Foveal hypoplasia has generally been associated with other disorders such as aniridia, ocular albinism, microphthalmia, retinopathy of prematurity, incontinentia pigmenti, myopia or achromatopsia. However, recent studies have uncovered rare cases of isolated foveal hypoplasia. Isolated foveal hypoplasia is a disorder characterized by the lack of foveal depression and the absence of foveal pigmentation or the foveal avascular zone. Patients with FVH1 usually have low visual acuity and congenital nystagmus.
FVH1 is diagnosed by optical coherence tomography (OCT). There are currently no treatment options available besides cataract surgery for patients with significant lens opacity.
Several cases of isolated foveal hypoplasia have been associated with mutations in the Pax6 gene and have been shown to follow an autosomal dominant pattern of inheritance. Pax6 is a transcriptional factor involved in ocular morphogenesis. Genetic defects in Pax6 have generally been linked with aniridia, albeit certain mutations were only associated with FVH1. These include a heterozygous 799C-T mutation in exon 7 resulting in R125C missense mutation; a heterozygous 553G-T transition, predicted to result in G64V substitution; and a heterozygous gene splice mutation (IVS4 + 5G>C) resulting in a mutant mRNA lacking exon 4. However, a recent study has reported a case of isolated foveal hypoplasia with no detected gene defects in Pax6 and a pattern of inheritance that is seemingly autosomal recessive.