Terramacyin or other OPTHAMALIC ointment, non-steroidal is about all you can do, unless you have full blown pink-eye, not just matting. Then, tetracyclene + sulfa is the most effective antibiotic treatment that I am aware of. Non-steroidal is important because if there is any scratch or abrasion on the eye that you are unaware of, steroid ointment will cause ulceration and more damage.
I wouldn't put something that isn't indended for opthamalic use in the eyes of anything. I sure wouldn't put it in my eyes. How do we know if there is an ingredient in an injectable formula that facilitates is effectiveness/ability to be absorbed and metabolized in the muscles and tissues that could burn, or be abrasive, or damaging to the eye somehow? I see a lot of people talk about using different drugs in ways they aren't specifically intended, IM vs. SC vs. oral, etc. and I just wonder if they have actually been advised by a vet or someone with pharmacology expertise to do these things, or if they are just making it up as they go along. Allen and I had a thread recently talking about pharmacology, this industry needs more of it, lots more of it.