Normal vernier acuity in infants with delayed visual maturation

Visuocortical bilirubin-induced neurological dysfunction

This review addresses the question whether elevated levels of total serum/plasma bilirubin (TB) cause measurable neurological effects, specifically to visuocortical functioning. Past research in the area of vision and its relation to jaundice has taken advantage of flash visual-evoked potentials (VEPs). Using a steady state VEP, we developed preliminary data suggesting that children who had jaundice with TB levels between 10 and 25mg/dL, but who did not have kernicterus, have measurable changes in visual function, when compared to control infants who did not have jaundice. This non-invasive test offers information about vision thresholds, signal amplitudes, and suprathreshold changes after brain exposure to bilirubin. Here, we review this novel tool, the steady state VEP, and data suggesting that neurological changes occur in infants with moderately elevated TB levels.

Delayed visual maturation in otherwise normal infants

BACKGROUND

Children may present in early infancy for evaluation of decreased visual responsiveness. Most such infants have systemic or ocular abnormalities that explain their poor fixation and tracking. Some infants, however, have no other medical or ocular problems. This study evaluated prognostic factors in this latter group of otherwise normal infants with decreased visual responsiveness.

METHODS

This was a retrospective cohort study in which medical records of infants evaluated for decreased visual responsiveness were reviewed to identify children who had no history of premature birth or systemic problems associated with developmental delay. Examination findings that were predicted to indicate a good prognosis included: the presence of some reaction to light, normal pupil responses, no nystagmus, and no structural ocular abnormalities. Follow-up information was obtained from office visits and telephone interviews. Main outcome measures were visual acuity and developmental status.

RESULTS

Thirty-two children met the criteria noted above. Six were excluded due to lack of follow-up. Four were normal by the time of their initial examination. Follow-up for the remaining patients ranged from 3 months to 11 years (mean 2.94 years). One patient developed strabismus and required surgery. The remaining patients all had normal vision and development.

CONCLUSIONS

Otherwise normal infants who present for evaluation of decreased visual responsiveness have a good prognosis if they have some reaction to light, normal pupil responses, absence of nystagmus, and no structural ocular abnormalities. The developmental prognosis for these infants appears to be good. Additional testing at the time of initial evaluation is not indicated.

Delayed Visual Attention Caused by High Myopic Refractive Error

Delayed visual maturation (DVM) is usually a retrospective diagnosis given to infants who are born with no or poor visually-directed behavior, despite normal acuity on objective testing, but who recover months later. This condition can be organized into several types based on associated neurodevelopmental or ocular findings, but the etiology of DVM is probably complex and involves multiple possible origins. Here we report two infants who presented with delayed visual maturation (attention). They were visually unresponsive at birth but were later found to have high myopic errors. Patient 1 had -4 D right eye, -5 D left eye. Patient 2 had -9 D o.u. Upon spectacle correction at 5 and 4 months, respectively, both infants immediately displayed visually-directed behavior, suggesting that a high refractive error was the cause of inattention in these patients. These findings could add to knowledge surrounding DVM and the diagnosis of apparently blind infants. Findings presented here also indicate the importance of prompt refractive error measurement in such cases.