Adult-Onset Vitelliform Lesions
Several types of symmetric yellow deposits that resemble Best disease may develop in the macula of older adults. The most common disorder, adult-onset foveomacular vitelliform dystrophy, is one of the pattern dystrophies (discussed later in this chapter). It is characterized by yellow subfoveal lesions that are bilateral, round or oval, and typically one-third disc diameter in size; they often contain a central pigmented spot (Fig 13-14). Occasionally, when the lesions are larger, they may be misdiagnosed as Best disease or even as age-related macular degeneration (AMD). This dystrophy generally appears in the fourth to sixth decades in patients who either are visually asymptomatic or have mild blurring and metamorphopsia. Eventually, the lesions may fade, leaving an area of RPE atrophy, but most patients retain reading vision in at least 1 eye throughout their lives. Autosomal dominant inheritance has been recognized in some affected families. The most common causative gene is PRPH2, and there is evidence of genetic heterogeneity for this phenotype. In some cases of post-surgical CME, acute onset of foveomacular subretinal deposits in the absence of drusen or intraretinal fluid have been seen; these respond well to standard therapy.
Patients with numerous basal laminar (cuticular) drusen may develop an unusual vitelliform exudative macular detachment (Fig 13-15). The yellowish subretinal fluid blocks background fluorescence early, often stains late in the angiogram study, and may be mistaken for choroidal neovascularization. Patients with yellowish macular detachments often maintain good visual acuity for many months but may eventually lose central vision because of geographic atrophy or choroidal neovascularization and disciform scarring.
In some patients with large, soft drusen, there is a large, central coalescence of drusen, or drusenoid RPE detachment, which may occasionally mimic a macular vitelliform lesion (Fig 13-16). Such lesions often have pigment mottling on their surface and are surrounded by numerous other individual or confluent soft drusen. They may remain stable (and allow for good vision) for many years, but eventually they tend to flatten and evolve into geographic atrophy.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.