Table 2. t-test comparisons of mean response amplitude differences between occipital and surround electrodes by study variable.

	Difference of means (dB)	t-stat	P
T2D	0.272	5.73	<0.0001
AMD normal fundus	0.532	3.70	0.0003
AMD Early	−0.109	1.34	0.1808
AMD Exudative	0.341	2.81	0.0056