DIAGNOSTIC SPOTLIGHT: Frequency Doubling Technology (FDT)

Detecting glaucoma early is a top priority, and it shouldn’t come at the expense of efficiency or patient experience. Frequency Doubling Technology (FDT) perimetry offers a fast, reliable way to catch visual field defects sooner — with more sensitivity and specificity than a suprathreshold and in less time than a 24-2.

FDT perimetry uses low spatial frequency gratings flickering at high temporal frequencies to create a frequency-doubling illusion, specifically targeting the magnocellular (M-cell) pathway — one of the first affected in glaucoma. Because it’s fast, easy to administer, and patient-friendly, FDT testing is an excellent addition to your diagnostic toolbox.

How Does FDT Compare to Other Visual Field Tests?

Understanding the advantages of FDT perimetry can help you choose the best approach for different clinical scenarios. Here’s how it compares to other methods:

• Humphrey Visual Field (HVF) Testing: Long considered the gold standard for in-depth glaucoma and neuro-ophthalmic visual field testing, but often slow and tiring for patients. Studies show patient fatigue can lead to less reliable tests.
• Goldmann Perimetry: Excellent for cases with poor fixation, but highly dependent on the examiner’s skill and time intensive.
• Virtual Reality FDT: Combines FDT’s speed with high precision in an easy-to-use, portable format. This advanced technology offers a quicker and more comfortable experience for patients while maintaining accuracy, making it the ideal choice for efficient and reliable visual field testing.

For busy ODs who need a quick, reliable way to screen for glaucoma and other optic nerve pathologies, FDT perimetry offers a smarter, more efficient approach without disrupting patient flow.

How to Make FDT Perimetry Work for Your Practice

You don’t need to overhaul your current workflow to incorporate FDT perimetry — it can fit seamlessly into daily clinical operations. Most optometrists often find that it enhances efficiency while maintaining diagnostic accuracy.

Best practices for integration:

• Train your staff to administer the test correctly — FDT is simple, so your technicians can easily manage it while you focus on patient care.
• Use it as a frontline screening tool for glaucoma suspects, diabetic patients, and those with unexplained visual disturbances.
• Educate your patients on why functional testing matters — explain that FDT can detect vision loss before they even notice symptoms, reinforcing the importance of regular exams.

Making Sense of Billing & Coding for FDT Perimetry

While clinical efficacy is crucial, understanding how to bill FDT perimetry correctly ensures that your practice benefits financially while improving patient care.

The CPT codes you’ll want to keep in mind include:

• 92081 for a limited visual field exam – Great for quick screenings in high-risk patients.
• 92083 for an extended threshold visual field exam – Best for tracking glaucoma progression and neuro-ophthalmic cases.

But when will insurance actually reimburse for FDT perimetry? Generally, you’re in the clear when testing glaucoma suspects, diabetic patients, or those with neuro-ophthalmic conditions. The key to maximizing reimbursement is proper documentation—linking the test to risk factors like high IOP, suspicious optic nerve changes, or systemic conditions that can affect vision. While it’s an excellent screening tool, FDT includes quantitative data and tests over 3 isopters teste within the central 30 degrees.

Additionally, be aware of payer-specific guidelines. Some insurers require additional justification for certain conditions, so make sure to stay up to date on Medicare and private insurance policies to avoid denials. Proper coding doesn’t just prevent claim rejections — it helps you get paid for the valuable diagnostic services you provide.

Is FDT Perimetry Available on the VF2000?

VF2000 G2 – YES

VF2000 NEO – YES

If you’re looking for a portable, high-tech, and efficient way to integrate FDT perimetry into your practice, the VF2000 NEO or VF2000 G2 model can be your solution. This cutting-edge VR-based perimeter has an optional module for FDT-based rapid screening tests along with full-threshold perimetry, making it an all-in-one tool for modern optometrists.

Why Choose the VF2000 for FDT Testing?

• Unmatched Speed & Efficiency: Complete FDT tests in about a minute per eye—perfect for busy practices.
• Portable & Wireless: No need for a dedicated dark room. Use it anywhere, even in satellite clinics or for mobile optometry.
• Better Patient Experience: No bulky machines—just a comfortable, intuitive VR headset that patients prefer.
• Seamless Integration: No steep learning curve—just improved workflow and better patient outcomes.

The VF2000 isn’t just an upgrade — it’s a game changer. Experience this cost-effective, space-saving solution that modernizes visual field testing firsthand. Schedule a demo today or contact us to learn more!