Anterior segment dysgenesis with bilateral acorea and microphthalmia associated with compound heterozygous FOXE3 pathogenic variants: outcomes after optical iridectomy

Background FOXE3-related anterior segment dysgenesis produces a spectrum of severe ocular malformations, and bilateral congenital acorea is a rare presentation within that spectrum. Management is complicated when standard visual function tests, such as flash VEP, fail to record.Patient A 1 month old boy with bilateral microphthalmia and congenital acorea underwent slit lamp exam, ultrasound biomicroscopy, B scan ultrasonography, flash VEP, and MRI. Whole exome sequencing was performed to identify a genetic cause.Results Whole exome sequencing identified compound heterozygous FOXE3 variants: a novel missense variant c.477C>G (p.Ser159Arg) inherited from the mother, and a known likely pathogenic nonsense variant c.720C>A (p.Cys240*) inherited from the father. This is consistent with autosomal recessive anterior segment dysgenesis type 2. Flash VEP was non-recordable, but imaging showed intact posterior segment anatomy, and the patient proceeded to bilateral optical iridectomy with pupilloplasty and anterior vitrectomy. At 2 years 5 months follow up, the patient had binocular fixation, smooth pursuit, and independent ambulation with aphakic spectacles, with no secondary complications.Conclusion Non-recordable flash VEP does not rule out surgical candidacy when posterior segment anatomy is normal. Early surgical intervention can achieve meaningful visual rehabilitation in bilateral acorea. These compound heterozygous FOXE3 variants extend the genotypic spectrum of anterior segment dysgenesis and support a developmental continuum between microcoria and acorea.