Abstract
Purpose Peter's anomaly is a rare developmental malformation involving the anterior segment of the eye culminating in congenital blindness, with or without systemic associations. herein, we report an incidence of this anomaly in twins with novel associations. Methods Chart review, clinical and radiological assessment. Results The probands are 2 year old Saudi boys (twin I and twin II) born to consanguineous mates at 36 weeks following uneventful pregnancy. On examination: both twins were not blinking in response to light and were not able to fixate and follow a moving object with prominent horizontal nystagmus. Slit lamp examination demonstrated varying degrees of central leukoma (corneal opacity) associated with iridocorneal adhesion characteristic of type I peter anomaly in both twins. No catarctous changes were observed. A normal intraocular pressure with intact retinas were seen in both twins. Striking pupillary abnormalities include bilaterally underdeveloped pupil (twin I) and bilateral absence of the pupil (twin II). Ocular ultrasound: revealed bilateral vitreous hemorrhage mostly linked to deranged coagulation. Ocular MRI: showed bilateral microophtalmia and optic nerves hypoplasia with small optic chiasm in both twins. Systemic associations: both twins have coarse facial features and a thrombophilia state secondary to homozygous protein C deficiency; a rare thrombotic condition seen in 1\4,000,000 live birth. Twin II developed bilateral inguinal hernia and cryptorchidism Conclusions The novel concordance of peter's anomaly in these twins is probably an emerging evidence supporting the genetic basis of this defect. Optic nerve and optic chiasm hypoplasia along with the severe protein C deficiency and bilateral absence of the pupil are all important associations which have never been reported previously with this anomaly.