[souffle]

What you describe as itching - is it just washing and scratching at his face? I have seen this in hamsters with eye problems and our vet said it was due to a chronic eye infection that caused the tear glands to be affected and secrete more sticky tears which do not lubricate the eye properly. The tear duct becomes blocked and so the tears cannot drain in to the nose anymore so they spill out over the face and cause the irritation you are seeing. Maxitrol drops can help but these are only used short term as they contain a steroid. We ended up using human eye lubricant drops daily (Isothalmic eye drops) to keep the eye lubricated. I wouldn't use any more mite treatment till you see what the vet thinks. There should really be a 2 week gap between treatments.
Many hamsters live with (and in) Ikea furniture so I'm almost certain it is not this.
Did this start with the new food? If so I would return to the old food right away.
Sometimes the eye issue is a symptom of something else going on inside like a hormonal problem or imbalance or diabetes other organ insufficiency and some of these problems are not treatable. I hope you get an answer on Saturday.