Nice fanfic Tsukuyomi gonna hit Naruto before he can even close his eye's. :sdo3:
You people act as if Itachi is just going to instantly start the battle with tsukuyomi from the start. You also assume that Naruto is going to look into his eyes at all. Naruto can fly for crying out loud!
Naruto could just stay up in the air (thus keeping him out of position for eye contact) and rain down bijuudama rasenshurikens. Since these use truth seeking ball as their base, even Itachi's susanoo would be destroyed since the gudodamas negate ninjutsu and they can also cause massive explosions.
Also, how would Itachi cast it before Naruto could close his eyes? It takes less than a second to close your eyes, while Itachi has to take the time to establish eye contact. He also has to take the time to switch to MS.