I had this issue fixed on my mid-2012 15" rMBP. It's known issue with some of the early LG panels on that model. The technician at the Apple store ran some standard image persistence diagnostic script to replicate the issue.

They replaced the display for free outside of AppleCare. I didn't have to argue with them at all, so I suspect that this is their standard response. YMMV if you have a newer model.

Just call - there is a good chance that they will help you out, even if you have to bitch and moan for a little bit.

There is a repair extension programme for video issues on the macbook pro's

https://www.apple.com/uk/support/macbookpro-videoissues/

Not the same issue, these were for GPU issues. This one is a defect of the display, not GPU.

However, for the OP, don't let this stop you. Call and ask, they often are generous enough to replace it for you even out of warranty. If the first time doesn't work out, try again 2-3 more times before giving up.

My serial number is affected, but they want to keep the test running 24h to make sure the GPU is faulty. Also, they refused to replace my 2012 LG screen with obvious ghosting.

The AppleCare for my 2012 rMBP has expired, but is it normal for an Apple store to be so stingy about repair extension programs?

The best way to show the problem for me was to set the wallpaper to some grey colour (try which shade works the best). Open a browser (or any other mainly white screen with some text) keep it there for like 3 minutes. Log off and the grey background will be showing the problem more clearly. Maybe that will help. Mine was out of warranty but they fixed mine!