Morning Glory Syndrome (MGS) is a rare eye condition present from birth, affecting the optic nerve. It is characterized by an unusual appearance of the optic disc, the point where the optic nerve connects to the retina. The name “morning glory” stems from its resemblance to the center of a morning glory flower. This condition results from disruptions during the eye’s development before birth.
Clinical Presentation and Symptoms
During an eye examination, the optic disc in MGS appears enlarged and has a distinctive funnel shape. A central tuft of white or grayish tissue often fills this deep excavation. Retinal blood vessels emerge radially from the edge of the optic disc, spreading out like flower petals. A ring of pigmentary changes surrounding the disc is also a common observation.
The structural differences caused by MGS lead to reduced vision in the affected eye. Visual acuity can vary significantly, ranging from near-normal to very poor, sometimes even resulting in legal blindness. Individuals may also experience visual field defects, such as enlarged blind spots. MGS typically affects only one eye, though bilateral cases have been reported rarely.
Associated Systemic Abnormalities
Morning Glory Syndrome is not always an isolated eye condition; it can be linked to other health issues affecting various body systems. Neurological abnormalities are among the most frequently observed associations, including basal encephalocele, a protrusion of brain coverings through a skull defect. Another neurological finding is agenesis of the corpus callosum, a condition where the band of nerve fibers connecting the two brain hemispheres is underdeveloped or absent.
Cerebrovascular problems, specifically Moyamoya disease, are also associated with MGS. Moyamoya disease involves the narrowing of cerebral arteries, which can lead to the formation of a network of tiny collateral vessels in the brain, resembling a “puff of smoke” on imaging. This condition carries a risk of serious neurological complications such as stroke or seizures. Endocrine dysfunction, particularly involving the pituitary gland, has also been reported in individuals with MGS. Such dysfunction can manifest as abnormal levels of hormones like growth hormone, thyroid-stimulating hormone, and gonadotropins, or even conditions like diabetes insipidus.
The Diagnostic Process
Diagnosis of Morning Glory Syndrome often begins during a comprehensive eye examination, especially in early childhood. An ophthalmologist uses an ophthalmoscope to visualize the characteristic appearance of the optic disc, which helps in initial identification. The distinctive funnel-shaped excavation, central glial tuft, and radial blood vessel pattern are key indicators.
Further testing, particularly neuroimaging, is routinely performed to confirm the diagnosis and screen for associated systemic abnormalities. Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA) of the brain and orbits are commonly used. These scans provide detailed images of the optic nerve and surrounding structures, helping to identify conditions like basal encephalocele or Moyamoya disease that may not be apparent without imaging.
Approaches to Management
While there is no direct cure for the malformation of the optic nerve in Morning Glory Syndrome, management focuses on addressing symptoms and preventing or treating complications. For visual impairment, corrective lenses are prescribed to address refractive errors like nearsightedness. Occlusion therapy, which involves patching the unaffected eye, is a common approach to treat or prevent amblyopia, also known as lazy eye, in the affected eye.
Monitoring for complications is an ongoing aspect of care, with a particular focus on the elevated risk of retinal detachment. If a retinal detachment occurs, surgical interventions, such as vitrectomy, may be necessary to reattach the retina and preserve vision. Due to the potential for associated neurological, cerebrovascular, and endocrine conditions, a multidisciplinary healthcare team is often involved in managing individuals with MGS. This team may include ophthalmologists, neurologists, and endocrinologists, ensuring comprehensive care for all identified health concerns.