Singapore diploma to degree

Hi all. I'm new here.
I'm gonna pass out as a registered nurse in singapore coming april from Nanyang Polythecnic.
Im planning to do a degree in australia or uk. and recently I found out that the duration of "top up" degree has changed from one year to two years. universities like latrobe, curtin, griffith.
though i figured there are still minority of universities offering one year degree though they arent the best universities. and im afraid these minority university degrees wont be recognised internationally.
I would like to know what is the difference between a one year degree to a two year degree keeping in mind that I will have a diploma in nursing(singapore) and will be a registered nurse here(singapore). I just want to top up my diploma to a degree.
Appreciate it if you read through this.