Baytril and enrofloxin are the same medication with Baytril being a brand name and enrofloxin the generic
Amtyl is a compound [two drugs] antibiotic. I have no experience using it.
My rehabber friend says that their vet previously used Baytril but is currently using SMZ-TMP...
I think you are doing the best for a presumed eye infection. It does sound like there is a neurological problem as well.
Keeping you duck calm and happy is all you can do