History:

This cat was a male neighborhood stray.  My neighbor and I used to feed
him if he showed up.  One night last January he showed up with an eye
swollen shut and sneezing.  My neighbor took him to the vet who
prescribed chloramphenicol ointment and also vaccinated him with the
normal cat vaccines.  (My neighbor also had him neutered 4 weeks later
and now keeps him.)  The sneezing and the eye swelling went down.  (BTW,
my neighbor also had a female, indoor, vaccinated cat who came down with
mild sneezing when exposed to this cat but then recovered completely in
about a week.) Although the eye swelling went down and the sneezing
stopped, the cat has a persistent fluid (sometimes pinkish--blood?)
discharge from the affected eye.  The cat does not seem to be in any
discomfort from this.  He neither squints the eye nor rubs it.

Another trip to the vet and this time a course of terramycin ointment.
No improvement.  A trip to another vet for a second opinion and another
,different antibiotic.  No improvement.

Could this be a persistent virus?  Would interferon help?  How expensive
is it?  As the condition does not seem to cause the cat any discomfort,
should it just be left alone unless it gets worse?

Opinions??