Question: Is there a code for "diurnal curve testing," in which the ophthalmologist checks pressures over the course of several hours, for glaucoma?
Missouri Subscriber
Answer: Code 92100 (Serial tonometry [separate procedure] with multiple measurements of intraocular pressure over an extended time period with interpretation and report, same day [e.g., diurnal curve or medical treatment of acute elevation of intraocular pressure]) describes diurnal curve testing. Most Medicare carriers require that three tests be done over six or more hours before it can be considered serial tonometry.
Don't report 92100 just because the ophthalmologist performed tonometry once or twice during an eye exam. Medicare and CPT both consider tonometry incidental to an intermediate or comprehensive exam for a new or established patient (92002-92014) or E/M service. This is true even if the ophthalmologist repeats the tonometry during the exam.
The ophthalmologist may not perform all of the serial tonometry tests in the same day, but even if the tests are spread over several days, you can still only report 92100 once. Medicare considers the procedure bilateral, so only code it once whether one or both eyes are tested.