How do the eyes of doctor T.J. Eckleburg relate to the American dream in The Great Gatsby?

In the Valley of Ashes, the eyes of T. J. Eckleberg "brood...over the solemn dumping ground" of materialism and the moral decay of people. 

In The Great Gatsby, a satire of the American Dream, Fitzgerald depicts the Valley of Ashes as an objective correlative for the vulgarity and emptiness that characterizes an age in which America has subjected its vitality to the avaricious pursuit of money and materialism. Certainly, what has appeared golden and romantically lovely in Chapter One has its gilded material laid waste in Chapter Two. For, in this chapter, the romance is sullied as Nick accompanies Tom Buchanan to the home of his mistress, which lies in the midst of this wasteland, and they go to the city for a pleasure-seeking party. Thus, the wasteland between West Egg and New York also symbolizes moral decay.

In addition, the eyes of Dr. Eckleberg represent the excessive advertising and materialism of the Jazz Age. In fact, at one point in the narrative, Daisy tells Gatsby that he reminds her of an advertisement because she senses his illusions of success and wealth.

Later in the narrative, after the death of his wife, Myrtle, George Wilson perceives the billboard with the eyes of T.J. Eckleberg as the eyes of God, "brood[ing] on over the solemn dumping ground" that represents the souls of the rich who simply exploit people and opportunities in their insatiable appetite for material possessions. It is an appetite that leads to only hopelessness and defeat because the American Dream has been built upon the ephemeral rewards of materialism and hedonism.