Your eye will stay red no matter what drops you put in it. It will get somewhat better---over time. Your docs are not concerned because they knew this up front.
You seem to be absolutely correct. :)
One of our most knowledgable and faithful posters here JodieJ had a similiar problem and it was ultimately found to be a suture that had eroded to the surface and was hard to see but the cause of the problem.
Your problem is not unusual. Ask the retina MD and your personal ophthalmologist to check for exposed suture, eroding retina hardware, ask them to flip the upper eyelid and check for problems there.
Try regular artifical tears 3-4 times/day for a couple of weeks to see if that helps. Blink or Soothe are good choices. Use of murine and visine like products often just make it worse due to rebound redness.
If all else fails ask about use of restasis as over 4-6 months it not only produces a better tear but reduces inflammation on the surface of the eye without the possible effects of long term steroid drops.
JCH MD
yes vasoconstrictors are available otc, most commonly known to people as "Visine" (although there are other "red-eye relief" drops available). However, they often cause rebound redness, so it's really not a good permanent option.
I would try different artificial tears and using them more frequently.