PurposeTo investigate the feasibility of increasing the stiffness of human tarsal tissue following treatment with riboflavin and ultraviolet A (UVA) to induce cross-linking of collagen fibers.MethodsIn this case control study, 18 right and left upper eyelids were excised en bloc from 18 fresh-frozen cadavers. One side served as the control while the samples from the opposite side were cross-linked. Four 2 × 6-mm vertical strips of central tarsus were cut from the superior to inferior border of each tarsal plate. Sample tissue was irradiated with UVA at 6 mW/cm2 for 18 minutes. A microtensile load cell and an optical coherence tomography scanner allowed calculation of stiffness (Young's modulus). Six cross-linked samples and corresponding controls were stained with hematoxylin and eosin (H&E) and Masson trichrome stains. Four controls and four cross-linked samples were also reviewed with a transmission electron microscope.ResultsMean Young's modulus in the linear region for controls was 28 ± 9 MPa and was much higher at 138 ± 8 MPa for cross-linked samples (P < 0.001), yielding a 493% mean stiffness increase. Staining with H&E and Masson did not reveal any histologic changes. Transmission electron microscopy showed a decrease in average diameter of 50 randomly selected collagen fibers from 47.2 ± 1.9 nm prior to cross-linking to 34.2 ± 1.1 nm post cross-linking (P < 0.001). Qualitatively, the collagen fibers appeared more closely packed following cross-linking.ConclusionsThe findings of this study suggest that collagen cross-linking is a viable and effective modality for increasing the stiffness of human tarsal plates.Translational RelevanceThis work provides proof that collagen cross-linking produces stiffening of the human tarsal plate and may be used in disorders that cause eyelid laxity.
The coronavirus disease 2019 (COVID-19) pandemic dramatically changed how people socialized. However, little is known about the extent to which the pandemic changed the social connections of people with tenuous interpersonal relationships at baseline, including homeless-experienced people and people with psychotic disorders. We sought to understand how these populations experienced changes in their social connectivity and to identify coping strategies employed. We conducted 43 semi-structured interviews with 27 vulnerable participants (11 homeless-experienced people and 16 people with psychotic disorders) and 16 comparison group participants, all of whom used services at the Department of Veterans Affairs (VA). Vulnerable participants in both groups had sparse prepandemic social connectedness; few perceived pandemic-related social network changes. While many homeless-experienced participants struggled with transitioning to technology to communicate, participants with psychotic disorders used technology to stay connected. Resilience derived from military service experiences was adaptive during the pandemic, complemented by VA services that provided supports.
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