CASE REPORT Open Access Ophthalmic manifestations of congenital protein C deficiency: a case report and mini review Fariba Ghassemi 1,2,3* , Fatemeh Abdi 4,1 and Mandana Esfahani 1 Abstract Background: Homozygous protein C (PC) deficiency is a potentially fatal disease with ocular blinding presentation or sequela. Case presentation: A 5 month-old boy was presented for evaluation of leukocoria. He had a history of frequent bruises and PC deficiency, treated with warfarin. His intraocular pressure was normal. In the left eye leukoma with anterior segment dysgenesis, shallow anterior chamber, and cataract were observed. Fundus was not visible. B-scan revealed a closed funnel retinal detachment. His right eye had a normal anterior segment and a thin retina with anomalous retinal vascular branching at equator and peripheral retina. A fibrovascular tuft on the optic nerve head with induced traction on superior arcade was visible. Total loss of a and b wave of both were appreciated in electroretinography (ERG). Fluorescein angiography (FA) showed very severe leakage at the junction of the vascularized and non-vascularized retina and optic nerve head. Favorable outcome was achieved with lasering of avascular retina in the right eye. Conclusion: The potential for protein C deficiency should be assessed in all infants with leukocoria, anterior segment dysgenesis, retinal detachment and retinal dysplasia. Early diagnosis could save the child’s life and vision. Keywords: Protein C deficiency, Congenital, Ophthalmic manifestations, Retinal detachment, Retinal dysplasia Background Protein C (PC), first described by Stenflo in 1976, is a vitamin K dependent anticoagulant enzyme that inacti- vates the plasma factors Va and VIIIa by limited prote- olysis, thereby inhibiting the conversion of factor X to factor Xa and of prothrombin to thrombin [1]. Heredi- tary (congenital) PC deficiency is a rare autosomal dis- order that predisposes to potentially blinding and fatal thromboembolic attacks [2]. Homozygotes have very low or undetectable PC activity (usually less than 1%, normal 70–140%) and do present within the first few days of life [2]. Heterozygotes have about 50% levels of PC and usu- ally remain asymptomatic until adolescence or adult- hood. Neonatal PC deficiency may also be acquired and transient, especially in preterm ill infants [3] with subse- quent thrombosis being as severe as in the homozygous condition. Herein, we present a case of congenital PC deficiency with asymmetric ophthalmic manifestations. Fluorescein angiography (FA) and electroretinography (ERG) have been performed. The better eye was treated with indirect laser and the vision was saved. Case presentation The patient was a full term Iranian male that was deliv- ered with normal labor and was the first child of first © The Author(s). 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. * Correspondence: fariba.ghassemi@gmail.com 1 Eye research center, Farabi Eye Hospital, Tehran University of Medical Sciences, Qazvin Square, Tehran, IR, Iran 2 Retina & Vitreous Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, IR, Iran Full list of author information is available at the end of the article Ghassemi et al. BMC Ophthalmology (2020) 20:282 https://doi.org/10.1186/s12886-020-01424-x