North Carolina Macular Dystrophy.

North Carolina Macular Dystrophy (NCMD) is an autosomal dominant, congenital, completely penetrant non-progressive macular malformation. The NCMD phenotype is highly variable even within the same family (Fig. 21.1). Grade 1 individuals have few drusen centrally while grade 2 can appear with confluent drusen to central vitelliform lesions. Grade 3 appears as dramatic choroidal excavations and coloboma like lesions (Small 1989; Small et al. 1991, 2022a). There can be some vision decline secondary to the development of choroidal neovascular membranes (CNVMs) (Bakall et al. 2018). Patients who develop CNVMs are the subjects who experience progressive moderate to severe vision impairment, typically confined to one eye. In grade 3 lesions, the CNVMs and resulting fibrosis typically occur along the temporal edge of the "coloboma" and do not affect the visual acuity. Peripheral drusen are variably reported.