Table 2.

Dark adaptation impairment increased with disease severity

	Young Normal	Old Normal	Borderline ARM	Early ARM	Intermediate ARM	Advanced ARM
Sample Size	8	9	5	6	5	1
AREDS Fundus Grade	N/Aa	1	2	3,4,5	6,7,8,9	≥10
Rod Intercept, min mean (SD)	8.2 (1.4)	8.7 (1.9)	13.8 (4.4)	17.2 (2.7)	20 (b)	20 (b)

^aFundus photography and grading was not performed on young normal group.

^bAll subjects failed to reach the rod intercept within the 20-minute test duration. Rod intercepts were set at 20 minutes for comparison purposes.