Anomaly Detection and Biomarkers Localization in Retinal Images.

Background: To design a novel anomaly detection and localization approach using artificial intelligence methods using optical coherence tomography (OCT) scans for retinal diseases. Methods: High-resolution OCT scans from the publicly available Kaggle dataset and a local dataset were used by four state-of-the-art self-supervised frameworks. The backbone model of all the frameworks was a pre-trained convolutional neural network (CNN), which enabled the extraction of meaningful features from OCT images. Anomalous images included choroidal neovascularization (CNV), diabetic macular edema (DME), and the presence of drusen. Anomaly detectors were evaluated by commonly accepted performance metrics, including area under the receiver operating characteristic curve, F1 score, and accuracy. Results: A total of 25,315 high-resolution retinal OCT slabs were used for training. Test and validation sets consisted of 968 and 4000 slabs, respectively. The best performing across all anomaly detectors had an area under the receiver operating characteristic of 0.99. All frameworks were shown to achieve high performance and generalize well for the different retinal diseases. Heat maps were generated to visualize the quality of the frameworks' ability to localize anomalous areas of the image. Conclusions: This study shows that with the use of pre-trained feature extractors, the frameworks tested can generalize to the domain of retinal OCT scans and achieve high image-level ROC-AUC scores. The localization results of these frameworks are promising and successfully capture areas that indicate the presence of retinal pathology. Moreover, such frameworks have the potential to uncover new biomarkers that are difficult for the human eye to detect. Frameworks for anomaly detection and localization can potentially be integrated into clinical decision support and automatic screening systems that will aid ophthalmologists in patient diagnosis, follow-up, and treatment design. This work establishes a solid basis for further development of automated anomaly detection frameworks for clinical use.

An automated process for bulk downloading optical coherence tomography scans.

OBJECTIVE: To develop an automated method for efficiently downloading a large number of optical coherence tomography (OCT) scans obtained using the Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany) platform. METHODS: The electronic medical records and OCT scans were extracted for all patients with age-related macular degeneration treated at the Hadassah University Hospital Retina Clinic between 2010 and 2021. A macro was created using Visual Basic for Applications (VBA) and Microsoft Excel to automate the export process and anonymize the OCT scans in accordance with hospital policy. OCT scans were extracted as proprietary Heidelberg E2E files. RESULTS: The VBA macro was used to export a total of 94,789 E2E files from 2807 patient records, with an average processing time of 4.32 min per volume scan (SD: 3.57 min). The entire export process took a total of approximately 202 h to complete over a period of 24 days. In a smaller sample, using the macro to download the scans was significantly faster than manually downloading the scans, averaging 3.88 vs. 11.08 min/file, respectively (t = 8.59, p < 0.001). Finally, we found that exporting the files during both off-clinic and working hours resulted in significantly faster processing times compared to exporting the files solely during working hours (t = 5.77, p < 0.001). CONCLUSIONS: This study demonstrates the feasibility of using VBA and Excel to automate the process for bulk downloading data from a specific medical imaging platform. The specific steps and techniques will likely vary depending on the software used and hospital constraints and should be determined for each application.

The pseudohypopyon stage in adult-onset foveomacular vitelliform dystrophy.

PURPOSE: To gain insight into the pathogenesis of adult-onset foveomacular vitelliform dystrophy (AFVD) via assessment of its pseudohypopyon stage (PHS). METHODS: Retrospectively, data were collected in a tertiary center from established cohorts of a genetically evaluated AFVD and best vitelliform macular dystrophy (BVMD) eyes in the pseudohypopyon stage. Best-corrected visual acuity (BCVA, LogMAR), lesion characterization, including lesion dimensions, liquefaction areas and patterns (altitudinal or lateral), and ellipsoid zone integrity were analyzed from spectral-domain optical coherence tomography images. RESULTS: Out of 167 eyes of 90 AFVD patients and 56 eyes of 28 BVMD patients, 8 eyes of six AFVD patients and five eyes of four BVMD patients were at the PHS were included. The mean LogMAR BCVA ± SD was 0.21 ± 0.20 and 0.41 ± 0.10 in AFVD and BVMD diseases, respectively (p = 0.13). Seven AFVD eyes (87.5%) demonstrated lateral liquefaction, while all BVMD eyes demonstrated an altitudinal pattern (p = 0.005). Maximal horizontal lesion diameters were 1.41 ± 0.46 mm and 2.64 ± 0.77 mm in AFVD and BVMD, respectively (p = 0.02). AFVD patients were older (69 ± 14) than BVMD patients (22 ± 13; p = 0.009). CONCLUSION: The pseudohypopyon stage in AFVD is often characterized by a lateral liquefaction pattern, unlike the altitudinal pattern characterizing BVMD. Age, lesion size, or pathogenesis pathways may underline the different pseudohypopyon stage patterns in AFVD and BVMD.