People EITHER read or listen to online presentations. If they’re reading your slide which is chock full of text then they’re NOT LISTENING to you.
If you’re intent in putting up a slide with tons of text, just email participants your presentation and don’t bother talking through it. There’s no reason.
If you want participants to listen to what you’re saying, DO NOT WRITE IT OUT on your slide. Put up a single image, then talk.
To learn more READ THESE: Top Ten Slide Tips