Optometry Coding & Billing Alert

Question: Is there a code for "diurnal curve testing," during which the optometrist 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 the optometrist perform three tests over six or more hours before it can be considered serial tonometry.

Don't report 92100 just because the optometrist 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 ophthalmologistrepeats the tonometry.

Don't miss: The optometrist may not perform all of the serial tonometry tests in the same day, but even if he spreads the test out over several days, you can still report 92100 only once. Medicare considers the procedure bilateral, so only code it once whether the physician tests one or both eyes.