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Application of Mobile and Wearable Technology in Data Collection for Ophthalmology
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Ashwin Venkatesh, Pradeep Ramulu
Metamorphopsia is a perceived distortion of visual space, commonly seen in disorders of macular function. The ForeseeHome device (Notal Vision, Tel Aviv, Israel) uses preferential hyperacuity perimetry to measure visual distortions in age-related macular degeneration and is designed for unsupervised use by patients in their homes. The test involves 500 retinal data points over 14° of the patient’s central visual field, collected in approximately 3 minutes, and allows quantitative monitoring of changes in macular function in metamorphopsia with greater sensitivity than the Amsler grid.14 Results are automatically transmitted to Notal Vision’s Monitoring Center, where they are logged with all previous tests from that patient. Patients who generate an alert on the ForeseeHome test trigger an immediate recall to their ophthalmologist’s office for additional diagnostic testing and examination. The utility of this device is highlighted by the AREDS2-HOME clinical trial, which concluded that the ForeseeHome device enabled earlier detection of choroidal neovascularization in high-risk patients with age-related macular degeneration.15
Write short notes on the classification of visual acuity
Published in Nathaniel Knox Cartwright, Petros Carvounis, Short Answer Questions for the MRCOphth Part 1, 2018
Nathaniel Knox Cartwright, Petros Carvounis
To measure visual acuity is to measure the spatial limits of visual discrimination and involves the determination of thresholds. There are several different ways of classifying visual acuity: minimum visible (‘is that object visible or not?’): – requires detection of a visible stimulus against a uniform background– can be achieved at visual angles of 1 second of arc or less– changes in object size below 1 minute of arc visual angle are perceived as variation in contrast and not sizeminimum resolvable (‘is that one object or two?’): – a measure of the ability to distinguish two stimuli as being separate– relies on detection of contrast differences between retinal ‘detecting units’– greatest at the fovea and least in the periphery– at threshold it corresponds to between 30 seconds and 1 minute of visual angleminimum discriminate (Vernier acuity or hyperacuity): – is the determination of the relative locations of two or more visible points– threshold of hyperacuity is 3–12 seconds of visual arc– possible despite a minimum cone separation at the fovea of 1 minute of arc due to cortical processingstereoacuity:– stereoacuity is the smallest binocular disparity that can be reliably detected– threshold for stereoacuity is 3–12 seconds of arc, similar to hyperacuity.
Clinical Update on Metamorphopsia: Epidemiology, Diagnosis and Imaging
Published in Current Eye Research, 2021
Daren Hanumunthadu, Benedicte Lescrauwaet, Myles Jaffe, Srinivas Sadda, Emily Wiecek, Jean Pierre Hubschman, Praveen J. Patel
Preferential hyperacuity perimetry can be used for monitoring metamorphopsia and has been used to demonstrate distortion in response to many conditions including neovascular AMD.59 Newer home versions (eg. ForseeHome, Notal Vision Ltd, Tel Aviv, Israel) have been shown to have good levels of sensitivity and could be used to help determine development of active forms of neovascular AMD in patients known to have non-neovascular phenotypes.60 During the test, the subject is presented with a dotted line, with some dots misaligned relative to the centre of the line. The subject’s task is to detect the misalignment of the dots. Successive lines are presented across the whole field of vision corresponding to the macula. The preferential hyperacuity perimetry stimulus used for ForeseeHome is available on https://www.foreseehome.com/hcp/how-it-works-technology/.
Perspectives on remote patient monitoring with self-operated OCT for management of neovascular age-related macular degeneration
Published in Expert Review of Ophthalmology, 2021
Anat Loewenstein, Tiarnan D. L. Keenan
All of these challenges can be resolved. The high cost of a portable OCT will decrease in the future, as many technologies did over time. As to the accessibility issue, some studies have already shown that, the portable home OCT device is accessible for the elderly population and most of them can perform self-imaging with good quality. The detection and quantification of important biomarkers performed by home OCT has proven to be accurate and help facilitate treatment course and implement a true individualized regimen. [34,35] User interface, self-alignment and data transmission must be easy to operate by visually impaired patients. On-device video tutorials and visual ques for self-guided operation have to meet special needs. Moreover, capturing meaningful fluid volume trajectories requires good patient compliance with up to daily self-imaging. Physician led monitoring centers that provide not only home use devices and data analytics but also patient compliance monitoring and engagement services play an important role in remote digital technology enabled health-care models. Compliance data from the remote monitoring center supported ForeseeHome AMD Monitoring Program (Notal Vision Inc., Manassas, Virginia) has shown elderly patients testing 5.6-times per week with a preferential hyperacuity perimetry device at home in a real-world cohort of 8,991 prescribed individuals validating the provider model[36].
Advances in Telemedicine in Ophthalmology
Published in Seminars in Ophthalmology, 2020
Deep Parikh, Grayson Armstrong, Victor Liou, Deeba Husain
ForeseeHome device (Notal Vision Ltd, Tel Aviv, Israel) was granted 510(k) approval by the FDA in 2010 to monitor patients for detection of AMD-associated choroidal neovascularization (CNV). This at-home device, which received Medicare coverage in 2015 and is now commercially available, relies on preferential hyperacuity perimetry to help detect metamorphopsia in the central 14 degrees of the visual field. Results of the testing are sent to the Notal Vision Diagnostic Center where the results are then analyzed. The patient and ophthalmologist are notified if there has been a significant change in testing.3,20,21 In a randomized, controlled clinical trial comparing 763 patients who received at-home device monitoring and 757 patients who received standard care using an Amsler grid and other standard screening guidelines, researchers found that patients in the device arm lost a median of 4 letters from baseline to CNV detection while those in the standard care group lost a median of 9 letters.21