Yes I am in the same situation although possibly not so far down the line.
My father has had a dx from mental health nurses but is awaiting a hospital appointment with the doctors and a brain scan. He is going to get monthyly visits from the nurses.
He is also partially sighted due to age realted macular degeneration.
He is in denial about it all too. Just says that everybody forgets things when they get older. He even denies that he has much wrong with this eyes and claims that eating spinach once a week has cured him. Never mind the operations and the visits to the consultants and the fact that he still can't see to read or do anything with detail.
He is 79 and is currently being cared for by my poor mother who is being driven batty by him and is having to deal with his control freakery and general nastiness. She is coping but mainly by going out a lot. If he gets much worse she won't be able to do that and I dread to think what will happen then. He has also taken to downing too much alcohol (a bottle of wine in about 20 minutes although thankfully contained to twice a week at the moment). He also smokes. The nurse did say that as they get worse they forget to smoke and drink so maybe that problem will sort itself out.
My father is also abusive although emotionally rather than physically. He seems to have all the traits of narcissistic personality disorder and unfortunately, it seems to be getting worse as a result of the dementia. The nurses picked up on controlling ways and his current obsession with God.
I see them a couple of times a week with my boys but my father is fixated on asking my DS1, who is only 9, whether he believes in God and then goes off on God related rants at the poor boy. I wouldn't mind but it is utter garbage (I say that as a church goer too).
I am torn between wanting to help my mother out and letting her see the boys and wanting to keep the DC away from my father.
Not sure how much help my DB will be - he just says that my dad would be better off dead which is a bit harsh but probably true, although I hate to say it.
Anyway, compared some of the others on this thread we have it easy at the moment but I am now a bit scared about the horrors to come.