Konan Medical USA recently announced the U.S. commercial launch of the objectiveFIELD Analyzer (OFA)—the latest addition to the ophthalmic diagnostic device portfolio.
Let’s start with Konan Medical.
Launched in 2008, the Irvine, California-based manufacturer and distributor specializes in providing services and products such as:
- Diagnostic devices
- Clinical trial rentals
- Eye banking
- Fully-automated specular microscopes
- Objective visual functional diagnostics
Its focus: Manufacturing and distributing ophthalmic diagnostic devices that may aid clinicians in diagnosing and managing disorders that pose risks to both vision and overall well-being.
Now to this new product.
This objective visual field (VF) analyzer is marketed as the “first and only truly objective perimeter FDA 510(k)-cleared to assess (VF) abnormalities” via the use of pupillary responses.
How it does this: By utilizing a method known as “multifocal pupillographic objective perimetry (mfPOP)” which is analogous to multifocal electroretinography(mfERG) and visual evoked potential (mfVEP) tests (see some background on those tests).
- The difference from those tests: The OFA requires no electrodes.
Note: Although it’s FDA 510(k)-cleared, the OFA is not cleared for the specific diagnosis of any condition (but neither is any other perimeter).
- See its product specifications.
Talk about the exam.
Per the company, both the 30° and 15° exams are conducted bilaterally over the course of either 90 seconds or 7 minutes for both eyes (depending on which test protocol is selected).
As for the actual eye testing, each is evaluated individually at the same time (i.e., a dichoptic presentation).
Plus, there is no:
- Patient response required
- Why: There’s no button to push
- Eye patching
- Variability evident between the OD and OS exams
Are disposables used?
Nope! As with other diagnostic devices, OFA’s forehead rest just needs to be sanitized in between patients via alcohol wipes.
And how does this compare to traditional SAP?
First and foremost: OFA is 100% objective.
Whereas traditional subjective standard automated perimetry (SAP) relies on a patient’s manual responses to visual stimuli, that’s not the case for the OFA.
Instead, Konan Medical noted, OFA uses advanced infrared video cameras to measure pupil responses to spatially resolved stimuli.
- As a bonus: OFA stimuli are also designed to be less susceptible to refractive errors.
What does that measuring involve?
Two key analyses of the following:
- Amplitude (ie: sensitivity)
- Time-to-peak constriction (ie: delay)
Let’s get into VF testing protocols.
Included are test protocols for 30 & 24 (together), 15° and 10° per-eye.
Per the company: “The OFA 30 test protocol delineates a 24° field at the same time, in the same report, as no extra time is required to test a 30° (VF) vs 24°.”
So what does it measure?
The visual field per each eye is optically separated—giving a patient a fused “cyclopean view”—after which novel stimuli are then presented (individually, keep in mind), with non-overlapping timing of every ¼ second.
As for pupillary responses: These are recorded via those aforementioned infrared cameras and evaluated via pupil tracking.
- In terms of sensitivity: This is measured objectively from the amplitude of the pupillary response and converted to the decibel scale.
- For latency (aka time-to-peak constriction): These are measured in milliseconds.
What’s the result?
Four VFs per eye, according to Konan Medical.
These include:
- OD/OS sensitivity, direct
- OD/OS sensitivity, consensual
- OD/OS latency, direct
- OD/OS latency, consensual
And how is this reported?
The data is then aggregated into two reports (sensitivity and latency) for both eyes.
Two viewing options are available for clinicians, with each incorporating grey-scale / numeric maps plus tables with standard VF index:
- A “legacy” report format
- A more detailed “OFA” format
Nice! So, how can I add this to my practice?
Contact the company to request more information—including its cost.
To note: OFA is now available in the U.S., Canada, Japan, and select international markets (with CE mark certification currently pending in the European Union).
Editor's note: This article was updated on Nov. 18, 2024.