Edward Flaherty, 74, was convicted of strangling 69-year-old Ina Flaherty with a tie after she refused to give him money to go out drinking.
Lord Matthews said Flaherty’s dementia made him unsuited to prison.
He imposed a year-long restriction of liberty order which will keep him inside his home during opening hours.
The pensioner will be tagged and banned from leaving his home in the city’s Drygate area between 1100 and 2300 BST after being found guilty of culpable homicide.
At the High Court in Glasgow, Lord Matthews told Flaherty that under normal circumstances he would have been given a prison sentence in double figures.
He said: I have read and considered a number of reports from experts. It is plain to me that if I were to impose that sort of sentence you would be released in a very short time because prison would not be able to cope with your condition.
Sentencing you would just be a token gesture. I am anxious to impose a sentence that restricts your liberty.
You still go to the pub where you went with your wife. That must annoy her relatives.
Not being able to go there will be a more meaningful disposal than a prison sentence which will not last long.
During the trial the jury heard that Flaherty said he had no recollection of the moment he throttled his wife of 52 years in April last year.
When asked who killed her, he said: It must have been me. There are no ghosts running about the house who would have done that.
Defence QC Donald MacLeod said: “The report prepared for the court paints a picture of a man in significant physical and mental decline.
There is a clear diagnosis of dementia setting in. It is a progressive condition and ultimately he will need 24-hour care.
I am deeply conscious there has been a death here, but this man is very unwell.
He was always willing to plead guilty to culpable homicide, but this was flatly rejected by the Crown and that is why a trial was necessary.
BBC News, 4 August 2008