Table 3.
Percentage Improvement among Patients in Groups A and B*
| Group A (n = 33) |
Group B (n = 22) |
Statistical Significance (Mann-Whitney Test) | |||
|---|---|---|---|---|---|
| Proportion Improving | Mean Improvement (%) | Proportion Improving | Mean Improvement (%) | ||
| vn, vision; PL−ve, no perception of light; PL+ve, perception of light. | |||||
| Preop vn = PL−ve† (n = 13) | 1/9 | 1.6 | 0/4 | − | − |
| Preop vn > PL−ve† (n = 42) | 20/24 | 46.4 | 14/18 | 32.8 | 0.10 |
| Subsequent Analysis Restricted to Patients with Residual Vision before Surgery (vn > PL−ve†) | |||||
| n = 24 | n = 18 | ||||
| Fracture (optic canal/postorbit) | |||||
| • Fracture present (n = 12) | 4/6 | 30.3 | 4/6 | 29.0 | 0.87 |
| • No fracture (n = 30) | 16/18 | 51.8 | 10/12 | 34.6 | 0.07 |
| Grade of injury‡ | |||||
| • Grade 2 (n = 22)(no fracture, vn > PL−ve & ≤ 6/60) | 13/14 | 57.5 | 8/8 | 43.0 | 0.10 |
| • Grade 3 (n = 15) (fracture or PL−ve) | 6/8 | 35.2 | 5/7 | 28.2 | 0.60 |
| • Grade 4 (n = 5) (fracture & PL−ve) | 1/2 | 13.5 | 1/3 | 16.1 | − |
*
Group A patients had optic canal decompression supplemented with incision of the nerve sheath; group B patients had canal decompression alone and no incision of the nerve sheath.
†
Categorization of patients into vn = PL−ve and Vn > PL−ve is based on the preoperative vision after medical treatment and spontaneous improvement. Patients with persistent PL−ve despite medical treatment and spontaneous therapy are considered an extremely poor prognostic group.
‡
Grade of injury is based on fractures of the optic canal or posterior orbit and the worst recorded vision.