http://www.aafp.org/fpm/2004/1000/p21.html
"According to CPT, separate, significant physician evaluation and management (E/M) work that goes above and beyond the physician work normally associated with a preventive medicine service or a minor surgical procedure is additionally billable. The code that tells the insurer you should be paid for both services is modifier -25. The key is recognizing when your extra work is “significant” and, therefore, additionally billable. CPT does not define “significant,” but asking yourself the following questions should lead you to the answer:
Did you perform and document the key components of a problem-oriented E/M service for the complaint or problem?
Could the complaint or problem stand alone as a billable service?
Is there a different diagnosis for this portion of the visit?
If the diagnosis will be the same, did you perform extra physician work that went above and beyond the typical pre- or postoperative work associated with the procedure code?
If your answers to these questions are yes, then you should report the appropriate E/M code with modifier -25 attached as well as the preventive medicine service code or minor surgical procedure code. You can increase the likelihood that the insurer will pay for both services by organizing your note so that documentation for the problem-oriented E/M service is separate from documentation for the preventive service or procedure. You may even want to use headers or a phrase such as “A significant, separate E/M service was performed to evaluate … .”
The question you have to ask is: "When the RAC auditor comes knocking on my door, will my documentation support the additional billing?"
http://www.novitas-solutions.com/webcenter/content/conn/UCM_Repository/uuid/dDocName:00004955
The above website has an audit sheet for Eye exams, and this should help you.