Visual function in infants with congenital hydrocephalus with and without myelomeningocoele

Congenital hydrocephalus without or with associated myelomeningocoele has impaired visual function as a potential complication. The present study was embarked on to determine the frequency of optic nerve deficits and refractive errors in this group of children and document any relationship to neuroradiological measurements.

All infants with congenital hydrocephalus associated with myelomeningocoele (MHC) and congenital hydrocephalus without myelomeningocoele (HC) were prospectively studied. The children underwent clinical neuro-ophthalmological evaluation and neuroimaging. Radiological confirmation and severity of hydrocephalus was by Evans ratio (frontal and occipital) and third ventricular diameter.

There were 50 children (27 boys and 23 girls, median and mean age of 6 and 5.4 months, respectively) included in the study. Eighteen patients (36%) had no or poor visual tracking and fixation, while nine (18%) patients had optic atrophy. Optic atrophy was significantly associated with the HC group (p = 0.007), while the MHC group was significantly associated with a lower Evans ratio (occipital ratio, p = 0.000; frontal ratio, p = 0.000). Forty-nine patients had anisometropia. The refractive errors were more commonly hypermetropia (46 patients). This was not significantly associated with HC or MHC (0.309).

Optic atrophy rarity in MHC is probably due to early presentation of the patients and lower Evans ratio (occipital and frontal). Evans ratio is a good predictive index for optic atrophy in infantile congenital hydrocephalus. Refractive errors frequency is not dependent on an association of myelomeningocoele with or without hydrocephalus.