Study: Home monitoring device identifies new CNV faster with less vision loss

November 1, 2014

Earlier detection of new choroidal neovascularization using a home monitoring device may identify progression faster than when relying on standard care alone, suggests a recent study.

 

By Lynda Charters; Reviewed by David S. Boyer, MD

Los Angeles-The HOme Monitoring of the Eye (HOME) study-part of the Age-Related Eye Disease 2 (AREDS 2) study-indicated that earlier detection of new choroidal neovascularization (CNV) using the preferential hyperacuity perimetry device (ForeseeHome, Notal Vision Ltd.) may identify AMD progression faster than when relying on standard care alone, which includes prescheduled appointments and use of the Amsler grid.

The monitoring device can identify metamorphopsia in patients with wet AMD before they notice any visual changes, making early treatment and better visual outcomes possible.

The 1,520 patients in the HOME Study were randomly assigned almost 1:1 to either standard care or use of the device and standard care. The mean patient follow-up was 1.4 years. The primary outcome of the HOME Study was the median change in the visual acuity compared with baseline. Among the patients with a CNV event, the standard care group had a median loss of nine letters of vision compared with a median loss of four letters in the device and standard care group. That difference reached significance (p = 0.021).

David S. Boyer, MD-who reported the results of the HOME Study on behalf of the National Eye Institute (NEI) AREDS 2 Study Group-pointed out that the results beg the question about the effectiveness of standard monitoring.

In the study under discussion to determine which monitoring protocol identified patients with new CNV more rapidly, patients in both arms underwent prescheduled visits. The standard care group underwent these examinations until visual symptoms developed. Patients in the device and standard care group used the device until it alerted them to the presence of new CNV.

In the standard care group, 17 new cases of CNV were identified, for a detection rate of 26% and an 11.5-letter vision loss.

In contrast, in the device and standard care group, 37 cases of new CNV were identified, for a detection rate of 12% and a three-letter vision loss, Dr. Boyer noted.

 

“In the standard care group, routine visits provided a poorer detection rate compared to use of the device plus symptoms in between routine visits,” said Dr. Boyer, clinical professor of ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles. “Therefore, patients may be able to eliminate some of the routine visits.”

However, decreasing the number of routine visits in standard care does not seem to be a viable option, because without the device and trusting only symptoms can lead to a significant visual acuity loss (–11.5 letters), he explained.

“Based on these results, in the device and standard care group, the investigators found a 16-fold increase in CNV detection versus pre-scheduled visits,” Dr. Boyer said. “In the device group, patients had a mean visual loss of three letters compared with an 11.5-letter loss in the standard care group, which was a significant difference.”

While Dr. Boyer noted that the standard of care for patients with AMD is effective, the investigators found that patients with CNV sustained high visual acuity losses when they first presented. In contrast, when the standard of care and use of the Amsler grid was combined with use of the device, the amount of vision that was lost was reduced significantly, Dr. Boyer noted.

Currently, he believes that ophthalmologists may not be doing an adequate job by using just the standard of care or based on ever 6-month evaluations.

The study investigators concluded that pre-scheduled office visits use medical/social resources and seldom identify new CNV (<1% of visits). Symptom realization is an important potential indicator of new CNV.

However, symptomatic patients generally present with substantial vision loss of –11.5 letters. The home monitoring strategy substantially increased the detection rate of new CNV by 16-fold, especially in the setting of minimal vision loss (–3.0 letters).

 

The investigators also found that the results allow consideration of increasing the interval between routine office visits for patients using the home device, which can potentially reduce the burden of management of AMD for the patients, families, and physicians.

“Adding the device makes a big difference because these patients can be identified earlier, treated earlier, and hopefully, obtain better visual results,” Dr. Boyer said.

 

David S. Boyer, MD

E: vitdoc@aol.com

This article was adapted from Dr. Boyer’s presentation during the 2014 meeting of the American Society of Retina Specialists. Dr. Boyer is an investigator in the National Eye Institute (NEI) AREDS2 Study and a consultant to Notal Vision Ltd., which sponsored the study in collaboration with the NEI.