Electrophysiological findings of Bardet–Biedl syndrome: a case series

Abstract

Background Bardet–Biedl syndrome (BBS) is a very rare autosomal recessive genetic disease with multiple manifestations including the ocular system. Aim This study presents different electrophysiological and clinical findings in three female patients with BBS. Patients and methods 3 female patients (9, 10 and 16 years old) with BBS were complaining of progressive visual loss. Full ophthalmological examination, optical coherence tomography (OCT) and various electrophysiological tests were performed to the 3 cases. Results The fundoscopic findings in all three patients did not show evidence of obvious characteristic signs of retinitis pigmentosa. They presented clinically with atypical form of pigmentary retinal dystrophy. Flash electroretinogram showed severe form of Rod-cone dystrophy in the 3 cases associated with macular dysfunction evident by reduced amplitude and increased implicit time of P1 wave of the multifocal electroretinogram in all rings. The pattern electroretinogram was with poor formed P50 wave. Pattern visual evoked potential showed prolonged latency and reduced amplitude of P100 wave in large and small checks. Conclusion Very reduced flash and multifocal electroretinogram is a Characteristic electrophysiological finding in BBS, which may precede the funduscopic changes, electrophysiological tests may help in the early diagnosis of such cases.