A green line appeared in my screen MacBook Pro Retina display late 2013

I would try safe booting. To do this, hold the Shift key at startup. It may take a little longer to boot, but once it boots, see if the issue persists. If not, just try restarting the system normally. Sometimes, a safe boot will self-correct the problem. If the issue returns, I would run an Etrecheck and post the results to this thread, so we can all see what's going on.

I would try resetting your NV/PRAM. To do this, hold the Cmd + Option + P + R keys and then power on the machine. It will begin to start then restart. You should hear the machine chime twice. Once it chimes twice, release the keys and allow it to boot. For more info, see: https://support.apple.com/en-us/HT204063

If neither of these work, I would take it to an Apple store or an AASP (Apple Authorized Service Provider) to get official diagnostics run.

Best of luck!

Hi,

Best to take your Mac to an Apple Store > Apple Store - Find a Store - Apple

Or you can make an appoinment at a Genius Bar (Apple) in advance > Genius Bar Reservation and Apple Support Options - Apple

It's likely a hardware issue.