Optic disc cupping and the frequency of optic nerve compression in NTG
| NTG | Number of eyes | No compression(%) | Compression (%) |
|---|---|---|---|
| C/D ratio, cup/disc ratio; NTG, normal tension glaucoma. | |||
| Eyes with a C/D ratio ⩾0.7 | 95 | 45 (47.4%) | 50 (52.6%) |
| Eyes with C/D ratio <0.7 | 8 | 7 (87.5%) | 1 (12.5%) |