Employee should not be able to update key attributes of a goal after approved

Summary

Employee will add a goal with all key attributes and submit for approval.After got approved by manager, the key attributes should not be able to edit, but only comment field should be able to edit.

Content

The requirement is that once the manager approved the goal, the employee should not be able to edit the key attributes of a goal but only provide comments. Because once the manager approved a goal the employee only needs to work on it. Is there any solution to this?