Pear tree leaves -help!

[Want to Grow]

Hello, me again! I have the most beautiful pear tree that has fruited only one pear this season. The tips of the leaves are like this (see photo) - any idea what this is and what I need to do? When do I prune pear trees? Sorry so many questions, just have no idea!
Thank you!!

[DavidT]

That looks like leaf curl virus, unless there are signs of aphids or caterpillars.