Faculty Bibliography

The availability of big data can transform the studies in biomedical research to generate greater scientific insights if expert labeling is available to facilitate supervised learning. However, data annotation can be labor-intensive and cost-prohibitive if pixel-level precision is required. Weakly supervised semantic segmentation (WSSS) with image-level labeling has emerged as a promising solution in medical imaging. However, most existing WSSS methods in the medical domain are designed for single-class segmentation per image, overlooking the complexities arising from the co-existence of multiple classes in a single image. Additionally, the multi-class WSSS methods from the natural image domain cannot produce comparable accuracy for medical images, given the challenge of substantial variation in lesion scales and occurrences. To address this issue, we propose a novel anomaly-guided mechanism (AGM) for multi-class segmentation in a single image on retinal optical coherence tomography (OCT) using only image-level labels. AGM leverages the anomaly detection and self-attention approach to integrate weak abnormal signals with global contextual information into the training process. Furthermore, we include an iterative refinement stage to guide the model to focus more on the potential lesions while suppressing less relevant regions. We validate the performance of our model with two public datasets and one challenging private dataset. Experimental results show that our approach achieves a new state-of-the-art performance in WSSS for lesion segmentation on OCT images.

PURPOSE:To assess the association of a novel spectral domain optical coherence tomography biomarker with 6-month visual acuity in in the Study of COmparative Treatments for REtinal Vein Occlusion 2. METHODS:Spectral domain optical coherence tomography volume scans were evaluated for inner retinal hyperreflectivity, quantified by optical intensity ratio (OIR) and OIR variation. Baseline visual acuity letter score (VALS), baseline OCT biomarkers, and month 1 OIR were correlated with VALS at month 6. Regression trees, a machine learning technique yielding readily interpretable models, were used to assess for variable interaction. RESULTS:Only baseline VALS correlated positively with month 6 VALS in multivariate regression. Regression trees detected a novel functional and anatomical interaction in a subgroup. Among patients with a baseline VALS worse than 43, those with an OIR variation at month 1 of more than 0.09 had a mean of 13 fewer letters of vision at 6 months compared with patients with an OIR variation of 0.09 or less. CONCLUSIONS:Baseline VALS was the strongest predictor of month 6 VALS. Regression tree analysis detected an interaction effect, in which higher OIR variation at month 1 predicted worse 6-month VALS in patients with low VALS at baseline. OIR variation may serve as a predictor for poor visual outcome despite treatment of macular edema secondary to retinal vein occlusion in patients with poor vision at baseline. TRANSLATIONAL RELEVANCE:Pixel heterogeneity in three-dimensional OCT data may serve as measure of disruption of the retinal laminations, and this factor may carry visually prognostic value.

PURPOSE OF REVIEW/OBJECTIVE:In this review, we focus on artificial intelligence (AI) algorithms for diabetic retinopathy (DR) screening and risk stratification and factors to consider when implementing AI algorithms in the clinic. RECENT FINDINGS/RESULTS:AI algorithms have been adopted, and have received regulatory approval, for automated detection of referable DR with clinically acceptable diagnostic performance. While these metrics are an important first step, performance metrics that go beyond measures of technical accuracy are needed to fully evaluate the impact of AI algorithm on patient outcomes. Recent advances in AI present an exciting opportunity to improve patient care. Using DR as an example, we have reviewed factors to consider in the implementation of AI algorithms in real-world clinical practice. These include real-world evaluation of safety, efficacy, and equity (bias); impact on patient outcomes; ethical, logistical, and regulatory factors.

PURPOSE/UNASSIGNED:To describe delayed detection of pericentral hydroxychloroquine (HCQ) toxicity. METHODS/UNASSIGNED:67-year-old Dominican woman with rheumatoid arthritis on HCQ presented for examination. RESULTS/UNASSIGNED:Spectral-domain optical coherence tomography (SD-OCT) demonstrated bilateral cystoid macular edema with parafoveal attenuation of the external limiting membrane (ELM) and the ellipsoid zone (EZ). ELM and EZ disruption was present in inferior macula. While subtle superior defects were present on 10-2 visual fields, superior pericentral defects were noted on 24-2 testing. Hyperautofluorescence along inferior arcades corresponded to SD-OCT and visual fields. Examination 2 years prior demonstrated nonspecific points of depression on 10-2 visual fields and normal central SD-OCT findings. EZ and ELM disruption was present in the perifoveal inferior macula. CONCLUSIONS/UNASSIGNED:Early pericentral distribution of HCQ toxicity is not limited to Asian patients. Detecting pericentral HCQ toxicity involves reviewing entire macular cube on OCT. When OCT changes are suspected on parafoveal OCT B-scans, visual field testing with 24-2 may be more sensitive than 10-2.

PURPOSE/OBJECTIVE:To describe the vascular anatomy and intraluminal flow characteristics of segmental retinal arteritis (SRA) using structural and angiographic optical coherence tomography (OCT). METHODS:Retrospective case series of consecutive patients presenting with SRA. All patients were evaluated at presentation with fundus photography, spectral domain OCT, and OCT angiography. One patient was imaged with dense B-scan OCT angiography. RESULTS:Three eyes of three male patients were evaluated. All examinations were consistent with reactivation of ocular toxoplasmosis with an area of active retinochoroiditis adjacent to a focal chorioretinal scar. Spectral domain OCT through areas of SRA noted on clinical examination demonstrated areas of hyperreflectivity circumscribing the affected vessel with a normoreflective lumen. Optical coherence tomography angiography and dense B-scan OCT angiography demonstrated narrowing of the intraluminal flow signal that correlated with areas of segmental hyperreflectivity on spectral domain OCT. Vascular sections proximal and distal to areas of SRA showed normal flow signal. CONCLUSION/CONCLUSIONS:Vessels with SRA demonstrated hyperreflectivity highlighting the vessel wall on spectral domain OCT. Optical coherence tomography angiography showed narrowing of the flow signal within these segments suggesting reduced lumen diameter. Coupling these finding with previous indocyanine green imaging findings in SRA, the collective data suggest the plaques are localized within the vessel wall to either the endothelium or the muscular tunica media without occlusion of the vessel lumen.

PURPOSE/OBJECTIVE:To report a detachment that apparently separated photoreceptor inner segment myoids from inner segment ellipsoids as a manifestation of toxoplasmosis chorioretinitis in a patient with pachychoroid spectrum disease. METHODS:Multimodal imaging including fundus photography, spectral domain and enhanced-depth imaging optical coherence tomography (OCT), indocyanine green angiography, and OCT angiography. RESULTS:A 33-year-old man with a history of toxoplasmosis chorioretinitis reported 1 week of decreased vision to 20/200 in his right eye. Examination of the right eye demonstrated mild vitritis with recurrent chorioretinitis inferior to the fovea and adjacent to a chorioretinal scar. A dome-shaped, foveal photoreceptor layer-splitting detachment was noted on OCT. Because degenerating cone photoreceptors are capable of shedding their inner segments, we inferred the location of the detachment at the level of the inner segment myoid and provided a histological example of such from an unrelated donor case. In addition, multimodal imaging revealed dilated choroidal veins (pachyvessels) with attenuation of the inner choroid in both eyes and asymptomatic findings of central serous chorioretinopathy in the left eye. After 1 month of antibiotic and steroid therapy, the chorioretinitis resolved, as did the detachment. Hyperreflective foci on the vitreoretinal interface were appreciated with en face OCT that appeared to aggregate throughout the course of therapy, induce inner retinal striae, and resolve without inducing epiretinal membrane formation. CONCLUSION/CONCLUSIONS:Patients with preexisting pachychoroid spectrum disease may manifest a more significant retinal fluid accumulation in the setting of superimposed chorioretinal inflammation. In this case of macular toxoplasmosis chorioretinitis, inflammation manifested as a retinal detachment at the level of photoreceptor inner segment myoids that we named as a bacillary layer detachment. In this case, inflammatory sequelae of toxoplasmosis reactivation responded well to oral and intravitreal therapy.

PURPOSE/OBJECTIVE:To report a retinal pigment epithelium (RPE) tumor with exudative maculopathy, originating from an atypical RPE lesion presumed to represent congenital hypertrophy of the RPE or RPE hyperplasia. METHODS:Multimodal imaging including fundus autofluorescence, optical coherence tomography, fluorescein angiography, and optical coherence tomography angiography. RESULTS:A 76-year-old West African man noted visual acuity reduction to count fingers in the right eye and 20/400 in the left eye. Features of chronic glaucoma were noted. In addition, there was a fairly well-circumscribed darkly pigmented RPE lesion in the paramacular region in the right eye, measuring 4 mm in diameter and flat and consistent with atypical congenital hypertrophy of the RPE or RPE hyperplasia. On the posterior margin of this mass was an RPE tumor, presumed to represent RPE adenoma, producing exudative maculopathy and cystoid macular edema. Multimodal imaging was used to distinguish the RPE tumor from macular neovascularization. A similar atypical congenital hypertrophy of the RPE without retinopathy measuring 3.5mm in diameter was noted in the temporal macular region in the left eye. After six monthly doses of intravitreal bevacizumab (1.25 mg/0.05 mL) in the right eye, the maculopathy resolved and the RPE mass showed partial involution with visual acuity return to baseline 20/200. CONCLUSION/CONCLUSIONS:Congenital hypertrophy of the RPE and RPE hyperplasia can produce RPE adenoma with related exudative maculopathy. In this case, the maculopathy responded to bevacizumab.