Morning glory disc anomaly is an optic nerve dysplasia thought to be secondary to one of several mechanisms, including defective closure of the embryonic fissure, abnormal enlargement of the optic stalk during development, or primary mesenchymal or mesodermal abnormality.1–3 Morning glory disc anomaly was named for its morphological similarities to the morning glory flower because the optic disc shows a characteristic funnel-shaped appearance with radially oriented thin, straight vessels emanating toward the retinal periphery. The prevalence of this condition is unknown and most authors agree that this anomaly is exceedingly rare.4 Based on case reports and small series, morning glory disc anomaly is detected in most patients in childhood, manifesting strabismus, amblyopia, or leukocoria, and only 30% ultimately retain a visual acuity of 20/40 or better.5
Morning glory disc anomaly can be an isolated finding without systemic abnormalities. However, there are important and life-threatening associations with this condition, including midline facial abnormalities, basal encephalocele, agenesis of the corpus callosum, endocrine abnormalities (most commonly diabetes insipidus), and optic nerve glioma, as well as Moyamoya disease and intracranial vascular anomalies, which are found in 45%6 of patients with morning glory disc anomaly.2–7 Additional ophthalmic considerations include increased risk for retinal detachment, choroidal neovascularization, and amblyopia.2 A review of the literature revealed one case of documented co-occurrence of morning glory disc anomaly with Chiari type I malformation in a 44-year-old woman.3 Herein, we describe a second case with the co-occurrence of both conditions in a male infant.
A 2-month-old male infant with uncomplicated gestation and delivery was found to have a decreased red reflex in the right eye. On referral at 6 months, visual acuity was fix and follow bilaterally with 15 prism diopters of right esotropia. Intraocular pressures were 11 mm Hg in both eyes. The left eye was completely normal.
Examination of the right eye disclosed persistent pupillary membrane in the nasal quadrant. On ophthalmoscopy, there was an enlarged non-edematous optic disc, measured at 6 × 5 × 3.1 mm with radially emanating thin, straight vessels and prepapillary gliosis (Figure 1). Circumpapillary retinal pigment epithelium hyperplasia and atrophy were present. There was no foveal depression, no remnant of the fetal vitreous or hyaloid artery, and no retinal detachment. Fluorescein angiography disclosed superonasal and inferonasal looping of vessels and peripheral non-perfusion without neovascularization (Figure 1). Axial length by ultrasonography was 20.4 mm in the right eye and 21 mm in the left eye. These features were consistent with morning glory disc anomaly.
Funduscopic and fluorescein angiography of the right and left eyes. (A) Morning glory disc anomaly in the right eye with enlarged optic disc, prepapillary gliosis, and radially emanating vessels with circumpapillary hyperpigmentation and retinal pigment epithelium atrophy. (B) The normal funduscopic findings in the left eye. (C) On fluorescein angiography the right eye demonstrated supernumerary radial vessels in linear orientation with ‘spoke wheel appearance’. (D) The normal fluorescein angiogram in the left eye.
External examination showed no signs of midline maldevelopment (no hypertelorism or cleft lip/palate) and there were no neurologic defects. Magnetic resonance imaging confirmed intact optic nerve. However, magnetic resonance imaging importantly disclosed herniation of the cerebellar tonsils 5 mm below the foramen magnum and into the cervical spinal canal, consistent with Chiari type I malformation (Figure 2). Observation for both the eye and the brain was advised.
T2-weighted magnetic resonance imaging demonstrating 5 mm herniation of cerebellar tonsils beneath the foramen magnum. The dotted (yellow) line spans the opisthion (O) and basion (B) and defines the lower limit of the posterior cranial fossa. The solid (white) arrow demonstrates cerebellar herniation that has adopted a conical, as opposed to peg shape, consistent with Chiari type I malformation.
Morning glory disc anomaly was first described by Kindler in 1970 and named due to its similarities in morphology to the morning glory flower.1 It is typically unilateral with no predilection for gender, and results in a wide spectrum of visual acuity, with some patients retaining 20/20 visual acuity and others with no light perception.2,3 Morning glory disc anomaly is considered to be an anomaly with limited evidence to suggest a genetic component.2 Most agree that morning glory disc anomaly stems from a mesenchymal abnormality due to reduced development of the lamina cribosa and an enlarged posterior scleral defect.2,8 Additionally, persistent fetal vasculature is often coexistent with morning glory disc anomaly, further supporting the theory that morning glory disc anomaly develops from a mesodermal abnormality.9
Chiari malformation represents a spectrum of hindbrain dysgenesis ranging from type I to IV, with Chiari type I being the most common and least severe.10 Chiari type I malformation is estimated to affect at least 0.1% of the population11,12 and is believed to be due to insufficient growth of mesodermal occipital somites, resulting in an underdeveloped occipital bone and overcrowding in the posterior cranial fossa.11 Chiari type I malformation is generally diagnosed by imaging the ectopic, downward displacement of one or both of the cerebellar tonsils at least 5 mm below the foramen magnum.11 Additional findings in Chiari type I malformation include syringomyelia, brainstem elongation, and medullary kinking, among others.3,11,12 Although patients with Chiari type I malformation can remain asymptomatic, those who demonstrate symptoms usually develop manifestations after the second decade of life.12 Symptoms from Chiari type I malformation are often nonlocalizing and include Valsalva-induced headache, neck, back, and upper extremity pain, as well as blurred vision, photophobia, and disequilibrium.13 These manifestations are thought to be secondary to obstruction of the cerebrospinal fluid flow.3,12
Evidence supports that both morning glory disc anomaly and Chiari type I malformation are likely secondary to embryological mesodermal dysgenesis.3,11,14 The proposed mesodermal defect in morning glory disc anomaly is believed to occur during the first trimester.14 Similarly, the formation of the occipital bone and posterior fossa implicated in Chiari type I malformation also occurs during the first trimester.3,12 Although Chiari type I malformation and morning glory disc anomaly could theoretically stem from a similar mesodermal etiology, further studies with larger numbers of patients need to be conducted to formally establish a clinical association between these two manifestations.
- Rojanaporn D, Kaliki S, Shields CL, Shields JA. Morning glory disc anomaly with peripheral retinal nonperfusion in 4 consecutive cases. Arch Ophthalmol. 2012;130:1327–1330. doi:10.1001/archophthalmol.2012.505 [CrossRef]
- Lee BJ, Traboulsi EI. Update on the morning glory disc anomaly. Ophthalmic Genet. 2008;29:47–52. doi:10.1080/13816810801901876 [CrossRef]
- Razeghinejad MR, Masoumpour M. Chiari type I malformation associated with morning glory disc anomaly. J Neuroophthalmol. 2006;26:279–281. doi:10.1097/01.wno.0000249325.57604.34 [CrossRef]
- Chan RT, Chan HH, Collin HB. Morning glory syndrome. Clin Exp Optom. 2002;85:383–388. doi:10.1111/j.1444-0938.2002.tb02390.x [CrossRef]
- Harasymowycz P, Chevrette L, Décarie JC, et al. Morning glory syndrome: clinical, computerized tomographic, and ultrasonographic findings. J Pediatr Ophthalmol Strabismus. 2005;42:290–295.
- Lenhart PD, Lambert SR, Newman NJ, et al. Intracranial vascular anomalies in patients with morning glory disk anomaly. Am J Ophthalmol. 2006;142:644–650. doi:10.1016/j.ajo.2006.05.040 [CrossRef]
- Bandopadhayay P, Dagi L, Robison N, Goumnerova L, Ullrich NJ. Morning glory disc anomaly in association with ipsilateral optic nerve glioma. Arch Ophthalmol. 2012;130:1082–1083. doi:10.1001/archophthalmol.2012.412 [CrossRef]
- Dutton GN. Congenital disorders of the optic nerve: excavations and hypoplasia. Eye. 2004;18:1038–1048. doi:10.1038/sj.eye.6701545 [CrossRef]
- Manschot WA. Morning glory syndrome: a histopathological study. Br J Ophthalmol. 1990;74:56–58. doi:10.1136/bjo.74.1.56 [CrossRef]
- Siasios J, Kapsalaki EZ, Fountas KN. Surgical management of patients with Chiari I malformation. Int J Pediatr. 2012;2012:640127. doi:10.1155/2012/640127 [CrossRef]
- Milhorat TH, Bolognese PA, Nishikawa M, McDonnell NB, Francomano CA. Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and chiari malformation type I in patients with hereditary disorders of connective tissue. J Neurosurg Spine. 2007;7:601–609. doi:10.3171/SPI-07/12/601 [CrossRef]
- Vannemreddy P, Nourbakhsh A, Willis B, Guthikonda B. Congenital Chiari malformations. Neurol India. 2010;58:6–14. doi:10.4103/0028-3886.60387 [CrossRef]
- Tubbs RS, Beckman J, Naftel RP, et al. Institutional experience with 500 cases of surgically treated pediatric Chiari malformation type I. J Neurosurg Pediatr. 2011;7:248–256. doi:10.3171/2010.12.PEDS10379 [CrossRef]
- Holmström G, Taylor D. Capillary haemangiomas in association with morning glory disc anomaly. Acta Ophthalmol Scand. 1998;76:613–616. doi:10.1034/j.1600-0420.1998.760521.x [CrossRef]