Orbifloxacin...cause blindness? Help!

I have male 16 year old cat put on orbifloxcin for what we believe might be a severe infection. Previously we have done other antibiotics and llysine,everything that you can think of for cat suffering from a herpes outbreak.He's been on this for 5 days at 1ml once daily with food. Tonight I noticed his pupils are fully dilated and he seemed almost unaware if I was in the room. I've been so worried and distracted about his congested breathing,I'm not sure if this started sooner or what. He's pupils do respond to light but only if it's very bright and directly in his eyes and he will blink. I've dropped a cottonball right in front of him without touching his whiskers and he does not blink. He's very slow almost as if he isn't quite sure...I know my cat and he seems off. He is eating and drinking,at the foot of the bed eating treats because he heard me move the bag,I put them in front of him and he eats. He's been slow and doesn't do much because he has been sick but I'm worried he is going blind. I read in the insert for the antibiotic and it did say "adversely affect the retina" and "blindness had been reported post approval in cats". I did not give him his dose tonight because I'm concerned this has caused a problem. My vet is on the agenda first thing tomorrow but I was wondering if anyone else has had this happen or has any other ideas. Thanks

It seems you may have a very rare - perhaps not seen before though your vet could easily serach VIN if a member - side-effect. It hasn't been observed in felines before, according to this article with no date on it, in this particular antibiotic - but it has been seen in this CLASS of antibiotic:

"The recently described problem with blindness in cats associated with higher doses of enrofloxacin has not been reported in orbifloxacin. Orbifloxacin has a slightly different chemical structure that leads to less drug accumulation in feline eyes."

http://www.veterinarypartner.com/Content.plx?P=A&A=676&S=0&EVetID=3001644

I would stop administration until you can talk to the vet.