In 2014, iCare COMPASS revolutionized visual field testing by combining an active retinal tracker and a scanning ophthalmoscope into a single device. Enter the story of early recognition of glaucoma and discover what’s possible in optometry, ophthalmology, and neurology.
Due to glaucoma, a patient’s vision gradually deteriorates. Furthermore, the disease is often diagnosed too late because early symptoms can be subtle or absent. The lack of early detection makes glaucoma the second leading cause of blindness worldwide. A significant step in controlling the disease was taken when the automated perimeter with active retinal tracking, iCare COMPASS, was launched¹.
Focus on the users and automation in visual field testing
The core of glaucoma diagnosis is the assessment of optic nerve changes. In a visual field test, an initial baseline map is created, and the test is repeated regularly, allowing early detection of vision changes. The patient looks at a green fixation target throughout the test and presses a button each time when seeing a flash of white light (stimulus) somewhere in the visual field. The brightness and location of the stimulus can vary during the test. The device then maps the visual field and determines the dimmest light visible at each point, known as the threshold. Then, new tests are compared to the previous results, revealing glaucoma’s progress.
When iCare COMPASS was launched, visual field testing was already used to diagnose and monitor glaucoma and other eye diseases. However, the testing procedures were complex and often took over half an hour and demanded sustained patient concentration.
“If the patient’s eyes moved or blinked, the results were unreliable, or the test got longer or both. Thus, the procedure wasn’t optimal in clinical use. We focused on the users and automation to make it as smooth and quick as possible without sacrificing reliability,” says Jouni Onnela, Global Product Manager at iCare.
New points of view on glaucoma brought into light
The iCare COMPASS enhanced visual field testing in many terms: it uses automated retinal eye-tracking, integrates retinal imaging for a fuller view of glaucoma progression, simplifies procedures to reduce patient fatigue, and enables reliable follow-up to detect subtle changes over time.
“Using iCare COMPASS, the automated retinal tracking automatically adjusts the testing grid to align with eye movements, ensuring consistent measurements and reducing errors. It also allows free blinking by automatically retesting if the stimulus was presented during the blink. The patients can even take breaks, as iCare COMPASS automatically pauses until they are ready to continue, requiring no operator intervention and ensuring no data is lost,” Onnela explains.
Furthermore, the dimmest light the patient’s eye can detect is recorded as a decibel value at each point on the map, which is overlayed on the high-resolution fundus image, combining functional vision data with the corresponding anatomical location on the retina—a unique functionality to this day.
Thirdly, iCare COMPASS captures exceptionally high-quality, true-color images using white light, maintaining a well-balanced color spectrum. iCare COMPASS provides authentic color images of the retina in a single exposure, unlike devices that use multiple-colored lasers, which require separate exposures and produce post-colored monochromatic images. In contrast, traditional fundus cameras use a flash lamp with broad-spectrum illumination without confocal optics, resulting in the reflected signal from all tissue levels, blurring, and poor contrast in images by light scattering.
“In a year after the launch, iCare COMPASS halved the visual field-testing time while maintaining accuracy and ensuring reliable results². From the beginning, the device has helped clinicians dependably differentiate between healthy and defective regions of the retina, regardless of the stage of eye disease,” Onnela notes.
Continuous development for better perception
In 2017, iCare COMPASS was further developed to produce stereoscopic images, capturing two images of the same retinal point from slightly different angles to create a stereo pair. When viewed through the provided 3D glasses, the users can perceive the images as three-dimensional, aiding in anatomical analysis and simplifying interpretation.
In 2023, more innovations followed: iCare launched its ZEST Fast strategy, further reducing the testing time from six to just three to four minutes—30-40% faster without compromising accuracy³.
“With the ZEST Fast strategy, we accomplished to save even more time for both clinicians and patients, reduce fatigue’s impact on test quality, and enhance patient comfort, which is especially important for older individuals or those with existing vision issues,” Onnela adds.
Concurrently, iCare COMPASS was enhanced with the Smart Progression Analysis (SPA) and the SmartMosaic feature. It enables the acquisition of high-definition TrueColor images from the posterior pole to the periphery and creates a seamless 100° montage.
“Drawing from baseline and follow-up points from at least five prior examinations in three or more years, the SPA creates a comprehensive one-page report to review information such as two baseline and the last follow-up results with optic nerve head color images, grayscale visual field map with the difference between the last follow-up and the average of the baseline exams, progression event analysis with event assessment, global trend analysis with prediction, cluster MDs trend, pointwise trend analysis,” Onnela states.
A bright future for visual field testing: More diagnosis, new business opportunities
Globally, around 80 million people live with glaucoma, including over 3 million in the U.S. Yet more than 50% remain undiagnosed, even in high-income countries. The numbers emphasize the need for regular eye screenings and accessible diagnostic tools that enable early detection outside traditional ophthalmology.
iCare COMPASS allows optometrists and small eye clinics to conduct visual field tests and follow-ups effectively and independently.
“iCare COMPASS is a smart investment for starting a new business, starting glaucoma management or improving the clinic’s workflow. Using a single device for comprehensive assessments of retinal health and glaucoma progression saves space and money. iCare COMPASS is cost-effective considering its multiple features”, Onnela says.
At hospitals, iCare COMPASS can serve as a backup device for aging hardware and concurrently apply to glaucoma research and treatment settings. In addition, the device has potential in neurology for its simultaneous structure and function assessment, as specific changes in the visual field and optic nerve head may indicate brain-related issues. iCare COMPASS can serve as a guiding tool for further investigational strategies and to refer relevant patients more accurately for neuroophthalmological expertise4.
Most importantly, iCare COMPASS keeps evolving for the patients. In addition to the improvement in diagnosis of glaucoma during the past decade, even individuals with severe vision impairment can now be taught to locate and use the healthy areas of their retina. By guiding them to look in a specific way, they can enhance their ability to focus on critical areas of the retina, allowing them to read letters from a page.
“Although we still can’t stop glaucoma from progressing, using the new technologies, the future looks bright,” Onnela encourages.
References:
¹ https://www.icare-world.com/product/icare-compass/
² Montesano G et al., A comparison between the Compass fundus perimeter and the Humphrey Field Analyzer. Ophthalmology. 2019 Feb;126(2):242-251. PMID: 30114416.
³ Romano D et al., Comparison Between 24-2 ZEST and 24-2 ZEST FAST Strategies in Glaucoma and Ocular Hypertension Using a Fundus Perimeter. J Glaucoma. 2024 Mar 1;33(3):162-167. PMID: 38245812.
4 Rissan Z et al., Fundus imaging and perimetry in patients with idiopathic intracranial hypertension—an intermethod and interrater validity study. Eur J Neurol. 2023;00:1–10. PMID: 38245812.
