Unilateral Pediatric Cataract Secondary to Atypical Anterior Persistent Fetal Vasculature: A Case Report

Persistent fetal vasculature (PFV) is a congenital disorder resulting from the failure of regression of the vasculature of the primary vitreous and hyaloid, leading to a wide clinical spectrum generally classified into anterior, posterior, and mixed types. The anterior type is associated with cataract, posterior capsular opacity, fibrovascular membrane behind the lens, and ciliary body elongation, while the posterior type is related to fibrovascular stalks connecting the vitreous vascular membrane and the optic disc. Recognizing the clinical features and spectrum of PFV, particularly that of the anterior type and including its possible atypical presentations, is essential in pediatric cataract surgeries for surgical planning and postoperative management. This report aims to discuss the diagnosis and pathogenesis of anterior PFV and describes a case presenting with an intralenticular membrane and the absence of ciliary process elongation - two atypical features that have never been reported to coexist in a single case. A four-year-old male presented with a unilateral, sporadic cataract of the left eye, first noted at three years of age, associated with esotropia. Initial clinical examination and B-scan ultrasonography did not support a diagnosis of PFV preoperatively. However, intraoperative findings revealed an anterior PFV with atypical features. These included an intralenticular location of the anterior PFV and the absence of ciliary process elongation or anterior segment abnormalities on postoperative ultrasound biomicroscopy. Despite being atypical, these findings can be explained by proliferation from the posterior capsule to the lens, leading to the intralenticular location, and continued regression, resulting in the absence of anterior segment abnormalities. This is the first reported case presenting with both of these atypical features. This case illustrates that anterior PFV can manifest with rare, atypical features, specifically an intralenticular membrane and the absence of ciliary process elongation, likely due to continued vascular regression. Recognizing this variable spectrum is essential in preoperative planning. Routine evaluation for PFV in unilateral, sporadic pediatric cataracts using ultrasound biomicroscopy is recommended to detect such anomalies. Identifying these features preoperatively is crucial for anticipating intraoperative complications and optimizing surgical outcomes.