Congenital retino-pigment epithelial malformation, previously described as hamartoma

Six patients with a congenital malformation of the retina and pigment epithelium had a slightly elevated greenish-blue or gray lesion in the macular area or fundus periphery composed of a flat, outer pigmented portion consisting of a layer of hyperpigmented, presumably hypertrophied retinal pigment epithelium and a prominent, unpigmented inner portion consisting of malformed thickened retina. Marked tortuosity of the retinal vessels was explained by an intraretinal disturbance of the retinal layering and the presence of preretinal membranes. Angiography revealed blockage of the background fluorescence caused by the abnormal retinal pigment epithelium and leakage from dilated, abnormal capillaries. Typically, the lesion was unilateral and was found in children or young adults who had monocular strabismus, reduced visual acuity, and often hyperopia. Most of the patients were males, and their cases were frequently misdiagnosed as tumors.