Comparison of Clinical and Radiological Findings between Congenital Orbital Fibrosis and Congenital Fibrosis of the Extraocular Muscles.

Purpose/Aims: To compare the clinical and radiological findings of the two rare entities of congenital orbital fibrosis and congenital fibrosis of the extraocular muscles (CFEOM). Materials Methods: Clinical characteristics and magnetic resonance imaging (MRI) findings of three congenital orbital fibrosis patients were analyzed and compared to 13 CFEOM patients.

RESULTS: In all three patients with congenital orbital fibrosis, unilateral EOM limitation and enophthalmos were found with a retrobulbar infiltrating mass and normal oculomotor and abducens nerves on MRI. Conversely, most of the patients with CFEOM showed bilateral involvement with hypoplasia of oculomotor nerves and/or abducens nerves and hypotrophic EOM on MRI.

CONCLUSION: All the patients with congenital orbital fibrosis had normal oculomotor and abducens nerves with a retrobulbar mass infiltrating between EOMs, suggesting that congenital orbital fibrosis is a unique disease entity distinguished from CFEOM.