Question: A patient taking Plaquenil for her arthritis needs to have her eyes monitored to make sure the drug is not harming the lens or retina. The patient, who is otherwise healthy, underwent visual field tests. What codes should I use to report the ophthalmologist's work? New York Subscriber Answer: Your key here is the diagnosis code you'll use. You should use a V code that shows the patient is on a drug long-term, such as V58.69 (Long-term [current] use of other medications). Without the V code, the tests appear medically unnecessary to your carrier if the ophthalmologist doesn't find any ocular changes. Don't overlook: Be sure to code the patient's systemic condition, such as rheumatoid arthritis (714.x, Rheumatoid arthritis and other inflammatory polyarthropathies), as the secondary diagnosis. Alternative: If the ophthalmologist does find ocular changes, list that diagnosis (such as 371.2x, Corneal edema) as the primary ICD-9 code for Medicare. For these claims, you'll use V58.69 as the secondary diagnosis and the underlying condition as a third diagnosis. For non-Medicare carriers, list V58.69 as the primary diagnosis, the ocular change (for example, 371.2x) as secondary, and the underlying condition (such as 714.0) as a third diagnosis. For the office visit, report the appropriate E/M code based on whether the patient is new to your practice or already established.