I have seen something like this (bagginess) a couple of times over the years but I don't know what the diagnosis was with any of the ones I saw/heard of. (They weren't my chameleons and I didn't hear/read the follow-up on any of the cases.)
I have also seen something similar to this that occurred after surgery for a sinus infection. The chameleon came to me looking fine, but deveoped a swelling near the eye that was a sinus infection. The surgery caused swelling and when the swelling went down, the eye looked baggy like your chameleon's. Was your chameleon's eye ever swollen?
As for using human meds for the chameleon...you don't know what bacteria is involved (if there even is any involved) and most bacteria that chameleon's get are gram negative while humans get mostly gram positive bacteria. The strength of the meds for humans may be different than what a chameleon would get too.
I would advise you to ask a vet about it.