Postoperative outcomes after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in keratoconus eyes
| Outcomes | DALK group (n=228) | Big bubble-DALK subgroup (n=118) | Manual dissection-DALK subgroup (n=110) | PK group (n=274) | P value (DALK versus PK) |
| Postoperative complications | |||||
| Immune failure | 1 (0.4%) | 0 (0.0%) | 1 (0.9%) | 4 (1.5%) | 0.25 |
| At least one rejection episode | 38 (16.7%) | 17 (14.4%) | 21 (19.1%) | 52 (19.0%) | 0.50 |
| Non-immune failure‡ | 6 (2.6%) | 4 (3.4%) | 2 (1.2%) | 4 (1.5%) | 0.35 |
| Late endothelial failure | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 3 (1.1%) | 0.11 |
| Elevated IOP requiring treatment | 27 (11.8%) | 11 (9.3%)* | 16 (14.6%) | 59 (21.5%) | 0.004 |
| Infection | 4 (1.7%) | 3 (2.5%) | 1 (0.9%) | 7 (2.6%) | 0.54 |
| Epithelial complications | 5 (2.2%) | 3 (2.5%) | 2 (1.8%) | 2 (0.7%) | 0.16 |
| Trauma | 2 (0.9%) | 1 (0.9%) | 1 (0.9%) | 9 (3.3%) | 0.07 |
| Cataract | 7 (3.1%) | 3 (2.5%) | 4 (3.6%) | 6 (2.2%) | 0.53 |
| Other postoperative complications§ | 21 (9.2%) | 10 (8.5%) | 11 (10.0%) | 18 (6.6%) | 0.27 |
| 15-year graft survival | 97.1% | 96.1% | 98.1% | 96.4% | 0.97 |
| 15-year rejection-free graft survival | 71.3% | 73.7% | 68.1% | 67.6% | 0.40 |
| 15-year ocular hypertension-free graft survival | 82.9% | 85.7%* | 80.1% | 73.6% | 0.03 |
| 15-year infection-free graft survival | 97.7% | 97.0% | 98.5% | 97.8% | 0.92 |
| 15-year trauma-free graft survival | 96.4% | 97.7% | 95.3% | 96.6% | 0.66 |
| Best spectacle-corrected visual acuity (LogMAR) | |||||
| 1 year | 0.29 (2.4 lines) | 0.20 (1.8 lines)*† | 0.39 (2.6 lines)* | 0.30 (2.7 lines) | 0.61 |
| 3 years | 0.23 (2.2 lines) | 0.15 (1.9 lines)† | 0.32 (2.3 lines)* | 0.18 (2.1 lines) | 0.03 |
| 5 years | 0.21 (2.8 lines) | 0.12 (1.8 lines)† | 0.29 (3.3 lines)* | 0.14 (1.7 lines) | 0.06 |
| 10 years | 0.17 (1.6 lines) | 0.13 (3.9 lines) | 0.20 (1.5 lines) | 0.23 (3.9 lines) | 0.21 |
| Last examination | 0.19 (1.9 lines) | 0.15 (1.5 lines) | 0.23 (2.1 lines) | 0.22 (3.3 lines) | 0.54 |
| Refractive astigmatism (D) | |||||
| 1 year | 3.8 (2.1) | 3.9 (2.3) | 3.7 (1.9) | 3.7 (2.0) | 0.57 |
| 3 years | 3.9 (1.9) | 3.5 (2.1) | 4.4 (1.6)*† | 3.4 (1.8) | 0.06 |
| 5 years | 4.2 (1.9) | 4.1 (2.1) | 4.3 (1.9) | 4.0 (2.1) | 0.53 |
| 10 years | 4.6 (1.9) | 4.8 (2.1) | 4.5 (1.8) | 4.5 (2.1) | 0.84 |
| Last examination | 4.6 (2.2) | 5.0 (2.5) | 4.3 (2.2) | 5.0 (2.5) | 0.37 |
| IOP (mm Hg) | |||||
| 1 year | 15.7 (3.6) | 15.9 (3.6) | 15.6 (3.4) | 14.9 (3.6) | 0.04 |
| 3 years | 14.6 (3.0) | 14.9 (3.6) | 14.3 (3.0) | 14.3 (3.6) | 0.50 |
| 5 years | 14.0 (3.0) | 14.1 (2.9) | 13.8 (3.0) | 13.6 (3.0) | 0.43 |
| 10 years | 13.7 (2.6) | 12.7 (2.4) | 14.2 (2.6) | 13.5 (3.3) | 0.71 |
| Last examination | 14.2 (3.4) | 14.8 (3.9) | 13.6 (2.7) | 13.3 (3.1) | 0.14 |
| Central corneal thickness (µm) | |||||
| 1 year | 541.7 (47.6) | 520.3 (37.7)*† | 561.2 (47.5)* | 537.1 (50.6) | 0.41 |
| 3 years | 559.3 (48.3) | 543.9 (47.4)† | 574.6 (44.4)* | 550.2 (43.9) | 0.14 |
| 5 years | 562.7 (61.3) | 544.9 (75.3)† | 579.1 (38.8) | 564.2 (48.6) | 0.86 |
| 10 years | 564.8 (50.6) | 543.9 (47.1)*† | 578.0 (48.7) | 576.0 (56.8) | 0.25 |
| Last examination | 562.5 (42.6) | 551.1 (39.2)*† | 572.7 (43.5) | 583.6 (45.0) | 0.006 |
| Corneal endothelial cell density (cells/mm2) | |||||
| 1 year | 2372 (471) | 2402 (448)* | 2342 (494)* | 1814 (457) | <0.00001 |
| 3 years | 2234 (452) | 2258 (417)* | 2210 (485)* | 1490 (490) | <0.00001 |
| 5 years | 2120 (416) | 2131 (335)* | 2110 (471)* | 1187 (446) | <0.00001 |
| 10 years | 1966 (397) | 1916 (421)* | 2010 (373)* | 827 (269) | <0.00001 |
| Last examination | 2022 (428) | 1945 (397)* | 2102 (450)* | 733 (206) | <0.00001 |
| Topographic simulated mean keratometry (D) | |||||
| 1 year | 44.8 (2.5) | 44.9 (2.3)* | 44.7 (2.6)* | 43.3 (2.5) | 0.0009 |
| 3 years | 47.0 (3.1) | 47.1 (3.1)* | 46.8 (3.1)* | 45.0 (2.0) | 0.0003 |
| 5 years | 47.7 (3.2) | 48.0 (3.4)* | 47.5 (2.9)* | 45.4 (2.1) | 0.0003 |
| 10 years | 47.8 (2.7) | 48.1 (2.6)* | 47.6 (2.8)* | 46.0 (2.3) | 0.0002 |
| Last examination | 47.9 (3.0) | 48.6 (3.3) | 47.2 (2.5) | 46.6 (2.9) | 0.06 |
Shown are the number (percentage) and mean (SD). The number of eyes with clear graft assessed for complications, visual acuity, refractive astigmatism, IOP, CCT and ECD at 1 year/3 years/5 years/10 years/last exam (ie, >10 years) was, respectively, 405/309/237/143/135. This figure for simulated keratometry was, respectively, 161/190/170/188/94.
*p<0.05 versus PK group.
†p<0.05 versus manual dissection-DALK subgroup.
‡Excluding late endothelial failure.
§Elevated IOP not requiring treatment (n=27), surgical correction of high astigmatism (n=5), double anterior chamber after DALK (n=5), late peripheral hydrops after PK (n=1), significant cornea guttata after PK (n=1).
CCT, central corneal thickness; ECD, endothelial cell density; IOP, intraocular pressure.