For a story that needs to mention this, just have them take drugs while in space designed to address it.  If increased pressure is the problem, then the same treatments used today for other causes of that condition ought to work.

##update:

Since the available drugs that would suggest themselves *have* been tried and don’t work, some new drug would need to be found in time for your story.

You can remark that it was developed soon after long-duration missions started, or go into a backstory on how it required long duration mice studies in space, to discover the underlying mechanism well enough to start targeting drugs.