Clinician-Driven AI: Code-Free Self-Training on Public Data for Diabetic Retinopathy Referral.

Importance: Democratizing artificial intelligence (AI) enables model development by clinicians with a lack of coding expertise, powerful computing resources, and large, well-labeled data sets. Objective: To determine whether resource-constrained clinicians can use self-training via automated machine learning (ML) and public data sets to design high-performing diabetic retinopathy classification models. Design, Setting, and Participants: This diagnostic quality improvement study was conducted from January 1, 2021, to December 31, 2021. A self-training method without coding was used on 2 public data sets with retinal images from patients in France (Messidor-2 [n = 1748]) and the UK and US (EyePACS [n = 58 689]) and externally validated on 1 data set with retinal images from patients of a private Egyptian medical retina clinic (Egypt [n = 210]). An AI model was trained to classify referable diabetic retinopathy as an exemplar use case. Messidor-2 images were assigned adjudicated labels available on Kaggle; 4 images were deemed ungradable and excluded, leaving 1744 images. A total of 300 images randomly selected from the EyePACS data set were independently relabeled by 3 blinded retina specialists using the International Classification of Diabetic Retinopathy protocol for diabetic retinopathy grade and diabetic macular edema presence; 19 images were deemed ungradable, leaving 281 images. Data analysis was performed from February 1 to February 28, 2021. Exposures: Using public data sets, a teacher model was trained with labeled images using supervised learning. Next, the resulting predictions, termed pseudolabels, were used on an unlabeled public data set. Finally, a student model was trained with the existing labeled images and the additional pseudolabeled images. Main Outcomes and Measures: The analyzed metrics for the models included the area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity, and F1 score. The Fisher exact test was performed, and 2-tailed P values were calculated for failure case analysis. Results: For the internal validation data sets, AUROC values for performance ranged from 0.886 to 0.939 for the teacher model and from 0.916 to 0.951 for the student model. For external validation of automated ML model performance, AUROC values and accuracy were 0.964 and 93.3% for the teacher model, 0.950 and 96.7% for the student model, and 0.890 and 94.3% for the manually coded bespoke model, respectively. Conclusions and Relevance: These findings suggest that self-training using automated ML is an effective method to increase both model performance and generalizability while decreasing the need for costly expert labeling. This approach advances the democratization of AI by enabling clinicians without coding expertise or access to large, well-labeled private data sets to develop their own AI models.

A customized regimen of intravitreal aflibercept for the treatment of choroidal neovascularization secondary to different chorioretinal diseases.

BACKGROUND: To assess the response of CNV secondary to chorioretinal diseases to IVA and to explore the adequate dosing regimen and the long-term results. METHODS: A retrospective study including patients with treatment-naïve active CNV secondary to chorioretinal diseases. All patients received an initial IVA injection followed by a PRN regimen. The main outcome measures were improvement of BCVA, improvement of anatomical morphology and vascularity of the CNV on SS-OCT, and SS-OCTA, respectively, and ocular or systemic complications attributed to IVA. RESULTS: The study included 17 eyes of 15 patients. Nine patients (60%) were females. The median age was 20 years. The main primary chorioretinal disease was vitelliform macular dystrophy (29%). The mean baseline BCVA was 0.16. The mean follow-up period was 15 months. Final BCVA improved by a mean of 6 lines. The CNV regressed or became inactive in all eyes. The median number of IVA injections was 2. There were no ocular or systemic complications attributed to IVA. CONCLUSION: The customized IVA regimen is effective in inducing long-term regression of secondary CNV and in improving BCVA. Multimodal imaging is fundamental in establishing the diagnosis of CNV, and in monitoring its response to IVA.

Multimodal imaging of macular telangiectasia type 2 in a pediatric patient.

PURPOSE: To describe findings of multimodal imaging in non-proliferative and proliferative stages of MacTel 2 in a pediatric patient, and results of aflibercept use for treating neovascularization secondary to MacTel 2. METHODS: Retrospective case report. RESULTS: An 11-year-old girl with no history of systemic disease. BCVA was 20/200 and 20/40 in the right and left eyes, respectively. FFA, SS-OCT and SS-OCTA revealed proliferative and non-proliferative stages of MacTel 2 in the right and left eyes, respectively. Intravitreal aflibercept (2mg/0.05mL) was started (PRN) in the right eye. The patient received 5 injections that led to involution of macular neovascularization and improvement of BCVA by 5 lines. BCVA in the left eye remained stable. CONCLUSION: MacTel 2 can develop in an earlier age than previously reported. SS-OCTA is an effective alternative to conventional imaging in diagnosis and follow-up especially in pediatric patients. Intravitreal aflibercept is effective in treating proliferative MacTel 2.

Customized Slab-Segmentation Method for Projection-Artifact Elimination in Best Vitelliform Macular Dystrophy: A Swept-Source Optical Coherence Tomography Angiography Study.

PURPOSE: To assess the efficacy of customized slab segmentation in eliminating projection artifacts in swept-source optical coherence tomography angiography (SS-OCTA) images of Best vitelliform macular dystrophy (BVMD). METHODS: Prospective case series including different stages of BVMD. We analyzed SS-OCTA images for flow signals in the outer retina and coregistered B-scan images for distortion of the segmentation slabs defining the outer retina. We applied a customized method for slab realignment whenever BVMD lesions produced distortion of the slabs. Afterward, we checked the images to determine whether the previously noted flow signal had persisted or disappeared, described as "true flow" or "pseudoflow", respectively. Categorical variables were analyzed with X2 or Fisher's exact tests, while quantitative variables were analyzed with independent t-test at p<0.05. RESULTS: The study included 39 eyes of 22 patients. We detected BVMD patterns I (dome-shaped hyperreflective lesion without neurosensory retinal detachment), II (knob-like hyperreflective lesion with localized neurosensory retinal detachment), and III (heterogeneous scattered hyperreflective material) in 49%, 23%, and 28% of eyes, respectively. Pseudoflow was evident mostly in eyes with pattern II lesions, presence of flow signal within BVMD lesions, and lesions whose height represented >80% of the retinal thickness (p<0.001). CONCLUSION: Customized slab segmentation is effective in eliminating projection artifact in SS-OCTA images of BVMD. SUMMARY: Projection artifact is a significant confounding factor in emerging SS-OCTA technology through production of pseudoflow signals that can lead to misinterpretation of images of BVMD lesions. The present study proposes a customized method for correction of segmentation errors to eliminate projection artifacts in SS-OCTA images of BVMD patients.

Intravitreal injections of anti-VEGF agents during COVID-19 pandemic: clinical audit from Tanta University Hospital.

BACKGROUND: The aims of this study were to provide real-life data about the effect of COVID-19 pandemic on the practice of anti-VEGF injections and to evaluate the safety of the modifications in the injection protocol imposed during the ongoing pandemic on the anatomical and functional outcome of patients. METHODS: All patients attending Tanta University hospital for receiving intravitreal anti-VEGF injections were screened. Patients who were previously deferred according to a modified protocol implemented in the hospital in response to the pandemic or who demonstrated deviation from it were included for further analysis. RESULTS: During the audit period, 83 patients attending for anti-VEGF injections were screened, of whom 40 met the abovementioned criteria and were included for analysis. In the deferred subgroup (11 eyes), predeferral mean values of logMAR best corrected visual acuity (BCVA) and central retinal subfield thickness (CST) were 1 ± 0.23 and 444.57 ± 200.1 µm, respectively. There was no significant change when the patients returned for their deferred injections, with the mean BCVA and CST values being 0.8 ± 0.22 and 413.71 ± 237.7 µm, respectively (p = 0.27 and p = 0.12). Moreover, 29 patients encountered a disturbed injection schedule, particularly skipping their injection appointments due to infection fear as found in 18 patients. CONCLUSION: The COVID-19 pandemic has imposed pressing challenges in maintaining essential health care while ensuring the prevention of spread of infection. Although the modified injection protocol confirmed to be safe for patients, the pandemic caused deflection from the optimum practice in the form of successive skipping of appointments and delays in the processing of patient injection schedules.

Management of Choroidal Neovascularization Associated with Optic Disc Melanocytoma with Intravitreal Aflibercept: A Case Report and Review of the Literature.

PURPOSE: To report a rare case of melanocytoma associated choroidal neovascularization (CNV) treated with intravitreal aflibercept. METHODS: We reviewed the literature for the previous reports and different methods of treatment. RESULTS: Optic disc melanocytoma has been considered as a benign melanocytic tumor that rarely affects vision. There is evidence in the literature of association between choroidal neovascular membrane and disc melanocytoma. CONCLUSIONS: In conclusion, our article provides a review of literature of such a rare association in which the ophthalmologists must be aware of its occurrence and possible ways of management.

Grading of macular perfusion in retinal vein occlusion using en-face swept-source optical coherence tomography angiography: a retrospective observational case series.

BACKGROUND: To evaluate the efficacy of swept -source optical coherence tomography angiography (SS-OCTA) in grading macular perfusion in retinal vein occlusion. METHODS: Retrospective observational case series including patients with different types of retinal vein occlusion (RVO). SS-OCTA utilizes OCTARA algorithm to examine the retinal vascular plexuses for the presence of morphological signs of ischemia according to a predetermined grading scheme. The findings were compared with fundus fluorescein angiography (FFA), and swept-source optical coherence tomography (SS-OCT) features. Bivariate correlation, coefficient of determination, and crosstabs procedures were used to calculate inter-variable linear correlation, relative contribution of the tested variables, and multivariate association, respectively. RESULTS: The study included 144 eyes of 138 patients. The most common type of RVO was branch retinal vein occlusion (BRVO) (53%). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) did not correlate with each other in all parameters tested. Increased central macular thickness (CMT) and disrupted retinal outer layers (DROL) were associated with increased severity of ischemia in DCP. Disorganized retinal inner layers (DRIL) correlated significantly with the presence of perifoveal capillary ischemia in the SCP and the DCP. Macular ischemia on FFA correlated with ischemia in the SCP layer only. Increased CMT, DROL and DRIL on SS-OCT, and SCP and DCP ischemia on SS-OCTA contributed significantly to diminished best-corrected visual acuity (BCVA). CONCLUSION: SS-OCTA is more precise in defining the extent and location of maximum ischemic insult following RVO compared to FFA, hence represents a more efficient grader for ischemic damage in the posterior pole. Increased CMT, DRIL, and DROL on SS-OCT, and SCP and DCP ischemia on SS-OCTA are significant predictors of poor visual outcome.

Imaging choroidal neovascular membrane using en face swept-source optical coherence tomography angiography.

PURPOSE: The aim of this study was to assess the efficacy of swept-source optical coherence tomography angiography (SS-OCTA) in delineating the morphology of choroidal neovascular membrane (CNV). PATIENTS AND METHODS: This was a retrospective observational case series reviewing clinical data and fundus fluorescein angiography (FFA), swept-source optical coherence tomography (SS-OCT), and SS-OCTA images of patients with CNV and comparing the findings. The swept-source technology enables deeper penetration and superior axial resolution. The incorporated blood flow detection algorithm, optical coherence tomography angiography ratio analysis (OCTARA), enables visualization of CNV in vivo without the need for dye injection. RESULTS: The study included 136 eyes of 105 patients. Active lesions on SS-OCTA images showed increased capillary density, extensive arborization, vascular anastomosis and looping, and peri-lesional hollow. Inactive lesions showed decreased capillary density, presence of large linear vessels, and presence of feeder vessels supplying the CNV. We detected positive correlation between SS-OCTA, FFA, and SS-OCT images in 97% of eyes. In the remaining 3%, SS-OCTA confirmed the absence of CNV, whereas FFA and SS-OCT either were inconclusive in the diagnosis of CNV or yielded false-positive results. CONCLUSION: SS-OCT and SS-OCTA represent a reproducible risk-free analog for FFA in imaging CNV. SS-OCTA is particularly versatile in cases where FFA and SS-OCT are inconclusive.

Detection of Silent Type I Choroidal Neovascular Membrane in Chronic Central Serous Chorioretinopathy Using En Face Swept-Source Optical Coherence Tomography Angiography.

PURPOSE: To evaluate the efficacy of SS-OCTA in the detection of silent CNV secondary to chronic CSCR compared to that of FFA and SS-OCT. PATIENTS AND METHODS: A retrospective observational case series reviewing the clinical data, FFA, SS-OCT, and SS-OCTA images of patients with chronic CSCR, and comparing the findings. SS-OCTA detects the CNV complex and delineates it from the surrounding pathological features of chronic CSCR by utilizing the blood flow detection algorithm, OCTARA, and the ultrahigh-definition B-scan images of the retinal microstructure generated by swept-source technology. The bivariate correlation procedure was used for the calculation of the correlation matrix of the variables tested. RESULTS: The study included 60 eyes of 40 patients. Mean age was 47.6 years. Mean disease duration was 14.5 months. SS-OCTA detected type 1 CNV in 5 eyes (8.3%). In all 5 eyes, FFA and SS-OCT were inconclusive for CNV. The presence of foveal thinning, opaque material beneath irregular flat PED, and increased choroidal thickness in chronic CSCR constitutes a high-risk profile for progression to CNV development. CONCLUSION: Silent type 1 CNV is an established complication of chronic CSCR. SS-OCTA is indispensable in excluding CNV especially in high-risk patients and whenever FFA and SS-OCT are inconclusive.

Macular choroidal thickness in normal Egyptians measured by swept source optical coherence tomography.

BACKGROUND: To provide a normal database of choroidal thickness (CT) in nine Early Treatment Diabetes Retinopathy Study (ETDRS) subfields in Egypt using deep-range imaging swept source optical coherence tomography (DRI SS OCT). METHODS: This study included a total of 129 eyes of 71 normal Egyptian subjects, comprising 63 males and 66 females. The mean age was 36.85 ± 14.22 years (range, 16-67 years). The mean axial length was 23.84 ± 0.78 mm. CT was measured in nine subfields as defined by the ETDRS-style grid using a DRI SS OCT, and line measurements of subfoveal choroidal thicknesses (SFCT) were also performed. RESULTS: Mean SFCT was 300.87 ± 72.256 µm for ring measurements and 319.72 ± 76.45 µm for line measurements (P = 0.04). CT was higher in the superior and temporal quadrants than the inferior and nasal quadrants. A negative correlation between subfoveal choroidal thickness and age was detected in all regions (P < 0.001) except the nasal quadrant. A negative correlation between the SFCT and axial length was also detected (P < 0.001). Males tended to have a thicker choroid than females; however, the difference was not significant. CONCLUSIONS: DRI SS OCT provides a topographic map of choroidal thickness with an ETDRS layout. This study establishes, for the first time, a normal database for CT in the Egyptian population. Age and axial length were associated with choroidal parameters in healthy subjects. Line measurements of the SFCT differed significantly from SFCT ring measurements, so it is recommended that each method be compared independently.

Diffuse retinal capillary leakage in coats disease.

PURPOSE: Coats disease is a rare condition characterized by retinal vascular telangiectasia, aneurysms, and leakage from these abnormal blood vessels. We report the phenomenon and treatment of Coats disease with diffuse hyperpermeability from angiographically normal retinal capillaries. METHODS: This case series describes two patients with Coats disease, diagnosed based on fundus photography and fluorescein angiography. The first patient was treated with intravitreal bevacizumab and limited laser photocoagulation. The second patient was treated only with limited photocoagulation. RESULTS: The diffuse exudation from normal retinal capillaries resolved with treatment of the focal primary vascular Coats lesions. CONCLUSION: Vasculopathies such as Coats disease may produce diffuse hyperpermeability of otherwise normal capillaries in the fundus. Limiting treatment only to the primary Coats lesions is a minimally invasive strategy that preserves normal capillaries.

Management of lipid exudates in Coats disease by adjuvant intravitreal triamcinolone: effects and complications.

AIM To evaluate the role of intravitreal Triamcinolone (TA) in the early management of Coats disease. METHODS Retrospective, interventional case series. RESULTS 15 consecutive cases with Coats disease were managed with 4 mg/0.1 ml intravitreal TA injection on presentation and were followed for a minimum of 1 year duration. Additional management strategies including drainage of subretinal fluid through an inferior sclerotomy, peripheral laser ablation and/or cryotherapy, cataract extraction and vitrectomy were performed. Improvement of visual acuity could be achieved compared with preoperative vision in all cases in this series, even when 40% needed cataract extraction with intraocular lens implantation. One patient needed antiglaucoma treatment to control raised intraocular pressure in this series. CONCLUSIONS Triamcinolone has a role in improving the rate of absorption of subretinal fluid and macular exudates in Coats disease. The major complication of 4 mg/0.1 ml intravitreal triamcinolone is cataract in 40% of cases in children.