Table 3.
The percentages within ±0.25, ±0.5, and ± 1.0 D of the targeted refraction using the Barrett Universal II and the SRK/T formulas.
| Keratometry | Within ± 0.25 D (%) | Within ± 0.5 D (%) | Within ± 1.0 D (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Barrett Universal II | SRK/T | p value | Barrett Universal II | SRK/T | p value | Barrett Universal II | SRK/T | p value | |
| Entire | 78 | 74 | 0.589 | 79 | 73 | 0.148 | 97 | 93 | 0.026 |
| Flat K group | 48 | 41 | 0.493 | 74 | 70 | 0.706 | 96 | 94 | 1.000 |
| Normal K group | 52 | 53 | 0.916 | 84 | 81 | 0.579 | 98 | 98 | 1.000 |
| Steep K group | 49 | 43 | 0.541 | 71 | 60 | 0.199 | 97 | 84 | 0.009 |
K = keratometric readings; D = diopter.