Objective: We evaluated the value of unusual electroretinogram (ERG) findings (negative ERG, which is selective reduction in the amplitude of the b-wave) in the differential diagnosis of night blindness in the military.
Methods: We surveyed 3 years of data. Presumptive and final clinical diagnoses before and after negative ERG recordings were evaluated.
Results: A total of 495 ERGs were included. The mean age was 22 +/- 2.5 years (range, 20-33 years). Twenty-two patients (4.4%) had negative ERG. Final clinical diagnoses could be made for all except two patients (9%). The diagnoses were congenital stationary night blindness (CSNB) (14 patients), X-linked juvenile retinoschisis (five patients), and muscular dystrophy (one patient). Seven (50%) of 14 patients with CSNB had normal fundal appearance, symptoms of night blindness, and a presumptive clinical diagnosis of malingering before the ERG test.
Conclusion: Negative ERG may prevent misdiagnosis of malingering for patients with CSNB with normal fundal appearance in the military.