When it comes to static perimetry, the Humphrey Field Analyzer has long held its position as the gold standard. However, in recent years, various manufacturers have launched new devices aiming to capture a share of Humphrey’s dominant market.
Despite its established reputation, the Humphrey system has faced ongoing challenges—especially in balancing test efficiency with reliability. In response to these issues, the visual function evaluation device imo vifa, developed by CREWT, has been gaining attention for offering impressive advancements in both efficiency and reliability.
In this article, we introduce the features and capabilities of the imo vifa.
Note: The “imo comfo” model, sold by Tomey Corporation, offers the same functionality as the “imo vifa,” which is distributed by Topcon Corporation.
Basic Information of imo vifa
| Item | Details |
|---|---|
| Model | imo vifa |
| Macular threshold tests | 30-2 / 24-2 / 10-2 / 24-2plus(1-2) / 24-2plus(1) |
| Threshold algorithms | AIZE EX / AIZE / AIZE Rapid EX / AIZE Rapid |
| Optional features | Contrast sensitivity test (optional) |
The 24-2plus(1-2) program offers similar functionality to Humphrey’s 24-2C, allowing for more detailed assessment of the macular region.
→ See also: [Comparing 24-2C and 24-2plus(1-2): How do they detect central visual field defects?]
The ‘AIZE’ Series – imo’s Unique Threshold Programs
- AIZE
An efficient threshold strategy that reflects adjacent point responses to enhance measurement accuracy. - AIZE Rapid
Equivalent to Humphrey’s SITA Fast. Reduces the number of stimuli for shorter test duration. - AIZE EX / AIZE Rapid EX
Comparable to SITA Faster on the Humphrey. Utilizes past test data to further reduce testing time.
Result Display (Compared with Humphrey)
Common display metrics (shared with Humphrey):
- Fixation monitoring
- False positive rate
- False negative rate
- Measured threshold & grayscale
- Total deviation (TD)
- Pattern deviation (PD)
- Glaucoma Hemifield Test (GHT)
- Mean deviation (MD)
- Pattern standard deviation (PSD)
- Visual field index (VFI)
- Gaze tracking
imo vifa’s unique display metrics:
- Defect Curve
Graph comparing overall sensitivity distribution to normative data. - GSS (Glaucoma Staging System)
Stages visual field defects from 0 to 5. - MS (Mean Sensitivity)
Average visual sensitivity across the field (unit: dB).
Differences in Testing Method
- Patients do not assume a forward-leaning posture (non-head-mounted system)
- Built-in eye-tracking for up to ±5° gaze deviation
- Monocular testing under binocular viewing conditions
(*Note: This is not simultaneous binocular field testing*)
Summary
While the Humphrey system still holds its position as the “gold standard” in perimetry, imo vifa is rapidly emerging as a serious contender. Through programs like AIZE and unique analytic parameters, it addresses the long-standing issues of test efficiency and reliability.
For facilities exploring new options for visual field testing or for clinicians seeking to reduce the burden on patients, imo vifa is a compelling candidate. We look forward to seeing continued advancements in this promising technology.
