorescent in fluorescein angiography (FA), giving a "stars-in-the-sky" appearance 1,2. A histopathological study revealed that cuticular drusen are located between the basal lamina of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane, similar to the soft drusen in age-related macular degeneration (AMD) 3,4. Imaging studies using spectral domain optical coherence tomography (SD-OCT) have also shown the similarity in location of cuticular drusen and soft drusen 4,5. Although cuticular drusen share many features in common with the soft drusen in AMD, there are also several differences between these two types of drusen. Cuticular drusen are more widely scattered on the fundus, with symmetrical distribution patterns in both eyes. In cuticular drusen, the age of onset is younger and genetic associations are stronger than in AMD 6-8. In addition, smoking, one of the most important environmental factors in AMD, is weakly associated with cuticular drusen 9. Cuticular drusen can cause vision loss as a result of vitelliform macular detachment, and it could be related to membranoproliferative glomerulonephritis type II and other renal diseases 2,4,10,11. Thus, cuticular drusen might be a unique subtype of AMD, with particular characteristics. Previous studies on cuticular drusen were performed mainly in white ethnic groups, and clinical features in other ethnic groups remain largely unknown 4,6,10,12-14. Yet, there are known ethnic differences in AMD. The prevalence of AMD varies in different ethnic groups, and the...

Clinical Manifestations of Cuticular Drusen: Current Perspectives

“…36 Another interesting finding in the cuticular drusen population is the peripapillary involvement that is quite common, reported between 63.3 and 75.3% of eyes. 6,32 Upon functional analysis, cuticular drusen present with similar retinal sensitivity values to soft and reticular pseudodrusen/SDD on both mesopic and dark-adapted red conditions, while the dark-adapted cyan condition demonstrated a significantly lower sensitivity for reticular pseudodrusen/SDD with respect to cuticular drusen. A dark-adapted cyan mean defect exceeding the darkadapted red defect suggested a predominant rod dysfunction in reticular pseudodrusen.…”

“…Another interesting finding in the cuticular drusen population is the peripapillary involvement that is quite common, reported between 63.3 and 75.3% of eyes. 6 , 32 …”

“… 38 The prevalence of acquired vitelliform lesions in patients with cuticular drusen varied by ethnic group from 1.2% in the Asian population to 24.2% in Caucasians. 6 , 32 …”

“…Large drusen (>200 μm), embodying the type 3 pattern according to Sakurada et al 7 classification, variably accompanied cuticular drusen in 25-59.3% of cases (Figure 4). 32,33 The presence of large drusen was often accompanied by pigmentary abnormalities in patients aged older than 60 years. 6 It has been proposed that large colloid drusen may constitute a variant of cuticular drusen, but further studies are necessary to confirm this hypothesis.…”

“…38 The prevalence of acquired vitelliform lesions in patients with cuticular drusen varied by ethnic group from 1.2% in the Asian population to 24.2% in Caucasians. 6,32 These lesions are usually bilateral, characterized by a myriad of drusen producing the typical "starry-sky" appearance, accompanied by a late hyperfluorescence, likely representing the late staining of the vitelliform material (Figure 5). 39 The vitelliform macular detachment on OCT appears as hyperreflective subretinal material with an overlying hyporeflective space, thus conferring the pseudohypopyon appearance in some cases.…”