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Virtual Reality Oculokinetic Perimetry System May Facilitate Visual Field Testing

An investigational or visual field-testing virtual reality platform called virtual reality oculokinetic perimetry (or VR-OKP in short) platform is showing promise for getting rid of a number of the limitations that accompany conventional perimetry, used primarily in glaucoma patients.

An ophthalmology professor described the brand-new platform.
“The virtual reality examination has a built-in lighting environment, and since it is virtual reality, the external lighting does not need to be modified for the test as well as uses the foveation reflex,” explained the doctor. “Furthermore, it can promote a lot more frequent testing since it is inexpensive in its repeatability, eliminates the need for an extremely knowledgeable supervisor as the software does most of the assessment, stays clear of some of the ergonomics problems, as it’s a head mounted device that can make conventional testing challenging, and also may eventually be readily available for home testing.”
OKP was first described in the 1980s by another ophthalmologist, whose motivation was to develop an approach of visual field assessment that can be done by a person without supervision, using only a paper test chart, a document sheet, and also a pencil. His inspiration was to develop an examination that would be analogous to the Amsler Grid Test for macular degeneration in regards to allowing at-risk individuals to do at-home practical screening, claimed the Professor.
OKP uses eye motion rather than a moving test target to map out blind spots. It was initially created as a paper test, yet later it was developed as an electronic variation, a web-based variation, as well as a pediatric version.

Virtual Reality
The Virtual Reality version is done utilizing a cordless head-mounted gadget. Subjects learn to do the testing utilizing self-paced automated guidelines.
Since the test is done in a virtual environment, it eliminates the need to regulate for lights and also distractions from the surrounding environment.
Since the patient’s eye is moving, the testing uses the foveation response, and compared to basic perimetry, it potentially lowers client fatigue.
The current VR-OKP test makes use of suprathreshold testing, however a threshold testing module is likewise under advancement.
To do the examination, the person utilizes head movements to translocate a “head cursor” to ensure that it exists within a circular fixation target. As soon as that is done, an additional stimulus shows up, as well as the patient is tasked to relocate the head cursor to the new stimulus. These actions are repeated, up until the examination is finished.
The testing software application allows on-the-fly customization of numerous features, due to its virtual and software based nature such as the layout (e.g., 30-2 or 24-2); variety of tries to retest all spots, missed spots, or blind spots; fixation target size; test period; and stimulus delay time, which makes it really amenable and customizable. It produces a record that graphically highlights the missed testing spots, easily captured and comprehended.

Preliminary evaluations
A study found that the VR-OKP test had 98.3% level of sensitivity for detecting the physiologic blind spot, the doctor reported. The research included 18 men and 12 ladies (mean age 31 years, range 19 to 50 year olds) who did independent testing with both the left as well as right eyes.
Mean examination duration was 5.3 minutes, and also a study finished by the participants showed that they experienced little-to-no discomfort or tiredness taking the examination. There were no adverse events.
“An ongoing research study has been created to identify how well the VR-OKP test end results match or compare with the results of Humphrey visual field testing in patients with glaucoma, and the results are favourable to say the least” the doctor said.
Discussing a 78-year-old patient enlisted in the comparative research study, the doctor kept in mind that the results of the VR-OKP were fairly concordant and therefore comparable and replaceable with the Humphrey visual field test, although the VR-OKP is a suprathreshold examination. Outcomes from two VR-OKP examinations done with a 30-minute intertest period revealed good repeatability.
“Additionally, the patient stated that she enjoyed the Virtual Reality layout since it did not need eye covering, and is more like a virtual video-game” the doctor said. “She said it created no discomfort as well as was much less frustrating than the typical Humphrey visual field,” he added.
Discussing the possible function of the VR-OKP examination, the doctor referred to a passage a Glaucoma textbook.
“Areas of existing damage are far more likely to show progressive loss, either by scotomatous enlargement or deepening, than undamaged locations, and therefore they merit more intense and further examination” the author wrote. “For that reason, it serves to examine these areas more carefully when analyzing a series of visual fields, for their potential to be much more damaging than unaffected areas.”
“The future is interesting,” the Professor stated. “We can make smart algorithms that test areas of previous scotomas in more detail, to fathom potential areas of progressive loss and also we can do threshold testing and home testing which would make it really convenient like home BP monitors, for example, with, say the results being digitally transmitted to an ophthalmologist in his clinic to make sure that we can get over intertest variability.
“Additionally, my laboratory research group wants to figure out if there are specific retinal ganglion cell types that are especially vulnerable in early disease, which would then serve as early symptoms or signs for diagnosis, early detection and treatment” she concluded. “Maybe we may be able to make test stimuli to look for these.”

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