Impact of Persisting Amblyopia on Socioeconomic, Health, and Well-Being Outcomes in Adult Life: Findings From the UK Biobank

Effects of environmental enrichment on GLUT expression in the visual cortex of amblyopic rats

OBJECTIVE

To investigate the potential changes of glucose metabolism and glucose transporter protein (GLUT) in the visual cortex of formally deprived amblyopic rats, as well as the effects of enriched environments on the levels of nerve conduction and glucose metabolism in the visual cortex of amblyopic rats.

METHODS

36 rats were randomly divided into three groups: CON + SE (n = 12), MD + SE (n = 12) and MD + EE (n = 12). The right eyelids of both MD + SE and MD + EE groups were sutured. After successful modelling, the MD + EE group was maintained in an enriched environment, and the other two groups were kept in the same environment. Pattern visual evoked potentials (PVEP) was used to confirm models' effect, glucose metabolism was analyzed by Micro-PET/CT (18F-FDG), and the protein as well as mRNA expression levels of GLUT were detected by Western Blot and quantitative RT-PCR (quantitative Reverse Transcription-Polymerase Chain Reaction) analyses, site of GLUT expression by immunofluorescence (IF).

RESULTS

After suture modelling, both the MD + EE and MD + SE groups objective visual nerve conduction function decreased, the glucose metabolism in the visual cortex was markedly lower. After the enriched environment intervention, it recovered in the MD + EE group. The expression levels of GLUT1 and GLUT3 were increased in the MD + EE group in comparison with the MD + SE group. GLUT1 was primarily expressed on astrocytes and endothelial cells, but GLUT3 was mainly expressed on neurons.

CONCLUSION

Enrichment of the environment exhibited a therapeutic effect on amblyopia, which could be related to the enhancement of glucose metabolism and GLUT expression in the visual cortex.

Associations between unilateral amblyopia in childhood and cardiometabolic disorders in adult life: a cross-sectional and longitudinal analysis of the UK Biobank

Background

Amblyopia is a common neurodevelopmental condition and leading cause of childhood visual impairment. Given the known association between neurodevelopmental impairment and cardiometabolic dysfunction in later life, we investigated whether children with amblyopia have increased risk of cardiometabolic disorders in adult life.

Methods

This was a cross-sectional and longitudinal analysis of 126,399 United Kingdom Biobank cohort participants who underwent ocular examination. A subset of 67,321 of these received retinal imaging. Data analysis was conducted between November 1st 2021 and October 15th 2022. Our primary objective was to investigate the association between amblyopia and a number of components of metabolic syndrome and individual cardiometabolic diseases. Childhood amblyopia, dichotomised as resolved or persisting by adulthood, cardiometabolic disease and mortality were defined using ophthalmic assessment, self-reported, hospital admissions and death records. Morphological features of the optic nerve and retinal vasculature and sublayers were extracted from retinal photography and optical coherence tomography. Associations between amblyopia and cardiometabolic disorders as well as retinal markers were investigated in multivariable-adjusted regression models.

Findings

Individuals with persisting amblyopia (n = 2647) were more likely to be obese (adjusted odds ratio (95% confidence interval): 1.16 (1.05; 1.28)), hypertensive (1.25 (1.13; 1.38)) and diabetic (1.29 (1.04; 1.59)) than individuals without amblyopia (controls, (n = 18,481)). Amblyopia was also associated with an increased risk of myocardial infarction (adjusted hazard ratio: 1.38 (1.11; 1.72)) and death (1.36 (1.15; 1.60)). On retinal imaging, amblyopic eyes had significantly increased venular caliber (0.29 units (0.21; 0.36)), increased tortuosity (0.11 units (0.03; 0.19)), but lower fractal dimension (-0.23 units (-0.30; -0.16)) and thinner ganglion cell-inner plexiform layer (mGC-IPL, -2.85 microns (-3.47; -2.22)). Unaffected fellow eyes of individuals with amblyopia also had significantly lower retinal fractal dimension (-0.08 units (-0.15; -0.01)) and thinner mGC-IPL (-1.14 microns (-1.74; -0.54)). Amblyopic eyes with a persisting visual deficit had smaller optic nerve disc height (-0.17 units (-0.25; -0.08)) and width (-0.13 units (-0.21; -0.04)) compared to control eyes.

Interpretation

Although further research is needed to understand the basis of the observed associations, healthcare professionals should be cognisant of greater cardiometabolic dysfunction in adults who had childhood amblyopia. Differences in retinal features in both the amblyopic eye and the unaffected non-amblyopic suggest generalised versus local processes.

Funding

Medical Research Council (MR/T000953/1) and the National Institute for Health and Care Research.

Do Socioeconomic Inequalities Exist Within Ophthalmology and Orthoptics in the UK?: A Scoping Review

Introduction

It is well documented that socioeconomic disadvantage adversely affects general health and ocular health worldwide. Within orthoptics, while clinicians recognise a relationship between socioeconomic situation and treatment outcome, no previous literature review was found to address this issue. Neither was a UK-specific literature review found to address the same issue for ophthalmology as a whole.

Aim

This literature review evaluates evidence for an association between socioeconomic situation and ophthalmic/orthoptic conditions and their treatment outcomes, specifically within the UK.

Methods

Keyword searches were conducted on Google Scholar and the University of Liverpool library catalogue. Results for the main analyses were limited to full papers, specific to the UK, written in English. Literature was only included from pre-2000 if more recent evidence was insufficient.

Results

There is evidence of socioeconomic disadvantage being associated with the following: reduced visual acuity; reduced attendance at diabetic retinopathy screening appointments; and delayed presentation of glaucoma, cataracts, and diabetic retinopathy. However, evidence linking socioeconomic disadvantage to AMD is mixed. There is limited evidence of the increased prevalence of amblyopia and subsequent barriers to its treatment for socioeconomically underserved children. There is also evidence of a reduction in quality of life for socioeconomically underserved adults with strabismus.

Conclusions

Health inequalities within ophthalmology and orthoptics are reported, but with confounding results for some conditions. Further research should explore the reasons behind the inequalities that are found and identify methods of reducing them.

Particular Anatomy of the Hyperopic Eye and Potential Clinical Implications

Background and Objectives: Hyperopia is a refractive error which affects cognitive and social development if uncorrected and raises the risk of primary angle-closure glaucoma (PACG). Materials and Methods: The study included only the right eye-40 hyperopic eyes in the study group (spherical equivalent (SE) under pharmacological cycloplegia over 0.50 D), 34 emmetropic eyes in the control group (SE between -0.50 D and +0.50 D). A complete ophthalmological evaluation was performed, including autorefractometry to measure SE, and additionally we performed Ocular Response Analyser: Corneal Hysteresis (CH), Corneal Resistance Factor (CRF); specular microscopy: Endothelial cell density (CD), Cell variability (CV), Hexagonality (Hex), Aladdin biometry: Anterior Chamber Depth (ACD), Axial Length (AL), Central Corneal Thickness (CCT). IBM SPSS 26 was used for statistical analysis. Results: The mean age of the entire cohort was 22.93 years (SD ± 12.069), 66.22% being female and 33.78% male. The hyperopic eyes had significantly lower AL, ACD, higher SE, CH, CRF. In the hyperopia group, there are significant, negative correlations between CH and AL (r -0.335), CRF and AL (r -0.334), SE-AL (r -0.593), ACD and CV (r -0.528), CV and CRF (r -0.438), CH (r -0.379), and positive correlations between CCT and CH (r 0.393) or CRF (r 0.435), CD and ACD (r 0.509) or CH (0.384). Age is significantly, negatively correlated with ACD (r -0.447), CH (r -0.544), CRF (r -0.539), CD (r -0.546) and positively with CV (r 0.470). Conclusions: Our study suggests a particular biomechanical behavior of the cornea in hyperopia, in relation with morphological and endothelial parameters. Moreover, the negative correlation between age and ACD suggests a shallower anterior chamber as patients age, increasing the risk for PACG.