|Year : 1991 | Volume
| Issue : 4 | Page : 186-187
Septo-optic dysplasia (case report)
Venkatesh Nayak, KR Bhat
Department of Ophthalmology, Medical College, Calicut, Kerala-673 008, India
'Ganesh Garden', Kadri, Mangalore - 575 003
Source of Support: None, Conflict of Interest: None
Septo optic dysplasia is a rare developmental anomaly involving bilateral optic nerve hypoplasia, midline anomalies of the brain and hypothalamo-pituitary dysfunction. A case of septo-optic dysplasia with pituitary dwarfism, optic nerve hypoplasia and absent septum pellucidum is reported.
|How to cite this article:|
Nayak V, Bhat K R. Septo-optic dysplasia (case report). Indian J Ophthalmol 1991;39:186-7
| Introduction|| |
Optic nerve hypoplasia is not recognised to be a common non-progressive developmental anomaly of the optic nerves. Optic nerve hypoplasia may be associated with developmental midline anomalies of the brain, such as absence of septum pellucidum, in which case it is termed septo optic dysplasia.
The association of septo optic dysplasia with hypopituitary dwarfism to the best of our knowledge is the first to be reported in Indian literature.
| Case report|| |
A 12 year old girl was referred to the Ophthalmology department for defective vision and jerky movement of the eyes. since early childhood. Antenatal history revealed that the child's mother had taken some ayurvedic medicine during the first trimester. Labour and delivery were normal. At the age of 6 months, the child had an episode of convulsions. It was treated by an ayurvedic doctor. There is no history of any further episode of convulsions. There was no history of any delayed developmental milestones. During the past few years the mother noticed growth retardation and treatment was of no avail.
General examination revealed that the child's height was only 116 cms (less than 3rd percentile for her age) [Figure - 1]. Weight was 17.5 Kgs and head circumference 49 cms. Ophthalmologic examinations revealed that the best corrected visual acuity was RE. 6/24 and LE. 6/24. Cycloplegic refraction was normal. Pupils were 4 mm in both eyes and reacted normally to light. Ocular motility examination revealed a bidirectional jerky nystagmus. Intraocular pressure measurements were normal. Ophthalmoscopy revealed severe bilateral optic nerve hypoplasia. Visual field charting revealed a marked peripheral constriction in both eyes.
Endocrinologic investigations revealed a growth hormone deficiency (stimulated level 2.3 ng/ml). T3, T4 and TSH levels were normal. Urine specific gravity was normal.
Radiographs of the wrist and hand revealed normal bone age. CT scan of the head revealed an absence of septum pellucidum. The lateral ventricles were enlarged [Figure - 2]a & b. The sulci were poorly developed and the cortical surface totally agyrial. The brain parenchyma was normal.
| Discussion|| |
Hypoplasia of the optic nerve is a nonprogressive developmental anomaly in which there is a subnormal number of axons within the affected nerve. The ophthalmoscopic picture of a typical case includes a small grey or pale optic nerve head, often one-third to one-half normal size, that is often surrounded by a yellowish mottled peripapillary halo bordered on either side by a dark ring of pigment, referred to as the 'double ring sign'. The retinal vessels are generally normal and the ratio of adult disc to arteriole is reduced to 6.1 to 12.2 (normal 14.6 ± 2.4).
A number of endocrine and central nervous system anomalies are associated with optic nerve hypoplasia. These anomalies are seen more often in patients with bilateral optic nerve hypoplasia, poor vision and nystagmus . In patients with segmental, and unilateral optic nerve hypoplasia they are seen less often. Septo optic dysplasia, includes absence of septum pellucidum partial or complete agenesis of corpus callosum, dysplasia of anterior third ventricle and bilateral optic nerve hypoplasia. Hoyt and co-workers  first described association of septo optic dysplasia with pituitary dwarfism. Subsequently a large number of endocrine abnormalities due to hypothalamo - pituitary dysfunction have been described . Though growth hormone deficiency is the commonest finding, hypothyroidism, diabetes insipidus and even panhypopituitarism can occur.
The etiology of optic nerve hypoplasia and septo-optic dysplasia are unknown. Familial occurrence has been noted which raises the possibility of autosomal recessive inheritence sub . But most cases are sporadic. Maternal viral infections during pregnancy have been implicated . Maternal ingestion of anticonvulsants during pregnancy have been associated with increased incidence of optic nerve hypoplasia. Recently it has been emphasised that optic nerve hypoplasia may be a common feature of the fetal alcohol syndrome .
Diagnosis of optic nerve hypoplasia is easy by direct ophthalmoscopy. But in infants with nystagmus and those with significant refractive error, magnetic resonance imaging is said to be useful . While CT scanning is useful in documenting many midline intracranial abnormalities that frequently coexist with optic nerve hypoplasia, they do not reliably identify the hypoplastic optic nerves and chiasma.
The diagnosis of endocrine dysfunction in cases of optic nerve hypoplasia is important since they are very much treatable.
| References|| |
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[Figure - 1], [Figure - 2]