Table 2. Comparison of reading studies in ARMD.

Data source	Measure	Speed, wpm 1-line space	Speed, wpm 2-line space	Improvement, wpm	Improvement, %
Calabrese et al 2010	Mean	43.02	50.17	7.14	16.60
(N=90 eyes, 61 Ss)	Median	38.20	45.75	6.32	16.55
Chung et al 2008, RSVP	Mean	43.10	62.59	19.49	45.22
(N=4 Ss)	Median	41.09	67.98	22.47	54.68
WS=1, high contrast	Mean	94.80	112.88	18.08	19.07
(N=24 Ss, our data)	Median	93.23	110.67	21.11	22.64
WS=2, high contrast	Mean	95.34	119.84	24.50	25.70
	Median	92.31	114.83	24.68	26.74
WS=1, low contrast	Mean	57.71	77.20	19.48	33.76
	Median	55.23	76.41	18.88	34.18
WS=2, low contrast	Mean	59.82	87.07	27.25	45.56
	Median	57.27	82.72	23.99	41.90

Summary of improved reading speeds with double line-spacing in three studies of ARMD patients. WS = word spacing. Ss = subjects. Improvement in wpm, for a given observer, is reading speed with double line spacing minus reading speed with single line spacing. The column ‘Improvement,wpm’ shows the mean or median improvement. For the median, this is not in general equal to the difference between the two median speeds. The column ‘Improvement, %’ is the mean (or median) improvement as a percentage of the mean (or median) reading speed with single-line spacing.