Table 2.

Pupil metrics before and after cerebral angiogram

Variable	Pre angiogram (n=50)	Post angiogram (n=50)	P value*
NPi
Left eye	4.29 (0.42)	4.33 (0.38)	0.612
Right eye	4.25 (0.75)	4.25 (0.77)	0.902
Absolute difference in left and right eye NPi values	0.05 (0.77)	0.08 (0.67)	0.621
Resting pupil diameter
Left eye	3.21 (1.07)	2.19 (0.49)	0.054
Right eye	3.07 (0.98)	2.24 (0.53)	0.699
Latency
Left eye	0.24 (0.05)	0.25 (0.05)	0.262
Right eye	0.25 (0.05)	0.29 (0.19)	0.140
Constriction velocity
Left eye	1.74 (0.90)	1.54 (0.92)	0.113
Right eye	1.58 (0.82)	1.52 (0.80)	0.737
Constricted pupil diameter
Left eye	3.22 (1.07)	2.91 (0.95)	0.028
Right eye	3.07 (0.98)	3.02 (0.94)	0.608
% change in pupil diameter
Left eye	23.21% (9.73)	22.5% (10.85)	0.635
Right eye	22.67% (9.75)	23.31% (10.93)	0.737
Dilation velocity
Left eye	0.72 (0.39)	0.65 (0.41)	0.259
Right eye	0.72 (0.39)	0.64 (0.35)	0.345
PLR categorisation*			0.321
Left eye
Abnormal	1 (2%)	0 (0%)
Normal	49 (98%)	50 (100%)
Right eye
Abnormal	2 (4%)	2 (4%)
Normal	48 (96%)	48 (96%)

*The pupillary light reflex (PLR) is considered abnormal if the NPi value is <3.0.