Table 1.
Preoperative characteristics.
| Characteristic | S1 | S2 | P value | ||
|---|---|---|---|---|---|
| 2004-2005 | 2006–2008 | ||||
| N (%) | 95% CI | N (%) | 95% CI | ||
| Previous PVR | 230 (47.8%) | 43.4%–52.3% | 295 (52.2%) | 48.1%–56.3% | |
| Retinal break | 0.062 | ||||
| Tear | 348 (72.5%) | 68.5%–76.5% | 391 (69.3%) | 65.5%–73.1% | |
| Hole | 86 (17.9%) | 14.5%–21.3% | 137 (24.3%) | 20.8%–27.8% | |
| Dialysis | 6 (1.3%) | 0.3%–2.2% | 6 (1.1%) | 0.2%–1.9% | |
| Giant tear | 20 (4.2%) | 2.4%–6% | 16 (2.8%) | 1.5%–4.2% | |
| Not visible | 20 (4.2%) | 2.4%–6% | 14 (2.5%) | 1.2%–3.8% | |
| Type of break | 0.264 | ||||
| Unique | 232 (50.2%) | 45.7%–54.8% | 293 (53.7%) | 49.5%–57.8% | |
| Multiple | 204 (44.2%) | 39.6%–48.7% | 228 (41.8%) | 37.6%–45.9% | |
| Posterior | 6 (1.3%) | 0.3%–2.3% | 11 (2%) | 0.8%–3.2% | |
| Not visible | 20 (4.3%) | 2.5%–6.2% | 14 (2.6%) | 1.2%–3.9% | |
| Size of breaks (clock hours) | 0.242 | ||||
| 0-1 | 318 (66.9%) | 62.7%–71.2% | 355 (64.2%) | 60.2%–68.2% | |
| 2-3 | 112 (23.6%) | 19.8%–27.4% | 153 (27.7%) | 23.9%–31.4% | |
| >3 | 25 (5.3%) | 3.3%–7.3% | 31 (5.6%) | 3.7%–7.5% | |
| Not visible | 20 (4.2%) | 2.4%–6% | 14 (2.5%) | 1.2%–3.8% | |
| Vitreous hemorrhage | 43 (9%) | 6.4%–11.6% | 81 (14.6%) | 11.7%–17.6% | 0.006 |
| Extension RD (quadrants) | 0.432 | ||||
| 0-1 | 80 (16.7%) | 13.4%–20% | 108 (19.3%) | 16%–22.5% | |
| 2-3 | 341 (71.2%) | 67.1%–75.2% | 395 (70.4%) | 66.6%–74.2% | |
| 4 | 58 (12.1%) | 9.2%–15% | 58 (10.3%) | 7.8%–12.9% | |
| Macula-on | 158 (33.1%) | 28.9%–37.3% | 223 (39.7%) | 35.6%–43.7% | 0.029 |
| Choroidal detachment | 3 (0.6%) | 0%–1.3% | 11 (2%) | 0.8%–3.1% | 0.062 |
| Previous uveitis | 25 (5.2%) | 3.2%–7.2% | 58 (10.4%) | 7.9%–12.9% | 0.002 |
| Previous surgery for RD | 60 (12.6%) | 9.6%–15.5% | 50 (8.9%) | 6.6%–11.3% | 0.062 |
| Previous PPV | 28 (5.9%) | 0%–11.9% | 30 (5.4%) | 0%–11.8% | 0.120 |
| Previous scleral surgery | 37 (7.7%) | 0.9%–14.6% | 19 (3.4%) | 0%–8.5% | 0.017 |
| Aphakia | 161 (33.5%) | 29.3%–37.8% | 221 (39.2%) | 35.2%–43.2% | 0.062 |
| PVD | 241 (50.1%) | 45.6%–54.6% | 256 (45.4%) | 41.3%–49.5% | 0.276 |
| Myopia | 187 (50.1%) | 45.1%–55.2% | 244 (60.5%) | 55.8%–65.3% | 0.012 |
| Ocular trauma | 13 (2.7%) | 1.3%–4.2% | 21 (3.7%) | 2.2%–5.3% | 0.357 |
| Previous ocular surgeries other than RD | 198 (41.2%) | 36.8%–45.6% | 263 (46.6%) | 42.5%–50.7% | 0.080 |
| RD in fellow eye | 38 (7.9%) | 5.5%–10.4% | 44 (7.8%) | 5.6%–10% | 0.945 |
| PVR in fellow eye | 39 (8.4%) | 5.9%–10.9% | 18 (3.2%) | 1.8%–4.7% | <0.001 |
| Previous VA | 0.051 | ||||
| <20/100 | 305 (65%) | 60.7%–69.3% | 325 (57.6%) | 53.5%–61.7% | |
| 20/100–20/40 | 59 (12.6%) | 9.6%–15.6% | 83 (14.7%) | 11.8%–17.7% | |
| ≥20/40 | 105 (22.4%) | 18.7%–26.2% | 156 (27.7%) | 24%–31.4% | |
| DM | 33 (7.1%) | 4.8%–9.4% | 52 (9.5%) | 7%–11.9% | 0.170 |
| RD family history | 15 (4.4%) | 2.2%–6.5% | 33 (7.6%) | 5.1%–10.1% | 0.075 |
| PVR family history | 2 (0.6%) | 0%–1.5% | 9 (2.2%) | 0.8%–3.6% | 0.123 |
N (%): number and percent of proliferative vitreo-retinopathy (PVR) cases; CI: confidence interval; macula-on: retinal detachment with macula attached; PPV: pars plana vitrectomy; PVD: posterior vitreous detachment; myopia: negative refractive error of any value; VA: visual acuity measured with Snellen test with pinhole if necessary; DM: diabetes mellitus.