[Clinical features of congenital stationary night blindness].

OBJECTIVE

To explore the clinical features of Chinese patients with congenital stationary night blindness (CSNB).

METHODS

An observational serial case study was conducted for 22 patients diagnosed as CSNB at Department of Ophthalmology, Peking Union Medical College Hospital from December 2003 through December 2011. Sixteen patients (72.7%) were males and 6 patients (27.3%) were females. Their age range was 4-73 years old. All of them underwent detailed ocular examinations including electroretinogram (ERG). Thirteen patients underwent optical coherence tomography (OCT) while 9 had visual field (VF) testing. Medical and family history was recorded.

RESULTS

Seven patients had a positive family history. Thirteen patients (59.1%) complained of a poor night vision. Best corrected visual acuity was < 0.8 in both eyes for 16 patients (72.7%). There were nystagmus (n = 4) and strabismus (n = 4). Except for 1 complicated with background diabetic retinopathy, all other patients showed normal or myopic fundi. Nine patients revealed peripheral visual field defects. Twenty-one (95.5%) patients had Schubert-Bornstein type negative ERG while another one had Riggs type ERG. Among 21 Schubert-Bornstein type patients, 13 (61.9%) patients showed complete type CSNB and 8 (38.1%) were of incomplete CSNB. Before referral to our tertiary hospital, only 2 patients were suspected as CSNB. The common primary diagnoses included pathogenic myopia, amblyopia and retinitis pigmentosa.

CONCLUSION

CSNB is frequently misdiagnosed in China. Poor visual acuity is one of the major complaints. And around 50% CSNB patients experience night vision problem. Complete CSNB is more common than incomplete type in China.