Finding related work to a paper

I'm having the following problem: There is some interesting paper (in machine learning) which is cited by 180 other papers (according to Google Scholar). From these 180, I want to find the papers that build up heavily on the original paper. I mean, not the ones that just mention the original paper briefly and are not REALLY related to it, but the ones in which the original paper is one of the, let's say three, main references.

Now, obviously I cannot read 180 abstracts/papers now. Any clever and experienced ideas? I'm a PhD student.

Thanks!