Thats simply not true, the Eastern Empire was on the verge of collapse, Turks had expanded accrost most of it's money generating territory accrost Arabia and had their sights set on what is now Istanbul. Given it had great defenses and would have been a hard city to take, the Turks very well would have eventually taken it, long before 145? when the Ottomans did. The Crusades beat back the Muslims from Europe's doorsteps and delt them a blow that it would take nearly 400 yaers for them to recover from, in which allowed Europe to progress rapidly allowing for the army's of Europe to come to a level which was a capable of repelling the Muslims once they broke though.
The Eastern empire tryed to emulate it's creator, but it never could. At it's strongest times it was a small empire centered around a few strong cities, with a significant amount of tributary citys surrounding it and a strong slave army with a core of professional soilders. But it never reached the power and domination that the Roman Empire/Republic held.