Hi, Pru,
You do not say what eye drops your vet prescribed. Have you asked him if he could give you different eye-drops or eye ontment, possibly one with a low dose of steroid?
Optrex and Brolen may help, and are unlikely to have any adverse effects, but I do think that your vet may be able to give your more assistance yet, if the worst comes to the worst by a referral to a veterinary ophthalmologist.
Walter