Table 1.

Demographic characteristics of blind patients affected by inherited retinal degeneration.

	Years ± SD	Range	Median	Normal distribution
Age	60.4 ± 13.8	40–90	59	Yes
Age at diagnosis	20 ± 13.9	6–60	16	No
Disease duration	40.4 ± 16.3	10–72	39	Yes
Blindness duration	15.2 ± 8.2	2–30	15	Yes

SD standard deviation.