Table 6. Six-Month Exotropia Control and PACT According to Treatment Group.
| Observation (N=87) | Patching (N=90) | P valued | |
|---|---|---|---|
|
| |||
| Exotropia control at distancea | |||
| At 6 months | |||
| Mean (SD) | 2.8 (1.3) | 2.3 (1.5) | 0.02 |
| Range | 0 to 5 | 0 to 5 | |
| Change between baseline and 6 months (pos=better)b | |||
| Mean (SD) | -0.3 (1.3) | 0.1 (1.5) | |
| Range | -3 to 4 | -4 to 3 | |
| ≥ 3 points better | 2 (2%) | 6 (7%) | |
| 2 points better | 3 (4%) | 10 (11%) | |
| 1 point better | 12 (14%) | 14 (16%) | |
| 0 | 32 (37%) | 34 (38%) | |
| 1 point worse | 19 (22%) | 16 (18%) | |
| 2 points worse | 17 (20%) | 3 (3%) | |
| ≥ 3 points worse | 1 (1%) | 7 (8%) | |
|
| |||
| Exotropia control at neara | |||
| At 6 months | |||
| Mean (SD) | 1.4 (1.4) | 1.1 (1.4) | 0.26 |
| Range | 0 to 5 | 0 to 5 | |
| Change between baseline and 6 months (pos=better)b | |||
| Mean (SD) | -0.3 (1.1) | -0.1 (1.3) | |
| Range | -3 to 3 | -5 to 3 | |
| ≥ 3 points better | 2 (2%) | 3 (3%) | |
| 2 points better | 2 (2%) | 7 (8%) | |
| 1 point better | 10 (12%) | 11 (12%) | |
| 0 | 42 (49%) | 45 (50%) | |
| 1 point worse | 21 (24%) | 14 (16%) | |
| 2 points worse | 6 (7%) | 5 (6%) | |
| ≥ 3 points worse | 3 (4%) | 5 (6%) | |
|
| |||
| PACT at distance (Δ)a | |||
| At 6 months | |||
| Mean (SD) | 27.9 (8.2) | 24.9 (9.4) | 0.02 |
| Range | 0 to 45 | 0 to 45 | |
| Change between baseline and 6 months (pos=better)c | |||
| Mean (SD) | -0.6 (8.1) | 2.0 (8.6) | |
| Range | -20 to 30 | -22 to 25 | |
| Decreased ≥8Δ | 8 (9%) | 22 (24%) | |
| Within <8 Δ | 66 (77%) | 59 (66%) | |
| Increased ≥8 | 12 (14%) | 9 (10%) | |
|
| |||
| PACT at near (Δ)a | |||
| At 6 months | |||
| Mean (SD) | 19.3 (9.6) | 17.0 (12.2) | 0.10 |
| Range | 0 to 40 | 0 to 45 | |
| Change between baseline and 6 months (pos=better)c | |||
| Mean (SD) | -1.8 (11.4) | 0.9 (12.8) | |
| Range | -30 to 25 | -30 to 25 | |
| Decreased ≥13 Δ | 7 (8%) | 16 (18%) | |
| Within <13 Δ | 66 (77%) | 60 (67%) | |
| Increased ≥13 | 13 (15%) | 14 (16%) | |
One observation group participant was missing control (distance and near) and PACT (distance and near) at the 6-month visit.
Change is calculated as control at baseline minus control at 6-month examination measures, therefore positive change = improvement (decreasing control score) and negative change = worsening (increasing control score).
Change is calculated based on baseline PACT minus 6-month examination PACT, therefore positive change = improvement (decreasing angle), negative change = worsening (increasing angle). Change in PACT at distance and near was classified using thresholds of ≥8Δ and ≥13Δ respectively because these amounts exceed the repeatability coefficients of 7.2Δ and 12.8Δ for PACT angles larger than 20Δ at distance and near.24
P values from analysis of covariance models adjusting for the baseline level of the outcome.
Δ = prism diopters; PACT = prism and alternate cover test; SD = standard deviation