My TB had/has ERU and we battled long and hard with conventional creams, bute etc. Finaly what worked was giving him 25 mils of Colloidal silver twice daily and using Photonic Therapy (red light therapy) on his accupressure points for eyes. He also wears, during daylight hours, a Gaurdian Eye Mask which blocks out 95% of UV rays. Hope this is of help to you, its devil of a thing and keeps coming back but, touch wood, he has been fine for the last 6 months. When he was bad though he wore racing pacifiers with the bad eye blacked out as we could not keep him locked in a dark stable during daylight hours, and he would have gone stir crazy anyway, but he was kept in a small yard.