Can you please post some photos of what they look like today?
Have you tried any other antibiotics in the past or present?
I looked at a couple of your other threads and you mentioned that your coop had Bad Air and likely need more ventilation. Did you correct that?
https://www.backyardchickens.com/th...one-half-way-closed-eye.1341301/post-21987018
Also you had another thread where you were using Denagard and birds did not seem to be responding, just as you have posted today that the Denagard is not helping.
Denagard only treats Mycoplasma, so you may be dealing with a virus, fungal or bacterial infection that Denagard won't treat.
https://www.backyardchickens.com/threads/denagard-12-5-antibiotic.1334989/post-21813411
It's hard to know what to suggest for you to give without knowing the cause of the symptoms you are seeing. Do the birds have pus in the eyes and a bad odor? Is there yellow or white cheesy material inside the beak and/or throat? Is there mold in the coop?
Have ventilation issues been addressed?
Getting some testing/sending some swabs to be analyzed will give you some great information so you know what you are dealing with, then you can come up with a treatment plan.
There are many respiratory diseases that chickens can have -some are viruses and will not respond to antibiotics. Others that are bacterial may require different types antibiotics, so knowing what you have is going to dictate how you treat.
Ohio state lab
https://agri.ohio.gov/wps/portal/gov/oda/programs/animal-disease-diagnostic-lab/
Independent Testing
http://www.zoologix.com/
http://www.vetdna.com/test-type/avian-bird