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/OBJECTIVE:To present the early post-operative evolution of retained subretinal perfluoro-n-octane (PFO) as captured on OCT. METHODS:Case report of a patient. RESULTS:A 58-year-old woman was noted to have subretinal PFO after undergoing autologous retinal graft for macular hole closure under PFO tamponade. Serial OCT identified the subretinal PFO as early as the first postoperative day and demonstrates progressive consolidation and encapsulation of the PFO bubble by the surrounding outer retina. CONCLUSION/CONCLUSIONS:Subretinal PFO is usually seen several weeks in the postoperative course once the gas endotamponade has resorbed sufficiently for OCT imaging. In this case, PFO tamponade enabled its imaging early. Its subsequent evolution into the classic "omega sign" may suggest a granulomatous encapsulation of the PFO bubble.

During the past 15 years, new treatment paradigms for neovascular age-related macular degeneration (nvAMD) have evolved due to the advent of intravitreal anti-vascular endothelial growth factor (VEGF) therapy and rapid advances in retinal imaging. Recent publications describe eyes with type 1 macular neovascularization (MNV) as showing more resistance to macular atrophy than eyes with other lesion types. We sought to explore whether the perfusion status of the native choriocapillaris (CC) surrounding type 1 MNV influences its pattern of growth. To evaluate this effect, we analyzed a case series of 22 eyes from 19 nvAMD patients with type 1 MNV exhibiting growth on swept-source optical coherence tomography angiography (SS-OCTA) over a minimum follow-up of 12 months. We observed an overall weak correlation between type 1 MNV growth and CC flow deficits (FDs) average size (τ = 0.17, 95% CI [- 0.20, 0.62]) and a moderate correlation with CC FD % (τ = 0.21, 95% CI [- 0.16, 0.68]). Type 1 MNV was located beneath the fovea in most of the eyes (86%) and median visual acuity was 20/35 Snellen equivalent. Our results support that type 1 MNV recapitulates areas of CC blood flow impairment while serving to preserve foveal function.

PURPOSE/UNASSIGNED:To discuss the pathophysiology, etiology, and current management strategies of uveitis-glaucoma-hyphema (UGH) syndrome. METHODS/UNASSIGNED:Literature review. RESULTS/UNASSIGNED:The classic UGH syndrome associated with anterior chamber intraocular lenses (ACIOL) have decreased in incidence with the modernization of IOL design and surgical techniques. The current UGH syndrome is increasing in prevalence largely related to a parallel increase in late onset dislocations of intraocular lenses (IOLs) and the developing techniques to remedy that condition. The modern features of UGH can present as cystoid macular edema, intraocular pressure elevation typically not attributed to UGH, and recurrent vitreous hemorrhage, unlike the original description as described by Ellingson in 1978. Medical management to control inflammation, reduce intraocular pressure, and reduced the bleeding diathesis are mainstays of therapy. However, surgery with IOL repositioning or exchange should be reserved for cases that are refractory to or progressing despite medical treatment. CONCLUSIONS/UNASSIGNED:UGH syndrome is an increasingly common, poorly understood, and often subtle, manifestation of an anatomic disturbance post intraocular surgery that persists with continued evolution of intraocular surgical techniques and new imaging modalities to aid in its diagnosis.

Purpose:To characterize macular blood flow connectivity in vivo using high-resolution optical coherence tomography (HighRes OCT). Methods:Cross-sectional, observational study. Dense (6-µm interscan distance) perifoveal HighRes OCT raster scans were performed on healthy participants. To mitigate the limitations of projection-resolved OCT-angiography, flow and structural data were used to observe the vascular structures of the superficial vascular complex (SVC) and the deep vascular complex. Vascular segmentation and rendering were performed using Imaris 9.5 software. Inflow and outflow patterns were classified according to vascular diameter and branching order from superficial arteries and veins, respectively. Results:Eight eyes from eight participants were included in this analysis, from which 422 inflow and 459 outflow connections were characterized. Arteries had direct arteriolar connections to the SVC (78%) and to the intermediate capillary plexus (ICP, 22%). Deep capillary plexus (DCP) inflow derived from small-diameter vessels succeeding ICP arterioles. The most prevalent outflow pathways coursed through superficial draining venules (74%). DCP draining venules ordinarily merged with ICP draining venules and drained independently of superficial venules in 21% of cases. The morphology of DCP draining venules in structural HighRes OCT is distinct from other vessels crossing the inner nuclear layer and can be used to identify superficial veins. Conclusions:Vascular connectivity analysis supports a hybrid circuitry of blood flow within the human parafoveal macula. Translational Relevance:Characterization of parafoveal macular blood flow connectivity in vivo using a precise segmentation of HighRes OCT is consistent with ground-truth microscopy studies and shows a hybrid circuitry.

PURPOSE/OBJECTIVE:To report the clinical and imaging characteristics of multiple evanescent white dot syndrome (MEWDS) from a large single-center cohort. DESIGN/METHODS:Single-center, retrospective cohort study. PARTICIPANTS/METHODS:A total of 111 patients previously diagnosed with MEWDS in the Kaiser Permanente Northern California system from 2012 to 2019. METHODS:Two retina specialists reviewed the medical records and all available retinal imaging, including Humphrey visual field testing, fundus photography (FP), OCT, fluorescein angiogram (FA), and fundus autofluorescence (FAF). Patients were excluded from analysis if confirmatory imaging was unavailable. MAIN OUTCOME MEASURES/METHODS:Patient characteristics, visual acuity, clinical examination and imaging findings, and final diagnosis. RESULTS:Seventy-three patients (65.8%) were confirmed to have the diagnosis of MEWDS. Fifty-eight (79.5%) were female, with a mean (standard deviation [SD]) age at presentation of 35.2 (14.2) years, and mean refractive error of -1.6 diopters. Initial mean (SD) visual acuity was logarithm of the minimum angle of resolution (logMAR) 0.39 (0.31) and improved to mean (SD) logMAR 0.07 (0.15) at final follow-up. Presenting symptoms included blurred vision (82%), scotomas (56%), photopsias (43%), and floaters (23%). Nine patients (12%) had a previously diagnosed autoimmune condition, and 2 patients (3%) had documentation of a recent vaccination. Antecedent upper respiratory infection was documented in 15 of 66 patients (23%). Noted clinical and imaging features include ellipsoid zone disruption (100%), white fundus lesions (92%), FA hyperfluorescence (92%), foveal granularity (74%), vitreous cell (53%), and optic disc edema (52%). Twenty-nine of the 111 patients (26%) were initially misdiagnosed with MEWDS and subsequently given an alternative diagnosis, including other white dot syndromes, syphilis, primary vitreoretinal lymphoma, myopic degeneration, and central serous chorioretinopathy. CONCLUSIONS:Multiple evanescent white dot syndrome is a rare self-limiting condition of the outer retina. Although a distinct set of clinical exam and imaging findings permit recognition of this disease, misdiagnosis is not uncommon.

PURPOSE/OBJECTIVE:To quantify the association between visit adherence and visual acuity (VA) in diabetic macular edema (DME). METHODS:This secondary analysis of the 2-year DRCRnet Protocol T study of 656 patients required one visit every 4 weeks in the first year, then at variable 4-16-week intervals in the second year. Visit adherence measured as number of missed visits, average (avg days) and longest (max days) visit interval, average (avg missed days) and longest (max missed days) unintended visit interval, and visit constancy (percentage of 3-month periods with at least 1 visit). Avg and max missed days were categorized as on time (0 days), late (> 0-60 days), and very late (> 60 days). Primary outcome was change in ETDRS VA between baseline study visit and last attended visit, using multivariate linear regression models controlling for age, gender, race, ethnicity, treatment arm, baseline VA, hemoglobin A1c, insulin use, and number of lasers and injections. RESULTS:Mean number of missed visits was 1.7. 616 (94%) patients had 100% visit constancy. A total of 331 (51%) patients were on time, 171 (26%) late, and 154 (23%) very late in avg missed days. Max missed days ranged 0-696 days. Adjusted, each missed visit was associated with 0.3-letter decrease (95%CI - 0.6, - 0.1, p = 0.02); being very late in avg and max missed days saw - 4.2 letters (95%CI - 6.4, - 2.0, p < 0.001) and - 4.0 letters (95%CI - 6.1, - 1.9, p < 0.001), respectively, than on time. Those that averaged > 4 days missed per attended visit saw 4.6 letters worse (95%CI - 7.3, - 2.0, p < 0.001). CONCLUSIONS:Visit adherence is associated with visual acuity outcomes in DME patients.