A Pilot Study of Subclinical Non-Capillary Peripapillary Perfusion Changes in Thyroid-Related Orbitopathy Detected Using Optical Coherence Tomography Angiography.

Purpose: Hemodynamic changes surrounding the optic nerve head are known to occur in thyroid-related orbitopathy (TRO). This pilot study explores the capillary and non-capillary peripapillary perfusion changes of the retina in TRO eyes without dysthyroid optic neuropathy (DON) using optical coherence tomography angiography (OCT-A). Methods: Non-capillary and capillary peripapillary perfusion densities were calculated using single 4.5 × 4.5mm en face "RPC layer" OCT-A scans of 8 TRO patients without DON (8 eyes, mean age 40.6 years, range 23-69 years). Results were compared to a previously published dataset of 133 healthy controls (133 eyes, mean 41.5 years, range 11-83 years). The strength of association was measured between OCT-A perfusion densities and clinical measures of TRO. Results: Non-capillary peripapillary perfusion density in TRO eyes was found to be significantly decreased compared to healthy controls (TRO group 15.4 ± 2.9% vs controls 21.5 ± 3.1%; p < 0.0001). Capillary peripapillary perfusion densities showed no significant difference (TRO group 42.5 ± 1.8% vs controls 42.5 ± 1.5%; p = 1.0). Clinical measures of disease did not correlate well with OCT-A perfusion densities (p>0.05). Conclusion: These findings may represent decreased blood flow and subclinical ischemia to the optic nerve. We discuss possible pathogenic mechanisms of thyroid-related vasculopathy, including vessel wall thickening due to immunologically-induced media enlargement.

From Race to Racism: Teaching a Tool to Critically Appraise the Use of Race in Medical Research.

INTRODUCTION: Despite the ubiquitous use of race within scientific literature, medical trainees are not taught how to critically appraise the use of racial categories. We developed a tool to appraise the use of race in medical literature and a workshop to teach this approach. METHODS: Third-year medical students and second- and third-year residents participated in workshops between 2015 and 2018. We evaluated our UME workshop with a postworkshop survey. We evaluated our GME workshop with a pretest, immediate posttest, and 6-month posttest on self-assessed knowledge, skills, and use of the Critical Appraisal of Race in Medical Literature (CARMeL) tool in subsequent journal clubs. RESULTS: We delivered this workshop to 560 students and 82 residents. Of the initial 140-student cohort evaluating the workshop, 99 (71% response rate) highly rated clarity of presentation, quality of teaching, and quality of slides. Of PGY 2 and PGY 3 residents, 67 (82% response rate) rated the workshop greater than 4.5 out of 5 on quality, clarity, and appropriateness of content. Residents had significant improvements in self-assessed knowledge and skills immediately after the session and 6 months later. Of residents, 74% reported using the CARMeL tool in subsequent presentations. DISCUSSION: We designed the CARMeL tool and a workshop to teach it. Trainees rated this workshop as useful, with the majority of residents later applying the tool. Limitations included a lack of objective assessment of knowledge acquisition. We recommend that institutions invest time in faculty development and pair new faculty with those experienced in anti-oppressive facilitation.

Interocular asymmetry of foveal avascular zone morphology and parafoveal capillary density in sickle cell retinopathy.

OBJECTIVES: To examine interocular asymmetry of foveal avascular zone (FAZ) and parafoveal capillary density metrics in sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A). METHODS: This cross-sectional, retrospective study evaluated SCR patients and unaffected controls who underwent 3x3mm macular OCT-A imaging using a spectral domain-OCT system. FAZ (area, perimeter, and acircularity index) and parafoveal capillary density metrics were computed for both eyes of each participant. In unaffected controls, interocular difference in FAZ and parafoveal capillary density metrics were evaluated using Bland-Altman plots. SCR patients with interocular difference outside the upper 97.5% and lower 2.5% limits of agreement from controls were defined as having interocular asymmetry. Area under receiver operating characteristic curve (AROC) was also performed to determine the ability of the absolute interocular difference to differentiate between subjects with SCR-including non-proliferative SCR (NP-SCR) and proliferative SCR (P-SCR)-and unaffected controls. RESULTS: Thirty-one patients with SCR (21 NP-SCR and 10 P-SCR) and 14 race-matched and age-matched controls were included for analysis. Interocular asymmetry was seen for all FAZ and parafoveal capillary density metrics in NP-SCR and P-SCR subjects. SCR subjects showed greater disease severity in the left-eye for FAZ and parafoveal capillary density metrics. CONCLUSIONS: NP-SCR and P-SCR patients demonstrated quantifiable interocular asymmetry in FAZ and parafoveal capillary density metrics compared to unaffected subjects, with left-eye predominance in disease severity.

Foveal avascular zone morphology and parafoveal capillary perfusion in sickle cell retinopathy.

BACKGROUND/AIMS: To assess foveal avascular zone (FAZ) morphology and parafoveal capillary perfusion in patients with various stages of sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A). METHODS: This is a multi-institutional retrospective study of patients with various stages of SCR compared with healthy controls. Parafoveal OCT-A images obtained using a commercial spectral domain-OCT system were reviewed. Foveal-centred 3×3 mm full vascular slab OCT-As were used for image processing and data analysis. FAZ area, perimeter, and acircularity index were determined on the OCT-A image after manual delineation of the FAZ border. Quadrant-based parafoveal capillary density and per cent area deviating from normal distribution were also measured. RESULTS: Fifty-two patients with SCR (33 non-proliferative and 19 proliferative) and 20 age and race-matched healthy controls were included. One randomly selected eye per study participant was analysed. FAZ perimeter and acircularity index were significantly greater in SCR eyes when compared with the controls. While parafoveal capillary density was significantly lower, per cent area deviated from normal distribution was significantly higher in SCR eyes than that of the control. However, no statistically significant difference between the two SCR stages was observed. In quadrant-based analysis, the temporal quadrant showed greater parafoveal capillary dropout due to SCR, with the most profound effect in patients with proliferative SCR. CONCLUSIONS: Abnormal FAZ morphology and altered parafoveal capillary perfusion were found in patients with SCR. Our customised OCT-A image analysis method uniquely highlights significant quantitative alterations in perfusion density mapping in a qualitative display, with minimal obscuration of OCT-A image detail.

Suspending Student Selections to Alpha Omega Alpha Honor Medical Society: How One School Is Navigating the Intersection of Equity and Wellness.

Medical education must provide students with a delicate balance of academic rigor, equity, and wellness. While the medical education community espouses all these values, the authors believe the way medical students are evaluated and rewarded undermines equity and wellness. Alpha Omega Alpha Honor Medical Society (AΩA) membership is arguably the highest honor that a medical student can achieve. In the short term, it opens doors to the most selective training opportunities, and in the long term, ushers students into an elite group of future physician leaders. Yet recent data have demonstrated that AΩA is disproportionately awarded to white students.At Icahn School of Medicine at Mount Sinai (ISMMS), the authors observed that students underrepresented in science and medicine were persistently underrepresented among those selected for AΩA. They describe efforts at ISMMS to reduce bias in the selection process and the ultimate decision to suspend medical student selection for AΩA altogether. The authors argue that selection to AΩA reinforces the structural biases and social privilege that are embedded in medical education and undermines the ability to deliver an educational experience that has as its core tenets equity and wellness. Suspending participation in student selection for AΩA is an important step toward recognizing that medical school learning environments continue to privilege white students over students who are underrepresented in medicine.

Flavoprotein Fluorescence Correlation with Visual Acuity Response in Patients Receiving Anti-VEGF Injection for Diabetic Macular Edema.

Anti-VEGF treatment of diabetic macular edema (DME) complicating diabetic retinopathy (DR) has greatly improved structural and visual outcomes for patients with diabetes mellitus. However, up to 50% of patients are either nonresponsive or refractory to anti-VEGF treatment (no improvement in BCVA or central macular thickness (CMT)). It is believed that factors such as mitochondrial structural and functional damage, due to oxidative stress, are partially responsible for this lack of improvement. Flavoprotein fluorescence (FPF) has been shown to be a sensitive marker of mitochondrial function and has been found to correlate with the degree of diabetic retinopathy. FPF may also provide additional information regarding therapeutic response of patients receiving anti-VEGF treatment for DME. Eight patients with DR and DME with clinically significant DME (CSDME) who underwent anti-VEGF (bevacizumab) treatment were imaged before injection and at follow-up visit using FPF in addition to standard color fundus photography and OCT CMT. A strong correlation r = 0.98 (p = 0.000015) between the FPF decrease and the BCVA improvement was observed; BCVA improved as FPF values decreased. Notably, in the same patients, the correlation between OCT CMT decrease and BCVA improvement (r = 0.688) was not found to be significant (p = 0.13). These findings suggest that FPF can detect improvement in metabolic function preceding structural improvement and even with small changes in edema. Additionally, FPF may be supplementary to current diagnostic methods for earlier detection of therapeutic response to anti-VEGF treatment in patients with DME.

Baerveldt Attached to XEN: A New Technique to Manage Failed XEN Glaucoma Surgery.

PURPOSE: To describe a new surgical technique for refractory glaucoma with failed XEN gel stent surgery with insertion of the Baerveldt implant. SURGICAL TECHNIQUE: In a patient with a failed XEN gel stent, a gentle conjunctival dissection was performed to expose the XEN and remove subconjunctival obstruction thus restoring patency and flow. A Baerveldt 250 implant was inserted in the superonasal quadrant above the extraocular muscles and sutured to the sclera. The Baerveldt tube was correctly positioned to accept insertion of the present XEN gel stent. The double lumen was sutured to secure the position. Two corneal patches were sutured over the tube to prevent exposure. The usual conjunctival suturing closure was performed. CONCLUSION: This technique is simple and restores lowering of intraocular pressure in patient with failed XEN and potentially increases the safety of refractory glaucoma surgeries in these patients.

Within-subject assessment of foveal avascular zone enlargement in different stages of diabetic retinopathy using en face OCT reflectance and OCT angiography.

Enlargement of the foveal avascular zone (FAZ) due to progressive capillary nonperfusion is associated with visual deterioration in patients with diabetic retinopathy. The FAZ area has long been considered an important clinical marker of advancing retinopathy. However, a large body of literature shows that the FAZ area varies considerably in healthy eyes, resulting in substantial overlap between controls and diabetics, thus reducing its discriminatory value. In this study, within-subject FAZ area enlargement was obtained by the comparison of the structural FAZ area to the functional FAZ area using simultaneously-acquired, corresponding en face OCT reflectance and OCT angiography images. Our study suggests that en face OCT reflectance images provide useful anatomic baselines of structural FAZ morphology prior to the onset of disease. Measurements of within-subject FAZ area enlargement appear to be a more sensitive method for identifying the onset of diabetic retinopathy as compared to using OCT angiographic measurements of FAZ alone.