Idiopathic macular hypoplasia: A report of four cases and refinement of the phenotype of so-called ateliotic macula

PURPOSE. To refine the phenotype of idiopathic macular hypoplasia, also referred to as ateliotic macula, by describing a series of cases with this diagnosis. METHODS. A review of the clinical characteristics of four patients as documented in medical records with regard to refractive error, visual acuity, anterior segment examination, retinal findings, and ancillary tests such as electroretinography (ERG). RESULTS. All patients had oval circumscribed or diffuse areas in the posterior pole where the retina appeared not to have developed normally; the fovea was involved in three patients with reduced visual acuity, and one patient had parafoveal lesions with preserved visual acuity. There were three males and one females. Patients' age ranged from 4 to 16 years. Errors of refraction ranged from severe myopia to hypermetropia and mild astigmatism. The anterior segment was normal in all patients. Three patients had strabismus and two had nystagmus. ERG was normal in the one patient in whom it was performed. One patient was mosaic for trisomy of chromosome 9. CONCLUSIONS. The term idiopathic macular hypoplasia can be applied to a spectrum of abnormalities in which a localized area of the posterior pole has a primordial or underdeveloped appearance. Lesions involving the fovea result in poor acuity. Generalized retinal dysfunction is absent. At least one of the genes involved in macular development may be located on chromosome 9.