Table 2.
Characteristics of patients and surgical procedures.
| Variable | Overall (n=77) | Type 1 big bubble (n=38) | No type 1 big bubble (n=39) | p value | |
|---|---|---|---|---|---|
| Mean/number | Range/percentage | Mean/number | Mean/number | ||
| Patient age (years) | 37.9 | [13; 77] | 39.3 | 36.6 | 0.43 |
| Preoperative diagnosis: | 0.0002 | ||||
| Keratoconus and other ectatic disorders | 62 | 80.5% | 27 | 35 | |
| Scar after infectious keratitis | 6 | 7.8% | 4 | 2 | |
| Stromal dystrophy | 6 | 7.8% | 5 | 1 | |
| Scar after trauma | 2 | 2.6% | 2 | 0 | |
| Stromal opacification after penetrating Keratoplasty | 1 | 1.3% | 0 | 1 | |
| Preoperative best-corrected LogMAR visual acuity | 1.23 | [0.5; 2.3] | 1.21 | 1.24 | 0.81 |
| OCT central epithelial thickness (µm) | 49 | [38; 66] | 49 | 49 | 0.89 |
| OCT minimal epithelial thickness (µm) | 29 | [8; 55] | 30 | 28 | 0.57 |
| OCT central corneal thickness (µm) | 418 | [144; 682] | 425 | 412 | 0.59 |
| Keratoconus OCT classification (Table 1): | 0.0001 | ||||
| Stage 1 | 3 | 4.8% | 1 | 2 | |
| Stage 2 | 13 | 21.0% | 7 | 6 | |
| Stage 3 | 22 | 35.5% | 17 | 5 | |
| Stage 4 | 23 | 37.1% | 2 | 21 | |
| Stage 5 | 1 | 1.6% | 0 | 1 | |
| Scar in posterior stroma: | 0.0002 | ||||
| Yes | 28 | 36.4% | 6 | 22 | |
| No | 49 | 63.6% | 32 | 17 | |
| Scar in midstroma: | 0.12 | ||||
| Yes | 52 | 67.5% | 23 | 29 | |
| No | 25 | 32.5% | 15 | 10 | |
| Scar in anterior stroma: | 0.72 | ||||
| Yes | 70 | 90.9% | 35 | 35 | |
| No | 7 | 9.1% | 3 | 4 | |
| Maximal-minimal corneal thickness > 220 µm (n=75): | 0.13 | ||||
| Yes | 43 | 57.3% | 18 | 25 | |
| No | 32 | 42.7% | 19 | 13 | |
| Preoperative recipient corneal endothelial cell density (cells/mm2) | 2654 | [1000; 3450] | 2631 | 2689 | 0.75 |
| Trephination diameter (mm) | 8.17 | [7.5; 8.5] | 8.18 | 8.17 | 0.74 |
| Trephination depth (µm) | 421 | [250; 550] | 435 | 408 | 0.03 |
OCT: optical coherence tomography. Data were available for the 77 patients unless indicated.