Office Presentation Service
You can use PowerPoint's Office Presentation Service to share your slide shows in real time online.
Go to the Slide Show tab and select Present Online . . . Office Presentation Service.
. . . you will be prompted with this message and can share your PowerPoint if you have a Hotmail account:
A web link will be created that you can share with others
Other people can even view your presentation in real time on their smart phone. My test PowerPoint worked fine when I put the link in the Chrome App on my iPhone 6. There was about a 5 second delay between slides advancing on my laptop and appearing on the phone.
You leave the current slide up for your audience, perform edits and then resume.