Onset‐offset visual evoked potentials in the diagnosis of ocular albinism in infantile nystagmus

Abstract

PurposeTo study the contribution of onset‐offset visual evoked potentials (VEP) in the diagnosis of ocular albinism in infantile nystagmus.MethodsCase report.ResultsObservations: Two girls aged respectively three‐year old and six‐year old presented with infantile nystagmus. Ophthalmic examination showed visual acuity of 2/10 bilaterally, a brown iris, with positive transillumination and depigmented fundus without any other depigmentation of skin or hair. Flash VEP showed probable crossed asymmetry of P2 amplitude. P100 wave was unrecordable in 60’ Pattern VEP. 60’ onset‐offset VEP were performed and showed evident crossed asymmetry in C1 and C2 waves which confirmed the diagnosis of ocular albinism. SD‐OCT was also performed and showed foveal hypoplasia.ConclusionsOcular albinism is more difficult to diagnose than the oculo‐cutaneous albinism since it is limited to ophthalmic manifestations. Onset‐offset VEP are very useful in nystagmus patients because they are less sensitive to ocular oscillations and showed more evident crossed asymmetry than flash or pattern VEP.