EMDR is very similar to PE. You focus upon a traumatic incident and then you process that one incident thoroughly, until a resolution is found by neutralising the impact of symptoms when recollected. EMDR adds a method of distraction, which has no science to date that it actually works (eye movements, beeps, lights, et cetera). PE does not use any distraction method, instead it focuses on SUDS within the process, trying to achieve nothing more than an 8 or 9, then reducing that level to a 5 or less.
Both do the same thing. PE has some statistically better results than EMDR, yet PE is older, and honestly, I don't trust either's statistics because the average model is not added with all the failed, unpublished study results.