Is Retin-A/Retinol recommend in the under eye area before getting the CO2 laser?

You can use a very gentle retinoid product and stop as recommended a week before. Try a gentle mild retinoid called Replenish Daily Retinoid Cream ("Level 1") developed by a Los Angeles Plastic Surgeon and Skin Specialist (not me). You should also use a product called Bruise Balm by Plato's Medicinals starting 1 week before your procedure. We use it extensively in our medical practice as it reduces brusing, pain and inflammation with laser procedures, resurfacing, injectable fillers, Botox, etc. It is available on the link below as well.