The Associations of Congenital Optic Nerve Hypoplasia With Microcornea/Sclerocornea

Purpose To highlight ophthalmic and imaging features associated with congenital optic nerve aplasia (ONA) in eyes with microcornea/sclerocornea. Methods This was a retrospective series of patients with microcornea/sclerocornea with suspected posterior segment pathology who underwent detailed clinical evaluation and imaging with ultrasound B-scan and magnetic resonance imaging (MRI). Evaluation by a low vision clinic for rehabilitation and genetic testing was offered to all infants and they were referred to a pediatrician/endocrinologist. Results Eight eyes of 5 infants (3 bilateral and 2 unilateral) presented between 3 months and 4 years of age, with microcornea in 6 of 8 eyes, of which sclerocornea was noted in 5 eyes. B-scan and MRI confirmed ONA and additional features included crumpled or dysplastic retina, total close funnel retinal detachment, or presence of a stalk-like structure (n = 5) or absent lens (n = 2). Three eyes had a view of the posterior segment and showed absent/rudimentary disk, absent retinal vessels, or crumpled retinal tissue with mottled pigmented or tessellated background. Two infants had chiasmal aplasia and 1 infant had a midline lesion in the parieto-occipital region with chiasmal deviation to the right. Balanced reciprocal chromosomal translocation and PITX3 mutation was noted in the patients. Conclusions ONA is possibly underdiagnosed due to a focus on other obvious findings, such as microphthalmos/microcornea, poor media clarity obscuring visualization, and lack of imaging to ascertain the optic nerve status. The diagnosis of congenital ONA is significant due to its genetic and systemic implications where the ophthalmologist has the chance to identify it and refer patients for genetic and pediatric assessment, in addition to playing an important role in initiating early visual rehabilitation.