Visual acuity, fundus changes, and electroretinographic findings in Egyptian children with Bardet-Biedl syndrome

Purpose The aim of the present study was to assess visual acuity, measure the degree of visual impairment, and examine fundus changes in Egyptian children with Bardet-Biedl syndrome (BBS), and to correlate these findings with the results of flash electroretinography (ERG). Materials and methods A cross-sectional study was conducted on infants and children with BBS. Diagnosis was carried out by a specialized pediatrician. Full ophthalmological examination, including slit-lamp examination, refraction, and indirect ophthalmoscopy, was carried out. Best-corrected visual acuity was measured and full-field flash ERG was performed. Results This study included 20 patients with BBS. The median age was 9 years (ranged from 1 day to 18 years). The mean age of onset of symptoms in the whole group was 6.5 ± 4.3 years. Visual impairment, defined as a best-corrected visual acuity in the better seeing eye of 20/60 (6/18) or less, was present in 11 patients (55% of the cases), and night blindness as a symptom was present in nine patients (45%); pigmentary retinopathy was clinically detected in 35% of the patients and retinal dystrophy as an ERG finding was detected in 60% of the patients. Conclusion Visual impairment in BBS is mainly caused by rod-cone dystrophy, which is one of the major criterion of diagnosis, which manifests with age. Before the age of 6, children rarely present with ocular manifestations, and usually have normal fundus examination; on the other hand, retinitis pigmentosa-like picture is usually seen in children older than 6. However, the electrophysiological changes may precede the fundus changes.