Optic nerve hypoplasia: associations and management.

Abstract

Since its first description optic nerve hypoplasia has been identified with increasing frequency, and a range of associated problems have been described. The major neurological and endocrine associations are well established, but those factors that predispose to the development of optic nerve hypoplasia remain unclear. To understand the aetiology of these problems better, and to formulate a management regime, we studied a consecutive series of 40 patients who were divided into three groups. Group 1 (n=24) had severe bilateral optic nerve hypoplasia; group 2 (n= 10) had mild, bilateral optic nerve hypoplasia; and group 3 (n=6) had unilateral optic nerve hypoplasia. Previously described aetiological factors (for example, low maternal age or maternal alcohol or drug ingestion) were not present in any of the groups; this removes the need to screen a specific population. It is important that careful neurological and developmental assessments are carried out in children with optic nerve hypoplasia to identify potential disease. The role of imaging is discussed.Patients and methods A diagnosis of optic nerve hypoplasia was made or confirmed by one of us (HEW) based on the appearance of a combination of features, the most important of which were (a) a small optic nerve head, (b) a second pigmented ring around the disc, and (c) tortuosity or abnormal origin of the vessels arising from the disc.'0 Rarely were all features present in any one eye. A detailed history was obtained from the mother in every case, specifically including the obstetric history, a history of smoking, alcohol consumption, or drug ingestion during pregnancy, and a history of problems in the neonatal period. The child's development and growth pattern were recorded and in all bilateral cases, and three unilateral, examination by a paediatric neurologist (SHG) was performed. In addition, most children had computed tomography performed, and, where it was considered appropriate, their endocrine state was investigated and any deficiency treated. Serial visual acuity measurements were taken using tests appropriate for age, and included preferred looking acuities in very young or retarded children.The diagnosis of optic nerve hypoplasia has been made with increasing frequency since its early descriptions,1 2 and it is no longer considered a rarity. A number of predisposing factors have been described, including maternal anticonvulsant ingestion,3 low maternal age,4 maternal alcohol or drug abuse,5 6 prenatal intracranial pathology,7 etc. In addition a wide range of neurological8 and endocrine9 associations have been recorded.In view of this array of associations it is difficult to identify a practical and appropriate management regime for each child with optic nerve hypoplasia. In particular, certain clinically important questions have not been directly addressed. Do only those children with severe optic nerve hypoplasia have neurological and endocrine problems? Do all children require some form of central nervous system imaging? Do positive resul...

Endocrine disorders in septo-optic dysplasia (De Morsier syndrome) — evaluation and follow up of 18 patients

“…Interestingly, as reported in the literature [ 11,24] maternal age of mothers of our patients with SOD was generally low: while in one study more than half of the patients had been born to mothers less than 20 years of age, in our survey, maternal age was 23 years (median). In addition, problems in the perinatal and neonatal periods were reported frequently in our survey as well as in other series of SOD patients [24,33]. Almost one third of the patients in Margalith's series [24,25] had required resuscitation after birth, four of our patients had needed mechanical ventilation after birth.…”

“…In another series of 22 SOD patients, 5 had congenital hemiparesis [27]. In addition, delayed mental development has been described in many individual patients with SOD [6,18,26,27,33,34].…”

Septo-optic dysplasia

“…The association of low maternal age with SOD is not consensus 3,15,16 . A revision study of 100 patients with ONH identified association with prematurity in 21%, fetal alcohol syndrome in 9%, maternal diabetes in 6% and endocrine abnormalities in 6% 17 .…”

“…The electroencephalogram (ECG) is normal in half of the cases 19,21 . The anomalies vary from developmental delay to focal deficits, like epilepsy and hemiparesis 7,15,20 . About 60% of the patients with bilateral ONH have some kind of neurological disorder, but the prevalence of developmental delay, mental retardation, cerebral palsy and seizures is not a consensus according to different studies 17,22 .…”

“…Etiology of the SOD Most SOD cases are sporadic and several etiologies have been postulated, like viral infections, gestational diabetes, environmental teratogens, vascular or degenerative injury and genetic mutations 10,12,[14][15][16] . The association of low maternal age with SOD is not consensus 3,15,16 .…”