If the scratches are bothering you while driving, then get them done. If not and are not so deep into the surface, leave them as is. Posting clear pictures will be of great help. Check your wiper rubber. Get the refill if there's the slightest doubt. We suually tend to change these when they really start screeching. For me, it was the part of Stage-! maintenance which included lubricants and filters changing. Rubber has a life too.
However, I'm also sure to some extent that the culprit might not be the wiper assembly itself. Check the entire windshield for chipping too.