With my 15 year old Scrumpy, the first change was with her hearing. Next, it was her sight. One would think that this would make it very difficult for her to manage but it isn't. She has been able to adapt extremely well even when she's in unfamiliar surroundings.
Another thing I noticed was a lack of stability in her front legs. I suspect that this stems from an old injury in her shoulder joint. To prevent her front legs from giving out, I carefully trim the hair on the bottom of her paws (with rounded scissors). I also started putting socks with rubberized bottoms on her front paws. This helps give her the stability and traction needed to walk on hard wood floors.
Our walks are now shorter but more frequent. It's important for her exercise to maintain her capabilities. This is when I become her seeing eye person! I always carry her up and down the stairs in the house but outside, she is able to manage climbing up steps. I take my queues from her which means that sometimes, it's more of a carry than walk.
One of the things that Scrumpy didn't need any assistance with was finding her food. With her diminished eyesight, her sense of smell has become acute. She is an expert at ferreting out not only her food bowl but any treats that might be tucked away in pockets.
Living with a geriatric dog means a few adjustments here and there to our normal routine but they are all well worth the effort!