Visual impairment and the prevalence of ocular pathology in homeless children and adults globally: a systematic review

BackgroundHomelessness is a global issue in developing and developed countries. This article is the first systematic review to explore its impact on visual health globally.MethodsA systematic literature search was conducted on OVID MEDLINE, EMBASE, and Cochrane CENTRAL. Peer-reviewed English-language studies with a focus on homeless children or adults that reported on ocular outcomes were included. Primary outcomes and secondary endpoints were reported via weighted averages. Primary outcomes between homeless children and homeless adults were compared using the Fisher exact test.ResultsThere were 5774 individuals across 23 full-text articles included in the review. For studies reporting primary outcomes, 36.8% of homeless individuals self-reported dissatisfaction with their vision, 26.8% self-reported a previous ocular pathology, 26.3% had uncorrected refractive error, 25.6% were functionally visually impaired, 9.2% had at least one previous eye surgery or procedure, and 4.0% had nonrefractive visual impairment. Upon screening, 25.1% of homeless individuals had some type of ocular pathology, which included cornea and external eye diseases (13.4%), glaucoma (7.4%), cataracts (6.3%), retinal diseases (5.3%), ocular motility disorders (4.7%), trauma (2.3%), neuro-ophthalmological conditions (1.7%), and oculoplastic conditions (0.7%). Homeless adults had significantly more visual impairment (p < 0.001), uncorrected refractive error (p < 0.001), ocular pathology (p < 0.001), cataracts (p < 0.001), retinal pathology (p < 0.001), and neuro-ophthalmological conditions (p < 0.001) relative to children.ConclusionsVisual impairment in homeless individuals is higher than the general population. Uncorrected refractive error is a leading cause of visual impairment in this population. Additionally, homeless adults have significantly more visual impairment and ocular pathology than homeless children. Future studies should also explore if these differences are consistent in developing countries and investigate ways to increase eye care access for homeless individuals.     

Absence of donor CD40 protects renal allograft epithelium and preserves renal function

Blocking the CD40‐CD154 pathway prevents allograft rejection and induces donor‐specific tolerance in various experimental models. However, the translation to clinical studies has been hampered by unexpected thromboembolic complications of CD154‐blocking antibodies. Thus, blocking CD40 instead is now considered as an alternative strategy. Here, we evaluated the role of donor CD40 in allospecific T‐cell responses in vitro and in an in vivo model for renal transplantation. Fully MHC‐mismatched allografts from CD40‐deficient donors displayed better renal function than wild type. These functional data correlated with a lower level of apoptosis in renal tubular epithelial cells and higher expression of PD‐L1, which is most probably because of a reduced Th17 response in recipients of a CD40‐deficient donor. This hypothesis was supported in vitro, where donor CD40 expression was important for the induction of direct allospecific T‐cell responses. Especially the induction of Th17 cells was critically dependent on donor CD40. IL‐17A in conjunction with interferon‐γ in turn rendered renal tubular epithelial cells to a more costimulatory state by upregulating CD40 and downregulating PD‐L1 expression. In conclusion, CD40 blockade not only reduces the allospecific T‐cell responses, but might also lead to protection of tubular epithelium from apoptosis and thereby preserve kidney allograft function.     

Pulse Wave Velocity for Assessment of Arterial Stiffness Among People With Spinal Cord Injury: A Pilot Study

Background/Objective: The most significant complication and leading cause of death for people with spinal cord injury (SCI) is coronary artery disease (CAD). It has been confirmed that aortic pulse wave velocity (PVW) is an emerging CAD predictor among able-bodied individuals. No prior study has described PWV values among people with SCI. The objective of this study was to compare aortic (the common carotid to femoral artery) PWV, arm (the brachial to radial artery) PVW, and leg (the femoral to posterior tibial artery) PVW in people with SCI (SCI group) to able-bodied controls (non-SCI group).

Methods: Participants included 12 men with SCI and 9 non-SCI controls matched for age, sex, height, and weight. Participants with a history of CAD or current metabolic syndrome were excluded. Aortic, arm, and leg PVW was measured using the echo Doppler method.

Results: Aortic PVW (mean ± SD) in the SCI group (1,274 ± 369 cm/s) was significantly higher (P < 0.05) than in the non-SCI group (948 ± 110 cm/s). There were no significant between-group differences in mean arm PVW (SCI: 1,152 ± 193 cm/s, non-SCI: 1,237 ± 193 cm/s) or mean leg PVW (SCI: 1,096 ± 1 73 cm/s, non-SCI: 994 ±178 cm/s) values.

Conclusions: Aortic PVW was higher among the SCI group compared with the non-SCI group. The higher mean aortic PVW values among the SCI group compared with the non-SCI group indicated a higher risk of CAD among people with SCI in the absence of metabolic syndrome.     

Enhanced thrombin generation in women with a history of oral contraception-related venous thrombosis

Introduction

In women who suffer venous thrombosis (VT) during oral contraceptive (OC) use, a transient risk factor (OC) is removed during the acute event, while most co-existing forms of thrombophilia persist and presumably continue to maintain hypercoagulability. The aim of this study was to establish if hypercoagulability persists long after OC-related VT and if it could be attributed to thrombophilia.

Materials and Methods

60 women (age 33.0 ± 8.5 years) were investigated 5 – 64 (median 33) months after OC-related VT (patients) and compared to 63 apparently healthy women (controls). All women were tested for thrombophilia, activated partial thromboplastin time (APTT), fibrinogen, D-dimer, P-selectin and C-reactive protein. Thrombin generation was measured by Technothrombin® TGA assay. Overall haemostasis potential (OHP) assay with overall coagulation potential (OCP) and overall fibrinolytic potential (OFP) as supplementary parameters were measured by repeated fibrin formation and degradation registration.

Results

In patients increased endogenous thrombin potential (4205 ± 440 nM x min vs 4015 ± 421 nM x min, p = 0.017), increased OCP (22.6 ± 4.6 Abs-sum vs 20.8 ± 4.1 Abs-sum, p = 0.025), shorter APTT (30.9 ± 3.8 s vs 33.4 ± 3.6 s, p < 0.001) and lower antithrombin activity (99, 93-105% vs 104, 100-109%, p < 0.05) were observed. Thrombophilia was observed in 22/60 (36%) patients and in 5/63 (7.9%, p < 0.001) controls. The only significant difference between thrombophilic and non-thrombophilic patients was higher soluble P-selectin in the former subgroup (22, 20-33 μg/L vs 17, 12-22 μg/L, p = 0.012).

Conclusions

In women with a history of OC-related VT persistent hypercoagulability was observed, which, however was not augmented by the presence of thrombophilia.     

The role of linguistic context in deriving word meanings in individuals with Down Syndrome

Deriving the meaning of unknown words from context and its relationship to text comprehension was investigated in 24 individuals with Down syndrome and in 24 typically developing children matched for the Peabody Picture Vocabulary Test (PPVT) score.The study consisted of three phases. Unknown words were identified during the first phase (PPVT). Those words were presented embedded in brief linguistic contexts during the second phase. Recognition (maintenance) of word meanings was verified in the third and final phase. Both groups of participants recognized the meanings of a noteworthy number of words in contexts and a high percentage of these was maintained when they were presented at a later date without the support of context. Over and above group differences and basic linguistic skills, text comprehension seems to predict the ability to use context. Context provides the semantic information necessary to extract word meaning by activating relevant world knowledge.