A new home telemedicine system generates valuable data on disease and the dynamics of fluid exudation.
The feasibility of home optical coherence tomography (OCT) monitoring with a patient self-operated device, automated data transmission, and analysis for disease surveillance was demonstrated in a longitudinal at-home pilot study1 in patients with wet age-related macular degeneration (AMD). The senior author of the paper, Dr Anat Loewenstein, stated that such daily monitoring can result in fewer clinic visits.
Home monitoring can also enable fluid recurrence to be detected earlier, resulting in faster re-treatment, and eliminate unnecessary routine injections of anti-vascular endothelial growth factor (anti-VEGF). The OCT monitoring technology whose performance Dr Loewenstein and her colleagues evaluated was the Notal Home (Notal Vision).
This system includes a spectral-domain OCT device by which patients perform self-imaging. It uploads the imaging data to a secure cloud-based system and applies a deep learning algorithm for automated OCT analysis. The goals of the study, Dr Loewenstein explained, were to evaluate the technology’s performance in daily image acquisition and automated analysis, and to characterise the dynamics of retinal fluid exudation in patients with neovascular AMD.
The prospective, observational, longitudinal study included four patients (mean age: 73.8 years) with unilateral or bilateral neovascular AMD who were being treated with anti-VEGF therapy. The participants monitored themselves at home using the OCT device for up to 3 months.
Each time they completed the self-imaging, the macular cube scans were uploaded automatically to the Notal Health Cloud. The Notal OCT Analyzer and human graders evaluated the scans for fluid, segmentation and volume. Dr Loewenstein set out the main aims of the study: to determine that the daily self-imaging had been completed correctly; to assess image quality and acquisition time; to evaluate agreement between the automated and human grading of retinal fluid; and to assess the temporal dynamics of fluid volume.
The four patients initiated a total of 240 self-imaging attempts. Of these, 211 (87.9%) were completed successfully. Of the completed attempts, 97.6% had satisfactory image quality.
Regarding the presence of retinal fluid, the automated analysis and human graders agreed in 94.7% of cases.
When the investigators looked at a subset of 24 scans in which fluid was present, the correlation coefficient between the measurements of fluid volume by the automated and the human graders was 0.996, and the mean absolute difference was 1.5 nanolitres. The respective inter-human agreements were 0.995 and 1.2 nanolitres.
The scans demonstrated wide variations in the dynamics of fluid exudation and treatment responses, according to Dr Loewenstein. Based on the results, the investigators concluded that the study patients were able to perform daily self-imaging at home and generate macular cube scans that were of satisfactory quality.
The agreement between the automated analysis and the human graders was high. In addition, the technology facilitated characterisation of the dynamics of fluid exudation and showed wide variation between eyes, which may lead to relevant disease biomarkers.
“Home OCT telemedicine systems provide an alternative method for physicians to monitor disease and may allow highly personalised re-treatment decisions, with fewer unnecessary injections and clinic visits,” Dr Loewenstein concluded. “The review of remote OCT data will offer new billing opportunities for ophthalmologists who utilise the service of a remote monitoring centre that provides Home OCT service to patients.”