Question: Which diagnosis code should I use to report visual field tests to evaluate the effects of Plaquenil on a patient?
Answer: Plaquenil is the trade name for hydroxy-chloroquine, a medication used to treat rheumatoid arthritis and lupus. It can harm the lens and retina of the eye. Primary-care physicians often refer a patient to an optometrist for monitoring ocular changes.
The diagnosis coding depends on whether the patient is now taking Plaquenil. For your primary diagnosis, if the patient has completed his course of treatment of the drug, use V67.51 (Follow-up examination; following completed treatment with high-risk medications, not elsewhere classified). If the patient is still being treated with the drug, use V58.69 (Long-term [current] use of other medications).
For your secondary diagnosis, code the reason the patient is on Plaquenil, the underlying condition, most typically lupus (710.0) or rheumatoid arthritis (714.0).