I don't think the Reformation in Western Europe had much real impact on Orthodoxy, but that is not to say that Orthodoxy was a static entity throughout history.

There was a huge schism in the Russian Orthodox Church in 1666. Basically there were parts of the Church who wanted to realign more closely with the Greeks and others who thought that was a bad idea. Those who thought it was a bad idea became known as the "Old Believers." They remained on the fringes of the Russian Empire throughout its history, many ending up in Alaska. I believe you can still find communities of Old Believers there today.

Interesting side not, these Old Believers were called Raskolniki, which is Russian for schismatic. Dostoevsky's main character in Crime and Punishment is a play on words from this term, Raskolnikov. Symbolizing the dual nature of the character.