Table 4.
Risk Factor Analysis for Failure in the PTVT Study
| Risk Factor | Number (%) | Cumulative Probability of Failure at 5 Years (%)† |
P-value |
|
|---|---|---|---|---|
| Univariable‡ | Multivariable§ | |||
| Stratum* | 0.54 | 0.55 | ||
| 1 | 108 (45) | 35 | ||
| 2 | 13 (5) | 29 | ||
| 3 | 121 (50) | 45 | ||
|
| ||||
| Age | 0.096 | 0.33 | ||
| <50 | 39 (16) | 51 | ||
| 50 to 70 | 142 (59) | 42 | ||
| > 70 | 61 (25) | 27 | ||
|
| ||||
| Gender | 0.56 | 0.95 | ||
| Male | 160 (66) | 39 | ||
| Female | 82 (34) | 40 | ||
|
| ||||
| Race | 0.22 | 0.29 | ||
| Black | 116 (48) | 48 | ||
| White | 95 (39) | 33 | ||
| Other | 31 (13) | 32 | ||
|
| ||||
| Hypertension | 0.50 | 0.80 | ||
| Yes | 118 (49) | 42 | ||
| No | 124 (51) | 38 | ||
|
| ||||
| Diabetes mellitus | 0.57 | 0.65 | ||
| Yes | 45 (19) | 37 | ||
| No | 197 (81) | 40 | ||
|
| ||||
| Previous ocular laser treatment | 0.82 | 0.23 | ||
| Yes | 83 (34) | 41 | ||
| No | 159 (66) | 39 | ||
|
| ||||
| Preoperative IOP (mmHg) | < 0.001 | < 0.001 | ||
| < 21 | 91 (38) | 63 | ||
| 21 to 25 | 84 (35) | 23 | ||
| > 25 | 67 (28) | 28 | ||
|
| ||||
| Preoperative number of glaucoma medications | 0.65 | 0.43 | ||
| 0 to 2 | 57 (24) | 41 | ||
| 3 | 87 (36) | 35 | ||
| > 3 | 98 (41) | 44 | ||
|
| ||||
| Preoperative Snellen VA | 0.81 | 0.96 | ||
| ≥ 20/50 | 207 (86) | 39 | ||
| ≤ 20/60 | 34 (14) | 46 | ||
|
| ||||
| Preoperative HVF MD (dB) | 0.97 | 0.88 | ||
| > −7.0 | 65 (28) | 34 | ||
| −7.0 to −17.0 | 84 (36) | 39 | ||
| < −17.0 | 83 (36) | 43 | ||
|
| ||||
| Clinical centers | 0.32 | 0.15 | ||
| Enrolled ≥ 50% patients | 145 (60) | 36 | ||
| Enrolled < 50% patients | 97 (40) | 45 | ||
|
| ||||
| Treatment | 0.21 | 0.065 | ||
| Tube | 125 (52) | 42 | ||
| Trabeculectomy | 117 (48) | 35 | ||
HVF = Humphrey visual field; IOP = intraocular pressure; MD = mean deviation; VA = visual acuity
*
Stratum 1 = no failed glaucoma surgery in fellow eye and age ≥ 50 years and not black race; stratum 2 = failed glaucoma surgery in fellow eye; stratum 3 = no failed glaucoma surgery in fellow eye and age < 50 years and/or black race
†
Kaplan-Meier survival analysis
‡
Log-rank test
§
Analysis conducted with Cox proportional hazards multiple regression. Randomization stratum and randomized treatment group were included in all models, and other variables in the table were allowed stepwise inclusion.