Table 3

Agreement with ETDRS measurements

Chart Mean difference 95% CI for the mean SD 95% CI for agreement
ETDRS 1− RLM A 10.00−0.03 to +0.030.10−0.20 to +0.20
ETDRS 1− RLM B 1+0.01−0.03 to +0.050.12−0.24 to +0.24
ETDRS 1− RLM C 1−0.01−0.05 to +0.030.12−0.24 to +0.24
ETDRS 1− Snellen 1 (single letter)+0.02−0.02 to +0.060.14−0.27 to +0.27
  • The figures show the level of agreement between each pair of chart designs shown in the first column as determined using the methods of Bland and Altman. “Single letter” scoring is used throughout.