Abdelbari Gdeh
Introduction
Morning Glory Syndrome (MGS) is a rare congenital optic disc anomaly, first described by Pedler in 1961 and later widely recognised by Kindler in 1970 (1). The condition is named for the resemblance of the optic disc to the trumpet-shaped morning glory flower (2). MGS is characterised by a funnel-shaped optic disc with a central glial mass and surrounding retinal pigmentary changes (3). It is typically unilateral and can lead to variable visual impairment, ranging from normal acuity to legal blindness (3).
Epidemiology
Morning Glory Syndrome is considered a rare anomaly, with a higher incidence in females and usually unilateral in presentation (4). The exact prevalence remains unclear due to its rarity (4). The anomaly is often diagnosed in early childhood, with a mean age of detection around four years (2). Although the condition is congenital, its full
recognition is sometimes delayed until the appearance of associated visual
defects (5).
Pathophysiology
The aetiology of MGS is not fully understood but is thought to result from abnormal embryologic development, potentially involving a defect in foetal fissure closure or a
mesenchymal abnormality (6). The optic nerve appears enlarged and funnel-shaped, with glial tissue filling the excavation. Retinal vessels emerge from this central mass in a straight radial pattern, often extending to the peripheral retina (1).
Clinical Presentation
Visual acuity in MGS can range widely, from 6/12 to legally blind (20/200 or worse), with about 90% of affected eyes showing a visual acuity of 6/60 or worse. Common symptoms include strabismus and amblyopia, with a risk of developing non-rhegmatogenous retinal detachments, often confined to the posterior pole. Other ocular abnormalities
may include hyaloid artery remnants, vitreous cysts, congenital cataracts, and
lid haemangiomas. The condition is generally non-progressive but requires
monitoring for complications like retinal detachment (7).
Diagnosis
MGS is diagnosed through a characteristic fundoscopic examination, revealing the enlarged optic disc, central glial tuft, and peripapillary retinal pigment changes. Imaging studies such as MRI or CT may be used to rule out systemic associations. The diagnosis
is confirmed clinically, though visually evoked potentials may be used in some
cases for additional functional assessment (8).
Differential Diagnosis
Differential diagnoses include optic nerve coloboma and peripapillary
staphyloma. Optic nerve colobomas typically appear as a white excavation
extending into the retina and choroid, lacking the glial tuft and vascular
changes seen in MGS. Peripapillary staphyloma also presents with a disc
excavation but without the central glial tissue. These conditions have distinct
systemic associations, such as CHARGE syndrome in colobomas (8).
Treatment
There is no curative treatment for MGS. Management focuses on optimizing visual outcomes to prevent amblyopia, particularly in children (8). Regular dilated fundus
exams are recommended to monitor for retinal detachments, which are often non-rhegmatogenous and may occur in 26 to 40% of affected eyes (9). Imaging to assess for any associated CNS abnormalities, including basal encephalocele or moyamoya disease, is crucial (8). Surgical management is usually not recommended due to the risks posed
by vital structures involved in associated anomalies (9).
Complications and Prognosis
MGS is associated with a high risk of non-rhegmatogenous retinal detachment, which occurs in a significant proportion of patients. Other complications may include progressive vision loss and visual field defects (1). However, the condition itself is generally non-progressive. The prognosis depends largely on the degree of optic nerve involvement and the presence of systemic associations, such as moyamoya disease or Aicardi syndrome. Retinal detachment and other ocular issues can worsen the prognosis
if not properly managed (10)
Conclusion
Morning Glory Syndrome is a rare congenital optic nerve anomaly that requires careful diagnosis and management to prevent complications such as retinal detachment and vision loss. Although treatment options are limited, early detection and monitoring can
optimize visual outcomes and prevent amblyopia. Neuroimaging is crucial for
assessing potential systemic associations, which may influence patient
management (8).
References
- Auber, A.E. and O’Hara, M., 1999. Morning glory syndrome: MR imaging. Clinical imaging, 23(3), pp.152-158.
- Gupta A, Singh P, Tripathy K. Morning Glory Syndrome. 2023 Aug 25. In: StatPearls (Internet). Treasure Island (FL) StatPearls Publishing; 2024 Jan–. PMID: 35593815.
- Manschot, W.A. (1990) ‘Morning glory syndrome: a histopathological study’, British Journal of Ophthalmology, 74(1), pp. 56-58.
- Ceynowa, D.J., Wickström, R., Olsson, M., Ek, U., Eriksson, U., Wiberg, M.K. and Fahnehjelm, K.T., 2015. Morning Glory Disc Anomaly in childhood–a population‐based study. Acta ophthalmologica, 93(7), pp.626-634.
- Koerner, J.C., Sweeney, J., Rheeman, C. and Kenning, T.J., 2019. Delayed presentation of morning glory disc anomaly and transsphenoidal encephalocele: a management dilemma. Neuro-Ophthalmology, 43(2), pp.95-101.
- Cennamo, G., de Crecchio, G., Iaccarino, G., Forte, R. and Cennamo, G., 2010. Evaluation of morning glory syndrome with spectral optical coherence tomography and echography. Ophthalmology, 117(6), pp.1269-1273.
- Kumar, J., Adenuga, O.O., Singh, K., Ahuja, A.A., Kannan, N.B. and Ramasamy, K., 2021. Clinical characteristics of morning glory disc anomaly in South India. Taiwan Journal of Ophthalmology, 11(1), pp.57-63.
- Lee, B.J. and Traboulsi, E.I., 2008. Update on the morning glory disc anomaly. Ophthalmic genetics, 29(2), pp.47-52.
- Brodsky, M.C. and Brodsky, M.C., 2010. Congenital optic disc anomalies. Pediatric neuro-ophthalmology, pp.59-96.
- Tankiwala, R.S. and Bahadur, M., 2010. Morning glory syndrome. Delhi Journal of Ophthalmology, 21(1), pp.46-47.