[Macular coloboma and alternating diffuse chorio-retinal dysplasia]

The author reports on two siblings. The elder, a 28-year-old woman has bilateral macular coloboma and a high degree of myopia. Her 27-year-old brother's left eye also has a macular coloboma, while his right eye has diffuse chorioretinal dysplasia with extensive nevoid choroidal pigmentation but no macular coloboma. His right eye is hyperopic, the left myopic. The eyes of the parents and their other, younger daughter are normal in all respects. Congenital syphilis and toxoplasmosis have been excluded as causes of the fundus deterioration of the first two offsprings. The macular colobomas of the two siblings (circumscribed macular dysplasia) and the alternating diffuse chorioretinal dysplasia must be classified as genetically conditioned maldevelopment of the optic cup ectoderm.