Table 1.

Mean of differences, 95% confidence intervals, and results of paired t tests for both repeatability data, with and without a disposable (Tonopen oculofilm) cover and the validity of measurements with the disposable cover

Condition	Mean difference (mm)	95% confidence intervals (mm)	t test result
Intrasessional repeatability without cover	0.027	± 0.44	p=0.20
(reading 1 − reading 2)			NS
Intrasessional repeatability with cover	0.028	± 0.38	p=0.59
(reading 3 − reading 4)			NS
Intrasessional validity	0.07	± 0.59	p=0.82
(reading 3 − reading 1)			NS
Intrasessional validity	0.10	± 0.60	p=0.37
(reading 6 − reading 5)			NS
Intersessional repeatability without cover	0.03	± 0.51	p=0.20
(reading 1 − reading 5)			NS
Intersessional repeatability with cover	0.002	± 0.51	p=0.72
(reading 3 − reading 6)			NS

NS = not significant.

Study reading 1= initial uncovered; 2 = repeat uncovered; 3 = initial covered; 4 = repeat covered; 5 = final uncovered; 6 = final covered.