Table 2: Mean spherical equivalent increases and SD over 2 years in 6-month intervals. The pre-study annual increase is shown in the first column. Statistically significant results are marked with an asterisk.

12 months before6 months12 months18 months24 months

Spherical equivalent changes (D)
SRRG−0.76 ± 0.27−0.06 ± 0.21−0.28 ± 0.38−0.39 ± 0.39−0.56 ± 0.51
OK−0.75 ± 0.25−0.16 ± 0.20−0.26 ± 0.44−0.32 ± 0.43−0.32 ± 0.53
SV−0.62 ± 0.25−0.27 ± 0.13−0.53 ± 0.25−0.80 ± 0.40−0.98 ± 0.58

Multiple comparisons contrast-
SV-SRRG0.660<
SV-OK0.1300.137<<
SRRG-OK0.5500.0920.1630.7900.965