Visual electrophysiological findings in CHARGE syndrome with bilateral colobomas: a case report

Colobomas are the major ophthalmic manifestation of CHARGE syndrome. Ophthalmological advice may be sought for an infant diagnosed with CHARGE syndrome presenting with coloboma, and electrophysiology can be particularly useful in assessing retinal and cortical function at an early age. Here we describe electrophysiology findings in a four-week-old infant born with bilateral coloboma, more extensive in the right eye, as part of CHARGE syndrome. The left eye showed robust ERGs indicating near-normal rod and cone function. The right eye ERG amplitudes were relatively reduced being around one half to two-thirds that of the left eye ERGs. Flash VEPs were present from both left and right eyes, but the right eye VEP was smaller and delayed relative to that of the left eye. By 5 years of age, right eye acuity was approximately 6/1000 and left eye acuity was 6/12 (Cardiff cards). In cases such as this, it is helpful to give parents a reasonable prediction of visual outcome as soon as possible, allowing instigation of appropriate management and permitting parents to begin to come to terms with the diagnosis. Electrophysiology can provide valuable information on visual function when behavioural testing is limited by the child's ability to co-operate, such as during the early weeks of life.