Alienware 15 screen freezing on startup?

I have an Alienware 15 R2  that is about 2 years old, so far I haven't had any major problems with it but recently whenever I close my laptop and reopen it (i.e. it doesn't fully shut down, just goes into sleep mode and then wakes up) the screen is frozen with a strange pixel pattern all across the screen. I've attached a photo of what this looks like. If I fully shut it down and start it up again it always works fine. Anyone have a similar problem/ know how to troubleshoot?