Technology extends beyond community outreach efforst directly to patients at home
This article was reviewed by Ying Han, MD, PhD
New technology for taking the evaluation, diagnosis, and management of glaucoma out of the clinic and directly to the patient is influenc-ing not only community outreach efforts but the feasibility of using teleglaucoma tools in the home.
Tools for home use have been developed for IOP measurement and visual field testing, according to Ying Han, MD, PhD, associate professor of oph-thalmology, co-director of the glaucoma service, and director of the glaucoma fellowship program at the University of California San Francisco.
Devices for IOP monitoring include the Icare HOME tonometer and the Triggerfish Contact Lens Sensor. The Icare tonometer provides information on IOP, time and date of measurement, which eye is being tested, and the quality level of the measurement.
In a 2017 study, Takagi et al. concluded that the device was feasible for use in self-monitoring of IOP but that the measurements tended to overes-timate IOP relative to the Goldmann applanation tonometer (GAT). The mean IOP of the 128 participants was 12.2 mm Hg as measured by a glaucoma specialist performing GAT, 12.8 mm when patients used the HOME
The Triggerfish contact lens sensor (Sensimed AG) is a soft disposable silicone contact lens with an embedded microsensor. It automatically re-cords continuous dimensional changes and IOP. De Moraes et al. conducted a study (JAMA Oph-thalmology 2018) in 445 patients and found that the contact lens sensor recordings may have a better association with visual field progression than Goldman mean IOP measured multiple times during office hours.
The authors concluded that the CLS may be useful in assessing the risk of func-tional loss, even when insufficient visual field information is available.Several methods of performing visual field tests at home are avail-able. The most applicable to home use at this time are the Visual Fields easy and the Melbourne Rapid Fields (MRF), which are iPad apps, and Peristat, an online perimetry test. Visual Fields easy is used for performing supra threshold paramet-ric screening and can be downloaded free from iTunes.
The 3.5-minute test covers 30° of the vIsual field.
According to Dr. Han, it showed good correla-tion with the Humphrey Visual Field testing ,and about 80% repeatability in a 2017 study in the American Journal of Ophthalmology by Johnson et al, who evaluated the app’s performance in Nepal. The MRF glaucoma app can be used to assess the central and peripheral visual field, using a seven-step process that tests 34 x 25 degrees of field and requires four to six minutes per eye.False positives, false negatives, and fixation loss can be monitored, and the app will send a notification to a desig-nated clinician if a significant change has been detected.
A 2016 study in Translational Vision Science and Technology demonstrated good test-retest reliability. Another option for patients is Peristat, a free web-based perimetry teat that can be performed on any computer with a 17-inch or larger screen and an Internet connection via keepyoursight.org.
This test maps 24 degrees of visual function and ensures reliability through measurement of fixation losses, false positives, and false negatives.
In a study comparing Peristat online perimetry with the Humphrey perimetry in a clinical setting, Peristat exhibited a reasonable ROC curve as well as significant correlation with the conventional HVF, said Dr. Han, who was the corresponding author of the 2016 study in Translational Vision Science and Technology.
In the analysis of Peristat’s ability to distinguish patients with moderate and severe glaucoma from those with normal vision, the area under the curve was 0.87-0.88, sensitivity was 80%, and specificity was 90%.
While the availability of teleglaucoma tools indicates a growing interest in allow-ing patients to be more involved in managing their care, Dr. Han pointed out several barriers that need to be resolved. First, it’s more challenging for physicians to manage large-scale data points from testing conducted in homes than in an of-fice setting.
“Doctors may have low confidence in their ability to make decisions based on images alone,” Dr. Han said. Then there are the nonclinical issues that need to be addressed, such as reimbursement and state licensure requirements that currently may limit a physician’s ability to provide care via teleglaucoma. Teleglaucoma, and particularly home-based screening, are still in the early stages, and time will determine which approaches and tools are most effective and convenient, Dr. Han concluded.