Can I hide index node if no document is linked

Hi

I want to hide an index node if there is no linked documents (due to document ACLs), this is to not disclose metadata information to uses that have no access to documents having such information.

for example I have metadata for source and destination of correspondences and the dates of when these correspondences took place, so I’ve made an index for the destinations then dates, this will expose to whom and when we’ve made correspondence (not only his allowed correspondences).

Thanks