Causes of electronegative ERG (after Koh et al21)
| Number of patients | |
|---|---|
| *Additional abnormal a-wave reduction. | |
| X linked juvenile retinoschisis | 19 |
| Congenital stationary night blindness | 17 |
| Central retinal artery occlusion | 13 |
| Birdshot chorioretinopathy | 7 |
| Toxic retinopathy (quinine, vincristine, vigabatrin) | 5 |
| Melanoma associated retinopathy | 4 |
| Batten disease | 1 |
| Unspecified inflammatory retinopathy | 3 |
| Photoreceptor dystrophy | 34* |
| Undiagnosed | 25 |
| Total | 128 |