Access to eye care and support services among adults from minority ethnic communities living with visual impairment in the United Kingdom

Background

Despite an increased risk of certain eye conditions which can lead to visual impairment (V.I.), there is evidence of a greater delay to treatment-seeking among adults from minority ethnic communities (MEC). MEC adults may also be underrepresented on V.I. registers, within early intervention services, and among the beneficiaries of national V.I. charities. However, much of this evidence is outdated or anecdotal.

Methods

This secondary analysis of V.I. Lives survey data explored use of eye health and support services and mobility aids among a matched control sample of 77 MEC and 77 adults aged 18 and over from white communities (WC). Participants were matched on age, gender, UK region and urban/rural setting. Additional subgroup analysis was conducted for Asian (n = 46) and black participants (n = 22).

Results

There were no significant group differences in areas such as eye health service use, registration status, contact with charities, and level of practical support received. But MEC participants were significantly more likely than WC participants to have received direct payments from social services to cover their care needs, Χ2 (1, 154) = 8.27, p = 0.004, and to use apps on their mobile for mobility, Χ2 (1, 154) = 5.75, p = 0.017. In contrast, WC participants were significantly more likely to agree that they were getting the level of emotional support to get on with their life, U = 3,638, p = 0.010, to feel confident to ask their friends for support, U = 2,416, p = 0.040, and to have a guide dog for mobility, Χ2 (1, 154) = 3.62, p = 0.057, although the latter did not reach statistical significance. Within the MEC group, Asian participants were significantly more likely than black participants to use a long cane, Χ2 (1, 68) = 7.24, p = 0.007, but they were significantly less likely to agree that they had received the right level of support when they started to experience V.I., U = 236.5, p = 0.040.

Conclusion

The preliminary findings suggests that there is scope to increase support provided by V.I. charities and the V.I. register, although, contrary to existing evidence, there were no statistically significant differences in eye health service use, registration status and use of wider support services. Further research is required to confirm these findings and explore reasons for differences.

Exploring mental well-being, the emotional impact of visual impairment and experiences of prejudice and discrimination among adults from minority ethnic communities in the UK

Background

Visual impairment (V.I.) has been associated with a negative impact on mental health outcomes, including a process of grief among those who lose their sight. Older adults with V.I. who had experienced discrimination have been found to be at increased risk of depression, loneliness, poorer life satisfaction and poorer quality of life. Adults from minority ethnic communities (MEC) may be at increased risk of V.I. and yet, research on the experiences of MEC adults with V.I. remains limited. This article forms part of a series which explores issues and status among MEC adults living with V.I. in the UK.

Methods

A secondary analysis of V.I. Lives survey data was performed to explore mental well-being assessed by the short Warwick-Edinburgh Mental Well-being scale (SWEMWBS), the emotional impact of V.I., and prejudice and discrimination among a matched control sample of 77 MEC and 77 adults from white communities (WC). Participants were matched by age, gender, UK region and urban/rural setting. Subgroup analyses were also conducted for the two largest MEC subgroups, Asian (n = 46) and black participants (n = 22).

Results

There were few statistically significant differences between the groups. MEC participants were significantly more likely than WC participants to rate emotional support to come to terms with their V.I. as important and to feel optimistic about their V.I. but they were significantly less likely to agree that they were receiving the level of emotional support they needed to get on with their life. Within the MEC group, participants from Asian communities had significantly poorer mental well-being, and they were also significantly more likely to agree that the general public were often prejudiced against people with V.I. and less likely to feel optimistic about their V.I. than black participants.

Conclusion

Although there were few statistically significant differences, participants from Asian communities were more likely to report poor mental and emotional well-being, and experiences of discrimination, than black and white participants. In contrast, participants from black communities fared the same as, or in some cases better than, white participants. Future research will need to confirm these findings and explore reasons for these.

Structural and functional insights into the role of BamD and BamE within the β-barrel assembly machinery in Neisseria gonorrhoeae

The β-barrel assembly machinery (BAM) is a conserved multicomponent protein complex responsible for the biogenesis of β-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Given its role in the production of OMPs for survival and pathogenesis, BAM represents an attractive target for the development of therapeutic interventions, including drugs and vaccines against multidrug-resistant bacteria such as Neisseria gonorrhoeae The first structure of BamA, the central component of BAM, was from N. gonorrhoeae, the etiological agent of the sexually transmitted disease gonorrhea. To aid in pharmaceutical targeting of BAM, we expanded our studies to BamD and BamE within BAM of this clinically relevant human pathogen. We found that the presence of BamD, but not BamE, is essential for gonococcal viability. However, BamE, but not BamD, was cell-surface-displayed under native conditions; however, in the absence of BamE, BamD indeed becomes surface-exposed. Loss of BamE altered cell envelope composition, leading to slower growth and an increase in both antibiotic susceptibility and formation of membrane vesicles containing greater amounts of vaccine antigens. Both BamD and BamE are expressed in diverse gonococcal isolates, under host-relevant conditions, and throughout different phases of growth. The solved structures of Neisseria BamD and BamE share overall folds with Escherichia coli proteins but contain differences that may be important for function. Together, these studies highlight that, although BAM is conserved across Gram-negative bacteria, structural and functional differences do exist across species, which may be leveraged in the development of species-specific therapeutics in the effort to combat multidrug resistance.

Expression and Purification of the Individual Bam Components BamB-E

BamB, BamC, BamD, and BamE are lipoproteins that, along with the integral membrane protein BamA, form the β-barrel assembly machinery (BAM) complex in the outer-membrane of Gram-negative bacteria. Elucidating the roles that these lipoproteins play in the β-barrel assembly process requires both structural and functional studies that rely on milligram quantities of pure protein. Here, we describe a simple protocol for expressing individual BamB-BamE proteins in Escherichia coli and purifying them by nickel affinity and size-exclusion chromatography. This protocol yields pure proteins in amounts that are sufficient for crystallization trials, in vitro protein-protein interaction studies, NMR, and other biochemical experiments.

Expression, Purification, and Screening of BamE, a Component of the BAM Complex, for Structural Characterization

In Gram-negative bacteria, integral outer membrane β-barrel proteins (OMP) are assembled by the β-barrel assembly machine complex, or BAM complex. This complex includes the essential components BamA, an OMP composed of a carboxyl terminal β-barrel domain and five polypeptide transport-associated domains (POTRA), and the lipoprotein BamD. In Escherichia coli, the complex contains an additional three lipoproteins, BamB, C and E required for efficient delivery of OMPs to the outer membrane. Here we provide methods for production, isotope labeling, purification, and functional screening of BamE for research purposes. Purification strategies of both the soluble and wild-type membrane-tethered forms of BamE are described using techniques including osmotic shock, Ni-NTA purification, and size-exclusion chromatography. Functional screening using a simple plate assay is also described which allows screening for defects in outer membrane permeability.