Clinical manifestations of cuticular drusen in Korean patients

Differentiating drusen and drusenoid deposits subtypes on multimodal imaging and risk of advanced age-related macular degeneration

Drusen are extracellular material considered a precursor lesion to advanced age-related macular degeneration (AMD), located either on the retinal pigment epithelium (RPE) or the sub-RPE; they contain various proteins associated with inflammation and lipids. Previous studies suggest that the lifecycle of drusen varies depending on drusen type and size. In general, conventional drusen grow and aggregate/coalesce in the first stage, and in the second stage, they regress with or without showing RPE atrophy. The risk of advanced AMD also varies depending on the drusen and drusenoid deposit types' along with their size and RPE abnormalities. In eyes with macular neovascularization (MNV), specific drusen/drusenoid deposits are closely associated with the MNV subtype. Recently, pachychoroid-associated drusen (pachydrusen) were proposed and clinical findings regarding this entity have been accumulating, as more attention is focused on drusen as well as pachychoroid diseases. With the advance in imaging modalities, various modalities can show specific characteristics depending on drusen types. To assess the risk of advanced AMD, it is essential for physicians to have accurate clinical knowledge about each druse/drusenoid lesion and correctly evaluate its imaging characteristics using multimodal imaging. This review summarizes the latest clinical knowledge about each druse/drusenoid lesions and documents their imaging characteristics on multimodal imaging, allowing clinicians to better manage patients and stratify the risk of developing advanced AMD. The most representative cases are illustrated, which can be helpful in the differential diagnosis of drusen and drusenoid deposits.

Cuticular drusen presenting with central serous chorioretinopathy in both eyes: A case report

RATIONALE

Drusen are precursor lesions to advanced age-related macular degeneration. Although cuticular drusen are located between the retinal pigment epithelium and Bruch's membrane, as are conventional drusen, they possess unique characteristics that are distinct from those of conventional drusen on clinical presentations. Central serous chorioretinopathy (CSC) is a rare complication in eyes with cuticular drusen.

PATIENT CONCERN

A 58-years-old man was referred to our institute for the treatment of persistent subretinal fluid (SRF) in both eyes. Spectral-domain optical coherence tomography revealed focal SRF that did not involve the central macula of the right eye and SRF in the central macula of the left eye. Fluorescein angiography exhibited focal leakage corresponding to SRF and hyperfluorescence resembling a "stars in the sky" appearance in both eyes. On initial presentation, the best-corrected visual acuity values were 1.2 and 0.9 in the right and left eye decimal formats, respectively.

DIAGNOSIS

Cuticular drusen presenting with CSC in both eyes.

INTERVENTIONS

No treatment was administered for CSC in the right eye, whereas photodynamic therapy was administered for CSC in the left eye.

OUTCOMES

At the 6-month visit, extrafoveal SRF persisted in the right eye and resolved in the left eye. Best-corrected visual acuity improved from 0.9 to 1.2 in the decimal format in the left eye.

LESSONS

Although cuticular drusen presenting with CSC are rare, physicians should be aware of the possibility of CSC development in eyes with cuticular drusen.

Evaluation of the microperimetry in eyes with cuticular drusen

Retinal sensitivity may vary by subtypes of cuticular drusen. This retrospective study included 52 eyes of 32 patients with cuticular drusen. All the patients underwent assessment of best-corrected visual acuity (BCVA), spectral-domain optical coherence tomography (SD-OCT), color fundus photography, fluorescein angiography, fundus autofluorescence, and microperimetry. The area occupied by drusen was counted using microperimetry. The cuticular drusen subtype was classified into 3 groups based on the SD-OCT findings. Age, BCVA, pattern standard deviation, area occupied by drusen, pupil size, and the false-positive rate were not significantly different (p > 0.05) according to the cuticular drusen type. The mean retinal sensitivity (MRS) (p = 0.063) and mean deviation (MD) (p = 0.098) showed marginally significant differences among the groups. In the subgroup analyses, type 1 and type 3 cuticular drusen showed significant differences in the MD (- 1.8 ± 2.1 vs - 5.1 ± 5.3; p = 0.011) and MRS (25.1 ± 2.2 vs 21.3 ± 5.7; p = 0.016) without differences in age, BCVA, or the area occupied by drusen (p > 0.05). The results indicate that depending on the subtypes of cuticular drusen type, the deterioration of retinal sensitivity is more likely to occur than decreased vision.

Age-related macular degeneration eyes presenting with cuticular drusen and reticular pseudodrusen

This study aimed to describe the clinical characteristics of age-related macular degeneration (AMD) eyes with both cuticular drusen (CD) and reticular pseudodrusen (RPD). Clinical records of patients diagnosed with CD or RPD with multimodal imaging was reviewed for patients diagnosed with both CD and RPD. The distribution patterns of CD (macular and diffuse type) and RPD (localized, intermediate, and diffuse type), presence of soft drusen, large drusen (> 200 µm), variant subretinal drusenoid deposits, and macular complications were investigated. Of the 220 eyes of 110 patients diagnosed with CD and 926 eyes of 463 patients diagnosed with RPD, 13 eyes of seven patients met the diagnostic criteria for both CD and RPD. The mean age at initial presentation was 71.4 ± 8.8 years and six patients were female. The mean subfoveal choroidal thickness was 143.8 ± 25.1 µm. The distribution of CD was of the macular type in all eyes. Distribution of RPD was localized in 11 eyes (84.6%) and intermediate in two eyes (15.4%). Soft drusen, large drusen, and variant subretinal drusenoid deposits were present in 13 (100%), 12 (92.3%) and, seven (53.8%) eyes, respectively. Macular neovascularization was observed in two eyes (15.4%). CD and RPD can coexist in eyes with AMD. Multimodal imaging should be used for AMD eyes with features suggestive of CD and RPD, considering the high likelihood of developing late AMD.

Clinical Manifestations of Cuticular Drusen: Current Perspectives

Cuticular drusen are part of the spectrum of age-related macular degeneration (AMD) with particular clinical and multimodal imaging characteristics. This drusen subpopulation shares several high-risk single nucleotide polymorphisms with AMD. Despite this feature, they can manifest at a relatively young age, presenting with a female preponderance. Multimodal imaging is essential for characterizing such lesions, using a combination of color fundus photographs, optical coherence tomography (OCT), fluorescein angiography (FA), and fundus autofluorescence (FAF). The classic starry-sky pattern visible on FA and the typical central hypoautofluorescent lesion with hyperautofluorescent rim on FAF is considered the result of a central retinal pigment epithelium (RPE) erosion from these triangular elevations of the RPE-basal lamina. This finding may also be responsible for the typical choroidal hypertransmission appreciated through OCT. The clinical course of cuticular drusen may be relatively benign at early stages, with small drusen presenting at a young age. However, the presence of clinical phenotypes characterized by diffuse involvement and/or accompanying large drusen in patients older than 60 years may confer a significant risk for either macular neovascularization or geographic atrophy.