FYI, the insulin our #1 diabetic cat used, and the one we SWITCHED our #2 diabetic cat TO, AFTER the inflammatory response that blinded him, is PZI. THAT is the GOOD one.......And YES, it is frightfully expensive, roughly 3-1/2 times the price of the bilge that blinded our guy...... and YES, the PZI, good as it is and expensive as it is, has also been DISCONTINUED-- we are working on existing stocks of manufactured PZI which expire in 2010, and praying that the company succeeds in getting FDA approval of their 'replacement' feline insulin BEFORE all existing PZI insulin expires. They've filed the NDA, now it's in FDA's hands. Meantime, we have a stable, happy, active, BLIND cat, whose diabetes is well-regulated and who's making the best of things.... it just took time.
So you all know: NO ONE we've dealt with in his situation has EVER seen this blindness reaction before--and we've dealt with a LOT of vets, generalist and specialist, in this guy's case-- so, it's NOT something anyone else should have to worry about or live in fear of. But getting your guy's diabetes regulated and stable is enough of a headache by itself.
Keep up the good work-- if he's bellowing for food and eating well, you're probably not TOO far from where you need to be-- next visit, double-check with the vet's and make sure your injection technique is OK, and injection-site0 location selection, and all that-- just keep taking any variables you can think of OUT of the picture, keep narrowing it down until his metabolism decides to be happy and regulated.....once it all falls into place, it's a wonderful thing. Even mostly to entirely blind, our guy is a VERY happy, healthy, good-living fellow now-- affectionate, playful, everything like it should be-- and since no one bothered to inform HIM that he's 'handicapped', the blindness doesn't seem to phase him much, he's adjusted, we just don't rearrange furniture much, is all (I'm not sorry for that excuse!). He's a happy guy and living a VERY good life, and telling us about it all the time-- which is the whole idea, right? HAPPY CAT, that's what we were after and that's what we've got!

Stay patient, stay informed, keep watching him, keep loving him-- and GOOD LUCK-- you'll get there- and both of you will love it when you arrive-