Best vitelliform macular dystrophy (VMD) is an autosomal dominant inherited dystrophy, most frequently caused by mutations in the BEST1 gene. The authors describe “choroidal caverns,” a previously unreported optical coherence tomography finding in the choriocapillary and choroid of Best VMD. Histopathologic examination in eyes with Best VDM shows extensive deposition of lipofuscin in the retinal pigment epithelium (RPE) throughout the retina and accumulation of fibrillar material under the RPE and in the choroid. This supports the hypothesis that choroidal caverns could be a sign of the degenerative process involving the choroid in eyes with Best VMD. © 2018 Slack Incorporated. All rights reserved.