Peter’s anomaly is a unilateral or bilateral central corneal opacity occurring in 3 out of 100,000 births. Eighty percent are bilateral, with glaucoma present in 50-70% of cases. The cause of this anomaly is relatively unknown, although some experts have identified 4 different developmental defects that could result in Peter’s anomaly. It is usually not inherited; however, there are some families who show a high incidence of Peter's anomaly. Some cases have been associated with maternal drug use. The cause of this corneal opacity is the congenital absence of two layers of the cornea (front surface of the eye): both Descemet's membrane and the corneal endothelium. Associated systemic anomalies have been described including cardiac defects, cleft lip, cleft palate, craniofacial dysplasia and skeletal changes. In most cases, however, the Peter's anomaly is isolated to the eye.
Treatment of Peter's anomaly depends on the severity of the opacity. If the opacity is bilateral and blocks the visual axis, nystagmus and dense bilateral amblyopia are common. Under these conditions, corneal transplantation is advised. The prognosis for corneal transplantation is guarded because of the complications of graft rejection and dense amblyopia. Because of the poor results with corneal transplantation, patients with unilateral Peter's anomaly are often treated conservatively without surgery if at all possible. Even so, some unilateral cases require early intervention. Because of the high incidence of glaucoma associated with Peter’s anomaly, these children require constant follow-up to make sure the pressures are under control. Vision in the affected eye varies, but is usually poor secondary to the glaucoma and dense amblyopia.
