(What's the story) morning glory? MRI findings in morning glory disc anomaly

PURPOSE

Morning glory disc anomaly (MGDA) is a rare congenital ophthalmologic disorder. Historically it has been diagnosed fundoscopically, with little in the literature regarding its imaging findings. The purpose of this study is to further characterize the orbital and associated intracranial magnetic resonance imaging (MRI) findings of MGDA in our tertiary pediatric center.

METHODS

A retrospective review was performed of fundoscopically-diagnosed cases of MGDA, that had been referred for MRI. All MRI studies were scrutinized for orbital and other intracranial abnormalities known to occur in association with MGDA.

RESULTS

18 of 19 cases of MGDA showed three characteristic MRI findings: funnel-shaped morphology of the posterior optic disc, abnormal soft tissue associated with the retrobulbar optic nerve, and effacement of adjacent subarachnoid spaces. The ipsilateral (intraorbital) optic nerve was larger in one patient and smaller in six. The ipsilateral optic chiasm was larger in two patients and smaller in one.

CONCLUSION

This study represents a comprehensive radiological-led investigation into MGDA. It describes the most frequently-encountered MRI findings in MGDA and emphasizes the importance of MRI in this cohort, i.e., in distinguishing MGDA from other posterior globe abnormalities, in assessing the visual pathway, and in screening for associated intracranial abnormalities - skull base/cerebral, vascular, and facial. It hypothesizes neurocristopathy as an underlying cause of MGDA and its associations. Caliber abnormalities of the ipsilateral optic nerve and chiasm are a frequent finding in MGDA. Optic pathway enlargement should not be labeled "glioma". (239/250).

Optic Nerve Abnormalities in Morning Glory Disc Anomaly: An MRI Study

BACKGROUND

The morning glory disc anomaly (MGDA) is a rare congenital malformation of the optic disc. 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. The objective was to report the anatomy of optic nerves on MRI in patients with MGDA.

METHODS

In this retrospective single-center study, files of patients with a clinical diagnosis of MGDA were identified through a rare disease database (CEMARA) and included. We reviewed every cerebral and orbital MRI available, performed between 2008 and 2018. Anatomy of the optic nerve from the optic disc to the chiasm was evaluated on MRI.

RESULTS

Nine patients were included. All presented unilateral MGDA. Age at first MRI was 0.6-62 years, median = 3.8 years. MRI showed posterior protrusion of the globe (staphyloma) centered by the optic disc in all cases (100%). Ipsilateral optic nerve abnormalities were found in all cases (100%). The optic nerve was found thinner than the contralateral one in its intraorbital, intracanalar, and intracranial portions in 1 case (11%); in 8 cases (89%), the thickness of the optic nerve was irregular and varied along its pathway: thick, normal, and/or thin. When gadolinium injection had been performed (3 cases), none exhibited gadolinium enhancement. When serial MRI scanning was available (4 cases), there was no evolution of the abnormalities.

CONCLUSION

In patients with MGDA, optic nerve and chiasm abnormalities are the rule, with most often a unique pattern of irregular optic nerve thickness-hypertrophy and hypoplasia-from the orbit to the chiasm. Such pattern should be recognized and points to a developmental abnormality, rather than an optic nerve glioma.

Morning glory disc anomaly and ipsilateral sporadic optic pathway glioma

Purpose

To present a rare case of morning glory disc anomaly in association with an ipsilateral low grade glioma.

Observations

A 5 year old male presented with a unilateral morning glory disc anomaly and an ipsilateral sporadic optic pathway glioma with chiasmal involvement. After a strict patching regimen his vision improved from 20/400 to 20/80.

Conclusions and importance

This report strengthens the recommendation for brain magnetic resonance imaging in patients with morning glory disc anomaly. Patching of the contralateral eye should be attempted since the role of amblyopia may be significant.

Morning glory disc anomaly with an ipsilateral enlargement of the optic nerve pathway

PURPOSE

To report three patients with an unilateral morning glory disc anomaly in association with an ipsilateral mild thickening of the optic nerve.

METHODS

Three children with a morning glory disc anomaly underwent a magnetic resonance imaging (MRI) of the brain. Ophthalmological, genetic and MRI findings at follow-up are reported. A literature search on the association of morning glory anomaly in association with optic nerve glioma is reported.¹ RESULTS: Three children with an unilateral morning glory anomaly and ipsilateral poor visual acuity were found to have an ipsilateral mild optic nerve enlargement on brain MRI. At serial MRI scanning, there was no progression of this finding.

CONCLUSIONS

The morning glory disc anomaly is a rare congenital malformation of the optic disc. It can be associated with central nervous system abnormalities. The association with an optic nerve glioma has been described once before.¹ Our three cases confirm the possible association between a morning glory disc anomaly and an ipsilateral optic nerve enlargement. Serial MRI showed no growth at follow-up. The awareness of this association by the ophthalmologists is important.

Morning glory disc anomaly with Chiari type I malformation

Morning glory disc anomaly is a rare optic nerve dysplasia associated with various neovascular abnormalities. Due to these associations, children with morning glory disc anomaly have brain imaging and angiography to detect other congenital defects. The authors report the case of an infant with morning glory disc anomaly and coexisting Chiari type I malformation.