IPoster: SD-OCT May Help Differentiate Adult-Onset Fovealmacular Vitelliform Dystrophy from Age-Related Macular Degeneration

Introduction: Adult-onset fovealmacular vitelliform dystrophy (AOFVD) is a retinal dystrophy, characterized by bilateral foveal, yellow, round elevated subretinal lesions. These lesions mimic drusen and are often misdiagnosed as age-related macular degeneration (AMD). SD-OCT may be a useful technique to assist in distinguishing these two conditions.

Case Report: Patient 1, an 85yo WM, complained of blurry vision OU. BCVA were 20/30 OD and 20/40 OS. Dilated eye exam revealed mild RPE changes OD, and a large elevated yellow lesion OS. SD-OCT revealed a small lesion between the inner/outer segment (IS/OS) interface and the RPE band OD, and a large vitelliform-like lesion OS consistent with AOFVD. Patient 2, a 72yo WM, reported blurry vision OS at distance. BCVA were 20/30 OD and 20/60 OS. Dilated eye exam revealed several small drusen OS>OD, and a large elevated lesion OS. SD-OCT confirmed small drusen OU, and a large pigment epithelial detachment (PED) with mild sub-retinal fluid OS, consistent with wet AMD.

Conclusion(s): AOFVD and AMD have similar clinical features making differentiation challenging. SD-OCT may distinguish subtle differences between these conditions. The early yellow subretinal deposits in AOFVD on OCT have been localized between the IS/OS interface and the RPE band. In contrast, AMD drusen have been described as irregularities generally within the level of the RPE on OCT. AOFVD progression presents as a large vitelliform lesion, similar to PED in AMD. It has been suggested that vitelliform lesions in AOFVD may maintain photoreceptor integrity and visual function longer than AMD, because the contact between the apical RPE and IS/OS is preserved. PED lesions in AMD exhibit RPE elevation and gradual IS/OS loss. Since both conditions may develop choroidal neovascularization leading to significant vision loss, SD-OCT is useful in differentiating between AOFVD and AMD, and identifying the need for further treatment.