Table 4.

Changes of optical density differences in particular groups—results after 1 year (baseline vs. follow-up 1).

Optical density difference	Group						p*
	I		II		III
	n	%	n	%	n	%	I vs. II	I vs. III	II vs. III
Decrease	65	36.5	123	60	113	69.3	< 0.001	< 0.001	0.08
No change	9	5.1	19	9.3	9	5.5	NS (0.17)	NS (0.96)	NS (0.25)
Increase	104	58.4	63	30.7	41	25.2	< 0.001	< 0.001	NS (0.29)

*p < 0.05 significant.