Table 4. Distributions of single, mixed, and unclassifiable types of optic disc appearances among subjects.
| Type | n (%) |
|---|---|
| Single type | 118 (63.1) |
| Mixed type | 30 (16.0) |
| Unclassifiable type | 39 (21.0) |
| Breakdown of single type (n = 118) | |
| pFI | 23 (19.5) |
| pGE | 24 (20.3) |
| pMY | 56 (47.5) |
| pSS | 15 (12.7) |
| Breakdown of mixed type (n = 30) | |
| pFI+pGE | 8 (26.7) |
| pFI+pMY | 3 (10.0) |
| pFI+pSS | 3 (10.0) |
| pGE+pMY | 2 (6.7) |
| pGE+pSS | 6 (20.0) |
| pMY+pSS | 8 (26.7) |
The single type is defined as an optic nerve head of one element with a probability of 60% or more. The mixed type is defined as an optic disc with more than one element and a probability of 60% or more, but either pair of the top two elements has a probability of 80% or more.
The unclassifiable type is defined as an optic disc other than the single and mixed types.
pFI, pGE, pMY, and pSS indicate respective types of optic disc appearances predicted by the Glaucoma Stereo Analysis Study classification formulas. pGE, formula-predicted focal ischemia; pMY, formula-predicted myopic glaucomatous; pSS, formula-predicted senile sclerotic; pGE, formula-predicted generalized enlargement.