Table 2.

Estimates for a linear mixed regression model on the effect of an eye patch assigned at diagnosis of infectious bovine keratoconjunctivitis (IBK) on ulcer size over time for 96 cases of IBK diagnosed in a group of 216 Angus cross steers between April and August 2019

Variable	N	Coefficient	Standard Error	P-value
Treatment
Control	47	Ref.
Eye patch	49	−0.289	0.366	0.44a
Days since enrolment		−0.141	0.013	<0.001
Treatment x Days since enrolment
Control		Ref.
Eye patch		−0.0635	0.020	0.001
Severity score at enrolmentb
2	45	Ref
3	35	1.59	0.37	<0.001
4	16	2.26	0.48	<0.001
Previous IBK in opposite eye
No	76	Ref.
Yes	20	0.93	0.38	0.01
Intercept		−2.72	0.32	<0.001

^a P for treatment indicates no difference at baseline, i.e., day 0, supporting successful randomization.

^b Score 2: lesion (ulcer and corneal edema) covers up to one-third of corneal surface area; score 3: lesion covers up to two-thirds of corneal surface area; score 4: lesion covers the entire corneal surface or ruptured globe.