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.

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.

Effect of Contact Lens Design on Objective Visual Acuity-Based Parameters in Pre-Presbyopic Patients in Photopic and Mesopic Lighting Conditions.

Presbyopia is often corrected by progressive soft contact lenses (CL), and the resulting visual acuity-based parameters can be affected by the lens design and pupil size under different lighting conditions. In this study, we examined the effect of CL design (spheric vs. aspheric) on objective parameters of visual acuity-based parameters under mesopic vs. photopic lighting conditions. In a prospective, double-blind study, pre-presbyopic and presbyopic patients were fitted with spheric (Dispo Silk; 8.6 base curve, 14.2 diameter) and aspheric (Dispo Aspheric; 8.4 base curve, 14.4 diameter) CLs. The low contrast (10%) and high contrast (100%) visual acuity (VA), amplitude of accommodation (AA) (push-away method, Diopters) and distance contrast sensitivity (CS) (FACT chart, cycles per degree (CPD)) were measured with both types of CLs under mesopic and photopic lighting conditions. The eye with the better visual acuity was tested and analyzed. Thirteen patients (age range: 38-45 years) were included. The mean CS was significantly better with spheric compared to aspheric lenses for low spatial frequencies (3 CPD: 81.69 ± 7.86, 67.62 ± 5.67, respectively; p < 0.05), though there was no significant difference for lower or higher spatial frequencies (1.5, 6, 12, 18 CPD). The low-contrast (10%) and high-contrast (100%) VAs were not different between the two lens designs. However, there were significant differences between near VA, distance low-contrast VA and AA obtained under mesopic (dim) vs. photopic (bright) conditions with the aspheric design correction modality. In conclusion, photopic lighting conditions improved both the visual acuity and measured amplitude of accommodation with both lens designs, though the amplitude of accommodation was significantly higher with aspheric lenses. However, contrast sensitivity demonstrated the superiority of the spheric lens at a 3 CPD spatial frequency. This suggests that the ideal lens differs from patient to patient, depending on the visual demands.

Correlation of response to intravitreal bevacizumab treatment between the first and second treated eyes in diabetic macular edema.

PURPOSE: To evaluate whether outcome of bevacizumab treatment in the first treated eye can guide the selection of compound for the second treated eye in patients with bilateral diabetic macular edema. METHODS: Demographic, clinical, and optical coherence tomography data were retrospectively collected from consecutive patients who underwent bevacizumab therapy for bilateral diabetic macular edema. Change in central subfield thickness and visual acuity were evaluated and compared between the first treated eye and second treated eye. RESULTS: A total of 66 eyes of 33 patients were included in the study. The mean ± SD follow-up time was 13 ± 5 months. The mean ± SD central subfield thickness at baseline was 464 ± 30 µm in the first treated eye and 461 ± 29 µm in the second treated eye (p = 0.91). Final central subfield thickness was reduced to 392 ± 27 µm in the first treated eye (p = 0.01 compared with baseline) and 416 ± 25 µm in the second treated eye (p = 0.03 compared with baseline). Using ≥5% or ≥10% reduction of central subfield thickness as diagnostic criteria to predict similar magnitude of thickness reduction in the first treated eye yielded a positive and negative predictive value ranging from 46% to 81%, and sensitivity and specificity ranging from 54% to 84%. Regression models did not show correlation between central subfield thickness reduction in first treated eye and the second treated eye at the end of follow-up. CONCLUSIONS: Bevacizumab therapy reduced macular thickness in both eyes in bilateral diabetic macular edema. Treatment outcome of the first treated eye could not predict the outcome of the second treated eye. Particularly, failure to reduce central subfield thickness in the first treated eye does not preclude a favorable response to bevacizumab therapy in the second eye.

Evaluation of three biometric devices: ocular parameters and calculated intraocular lens power.

Cataract surgery is among the most common medical procedures, and accurate ocular biometry measurements are key for successful visual outcome. The current study evaluated data obtained by the Eyestar 900, Anterion, IOLMaster700 biometers and the Pentacam corneal topographer. Compared values were axial length (AL), anterior chamber depth (ACD), steep- and flat-K, cylinder and axis. Clinical impact was assessed by calculating intraocular lens (IOL) power using the mean values of every parameter and the Barrett and Kane formulas, stratified by device and amount of cylinder. IOL was re-calculated for each device substituting Pentacam K-values. This study included 196 eyes (98 participants) of cataract surgery candidates. When comparing the IOLMaster to the Eyestar (157 eyes), no difference was found in mean AL or ACD measurements (P > 0.05). Steep-K measurements differed between these devices and the Pentacam (P = 0.01). AL and ACD measurements differed between the IOLMaster and Anterion (38 eyes; P < 0.05). Strong correlations (range 0.72-0.99) were found between all four devices. Bland-Altman analysis demonstrated excellent agreement between biometry devices other than ACD between the IOLMaster and Eyestar. Calculated IOL power was 0.50-1.00 diopter (D) lower with the IOLMaster. Cylinder power was 0.75D higher in all biometers when Pentacam K-values were substituted.

Cortical responses to prosthetic retinal stimulation are significantly affected by the light-adaptive state of the surrounding normal retina.

Objective.Restoration of central vision loss in patients with age-related macular degeneration (AMD) by implanting a retinal prosthesis is associated with an intriguing situation wherein the central prosthetic vision co-exists with natural normal vision. Of major interest are the interactions between the prosthetic and natural vision. Here we studied the effect of the light-adaptive state of the normal retina on the electrical visual evoked potentials (VEPs) arising from the retinal prosthesis.Approach.We recorded electrical VEP elicited by prosthetic retinal stimulation in wild-type rats implanted with a 1 mm photovoltaic subretinal array. Cortical responses were recorded following overnight dark adaption and compared to those recorded following bleaching of the retina by light (520 nm) at various intensities and durations.Main results.Compared to dark-adapted responses, bleaching induced a 2-fold decrease in the prosthetic cortical response, which returned to the dark-adapted baseline within 30 min to several hours, depending on the degree of bleaching. This reduction was neither observed in Royal College of Surgeons (RCS) rats with a degenerated photoreceptor layer nor following intravitreal injection of a GABAa receptor blocker (bicuculine), suggesting the involvement of photoreceptors and a GABAa-mediated mechanism.Significance.These findings show a robust effect of the retinal light-adaptive state on the obtained prosthetic responses. If a similar effect is found in humans, this will have immediate implications on the design of prosthetic devices, where both natural and prosthetic vision co-exist, such as in AMD patients receiving a photovoltaic retinal implant. Similarly, standardization of the retinal light-adaptive state in prosthetic clinical trials should be considered.

Cortical Interactions between Prosthetic and Natural Vision.

Outer retinal degenerative diseases, such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD), are among the leading causes of incurable blindness in the Western world [1]. Retinal prostheses have been shown to restore some useful vision by electrically stimulating the remaining retinal neurons [2]. In contrast to inherited retinal degenerative diseases (e.g., RP), typically leading to a complete loss of the visual field, in AMD patients the disease is localized to the macula, leaving the peripheral vision intact. Implanting a retinal prosthesis in the central macula in AMD patients [3, 4] leads to an intriguing situation where the patient's central retina is stimulated electrically, whereas the peripheral healthy retina responds to natural light stimulation. An important question is whether the visual cortex responds to these two concurrent stimuli similarly to the interaction between two adjacent natural light stimuli projected onto healthy retina. Here, we investigated the cortical interactions between prosthetic and natural vision based on visually evoked potentials (VEPs) recorded in rats implanted with photovoltaic subretinal implants. Using this model, where prosthetic and natural vision information are combined in the visual cortex, we observed striking similarities in the interactions of natural and prosthetic vision, including similar effect of background illumination, linear summation of non-patterned stimuli, and lateral inhibition with spatial patterns [5], which increased with target contrast. These results support the idea of combined prosthetic and natural vision in restoration of sight for AMD patients.