Clinical and Diagnostic Challenges of a Sporadic Adult-onset Vitelliform Macular Dystrophy.

Adult-onset vitelliform macular dystrophy (AVMD) is a relatively uncommon macular pattern dystrophy characterized by bilateral, symmetric, yellowish subretinal foveal lesions presenting in the fourth to sixth decades of life. It is frequently misdiagnosed as age-related macular degeneration or Best vitelliform macular dystrophy, making accurate diagnosis through multimodal imaging essential. We report a case of a 51-year-old male laundry worker who presented with bilateral gradual visual impairment and difficulty with near vision for 1 month. Best-corrected visual acuity was 6/6 in the right eye, whereas in the left eye, it was 6/36p-NI with appropriate correction. Anterior segment examination revealed bilateral posterior subcapsular cataracts and seborrheic blepharitis. Dilated fundus examination demonstrated multiple discrete yellowish subretinal deposits at the fovea in the right eye and a single, elevated, circular vitelliform lesion at the center of the macula in the left eye, with absent foveal reflex bilaterally. Fundus autofluorescence imaging confirmed focal hyperautofluorescence corresponding to the vitelliform deposits bilaterally. Structural optical coherence tomography (OCT) revealed dome-shaped subretinal hyperreflective material between the retinal pigment epithelium and photoreceptor layer in both eyes, consistent with Stage II vitelliform disease in the left eye and an earlier stage in the right eye. OCT angiography excluded choroidal neovascularization in both eyes. Karyotype report and Sanger sequencing show no chromosomal abnormality. A diagnosis of AVMD was established based on clinical and multimodal imaging findings. This case underscores the diagnostic value of multimodal imaging in establishing an accurate diagnosis of AVMD, a condition that carries a generally favorable prognosis when identified early and monitored appropriately. Clinician awareness of AVMD and its distinguishing imaging characteristics is critical to avoid misdiagnosis and ensure timely patient counseling and surveillance.