Multimodal testing reveals subclinical neurovascular dysfunction in prediabetes, challenging the diagnostic threshold of diabetes.

AIM: To explore if novel non-invasive diagnostic technologies identify early small nerve fibre and retinal neurovascular pathology in prediabetes. METHODS: Participants with normoglycaemia, prediabetes or type 2 diabetes underwent an exploratory cross-sectional analysis with optical coherence tomography angiography (OCT-A), handheld electroretinography (ERG), corneal confocal microscopy (CCM) and evaluation of electrochemical skin conductance (ESC). RESULTS: Seventy-five participants with normoglycaemia (n = 20), prediabetes (n = 29) and type 2 diabetes (n = 26) were studied. Compared with normoglycaemia, mean peak ERG amplitudes of retinal responses at low (16-Td·s: 4.05 µV, 95% confidence interval [95% CI] 0.96-7.13) and high (32-Td·s: 5·20 µV, 95% CI 1.54-8.86) retinal illuminance were lower in prediabetes, as were OCT-A parafoveal vessel densities in superficial (0.051 pixels/mm2 , 95% CI 0.005-0.095) and deep (0.048 pixels/mm2 , 95% CI 0.003-0.093) retinal layers. There were no differences in CCM or ESC measurements between these two groups. Correlations between HbA1c and peak ERG amplitude at 32-Td·s (r = -0.256, p = 0.028), implicit time at 32-Td·s (r = 0.422, p < 0.001) and 16-Td·s (r = 0.327, p = 0.005), OCT parafoveal vessel density in the superficial (r = -0.238, p = 0.049) and deep (r = -0.3, p = 0.017) retinal layers, corneal nerve fibre length (CNFL) (r = -0.293, p = 0.017), and ESC-hands (r = -0.244, p = 0.035) were observed. HOMA-IR was a predictor of CNFD (ß = -0.94, 95% CI -1.66 to -0.21, p = 0.012) and CNBD (ß = -5.02, 95% CI -10.01 to -0.05, p = 0.048). CONCLUSIONS: The glucose threshold for the diagnosis of diabetes is based on emergent retinopathy on fundus examination. We show that both abnormal retinal neurovascular structure (OCT-A) and function (ERG) may precede retinopathy in prediabetes, which require confirmation in larger, adequately powered studies.

Using the COM-B framework to elucidate facilitators and barriers to COVID-19 vaccine uptake in pregnant women: a qualitative study.

Since April 2021, COVID-19 vaccines have been recommended for pregnant women. Despite this, COVID-19 vaccine uptake in this group is low compared to the non-pregnant population of childbearing age. Our aim was to understand barriers and facilitators to COVID-19 vaccine uptake among pregnant women in Northern Ireland using the COM-B framework, and so to make recommendations for public health interventions. The COM-B proposes that human behaviour is influenced by the extent to which a person has the capability, opportunity, and motivation to enact that behaviour. Understanding the factors underpinning behaviour through this lens helps discern what needs to change to change behaviour, therefore supporting the development of targeted interventions.This study consisted of eight semi-structured interviews with new/expectant mothers who did not receive a COVID-19 vaccine dose while pregnant since April 2021, and a focus group with five participants who received at least one COVID-19 vaccine dose while pregnant. Interview and focus group data were analysed using semi-deductive reflexive thematic analysis framed by a subtle realist approach. The COM-B was used to categorise codes and subthemes were developed within each COM-B construct.Within Psychological Capability, subthemes captured the need for consistent and reliable COVID-19 vaccine information and access to balanced and jargon-free, risk-benefit information that is tailored to the pregnant individual. The behaviour/opinions of family, friends, and local healthcare providers had a powerful influence on COVID-19 vaccine decisions (Social Opportunity). Integrating the COVID-19 vaccine as part of routine antenatal pathways was believed to support access and sense of familiarity (Physical Opportunity). Participants valued health autonomy, however experienced internal conflict driven by concerns about long-term side effects for their baby (Reflective Motivation). Feelings of fear, lack of empathy from healthcare providers, and anticipated guilt commonly underpinned indecision as to whether to get the vaccine (Automatic Motivation).Our study highlighted that the choice to accept a vaccine during pregnancy generates internal conflict and worry. Several participants cited their concern was primarily around the safety for their baby. Healthcare professionals (HCPs) play a significant part when it comes to decision making about COVID-19 vaccines among pregnant women. HCPs and pregnant women should be involved in the development of interventions to improve the delivery and communication of information.

Longitudinal changes in corneal leucocyte density in vivo following transplantation.

AIMS: To prospectively evaluate the changes in corneal leucocyte density with in vivo confocal microscopy (IVCM) following transplantation and to determine if leucocyte density post-transplant is an indicator of graft rejection risk. METHODS: IVCM imaging of cornea pre-transplant and post-transplant at 1 week, 1, 3 and 12 months. The changes in leucocyte density associated with diagnosis, vascularisation, type of keratoplasty, topical steroid and immunosuppression treatment, allograft rejection and failure within 4 years post-transplant were analysed. RESULTS: Sub-basal nerve plexus total central leucocyte density (SBNP-TCLD) varied with diagnosis (p<0.001), interval post-transplant (p<0.001), degree of vascularisation (p=0.001) and rejection episodes in eyes off topical steroid (p=0.01). The highest SBNP-TCLD was found in eyes with inflammation pre-transplant. Mean 12-month SBNP-TCLD in eyes which had rejection episodes was almost double that in eyes which did not (79.0 and 39.8 cells/mm2, respectively). SBNP-TCLD >63.5 cells/mm2 was associated with a higher risk of rejection within 1 year (p=0.04) and 4 years (p=0.007). Changes in leucocyte density on the donor endothelium significantly differed between penetrating keratoplasty and deep anterior lamellar keratoplasty grafts (p<0.01) and in those in which rejection episodes were observed (p<0.001). CONCLUSIONS: Leucocyte density varies with corneal diagnosis, extent of vascularisation and interval post-transplant. Topical steroid treatment is associated with reduced leucocyte density and risk of graft rejection. Higher endothelium leucocyte density correlates significantly with previous or subsequent rejection episodes. Leucocyte density measurement by IVCM may be useful in identifying transplants at risk of rejection.

The Incidence of Binocular Visual Impairment and Blindness in Children with Bilateral Retinoblastoma.

PURPOSE: The study aimed to assess the incidence of and risk factors leading to visual impairment and legal blindness in children with retinoblastoma. PROCEDURES: This is a single-center, retrospective case series of all patients with bilateral retinoblastoma presenting from 2010 to 2014. RESULTS: A total of 44 patients were included in the study. Visual impairment was present in 14 (38%) children, legal blindness was present in 7 (19%) children. Bilateral macular tumors (BMT) were associated with visual impairment (12 of 18 patients with BMT, 2 of 19 patients without BMT, p = 0.0006) and legal blindness (7 of 18 patients with BMT, 0 of 19 patients without BMT, p = 0.003). The International Intraocular Retinoblastoma Classification (IIRC) of the better eye also predicted visual impairment (16% in IIRC Group a, b, c, 75% in IIRC Group D, E, p = 0.004) and blindness (3% eye in IIRC Group a, b, c, 50% in Group D, E, p = 0.005). Various non-Snellen visual acuity measures were able to predict visual impairment in pre-verbal children, providing them with early assistance. CONCLUSIONS: The rates of visual impairment and blindness reported in this paper can be used to counsel families regarding the risk of binocular visual impairment. Early detection and support for visually impaired infants are essential as development can be affected by severe visual impairment.

An assessment of medical students' awareness of radiation exposures associated with diagnostic imaging investigations.

OBJECTIVES: This study assessed students' awareness of radiation exposures and determined the impact a curriculum in clinical radiology (CICR) had on awareness. METHODS: Six hundred seventy medical students at one medical school were studied. CICR was delivered in yearly modules over the 5-year programme. Five hundred twenty-three students (years 1-5), exposed to increasing numbers of CICR modules and 147 students beginning medical school (year 0), represented the study and control groups, respectively. Students completed a multiple choice questionnaire assessing radiation knowledge and radiology teaching. RESULTS: Most students in the study population received CICR but 87% considered they had not received radiation protection instruction. The percentage of correctly answered questions was significantly higher in the study population than the control group (59.7% versus 38%, p < 0.001). Students who received CICR achieved higher scores than those who did not (61.3% compared with 42.8%, p < 0.001). Increasing exposure to CICR with each year of medical education was associated with improved performance. CONCLUSIONS: Assessment of students' awareness of radiation exposures in diagnostic imaging demonstrates improved performance with increasing years in medical school and/or increasing exposure to CICR. Findings support the Euroatom 97 directive position, advocating implementation of radiation protection instruction into the undergraduate medical curriculum.