Abstract
Purpose :
The morning glory disk anomaly (MGDA) is a rare congenital malformation of the optic disk. The association with a significant enlargement of the optic nerve has been recently reported in a few cases, raising the question of potentially associated optic nerve gliomas. We wanted to systematically evaluate the optic nerves in patients with confirmed MGDA, on magnetic resonance imaging (MRI) performed in order to rule out vascular progressing abnormalities.
Methods :
A retrospective single-center study was conducted. Files of patients with clinically confirmed MGDA were identified through a rare disease database (CEMARA) and included. Cerebral and orbital MRI performed in every patient between 2008 and 2018 were systematically reviewed. Anatomy of the optic nerve from the optic disk to the chiasm was evaluated on MRI.
Results :
Eleven patients were included. All presented unilateral MGDA. Age at MGDA diagnosis was: 6-36 months, mean=14 months; age at first MRI was: 0.5-61 years, mean=9 years. MRI showed staphyloma centered by the optic disk in 10 cases (91%) and ipsilateral optic nerve abnormalities in 9 cases (82%). The optic nerve was found thinner than the contralateral one in its intraorbitary, intracanalar and intracranial portions in one case (9%). In eight cases (73%), the thickness of the optic nerve was irregular and varied along its pathway: thick, normal and/or thin. When gadolinium injection had been performed (4 cases), none exhibited gadolinium enhancement. When serial MRI scanning was available (5 cases), there was no evolution of the abnormalities.
Conclusions :
In patients with MGDA, optic nerve and chiasm abnormalities are the rule, with most often a unique pattern of irregular optic nerve thickness, from the orbit to the chiasm. Such pattern should be recognized and points to a developmental abnormality, rather than an optic nerve glioma.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.