Table 2.
Mean preoperative characteristics of the Retina 1 series included in the G1 group.
| Whole series (Retina 1) | Macula-on group (G1) | p value | ||
|---|---|---|---|---|
| n (%) | n (%) | 95%CI | ||
| Previous PVR | ||||
| No | 522 (49.9%) | 203 (56.9%) | 51.7%; 62% | 0.0095 |
| A | 247 (23.6%) | 88 (24.7%) | 20.2%; 29.1% | 0.6823 |
| B | 278 (26.6%) | 66 (18.5%) | 14.5%; 22.5% | 0.0007 |
| Total | 1047 (100%) | 357 (100%) | ||
| Retinal break | ||||
| Tear | 739 (70.7%) | 252 (70.6%) | 65.9%; 75.3% | 1 |
| Hole | 223 (21.3%) | 74 (20.7%) | 16.5%; 24.9% | 0.8278 |
| Dialysis | 12 (1.2%) | 7 (2%) | 0.5%; 3.4% | 0.2346 |
| Giant tear | 37 (3.5%) | 14 (3.9%) | 1.9%; 5.9% | 0.805 |
| Not visible | 34 (3.3%) | 10 (2.8%) | 1.1%; 4.5% | 0.7421 |
| Total | 1045 (100%) | 357 (100%) | ||
| Type of break | ||||
| Single | 526 (52.1%) | 196 (56.5%) | 51.3%; 61.7% | 0.1164 |
| Multiple | 432 (42.8%) | 137 (39.5%) | 34.3%; 44.6% | 0.2306 |
| Posterior rupture | 17 (1.7%) | 4 (1.2%) | 0%; 2.3% | 0.5786 |
| Not visible | 34 (3.4%) | 10 (2.9%) | 1.1%; 4.6% | 0.7225 |
| Total | 1009 (100%) | 357 (100%) | ||
| Size of breaks (clock hours) | ||||
| Not visible | 34 (3.3%) | 10 (2.9%) | 1.1%; 4.6% | 0.7321 |
| 0-1 | 673 (65.4%) | 235 (66.6%) | 61.7%; 71.5% | 0.684 |
| 2-3 | 265 (25.8%) | 82 (23.2%) | 18.8%; 27.6% | 0.3067 |
| >3 | 57 (5.5%) | 26 (7.4%) | 4.6%; 10.1% | 0.1667 |
| Total | 1029 (100%) | 353 (100%) | ||
| Previous vitreous hemorrhage | ||||
| No | 908 (88%) | 304 (85.9%) | 82.3%; 89.5% | 0.2561 |
| Yes | 124 (12%) | 50 (14.1%) | 10.5%; 17.8% | 0.2561 |
| Total | 1032 (100%) | 354 (100%) | ||
| Extension RD (quadrants) | ||||
| 0-1 | 188 (18.1%) | 147 (41.4%) | 36.3%; 46.5% | <0.0001 |
| 2-3 | 736 (70.8%) | 208 (58.6%) | 53.5%; 63.7% | <0.0001 |
| 4 | 116 (11.2%) | 0 (0%) | 0%; 1.3% | <0.0001 |
| Total | 1040 (100%) | 355 (100%) | ||
| Macula | ||||
| On | 382 (36.7%) | 357 (100%) | 98.7%; 100% | <0.0001 |
| Off | 658 (63.3%) | 0 (0%) | 0%; 1.3% | <0.0001 |
| Total | 1040 (100%) | 357 (100%) | ||
| Previous aphakic | ||||
| No | 664 (63.5%) | 248 (69.7%) | 64.9%; 74.4% | 0.0179 |
| Yes | 382 (36.5%) | 108 (30.3%) | 25.6%; 35.1% | 0.0179 |
| Total | 1046 (100%) | 356 (100%) | ||
| PVD | ||||
| Unknown | 357 (34.1%) | 113 (31.7%) | 26.8%; 36.5% | 0.3578 |
| No | 193 (18.4%) | 80 (22.4%) | 18.1%; 26.7% | 0.0614 |
| Yes | 497 (47.5%) | 164 (46%) | 40.8%; 51.1% | 0.5985 |
| Total | 1047 (100%) | 357 (100%) | ||
| Myopia | ||||
| No | 346 (44.5%) | 94 (33.7%) | 28.1%; 39.2% | 0.0003 |
| ≤5 Dp | 206 (26.5%) | 92 (33%) | 27.5%; 38.5% | 0.0174 |
| >5 Dp | 225 (29%) | 93 (33.3%) | 27.8%; 38.9% | 0.1225 |
| Total | 777 (100%) | 279 (100%) | ||
| Preoperative VA | ||||
| <20/100 | 631 (61%) | 44 (12.3%) | 8.9%; 15.7% | <0.0001 |
| 20/100–20/40 | 142 (13.7%) | 79 (22.1%) | 17.8%; 26.4% | <0.0001 |
| ≥20/40 | 261 (25.2%) | 234 (65.6%) | 60.6%; 70.5% | <0.0001 |
| Total | 1034 (100%) | 357 (100%) | ||
n (%): number and percentage of patients in Retina 1 Project and macula-on group (G1); G1: macula-on group; CI: confidence Interval; PVR: proliferative vitreoretinopathy; PVR grades A and B as defined by the Retina Society Classification in 1983; PVD: posterior vitreous detachment; RD: retinal detachment; VA: visual acuity, best corrected visual acuity.