Abstract
Purpose :
We report SD-OCT findings of bilateral optic nerve coloboma (ONC) with inner retinal layer schisis in a 10-year-old patient with BOF syndrome due to a de novo TFAP2A mutation.
Methods :
The patient had an in-depth clinical and ophthalmological assessment, ultra-widefield (UWF) color picture with an emphasis on SD-OCT imaging. Retinal structure analysis was performed on 9mm horizontal scans through optic nerve head and fovea acquired using SD-OCT (Heidelberg Engineering, Heidelberg, Germany®).
Results :
A 10-year-old boy with BOF syndrome linked to a de novo c.769A>G (p.Arg257Gly) mutation in the TFAP2A gene was referred for recent near vision difficulties. He was known for profound right eye (RE) amblyopia, dacryocystorhinostomy history, conductive hearing loss and bilateral latero-cervical cutaneous aplasia. Relevant ophthalmic findings were nystagmus, bilateral inferior lacrimal duct stenosis and microcornea. Distance best corrected visual acuity (VA) was of 0.1logMAR in RE and near VA of 0.3logMAR in left eye (LE). Optic disk SD-OCT showed partial ONC in the LE and complete ONC in the RE. In the interpapillary-macular zone of the LE, splitting of the nerve fiber layer (NFL), ganglion cell layer (GCL) and inner nuclear layer (INL) with relative thickening of the inner plexiform layer (IPL) were observed. En-face OCT showed an arciform horseshoe shape of the lesion temporal to the ON. OCT of the RE revealed rare microcysts in the INL and minimal fluid in outer nuclear layer (ONL) adjacent to the ONC. Foveal regions and external retinal layers including retinal pigment epithelium/Bruch’s complex remained intact.
Conclusions :
Our case details SD-OCT features in a patient with BOF syndrome and bilateral ONC. The associated inner retinal layer splitting was disproportionate to the extent of ONC. The discrepancy appears consistent with the involvement of the TFAP2A mutation, given the protein's crucial role in neural crest development and its prominent expression in the ganglion cell layer (GCL) of the neural retina. These findings underscore the role of SD-OCT in diagnosing retinal abnormalities in genetic syndromes, warranting further investigation into the underlying pathophysiological mechanisms.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.