You can use widget to limit what users can see:
If you are using SP Online, here is an instruction.
And if you are using SP On-Premises, check out this one.
And if you want to assign item level permissions on tickets, you can still do it with the help of SharePoint Workflows. You can start a workflow on ticket creation and use another our product called Workflow Actions Pack to assign item level permissions.
That’s not the best solution, though. Restricting permissions on list item level permissions can lead to performance degradation of SharePoint. It is always better to restrict permissions on a higher level. You can find more details in this article.