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.