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Home-monitoring device helps to detect CNV earlier
Early detection leads to better preservation of vision.
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Home monitoring with a preferential hyperacuity perimetry device may allow for early detection of choroidal neovascularization-related changes in patients with early age-related macular degeneration.
The earlier neovascular AMD is treated, the better final visual acuity outcomes will be. However, early treatment requires early detection in order to be efficient.
The ForeseeHome AMD monitoring program (Notal Vision) is the first FDA-cleared system for home-based monitoring of at-risk patients in order to improve upon current standards of early detection.
“Early detection means better preservation of vision, better outcomes of therapy,” Anat Loewenstein, MD, OSN Europe Edition Board Member, said in a presentation at the FLOREtina meeting in Florence, Italy.
Importance of early detection
Subgroup analysis of the CATT trial, the U.K. Neovascular Age-Related Macular Degeneration EMR Database multicenter study and other studies with up to 5 years of follow-up showed that small lesion size and better visual acuity at baseline predict a better visual acuity outcome.
Current standard of care in detecting choroidal neovascularization (CNV) consists of prescheduled physician visits or using the Amsler grid. Loewenstein considers these methods ineffective in early detection.
“When you look at the visual acuity of patients who enter studies in the last 10 years, you can see that there is only a small percentage of them that come with a good function of visual acuity. And this is just in the studies, let alone in real life,” she said. “So, most CNV patients, when they show up, do not start or end with a functional visual acuity outcome.”
ForeseeHome test
The ForeseeHome test, based on preferential hyperacuity perimetry, allows early home-based detection of visual field distortions generated by CNV lesions.
With the technology, dotted lines are presented to the patient, with some dots deviating from the lines, termed “artificial distortion,” Loewenstein said.
The artificial distortion simulates the distortion that the patient may perceive from retinal elevation above the CNV lesion. Through preferential selection, the patient will choose one distortion over the other according to size. The distortions are flashed very fast in random locations for 160 milliseconds to avoid the patient from moving his fixation.
When a stimulus is projected on a healthy portion of the retina, the examinee identifies the artificial distortion and is likely to mark a correct location. On the other hand, if the stimulus is projected on a damaged region of the retina, a pathological distortion may be perceived instead of the artificial distortion, especially if the pathological distortion is more prominent than the artificial distortion.
When the stimulus is projected on an unhealthy area of the retina, the patient may perceive two or more distortions on the line: one corresponding to the artificial wave and the other corresponding to the patient’s pathological distortion, Loewenstein said.
Patients with early-stage AMD are prescribed to perform the test at regular intervals, and responses are automatically transmitted to the Notal Vision Data Monitoring Center; a baseline reference score and map are generated within the first few weeks.
“By using it over the years, we could see that the technology has excellent sensitivity and specificity to differentiating between CNV and intermediate AMD lesion,” Loewenstein said.
AREDS2-HOME study
The AREDS2-HOME study compared the outcomes of the ForeseeHome test vs. current standards of care.
In the group using the home-monitoring device, 51 CNV lesions were detected earlier compared with 31 events of CNV in the standard-of-care arm.
Patients lost fewer letters and had a higher chance of having functional vision at the time of diagnosis and at the end of the study.
Loewenstein believes that the device is a simple, effective way of improving results in AMD.
“We are fighting over letters in optimizing treatment, while with earlier detection we can save lines,” she said. – by Michela Cimberle and Kristie L. Kahl
- For more information:
- Anat Loewenstein, MD, can be reached at Tel-Aviv Medical Center, Department of Ophthalmology, 6 Weitzmann St., Tel Aviv, Israel 64239; email: anatl@tlvmc.gov.il.
Disclosure: Loewenstein reports she is a consultant to Notal Vision.