Ageing changes in the eye

Association Between Multimorbidity and Presence of Diagnosed Vision Problems Among the Middle-Aged and Older Population in India

PURPOSE

The aim of the study was to estimate the prevalence of diagnosed vision problems and to examine the association of single and multiple chronic conditions with vision problems among middle-aged and older adults in India.

METHODS

The study utilized data from the Longitudinal Ageing Study in India (LASI) Wave 1, (2017-18). Descriptive statistics along with bivariate and multivariable analyses were conducted to achieve the study objectives.

RESULTS

The prevalence of diagnosed vision problems in the sampled population was 48.2%. The older adults (60+ years) (55.3%) had shown a greater prevalence of vision problems than the middle-aged individuals (41%). Among chronic conditions, hypertension, diabetes, chronic lung diseases, chronic heart diseases, bone related diseases, psychiatric disorders, and high cholesterol were significantly associated with vision problems in the case of both middle-aged and older adults. Furthermore, odds of experiencing vision problems according to the presence of multimorbidity were higher in the middle-aged population [adjusted odds ratio (AOR) = 1.986; confidence interval (CI):1.855-2.126] than in the older population [AOR = 1.746; CI:1.644-1.854].

CONCLUSIONS

Middle-aged and older adults with chronic illnesses and multimorbidity were at greater risk of vision problems. Due to the high prevalence of vision problem, interventions aimed at prevention or early detection are warranted.

The reliability of retinal nerve fiber layer analysis to differentiate between papilledema and pseudopapilledema: A systematic review

Differentiating between papilledema and pseudopapilledema can be challenging in certain cases. Relying solely on subjective clinical examination may lead to confusion, and objective diagnostic confirmation methods may pose challenges such as cost, operator dependency, invasiveness or limited availability. This study seeks to assess whether retinal nerve fiber layer (RNFL) analysis can serve as a reliable measurement for establishing the diagnosis. A thorough literature search was conducted on PubMed, ProQuest, Google Scholar and Cochrane from 2012 to 2023, with the last search conducted on March 26, 2023. Non-English studies, review articles, case studies and editorial letters were excluded. The inclusion criteria comprised studies with available full text containing both papilledema and pseudopapilledema groups, with outcomes on sensitivity, specificity and/or area under the curve (AUC). This study adhered to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guideline. A total of 510 participants were included from seven different studies, all encompassing groups of papilledema and pseudopapilledema with or without optic disc drusen (ODD). The studies demonstrated the favorable accuracy of RNFL in differentiating papilledema from pseudopapilledema, with AUC values ranging from 0.78 to 0.91. However, specificity and sensitivity varied between 65%-100% and 33%-91%, respectively. Lower accuracy was observed when pseudopapilledema included only patients with ODD or when papilledema was limited to mild cases. In conclusion, RNFL proves to be a reliable measurement for differentiating papilledema from pseudopapilledema.

Undetected Visual Impairment Among Older People and Its Impact on Vision-Related Quality of Life: A Study Protocol

Background/Objectives: Ageing is a continuous process of physiological changes that occur over time and affect both ability and function, including vision. A major health issue for older people is visual impairment, which affects both daily activities and quality of life. Undetected visual impairment is a significant problem. Therefore, early detection is crucial to enable older people to optimise their vision and/or receive eye care. This study protocol aims to explore the prevalence of undetected visual impairment among the ageing population and its impact on their quality of life. Methods: This study has an exploratory design. We include participants attending a healthcare centre and participants attending an optician, aged 75 years and older, in Sweden. At baseline eye examinations, fundus photography, the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) and health economic data are collected. Individual semi-structured interviews (n = 25-30) will then be conducted about older people's experiences of visual impairment, both consequences and strategies for coping with visual impairment in daily life. The NEI VFQ-25 and health economic data will be collected at 6- and 12-month follow-ups. Conclusions: This study will provide important knowledge to facilitate early detection of visual impairment in older people, thereby providing a deeper understanding of methods to preserve visual function and quality of life despite the presence of visual impairment.

Plasma and Urine Metabolites Associated with Microperimetric Retinal Sensitivity in Age-Related Macular Degeneration

BACKGROUND

Best-corrected visual acuity (BCVA) is the current gold standard of retinal function measurement but is not affected in early and intermediate forms of age-related macular degeneration (AMD). Increasing evidence suggests that microperimetry is a sensitive measure of visual function. This study sought to analyze the associations between plasma and urine metabolites and microperimetry in AMD.

METHODS

We included data on 363 eyes (95 controls, 268 AMD). Microperimetry was performed in patients with or without AMD using the Macular Integrity Assessment (MAIA) microperimetry system, employing a 37-point full-threshold protocol. Plasma and urine samples were analyzed via ultra-high-performance liquid chromatography-mass spectrometry. Multilevel mixed-effects linear models were used to assess associations between the metabolites and retinal sensitivity. Statistical significance was determined by considering the number of independent tests that accounted for 80% of the variance (ENT80).

RESULTS

We identified two plasma and seven urine metabolites, which were significantly associated with mean retinal sensitivity in AMD, and the key results include metabolites in the lysine metabolism pathway.

CONCLUSIONS

To our knowledge, we present the first assessment of the associations between plasma and urinary metabolites and retinal microperimetry sensitivity in AMD. This work can reveal more insight into the pathogenesis of AMD.

A case study on experiences with integrated technologies in a care home for older adults

To facilitate independent living for the growing population of older adults, innovative housing solutions such as novel concepts of care homes with integrated technologies have been developed. This case study exposes a significant gap between the intended goal of fostering independence in older adults and the actual impact of technology on their daily lives. The study explored perceptions, experiences, and needs regarding residents' use of integrated technologies along with the technologies' contribution to handling their everyday life in a Care+ home. Data were analyzed through qualitative content analysis. The key finding is that one size does not 'fit' all, indicating that the standardized technology installed in the apartments often fails to meet the users' individual needs. This research identifies a critical gap in tailoring technologies to the unique needs of older users. Aligning technological solutions with aging-in-place policies focused on autonomy and well-being is essential for enhancing care environments.

The eye in forensic practice: In the living

Eye examination plays an important role when living individuals are forensically investigated. The iris colour, retinal scans and other biometric features may be used for identification purposes while visual impairments may have legal implications in employment, driving and accidents. Ocular manifestations provide clues regarding substance abuse, poisoning and toxicity, and evidence of trauma, abuse or disease can be revealed along with psychological traits and lifestyle. Thus, the eye is a valuable tool in forensic investigations of living subjects, providing identifying characteristics along with health information. This review focuses on the medico-legal aspects of the eye's contribution when the living are subjected to forensic examination.

Ocular Pharmacokinetics of Faricimab Following Intravitreal Administration in Patients With Retinal Disease

Purpose

To characterize faricimab ocular and systemic pharmacokinetics (PK) in patients with neovascular age-related macular degeneration (nAMD) or diabetic macular edema (DME) and to assess the effect of faricimab ocular exposure on clinical endpoints.

Methods

A population PK (popPK) model was developed using pooled data from phase 1 to 3 studies in patients with nAMD/DME. The dataset included 1095 faricimab aqueous humor (AH) concentrations from 284 patients and 8372 faricimab plasma concentrations from 2246 patients.

Results

Following intravitreal administration, faricimab PK was accurately described by a linear three-compartment model with sequential vitreous humor (VH), AH, and plasma compartments. Faricimab VH elimination to AH is the slowest process, with an estimated half-life (t1/2) of 7.5 days. Due to flip-flop kinetics, plasma, AH, and VH concentrations declined in parallel. Disease had no effect on faricimab PK. Plasma exposure was ∼6000-fold lower than VH exposure. Age, anti-drug antibodies, body weight, and sex statistically significantly influenced PK parameters but had no clinically meaningful effect on ocular and systemic exposure. VH t1/2 alone could not explain faricimab dosing frequency. Exposure-response analyses showed similar gains in best-corrected visual acuity across faricimab exposure ranges and dosing regimens.

Conclusions

Faricimab ocular and systemic pharmacokinetics were quantified and accurately described by the popPK model, developed using a large dataset from patients with nAMD/DME. Exposure-response analyses suggest that faricimab phase 3 dosing algorithms are appropriate to select the most suitable dosing regimen.

Translational Relevance

The popPK analysis suggested that faricimab dosing frequency was influenced by several factors and not by VH t1/2 alone.

Retinal hyperspectral imaging in mouse models of Parkinson's disease and healthy aging

Retinal hyperspectral imaging (HSI) is a non-invasive in vivo approach that has shown promise in Alzheimer's disease. Parkinson's disease is another neurodegenerative disease where brain pathobiology such as alpha-synuclein and iron overaccumulation have been implicated in the retina. However, it remains unknown whether HSI is altered in in vivo models of Parkinson's disease, whether it differs from healthy aging, and the mechanisms which drive these changes. To address this, we conducted HSI in two mouse models of Parkinson's disease across different ages; an alpha-synuclein overaccumulation model (hA53T transgenic line M83, A53T) and an iron deposition model (Tau knock out, TauKO). In comparison to wild-type littermates the A53T and TauKO mice both demonstrated increased reflectivity at short wavelengths ~ 450 to 600 nm. In contrast, healthy aging in three background strains exhibited the opposite effect, a decreased reflectance in the short wavelength spectrum. We also demonstrate that the Parkinson's hyperspectral signature is similar to that from an Alzheimer's disease model, 5xFAD mice. Multivariate analyses of HSI were significant when plotted against age. Moreover, when alpha-synuclein, iron or retinal nerve fibre layer thickness were added as a cofactor this improved the R2 values of the correlations in certain groups. This study demonstrates an in vivo hyperspectral signature in Parkinson's disease that is consistent in two mouse models and is distinct from healthy aging. There is also a suggestion that factors including retinal deposition of alpha-synuclein and iron may play a role in driving the Parkinson's disease hyperspectral profile and retinal nerve fibre layer thickness in advanced aging. These findings suggest that HSI may be a promising translation tool in Parkinson's disease.

VDAC in Retinal Health and Disease

The retina, a tissue of the central nervous system, is vital for vision as its photoreceptors capture light and transform it into electrical signals, which are further processed before they are sent to the brain to be interpreted as images. The retina is unique in that it is continuously exposed to light and has the highest metabolic rate and demand for energy amongst all the tissues in the body. Consequently, the retina is very susceptible to oxidative stress. VDAC, a pore in the outer membrane of mitochondria, shuttles metabolites between mitochondria and the cytosol and normally protects cells from oxidative damage, but when a cell's integrity is greatly compromised it initiates cell death. There are three isoforms of VDAC, and existing evidence indicates that all three are expressed in the retina. However, their precise localization and function in each cell type is unknown. It appears that most retinal cells express substantial amounts of VDAC2 and VDAC3, presumably to protect them from oxidative stress. Photoreceptors express VDAC2, HK2, and PKM2-key proteins in the Warburg pathway that also protect these cells. Consistent with its role in initiating cell death, VDAC is overexpressed in the retinal degenerative diseases retinitis pigmentosa, age related macular degeneration (AMD), and glaucoma. Treatment with antioxidants or inhibiting VDAC oligomerization reduced its expression and improved cell survival. Thus, VDAC may be a promising therapeutic candidate for the treatment of these diseases.

Elemental mass spectrometry to study metallo-transcriptomic changes during the in vitro degeneration of the retinal pigment epithelium

Trace elements play crucial roles in cellular biology. Their improper homeostasis may contribute to the progress of eye diseases, exacerbated during ageing. The retinal pigment epithelium (RPE) is progressively deteriorated during age-related neurodegeneration and metal homeostasis may be compromised. In this study, elemental mass spectrometry (MS) was combined with cellular and molecular biology techniques to identify changes in trace elements during the in vitro degeneration of human RPE cells. Cells were collected at 21, 91, and 133 days and processed for RNA sequencing; Ca, Na, P, Mg, and Cu quantification by flow injection analysis and inductively coupled plasma-MS; and protein analysis by immunocytochemistry. Four-month-old RPE cultures showed depigmentation, impaired barrier function, and antioxidant protection, manifesting signs of epithelial-to-mesenchymal transition. Na and P significantly increased in the cytosol of degenerated RPE cells (from 15 ± 20 to 13495 ± 638 ng·µg-1 and from 30.6 ± 9.5 to 116.8 ± 16.8 ng·µg-1, respectively). Mg decreased in both the cytosol and insoluble fraction of cells (from 2.83 ± 0.40 to 1.58 ± 0.56 ng·µg-1 and from 247.57 ± 11.06 to 30 ± 8 ng·g-1, respectively), while P and Cu decreased in the insoluble fraction after 133 days in culture (from 9471 ± 1249 to 4555 ± 985 ng·µg-1 and from 2251 ± 79 to 1054 ± 235 ng·g-1, respectively), along with changes in metal-dependent antioxidant enzymes and Cu transporters. This RPE model reflected metal homeostatic changes, providing additional perspectives on effects of metal regulation during ageing.

Digital Eye Straining: Exploring Its Prevalence, Associated Factors, and Effects on the Quality of Life

BACKGROUND

Digital eye strain (DES) has become a pervasive issue in contemporary society due to increased reliance on electronic devices. This study aims to comprehensively explore the symptoms, severity, and associated factors of DES, considering demographic, behavioral, and health-related variables.

METHODOLOGY

A cross-sectional study was conducted among participants with diverse demographic backgrounds. A structured questionnaire collected data on participant characteristics, electronic device usage patterns, symptoms of DES, and its impact on various aspects of quality of life. Statistical analyses, including chi-square tests, were employed to assess associations and significance.

RESULTS

The majority of participants reported symptoms of DES, with eye dryness, headache, and eye redness being the most prevalent. Symptom severity varied, with age, daily device usage, adherence to the 20-20-20 rule, and studying with electronic devices demonstrating statistically significant associations. Participants diagnosed with eye diseases exhibited higher symptom severity. While disagreement was common regarding DES increasing stress, a substantial proportion acknowledged its impact on productivity and attention.

CONCLUSION

The current study showed that there is a significant correlation between the incidence of digital eye straining and longer screen exposure time. The findings underscore the importance of age, behavior, and ocular health in understanding and addressing DES. The results contribute to the broader discourse on digital eye health and emphasize the need for targeted interventions to alleviate the impact of DES on daily life.

Barriers in older adults' decision-making process to use routine eye examinations in Hong Kong

CLINICAL RELEVANCE

The decision to have a routine eye examination involves individual- and service-level judgement. A deeper understanding of patient access barriers and expectations could facilitate the design of better-aligned service models in optometric practice, improving the utilisation rate of an important facet of primary healthcare services.

BACKGROUND

Routine eye examinations achieve several health objectives, including mitigation of sight-threatening risk factors. However, there are barriers to service uptake. Through the qualitative approach, a deeper understanding of these barriers can be realised and enhanced strategies designed to improve the uptake of the routine eye examination. A qualitative study was conducted to identify the factors influencing the decision-making process of older adults to use the routine eye examination service.

METHODS

This study was guided by the grounded theory approach. Participants were purposively recruited from six community elderly centres. Semi-structured interviews were conducted with 25 community-dwelling adults aged 65 years or above in Hong Kong. Data were transcribed and constant comparison techniques were used for data analysis.

RESULTS

Difficulty in prioritising and including the routine eye examination in the existing health service utilisation was the central theme associated with its lower use. Four sub-themes were identified to explain this phenomenon: (1) previous health care service utilisation as a reference for judging primary eye care; (2) low perceived primary eye care service needs; (3) low perceived self-efficacy on routine eye care utilisation; (4) service expectations.

CONCLUSION

Multiple modifiable factors influence decision-making by older adults, suggesting that their routine eye care seeking behaviour might be altered through behaviour change intervention. The context in which services are delivered requires further study, with a focus on exploring the factors influencing service experience and its subsequent impact on regular eye care seeking behaviour.

Retinal Pigment Epithelium Pigment Granules: Norms, Age Relations and Pathology

The retinal pigment epithelium (RPE), which ensures the normal functioning of the neural retina, is a pigmented single-cell layer that separates the retina from the Bruch's membrane and the choroid. There are three main types of pigment granules in the RPE cells of the human eye: lipofuscin granules (LG) containing the fluorescent "age pigment" lipofuscin, melanoprotein granules (melanosomes, melanolysosomes) containing the screening pigment melanin and complex melanolipofuscin granules (MLG) containing both types of pigments simultaneously-melanin and lipofuscin. This review examines the functional role of pigment granules in the aging process and in the development of oxidative stress and associated pathologies in RPE cells. The focus is on the process of light-induced oxidative degradation of pigment granules caused by reactive oxygen species. The reasons leading to increased oxidative stress in RPE cells as a result of the oxidative degradation of pigment granules are considered. A mechanism is proposed to explain the phenomenon of age-related decline in melanin content in RPE cells. The essence of the mechanism is that when the lipofuscin part of the melanolipofuscin granule is exposed to light, reactive oxygen species are formed, which destroy the melanin part. As more melanolipofuscin granules are formed with age and the development of degenerative diseases, the melanin in pigmented epithelial cells ultimately disappears.

Crystalline lens nuclear age prediction as a new biomarker of nucleus degeneration

BACKGROUND

The crystalline lens is a transparent structure of the eye to focus light on the retina. It becomes muddy, hard and dense with increasing age, which makes the crystalline lens gradually lose its function. We aim to develop a nuclear age predictor to reflect the degeneration of the crystalline lens nucleus.

METHODS

First we trained and internally validated the nuclear age predictor with a deep-learning algorithm, using 12 904 anterior segment optical coherence tomography (AS-OCT) images from four diverse Asian and American cohorts: Zhongshan Ophthalmic Center with Machine0 (ZOM0), Tomey Corporation (TOMEY), University of California San Francisco and the Chinese University of Hong Kong. External testing was done on three independent datasets: Tokyo University (TU), ZOM1 and Shenzhen People's Hospital (SPH). We also demonstrate the possibility of detecting nuclear cataracts (NCs) from the nuclear age gap.

FINDINGS

In the internal validation dataset, the nuclear age could be predicted with a mean absolute error (MAE) of 2.570 years (95% CI 1.886 to 2.863). Across the three external testing datasets, the algorithm achieved MAEs of 4.261 years (95% CI 3.391 to 5.094) in TU, 3.920 years (95% CI 3.332 to 4.637) in ZOM1-NonCata and 4.380 years (95% CI 3.730 to 5.061) in SPH-NonCata. The MAEs for NC eyes were 8.490 years (95% CI 7.219 to 9.766) in ZOM1-NC and 9.998 years (95% CI 5.673 to 14.642) in SPH-NC. The nuclear age gap outperformed both ophthalmologists in detecting NCs, with areas under the receiver operating characteristic curves of 0.853 years (95% CI 0.787 to 0.917) in ZOM1 and 0.909 years (95% CI 0.828 to 0.978) in SPH.

INTERPRETATION

The nuclear age predictor shows good performance, validating the feasibility of using AS-OCT images as an effective screening tool for nucleus degeneration. Our work also demonstrates the potential use of the nuclear age gap to detect NCs.

Neurotrophins and Trk Neurotrophin Receptors in the Retina of Adult Killifish (Nothobranchius guentheri)

Specific subpopulations of neurons in nerve and sensory systems must be developed and maintained, and this is accomplished in significant part by neurotrophins (NTs) and the signaling receptors on which they act, called tyrosine protein kinase receptors (Trks). The neurotrophins-tyrosine protein kinase receptors (NTs/Trks) system is involved in sensory organ regulation, including the visual system. An NTs/Trks system alteration is associated with neurodegeneration related to aging and diseases, including retinal pathologies. An emergent model in the field of translational medicine, for instance, in aging study, is the annual killifish belonging to the Nothobranchius genus, thanks to its short lifespan. Members of this genus, such as Nothobranchius guentheri, and humans share a similar retinal stratigraphy. Nevertheless, according to the authors' knowledge, the occurrence and distribution of the NTs/Trks system in the retina of N. guentheri has never been investigated before. Therefore, the present study aimed to localize neurotrophin BDNF, NGF, and NT-3 and TrkA, TrkB, and TrkC receptors in the N. guentheri retina using the immunofluorescence method. The present investigation demonstrates, for the first time, the occurrence of the NTs/Trks system in N. guentheri retina and, consequently, the potential key role of these proteins in the biology and survival of the retinal cells.

Ferroptosis: underlying mechanisms and involvement in neurodegenerative diseases

Ferroptosis, a mode of cell death that was recently identified in 2012, is driven by iron-dependent lipid peroxidation and distinct from other mechanisms of cell death such as autophagy and apoptosis. Ferroptosis has the unique features of disruptions in iron equilibrium, iron-induced lipid peroxidation, and the accumulation of glutamate-induced cellular toxicity. The regulation of ferroptosis mainly involves the iron, lipid, and amino acid metabolic pathways, which are controlled by system Xc-, voltage-dependent anion channels, p53 and other pathways. Neurodegenerative diseases involve gradual neuronal loss predominantly within the central nervous system and are categorized into both sporadic and rare hereditary disorders. These diseases result in the progressive decline of specific neuron populations and their interconnections. Recent investigations have revealed a strong correlation between the manifestation and progression of neurodegenerative diseases and ferroptosis. The pharmacological modulation of ferroptosis, whether by induction or inhibition, exhibits promising prospects for therapeutic interventions for these diseases. This review aims to examine the literature on ferroptosis and its implications in various neurodegenerative diseases. We hope to offer novel insights into the potential therapies targeting ferroptosis in central nervous system neurodegenerative diseases. However, there are still limitations of this review. First, despite our efforts to maintain objectivity during our analysis, this review does not cover all the studies on ferroptosis and neurodegenerative diseases. Second, cell death in neurodegenerative diseases is not solely caused by ferroptosis. Future research should focus on the interplay of different cell death mechanisms to better elucidate the specific disease pathogenesis.

Subjective dry eye symptoms and associated factors among the national general population in China during the COVID-19 pandemic: A network analysis

Background

The coronavirus disease 2019 (COVID-19) pandemic has presented numerous challenges to public health, including the emergence of subjective dry eye symptoms among individuals. However, there is currently a dearth of comprehensive knowledge regarding the associated factors with subjective dry eye symptoms in the general population.

Methods

A nationwide survey in China was carried out from 20 June to 31 August 2022, involving 21 916 participants. Subjective dry eye symptoms were assessed using the Ocular Surface Disease Index-6. We employed random forest classification to select potential associated factors based on the socioecological model. We also conducted univariate and multivariable logistic regression analyses to explore the factors associated with subjective dry eye symptoms. Network analyses were employed to explore the network structure of subjective dry eye symptoms and associated factors.

Results

The item "watching TV (or similar task)" displayed the highest node strength and exhibited the highest predictability within the network. The results of the multivariate logistic regression analysis demonstrated significant associations between subjective dry eye symptoms and several factors, including loneliness (odds ratio (OR) = 1.29; 95% confidence interval (CI) = 1.26 to 1.32), problematic Internet use (OR = 1.08; 95% CI = 1.08 to 1.09), family communication (OR = 1.01; 95% CI = 1.00 to 1.01), the presence of depression (OR = 1.53; 95% CI = 1.39 to 1.68) and anxiety (OR = 1.31; 95% CI = 1.17 to 1.47) symptoms, older age (OR = 1.01; 95% CI = 1.01 to 1.01), self-rated health status (OR = 0.99; 95% CI = 0.98 to 0.99), family health (OR = 0.97; 95% CI = 0.96 to 0.97), health literacy (OR = 0.98; 95% CI = 0.97 to 0.99) and the agreeableness personality trait (OR = 0.97; 95% CI = 0.95 to 0.99).

Conclusions

These findings have important implications for public health interventions targeting the prevention and management of subjective dry eye symptoms in the general population. Strategies addressing individual risk factors and supporting psychological well-being may prove beneficial in mitigating the burden associated with subjective dry eye symptoms.

Postoperative trachomatous trichiasis: a systematic review and meta-analysis study

BACKGROUND

Trachomatous trichiasis is the potential stage of trachoma in which the eyelashes scratch the surface of the globe, ultimately causing corneal opacity, visual impairment and blindness. The aim of this systematic review and meta-analysis is to obtain the pooled prevalence and associated factors of postoperative trachomatous trichiasis (PTT) in World Health Organization (WHO) trachoma-endemic regions.

METHODS

An inclusive literature search was undertaken using PubMed, Cochrane Library, Science Direct and Google Scholar databases from 30 May 2022 to 28 June 2022. I2 statistics and funnel plots were used to determine heterogeneity and publication bias among included studies. A random effects model was used to estimate pooled prevalence, incidence and odds ratios (ORs) with the respective 95% confidence intervals (CIs) using RevMan 5.4 software.

RESULTS

Eighteen articles were included in this meta-analysis and systematic review. The pooled prevalence of PTT was 19% (range 18-21). PTT was lower among young adults compared with old adults (OR 0.63 [95% CI 0.44 to 0.92]), single-dose oral azithromycin as compared with tetracycline eye ointment users (OR 0.82 [95% CI 0.69 to 0.99]) and minor trichiasis before surgery as compared with major trichiasis (OR 0.63 [95% CI 0.47 to 0.85]).

CONCLUSIONS

The incidence of PTT was higher than the WHO's recommendation. Prescribing single-dose oral azithromycin after surgery, periodic training for trichiasis surgeons, close follow-up and health education after surgery are crucial to minimize the recurrence.Study protocol registration on PROSPERO: CRD42022336003.

Modulation transfer function formula for different age ranges

The modulation transfer function (MTF) is one of the most complete tools to study the optical performance of the eye. We present the average radial MTF profiles measured in 68 subjects grouped in six age ranges (from 20 to 80 years) and a general formula to estimate the radial profile of human MTF as a function of pupil size and age. The mean MTF for each age group was fitted to an analytical expression to compute two parameters related to aging. The proposed formula fitted reasonably well to experimental data available in previous works and predicted the average changes with aging of different optical quality parameters obtained from MTF.

The Effects of Aging on Rod Bipolar Cell Ribbon Synapses

The global health concern posed by age-related visual impairment highlights the need for further research focused on the visual changes that occur during the process of aging. To date, multiple sensory alterations related to aging have been identified, including morphological and functional changes in inner hair cochlear cells, photoreceptors, and retinal ganglion cells. While some age-related morphological changes are known to occur in rod bipolar cells in the retina, their effects on these cells and on their connection to other cells via ribbon synapses remain elusive. To investigate the effects of aging on rod bipolar cells and their ribbon synapses, we compared synaptic calcium currents, calcium dynamics, and exocytosis in zebrafish (Danio rerio) that were middle-aged (MA,18 months) or old-aged (OA, 36 months). The bipolar cell terminal in OA zebrafish exhibited a two-fold reduction in number of synaptic ribbons, an increased ribbon length, and a decrease in local Ca2+ signals at the tested ribbon location, with little change in the overall magnitude of the calcium current or exocytosis in response to brief pulses. Staining of the synaptic ribbons with antibodies specific for PKCa revealed shortening of the inner nuclear and plexiform layers (INL and IPL). These findings shed light on age-related changes in the retina that are related to synaptic ribbons and calcium signals.

Mechanisms of Extraorbital Lacrimal Gland Aging in Mice: An Integrative Analysis of the Temporal Transcriptome

Purpose

This study used high-throughput RNA sequencing (RNA-Seq) and bioinformatics analysis to investigate the altered transcriptome profile of aging lacrimal glands in mice that occurs over the course of a 24-hour cycle.

Methods

Male C57BL/6J mice aged 12 weeks (young) and 20 months (aging) were housed in a pathogen-free setting with a 12-hour light/12-hour dark cycle. Throughout a 24-hour cycle, mouse extraorbital lacrimal glands (ELGs) were collected at eight time points at three-hour intervals. To prepare for the high-throughput RNA-Seq, whole mRNA was extracted. Differentially expressed genes (DEGs) in the young and aging groups were subjected to bioinformatic analysis based on diurnal patterns. Furthermore, the cell populations in which significant DEGs express and signaling pathways occur were validated at the single-cell RNA sequencing (scRNA-seq) level.

Results

The total transcriptome composition was significantly altered in aging ELGs compared with that in young mouse ELGs at eight time points during the 24-hour cycle, with 864 upregulated and 228 downregulated DEGs, which were primarily enriched in inflammatory pathways. Further comparative analysis of the point-to-point transcriptome revealed that aging ELGs underwent alterations in the temporal transcriptome profile in several pathways, including the inflammation-related, metabolism-related, mitochondrial bioenergetic function-associated, synaptome neural activity-associated, cell processes-associated, DNA processing-associated and fibrosis-associated pathways. Most of these pathways occurred separately in distinct cell populations.

Conclusions

Transcriptome profiles of aging lacrimal glands undergo considerable diurnal time-dependent changes; this finding offers a comprehensive source of information to better understand the pathophysiology of lacrimal gland aging and its underlying mechanisms.

Prevalence and predictors of vision impairment among older adults in India: evidence from LASI, 2017-18

BACKGROUND

Older adults experience a natural decline in health, physical and cognitive functionality, and vision impairment (VI) is one among them and has become an increasing health concern worldwide. The present study assessed the association of chronic morbidities such as diabetes, hypertension, stroke, heart diseases and various socioeconomic factors with VI among older Indian adults.

METHODS

Data for this study were derived from the nationally-representative Longitudinal Ageing Study in India (LASI), wave-1 (2017-18). VI was assessed using the cut-off of visual acuity worse than 20/80, and additional analysis was carried out using the definition of VI with a cut-off of visual acuity worse than 20/63. Descriptive statistics along with cross-tabulation were presented in the study. Proportion test was used to evaluate the significance level for sex differentials in VI among older adults. Additionally, multivariable logistic regression analysis was conducted to explore the factors associated with VI among older adults.

RESULTS

About 33.8% of males and 40% of females suffered from VI in India (visual acuity worse than 20/80). Meghalaya (59.5%) had the highest prevalence for VI among older males followed by Arunachal Pradesh (58.4%) and Tripura (45.2%). Additionally, Arunachal Pradesh (77.4%) had the highest prevalence for VI among females followed by Meghalaya (68.8%) and Delhi (56.1%). Among the health factors, stroke [AOR: 1.20; CI: 1.03-1.53] and hypertension [AOR: 1.12; CI: 1.01-1.22] were the significant risk factors for VI among older adults. Additionally, being oldest old [AOR: 1.58; CI: 1.32-1.89] and divorced/separated/deserted/others [AOR: 1.42; CI: 1.08-1.87] were significantly associated with VI. Moreover, older adults with higher educational status [AOR: 0.42; CI: 0.34, 0.52], currently working [AOR: 0.77; CI: 0.67, 0.88], from urban areas [AOR: 0.86; CI: 0.76-0.98] and from western region [AOR: 0.55; CI: 0.48-0.64] had lower odds of VI in this study.

CONCLUSION

This study identified higher rates of VI among those who are diagnosed with hypertension or stroke, currently unmarried, socioeconomically poorer, less educated and urban resident older people that can inform strategies to engage high risk groups. The findings also suggest that specific interventions that promote active aging are required for those who are socioeconomically disadvantaged as well as visually impaired.

Does Subretinal Fluid Optical Density Ratio Differ Among the Eyes with Acute Central Serous Chorioretinopathy,Vogt Koyanagi Harada Disease and Choroidal Hemangioma: A Cross-sectional Study

PURPOSE

To investigate the diagnostic value of optical density ratio (ODR) in various diseases with subretinal fluid (SRF) due to different pathophysiologies.

METHODS

Patients with acute central serous chorioretinopathy; CSCR (n=49), Vogt Koyanagi Harada disease; VKH (n=34), and choroidal hemangioma (n=17) characterized with SRF were included. Spectral-domain optical coherence tomography (SD-OCT) images were analyzed using ImageJ by three independent readers. The ODRs were calculated using "region of interest (ROI)" and "entire region (TOTAL)" selection methods from the SRF to the vitreous, retinal nerve fiber layer (RNFL), and retinal pigment epithelium (RPE) reflectivity ratios. A correlation analysis between age, central macular thickness (CMT), SRF height, SRF width, and ODRs were obtained.

RESULTS

Optical density (OD) measurement was highly reproducible (intraclass correlation coefficient> 0.9). Optical density of the SRF, vitreous, RNFL, and signal strength were comparable (p=0.360, p=0.247, p=0.105, and 0.628, respectively). There was no difference in SRF OD measurements between the two methods (p=0.401), while there was a significant difference in vitreous OD measurements (p=0.016). ANOVA test of ODR_(ROI), ODR_(TOTAL), ODR-RPE _(ROI) and ODR-RNFL _(ROI) revealed no significant difference among acute CSCR, VKH disease and choroidal hemangioma groups (p>0.05 for all). Correlation analysis revealed a significant negative correlation between SRF height (p < 0.05) and CMT (p < 0.01) with SRF ODR_(ROI).

CONCLUSION

ODR measurement appears to be a highly repeatable SD-OCT parameter for diseases characterized with SRF collection. Despite variations in their pathophysiology, the ODR was not statistically different in acute CSCR, VKH disease, and choroidal hemangioma.

The Role of Oxidative Stress in the Aging Eye

Given the expanding elderly population in the United States and the world, it is important to understand the processes underlying both natural and pathological age-related changes in the eye. Both the anterior and posterior segment of the eye undergo changes in biological, chemical, and physical properties driven by oxidative stress. With advancing age, changes in the anterior segment include dermatochalasis, blepharoptosis, thickening of the sclera, loss of corneal endothelial cells, and stiffening of the lens. Changes in the posterior segment include lowered viscoelasticity of the vitreous body, photoreceptor cell loss, and drusen deposition at the macula and fovea. Age-related ocular pathologies including glaucoma, cataracts, and age-related macular degeneration are largely mediated by oxidative stress. The prevalence of these diseases is expected to increase in the coming years, highlighting the need to develop new therapies that address oxidative stress and slow the progression of age-related pathologies.

Self-Reported Fall-Related Injury and Its Associated Factors among Adults with Visual Impairment Attending St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia

Background

Falls account for vast majority of fractures and are a significant reason for trauma related hospital admissions. The main aim of this study is to determine the prevalence of self-reported fall, related injuries, and associated factors among adult patients with visual impairment.

Methods

Hospital-based cross-sectional study was conducted from July to August 2021. Systematic random sampling technique was used. The data were entered into Epi-data version 3.1 and exported to SPPS version 26 for analysis. Frequency, mean, and percentage, were used to summarize the descriptive data. The association between the outcome variable and explanatory variables was assessed using binary and multivariate logistic regressions. The adjusted odds ratio was calculated, and variables with a p-value below 0.05 at the 95% confidence interval (CI) were considered statistically significant.

Result

A total of 487 study participants were involved in this study with a response rate of 93.83%. The mean age of the study participants was 52 ± 16.26 years. The overall prevalence of self-reported fall was 36.1 %. Being female, being older than 64 years of age, rural residence, fear of falling, and blind stage of visual impairment were significantly associated with falling.

Conclusion

The prevalence of self-reported fall was high among visually impaired individuals. Female sex, age more than 64 years, rural residence, fear of falling, and blind stage of visual impairment were significantly associated with falling. Reducing patients' chances of suffering from falling-related injuries and consequences requires raising awareness about the burden, danger, and effects of falling on persons who are visually impaired.

Factors affecting central macular thickness of diabetic macular oedema patients after an induction treatment of intravitreal ranibizumab

OBJECTIVE

Intravitreal ranibizumab is one of the anti-vascular endothelial growth factors used for the treatment of diabetic macular oedema, not always successfully. We aimed to identify the factors affecting the changes of central macular thickness after induction treatment with intravitreal ranibizumab, to predict the treatment effect and facilitate early treatment decisions.

METHODS

Cross-sectional study involving a retrospective record review of diabetic macular oedema patients who received an induction treatment of three monthly 0.5 mg intravitreal ranibizumab injections between 2016 and 2019. Central macular thickness was measured at baseline and 3 months post-treatment. Linear regression was applied to identify the factors associated with the changes of central macular thickness.

RESULTS

A total of 153 diabetic macular oedema patients were involved in this study. Their mean age was 57.5 ± 7.7 years, 54.9% were female. The mean change of central macular thickness from baseline to 3 months after completed induction treatment of intravitreal ranibizumab was 155.5 ± 137.8 μm. Factors significantly associated with changes of central macular thickness were baseline central macular thickness [b = 0.73; 95% (CI): 0.63, 0.84; p = <0.001] and presence of subretinal fluid [b = 35.43; 95% CI: 3.70, 67.16; p = 0.029].

CONCLUSION

Thicker baseline central macular thickness and presence of subretinal fluid were the factors significantly associated with greater changes of central macular thickness in diabetic macular oedema patients after receiving three injections of intravitreal ranibizumab.

Altered zinc homeostasis in a primary cell culture model of the retinal pigment epithelium

The retinal pigment epithelium (RPE) is progressively degenerated during age-related macular degeneration (AMD), one of the leading causes of irreversible blindness, which clinical hallmark is the buildup of sub-RPE extracellular material. Clinical observations indicate that Zn dyshomeostasis can initiate detrimental intracellular events in the RPE. In this study, we used a primary human fetal RPE cell culture model producing sub-RPE deposits accumulation that recapitulates features of early AMD to study Zn homeostasis and metalloproteins changes. RPE cell derived samples were collected at 10, 21 and 59 days in culture and processed for RNA sequencing, elemental mass spectrometry and the abundance and cellular localization of specific proteins. RPE cells developed processes normal to RPE, including intercellular unions formation and expression of RPE proteins. Punctate deposition of apolipoprotein E, marker of sub-RPE material accumulation, was observed from 3 weeks with profusion after 2 months in culture. Zn cytoplasmic concentrations significantly decreased 0.2 times at 59 days, from 0.264 ± 0.119 ng·μg^-1 at 10 days to 0.062 ± 0.043 ng·μg^-1 at 59 days (p < 0.05). Conversely, increased levels of Cu (1.5-fold in cytoplasm, 5.0-fold in cell nuclei and membranes), Na (3.5-fold in cytoplasm, 14.0-fold in cell nuclei and membranes) and K (6.8-fold in cytoplasm) were detected after 59-days long culture. The Zn-regulating proteins metallothioneins showed significant changes in gene expression over time, with a potent down-regulation at RNA and protein level of the most abundant isoform in primary RPE cells, from 0.141 ± 0.016 ng·mL^-1 at 10 days to 0.056 ± 0.023 ng·mL^-1 at 59 days (0.4-fold change, p < 0.05). Zn influx and efflux transporters were also deregulated, along with an increase in oxidative stress and alterations in the expression of antioxidant enzymes, including superoxide dismutase, catalase and glutathione peroxidase. The RPE cell model producing early accumulation of extracellular deposits provided evidences on an altered Zn homeostasis, exacerbated by changes in cytosolic Zn-binding proteins and Zn transporters, along with variations in other metals and metalloproteins, suggesting a potential role of altered Zn homeostasis during AMD development.

Surgical outcomes in only eye cataract surgery

INTRODUCTION

Performing cataract surgery in the setting of only one seeing-eye has significant benefits but also potential negative consequences for both patient and surgeon. This study investigates the surgical outcomes in patients undergoing cataract surgery on their only seeing-eye.

METHODS

A retrospective analysis was conducted in a single tertiary centre of all adult patients who had undergone cataract surgery on their only eye, where the fellow eye had a vision of 1.0 LogMAR or worse. Complication rates and visual outcomes were compared against data from the National Ophthalmology Database (NOD) Audit.

RESULTS

918 patients underwent cataract surgery on their only seeing-eye and had their postoperative visual acuity recorded. The overall unadjusted complication rate was 4.0% (versus 2.5% from NOD data) with the rate of posterior capsule rupture (PCR) being 1.9% (versus 1.14% from NOD data). 72.5% (versus 91.5% from NOD data) of patients attained a post-operative visual acuity of 0.3 LogMAR or better. The grade of surgeon performing the surgery did not have a statistically significant effect on the risk of complications.

DISCUSSION

In this cohort of only-eye patients undergoing cataract surgery, there was a small increased risk of operative complications including an increased, unadjusted risk of PCR, and fewer eyes achieved 0.3 LogMAR vision post-operatively compared to the NOD audit data. Grade of surgeon did not have an impact on the complication rate, indicating that with appropriate supervision, trainee surgeons may gain experience in only-eye surgery without additional risk to the patient. Further multicentre studies are recommended to assess reproducibility across units.

FMR protein: Evidence of an emerging role in retinal aging?

Aging is a multifactorial process that affects the entire organism by cumulative alterations. Visual function impairments that go along with aging are commonly observed, causing lower visual acuity, lower contrast sensitivity, and impaired dark adaptation. Electroretinogram analysis revealed that the amplitudes of rod- and cone-mediated responses are reduced in aged mice and humans. Reports suggested that age-related changes observed in both rod and cone photoreceptor functionality were linked to oxidative stress regulation or free radical production homeostasis. Interestingly, several recent reports linked the fragile X mental retardation protein (FMRP) cellular activity with oxidative stress regulation in several tissue including brain tissue where FMRP participates to the response to stress via protein translation in neurite or is involved in free radical production and abnormal glutathione homeostasis. Based on these recent literatures, we raised the question about the effect of FMRP absence in the aging retina of Fmr1^-/y compared to their WT littermates. Indeed, up to now, only young or adult mice (<6 months) were investigated and have shown a specific retinal phenotype. Herein, we demonstrated that Fmr1^-/y mice do not present the aging effect on retinal function observed in WT littermates since ERG a- and b-waves amplitudes as well as oscillatory potentials amplitudes were not collapsed with age (12/18 months old). Absence of FMRP and its consequences seem to protect the retina against aging effect, rising a pivotal role of FMRP in retinal aging process.

Corneal Biomechanical Parameters after 60-Year-Old

Purpose

To determine the distribution of corneal biomechanical parameters in an elderly population.

Methods

This cross-sectional study was conducted in subjects above 60 years living in Tehran. The participants were selected using multi-stage cluster sampling. Corneal biomechanical parameters were measured in a randomly selected subsample of this population using the Reichert Ocular Response Analyzer (Reichert Ophthalmic Instruments, Inc., Buffalo, NY, USA).

Results

Of 470 subjects, the data of 420 participants aged over 60 years were analyzed (mean age: 69.3 ± 6.5 years and range: 61-88 years), 363 (86.4%) of whom were male. The mean and standard deviation of corneal hysteresis (CH) and corneal resistance factor (CRF) were 8.37 ± 1.55 mmHg (95% confidence interval [CI]: 8.02-8.72) and 9.06 ± 1.70 mmHg (95% CI: 8.69-9.44), respectively. The mean CH was 8.27 ± 1.54 mmHg in men and 9.25 ± 1.28 mmHg in women, and the mean CRF was 9.00 ± 1.71 mmHg in men and 9.63 ± 1.37 mmHg in women. According to the results of multiple linear logistic regression analysis, CH had a significant association with younger age (β = -0.05, P = 0.032), female sex (β = 1.83, P < 0.001), reduced maximum keratometry (β = -0.22, P = 0.06), and increased anterior chamber volume (β = 0.01, P = 0.007). CRF had a significant correlation with a younger age (β = -0.06, P = 0.02), female sex (β = 1.01, P = 0.05), central corneal thickness (β = 0.02, P < 0.001), and reduced maximum keratometry (β = -0.39, P = 0.010).

Conclusion

The mean CH and CRF values were low in this sample of the Iranian population aged over 60 years indicating the weaker elasticity of the corneal connective tissue.

The adaptive significance of human scleral brightness: an experimental study

Homogeneously depigmented sclerae have long been proposed to be uniquely human-an adaptation to enable cooperative behaviour by facilitating interpersonal coordination through gaze following. However, recent evidence has shown that deeply pigmented sclerae also afford gaze following if surrounding a bright iris. Furthermore, while current scleral depigmentation is clearly adaptive in modern humans, it is less clear how the evolutionarily intermediate stages of scleral pigmentation may have been adaptive. In sum, it is unclear why scleral depigmentation became the norm in humans, while not so in sister species like chimpanzees, or why some extant species display intermediate degrees of pigmentation (as our ancestors presumably did at some point). We created realistic facial images of 20 individually distinct hominins with diverse facial morphologies, each face in the (i) humanlike bright sclera and (ii) generalised apelike dark sclera version. Participants in two online studies rated the bright-sclera hominins as younger, healthier, more attractive and trustworthy, but less aggressive than the dark-sclera hominins. Our results support the idea that the appearance of more depigmented sclerae promoted perceived traits that fostered trust, increasing fitness for those individuals and resulting in depigmentation as a fixed trait in extant humans.

Mapping Genetics and Epigenetics to Explore the Pathways beyond the Correlated Ageing Phenotype

Ageing is defined by the decline in the biological and physiological functions over time, which leads to health problems and increases risks of diseases. The modern societies are characterised by an ageing population, which represents challenges for the healthcare system. Within this context, there is a need to better understand the biological mechanisms beyond ageing in order to optimise geriatric therapies and medical approaches. Herein, we suggest exploring the genetic and epigenetic patterns related to ageing and correlate them with the ageing-related phenotype of the biological entities in order to establish mechanistic links and map the molecular pathways. Such links would have diverse implications in basic research, in clinics, as well as for therapeutic studies.

Efficacy and tolerability of a novel skin cream for improving periocular rhytids and dryness

OBJECTIVE

A novel topical cream was developed to address the appearance of aging periorbital skin. The goal of this study was to evaluate the efficacy and tolerability of this product (Total Eye® Firm & Repair Cream; Colorescience, Inc., Carlsbad, CA) for improving periorbital wrinkles, dryness, laxity, and dark circles.

METHODS

This 8-week open-label trial enrolled subjects 35-65 years old seeking periocular rejuvenation (N = 25; 22 female, 3 male). The product was applied each morning and evening after facial cleansing. Study endpoints were changes in Investigator Clinical Grading and Eye Appearance Assessments, Subject Self-assessment Questionnaires, and tolerability after 4 and 8 weeks of treatment.

RESULTS

Among subjects completing the study (n = 23), all (100%) showed some global improvement at Weeks 4 and 8 and almost half (48%) achieved moderate or marked improvement. Improvements were observed for all parameters and were most pronounced for wrinkles, laxity, and dark circles. Improvements for laxity and dryness were significant by Week 4 and for dark circles by Week 8. At Week 8, subjects agreed or strongly agreed that the product made their eyes feel more hydrated (100%), look and feel healthier (95%), and increased confidence in their eye appearance (91%). The product was well-tolerated.

LIMITATIONS

Modest number of subjects and open-label study design.

CONCLUSION

Twice-daily Total Eye® Firm & Repair Cream improved the overall appearance of the periorbital area. The product was well-tolerated and most treated subjects were satisfied with their results. The product is a viable option for treating periorbital wrinkles and laxity and should be considered a safe and effective skincare option.

Interplay between aging and other factors of the pathogenesis of age-related macular degeneration

Age-related macular degeneration (AMD) is a complex eye disease with the retina as the target tissue and aging as per definition the most serious risk factor. However, the retina contains over 60 kinds of cells that form different structures, including the neuroretina and retinal pigment epithelium (RPE) which can age at different rates. Other established or putative AMD risk factors can differentially affect the neuroretina and RPE and can differently interplay with aging of these structures. The occurrence of β-amyloid plaques and increased levels of cholesterol in AMD retinas suggest that AMD may be a syndrome of accelerated brain aging. Therefore, the question about the real meaning of age in AMD is justified. In this review we present and update information on how aging may interplay with some aspects of AMD pathogenesis, such as oxidative stress, amyloid beta formation, circadian rhythm, metabolic aging and cellular senescence. Also, we show how this interplay can be specific for photoreceptors, microglia cells and RPE cells as well as in Bruch's membrane and the choroid. Therefore, the process of aging may differentially affect different retinal structures. As an accurate quantification of biological aging is important for risk stratification and early intervention for age-related diseases, the determination how photoreceptors, microglial and RPE cells age in AMD may be helpful for a precise diagnosis and treatment of this largely untreatable disease.

Reticular Pseudodrusen Are Associated With More Advanced Para-Central Photoreceptor Degeneration in Intermediate Age-Related Macular Degeneration

Purpose

The purpose of this study was to examine retinal topographical differences between intermediate age-related macular degeneration (iAMD) with reticular pseudodrusen (RPD) versus iAMD without RPD, using high-density optical coherence tomography (OCT) cluster analysis.

Methods

Single eyes from 153 individuals (51 with iAMD+RPD, 51 with iAMD, and 51 healthy) were propensity-score matched by age, sex, and refraction. High-density OCT grid-wise (60 × 60 grids, each approximately 0.01 mm2 area) thicknesses were custom-extracted from macular cube scans, then compared between iAMD+RPD and iAMD eyes with correction for confounding factors. These "differences (µm)" were clustered and results de-convoluted to reveal mean difference (95% confidence interval [CI]) and topography of the inner retina (retinal nerve fiber, ganglion cell, inner plexiform, and inner nuclear layers) and outer retina (outer plexiform/Henle's fiber/outer nuclear layers, inner and outer segments, and retinal pigment epithelium-to-Bruch's membrane [RPE-BM]). Differences were also converted to Z-scores using normal data.

Results

In iAMD+RPD compared to iAMD eyes, the inner retina was thicker (up to +5.89 [95% CI = +2.44 to +9.35] µm, P < 0.0001 to 0.05), the outer para-central retina was thinner (up to -3.21 [95% CI = -5.39 to -1.03] µm, P < 0.01 to 0.001), and the RPE-BM was thicker (+3.38 [95% CI = +1.05 to +5.71] µm, P < 0.05). The majority of effect sizes (Z-scores) were large (-3.13 to +1.91).

Conclusions

OCT retinal topography differed across all retinal layers between iAMD eyes with versus without RPD. Greater para-central photoreceptor thinning in RPD eyes was suggestive of more advanced degeneration, whereas the significance of inner retinal thickening was unclear. In the future, quantitative evaluation of photoreceptor thicknesses may help clinicians monitor the potential deleterious effects of RPD on retinal integrity.

Involutional ectropion: etiological factors and therapeutic management

PURPOSE

Involutional Ectropion is commonly prevalent disorder of eyelid malposition caused by age-related degeneration of the periocular tissues. This study conducted to provide a summary and review of surgical practice for the management of lower eyelid involutional ectropion and enlist various causative factors that explain the pathogenesis.

METHODS

The review of literature on risk factors and surgical approaches for involutional lower eyelid ectropion, searched on PubMed from 1980 onwards.

RESULT

Multiple factors contribute to horizontal and vertical lower eyelid involutional ectropion. Several surgical practices have been described over the last years to address these factors. Lateral tarsal strip is the most used and effective surgery to treat horizontal laxity.

CONCLUSION

Knowledge of various contributing factors and surgical procedures will enable to design the most effective therapeutic management for lower eyelid involutional ectropion. surgical approaches are individualized depending on preoperative clinical evaluation of possible causative factors and concerning the predominant location of the ectropion will result in a high success rate.

Recent Advances in Age-Related Macular Degeneration Therapies

Age-related macular degeneration (AMD) was described for the first time in the 1840s and is currently the leading cause of blindness for patients over 65 years in Western Countries. This disease impacts the eye’s posterior segment and damages the macula, a retina section with high levels of photoreceptor cells and responsible for the central vision. Advanced AMD stages are divided into the atrophic (dry) form and the exudative (wet) form. Atrophic AMD consists in the progressive atrophy of the retinal pigment epithelium (RPE) and the outer retinal layers, while the exudative form results in the anarchic invasion by choroidal neo-vessels of RPE and the retina. This invasion is responsible for fluid accumulation in the intra/sub-retinal spaces and for a progressive dysfunction of the photoreceptor cells. To date, the few existing anti-AMD therapies may only delay or suspend its progression, without providing cure to patients. However, in the last decade, an outstanding number of research programs targeting its different aspects have been initiated by academics and industrials. This review aims to bring together the most recent advances and insights into the mechanisms underlying AMD pathogenicity and disease evolution, and to highlight the current hypotheses towards the development of new treatments, i.e., symptomatic vs. curative. The therapeutic options and drugs proposed to tackle these mechanisms are analyzed and critically compared. A particular emphasis has been given to the therapeutic agents currently tested in clinical trials, whose results have been carefully collected and discussed whenever possible.

Living Without a Diagnosis: A Patient's Perspective on Diabetic Macular Ischemia

Diabetic macular ischemia (DMI) is a common complication of diabetic retinopathy (DR) that can result in progressive and irreversible vision loss. DMI is associated with damage in the vessels that supply blood to the retina and the enlargement of the foveal avascular zone. Currently, there are no approved treatments specifically for DMI. Furthermore, there is limited published information about the prognosis, prevalence or outcomes of DMI, and there is no consensus regarding diagnostic criteria. It is vital to ensure that there is sufficient, accessible and accurate information available to support patients, caregivers and physicians. To lay the foundation for more research into DMI and its impact on patients, we (a patient with DMI and an expert ophthalmologist) have worked together to interweave our personal perspectives and clinical experiences with a review of currently available literature on DMI. The development of a set of confirmed diagnostic criteria for DMI would assist both patients and physicians, allowing patients to access validated information about their condition and supporting the development of clinical trials for treatments of DMI. Training for physicians must continue to emphasise the importance of treating a patient holistically, rather than only treating their symptoms. Most importantly, developing trust and a healthy rapport between a patient and their physician is important in managing health anxiety and ensuring adherence to beneficial treatments or lifestyle adjustments; physicians must cultivate an open and flexible management approach with their patients. Finally, holistic educational programmes for patients, physicians and the general public around DMI and how it can affect daily functioning would facilitate general understanding and disease awareness.

Diabetic macular ischemia (DMI) is a common problem for patients with diabetic retinopathy that can lead to sight loss. There is very little information available about DMI, particularly from a patient’s point of view. To address the lack of information about DMI, we (a person with DMI and her eye doctor) have worked together to examine what it is like to live with DMI. It is important to provide clear and accessible information about diseases to patients and carers. The lack of information about DMI may be upsetting for some people, and should be addressed with more research. Developing of a set of confirmed signs and symptoms for the diagnosis of DMI would allow people to be more confident in the information that they receive about their disease, and support the development of treatments for DMI. The support of others is central to the wellbeing of people with vision loss. Although people with vision loss may also lose independence, care from loved ones can help to improve quality of life. Most importantly, developing trust between a patient and their doctor is central to managing people’s fears about their eyesight, and making sure that they follow helpful advice. Doctors must use an open and flexible approach with their patients, providing information in an honest and understandable way.

Potential Prognostic Indicators for Patients With Retinal Vein Occlusion

The second most prevalent cause of retinal vascular disease is retinal vein occlusion (RVO). RVO raises intravascular pressure in the capillary and veins, triggering vessel barrier collapse and subsequent leaking of blood or plasma components into the tissue (edema). Macular edema (ME) is a major complication of RVO that results in significant visual impairment. Laser therapy, intravitreal steroid injections, and vascular endothelial growth factor (VEGF) inhibitors are the major therapeutic techniques. Different therapies reduce ME of RVO and improve visual activity. However, some people have no impact on the resolution of ME, while others have a poor visual prognosis despite full ME cure. There are many investigators who studied the relationship between indicators of various instruments with visual activity. However, a summary of those findings is currently lacking. Therefore, we will focus on the predictive factors of different studies associated with positive visual activity outcomes, which would be very useful and important to help address both treatment expectations and methods for patients with RVO.

Corneal Behavior during Tonometer Measurement during the Water Drinking Test in Eyes with XEN GelStent in Comparison to Non-Implanted Eyes

Biomechanics of the cornea have significant influences on the non-contact measurement of the intraocular pressure. The corneal behaviour during tonometry is a fundamental factor in estimating its value. The aim of the study was to analyse the behaviour of the cornea during tonometric measurement with the forced change in intraocular pressure during the water drinking test. Ocular Response Analyser (Reichert) was used to the measurement. Besides four basic parameters connected with intraocular pressure (IOPg, IOPcc) and biomechanics (corneal hysteresis CH and corneal resistance factor (CRF), other parameters representing the behaviour of the cornea during a puff of air were analysed. There were 47 eyes included in the study, including 27 eyes with a XEN GelStent implanted and 20 without it. The eyes of people with monocular implementation were the reference group. The values of analysed parameters were compared before and after 10, 25, 40, and 55 min after drinking the water. The intraocular pressure increased by 2.4 mmHg (p < 0.05) for eyes with a XEN stent and 2.2 mmHg for eyes without a stent (p < 0.05) in the tenth minute after drinking of water. This change caused a decreasing of corneal hysteresis (p < 0.05) without significant changes in the corneal resistance factor (p > 0.05). Corneal hysteresis changed similarly in the reference group and the group with a XEN GelStent. The analysis of additional parameters showed a difference in the behaviour of the cornea in eyes with a XEN GelStent in comparison to the corneas of eyes without a stent. This was particularly visible in the analysis of the cornea’s behaviour during the second applanation, when the cornea returns to its baseline state after deformation caused by air puff tonometry.

The Amyloid Precursor Protein Plays Differential Roles in the UVA Resistance and Proliferation of Human Retinal Pigment Epithelial Cells

Background:

Age-related macular degeneration (AMD) can be characterised by degeneration of retinal pigment epithelial (RPE) cells and the accumulation, in retinal drusen deposits, of amyloid beta-peptides proteolytically derived, by secretases, from the amyloid precursor protein (APP). Ultraviolet (UV) light exposure is a risk factor for the development of AMD.

Objectives:

In the current study, we investigated whether APP and/or its proteolysis are linked to the UVA resistance or proliferation of ARPE-19 human RPE cells.

Methods:

Cell viability was determined, following UVA exposure, with prior small interfering RNA-mediated APP depletion or secretase inhibitor treatments. APP levels/proteolysis were analysed by immunoblotting. Cells were also grown in the presence/absence of secretase inhibitors to assess their effects on longer-term culture growth. Finally, the effects of APP proteolytic fragments on ARPE-19 cell proliferation were monitored following co-culture with human embryonic kidney cells stably over-expressing these fragments.

Results:

Endogenous APP was depleted following UVA irradiation and β-secretase, but not α- secretase, and the processing of the protein was reduced. Experimental APP depletion or γ-secretase (but not α- or β-secretase) inhibition ablated the detrimental effect of UVA on cell viability. In contrast, α-secretase, and possibly γ-secretase but not β-secretase activity, appeared to promote the longer-term proliferation of ARPE-19 cells in the absence of UVA irradiation.

Conclusions:

There are clear but differential links between APP expression/proteolysis and the proliferation and UVA resistance of ARPE-19 cells indicating that the protein should be investigated further in relation to the identification of possible drug targets for the treatment of AMD.

Müller Glia maintain their regenerative potential despite degeneration in the aged zebrafish retina

Ageing is a significant risk factor for degeneration of the retina. Müller glia cells (MG) are key for neuronal regeneration, so harnessing the regenerative capacity of MG in the retina offers great promise for the treatment of age-associated blinding conditions. Yet, the impact of ageing on MG regenerative capacity is unclear. Here, we show that the zebrafish retina undergoes telomerase-independent, age-related neurodegeneration but that this is insufficient to stimulate MG proliferation and regeneration. Instead, age-related neurodegeneration is accompanied by MG morphological aberrations and loss of vision. Mechanistically, yes-associated protein (Yap), part of the Hippo signalling, has been shown to be critical for the regenerative response in the damaged retina, and we show that Yap expression levels decline with ageing. Despite this, morphologically and molecularly altered aged MG retain the capacity to regenerate neurons after acute light damage, therefore, highlighting key differences in the MG response to high-intensity acute damage versus chronic neuronal loss in the zebrafish retina.

OCT guided micro-focal ERG system with multiple stimulation wavelengths for characterization of ocular health

Inherited retinal disorders and dry age-related macular degeneration are characterized by the degeneration and death of different types of photoreceptors at different rate and locations. Advancement of new therapeutic interventions such as optogenetics gene therapy and cell replacement therapies are dependent on electrophysiological measurements at cellular resolution. Here, we report the development of an optical coherence tomography (OCT) guided micro-focal multi-color laser stimulation and electroretinogram (ERG) platform for highly localized monitoring of retina function. Functional evaluation of wild type and transgenic pigs affected by retinal degeneration was carried out using OCT guided micro-focal ERG (μfERG) with selected stimulation wavelengths for S, M and L cones as well as rod photoreceptors. In wild type pigs, μfERG allowed functional recording from rods and each type of cone photoreceptor cells separately. Furthermore, functional deficits in P23H transgenic pigs consistent with their retinal degeneration phenotype were observed, including decrease in the S and M cone function and lack of rod photoreceptor function. OCT guided μfERG based monitoring of physiological function will enable characterization of animal models of retinal degenerative diseases and evaluation of therapeutic interventions at the cellular level.

Common causes of visual impairment in the elderly

Background

Aging is not a disease; rather, it is a process. As people age, visual impairment (VI) becomes more common. In 2010, the overall prevalence rate of vision impairment in all races was 25.66% in individuals aged ≥ 80 years, according to the estimate of the National Eye Institute at the National Institutes of Health. This review aimed to address the common causes of VI in the elderly.

Methods

In this narrative review, an electronic search of the PubMed/MEDLINE database was conducted using "visual impairment" and "elderly" for the period between January 2010 and April 2021, to include randomized clinical trials and observational studies concerning VI in the elderly. The selected time period was chosen to provide an updated review.

Results

The search yielded 2955 articles published over the period of more than 11 years. The relevant randomized clinical trials or observational studies were included and reviewed. Cataracts, refractive errors, open-angle glaucoma, age-related macular degeneration, and diabetic retinopathy were the most common age-related ocular disorders leading to VI if untreated in the elderly. The loss of visual acuity can adversely affect quality of life in the elderly. Difficulty with activities of daily living related to VI can lead to social isolation, depression, and anxiety. Loss of vision in the elderly is linked to an increased risk of falls, hip fracture, depression, and poor quality of life.

Conclusions

The most common causes of VI in the elderly are cataracts and refractive errors. VI in most ocular diseases is more prevalent in women than in men due to longer lifespan. The overall prevalence of the main causes of VI in the elderly is expected to increase; therefore, health policymakers should consider this when planning for the health-enhancement program of the population.

Prevalence of Risk Factors of Retinal Diseases among Patients in Madang Province, Papua New Guinea

PURPOSE

To explore the prevalence of risk factors of retinal diseases among patients seeking services from Madang Provincial Hospital Eye Clinic in Papua New Guinea.

MATERIALS AND METHODS

A hospital-based retrospective study was conducted at the only eye clinic serving the entire Madang province of Papua New Guinea. Purposive sampling was used to obtain data from patients' record cards at the eye clinic from January to June 2021. The data collected included gender, age, presenting visual acuity, blood pressure, blood sugar level, body mass index, smoking habits, and history of cataract surgery. The data was analyzed using the International Business Machines Corporation's Statistical Package for Social Sciences version 21. A p-value of <0.05 was considered statistically significant.

RESULTS

Two hundred and fifty-five (255) patients went through diabetes and hypertension screening during the period of the study (January to June 2021). The mean age of the patients was 53.14 ± 11.20 years and there were more males (56.86%) than females. Nearly half of the patients (43.6%) were either visually impaired or blind. More than half (52.6%) had diabetes mellitus. Majority of the patients (73.3%) were hypertensive and more than half (57.0%) of the patients had unhealthy body mass index (BMI <18.525 kg/m² or > 25 kg/m²). Overweight was significantly associated with hypertension (p < 0.001) and diabetes mellitus (p < 0.001). A few of them were smokers or had a history of cataract surgery (13.7% and 2.0%, respectively).

CONCLUSION

There is a high prevalence of diabetes, hypertension, and overweight among ophthalmic patients in Madang. It is important that measures are put in place to eliminate barriers to health care and to strengthen eye care services in Papua New Guinea.

Shaping the Microglia in Retinal Degenerative Diseases Using Stem Cell Therapy: Practice and Prospects

Retinal degenerative disease (RDD) refers to a group of diseases with retinal degeneration that cause vision loss and affect people's daily lives. Various therapies have been proposed, among which stem cell therapy (SCT) holds great promise for the treatment of RDDs. Microglia are immune cells in the retina that have two activation phenotypes, namely, pro-inflammatory M1 and anti-inflammatory M2 phenotypes. These cells play an important role in the pathological progression of RDDs, especially in terms of retinal inflammation. Recent studies have extensively investigated the therapeutic potential of stem cell therapy in treating RDDs, including the immunomodulatory effects targeting microglia. In this review, we substantially summarized the characteristics of RDDs and microglia, discussed the microglial changes and phenotypic transformation of M1 microglia to M2 microglia after SCT, and proposed future directions for SCT in treating RDDs.

Influence of aging on the color visual field in humans: A cross-sectional study

ABSTRACT

Age-related narrowing of the visual field is observed in the elderly, which leads to reduced cognitive and psychomotor functions. The aim of the present cross-sectional study was to determine the influence of aging on the visual field for color vision in humans, with respect to angular thresholds for object detection and color detection.The subjects were divided into the elderly group (mean 76.1-year-old [70-89]) and the control group (25.2 [18-47]). Visual fields for different colors (blue, green, yellow, and red) were measured by manual kinetic perimetry and evaluated in terms of 2 measures of visual-field width: angular thresholds for object detection and those for color detection.While angular thresholds for object detection were significantly wider than those for color detection in the control group (P < .001), there was no difference in the elderly group (P = .06). Moreover, angular thresholds for object detection were significantly wider in the control group than in the elderly group (P = .019), but angular thresholds for color detection were not significantly different between the 2 groups (P = .903).The observed age-related changes in angular thresholds for object detection in color vision may reflect an age-related reduction in rod function. Stable cone function might explain the preserved angular thresholds for color detection in the elderly.

Prevalence and sociodemographic factors associated with vision difficulties in Ghana, Gambia, and Togo: a multi-country analysis of recent multiple Indicator cluster surveys

Background

The sense of sight is one of the important human sensory abilities that is required for independent functioning and survival. The highest burden of sight-related problems is recorded in low-and middle-income countries, especially in sub-Saharan Africa. Despite the burden, nationally representative analyses to understand the prevalence and determinants of vision difficulties are hard to find. Therefore, this study addressed this knowledge gap by estimating the prevalence of vision difficulties and its correlates in gender-stratified models in three West African countries: Ghana, Gambia, and Togo.

Methods

The study used the most recent Multiple Indicator Cluster Surveys of Ghana (2017–2018), Gambia (2018), and Togo (2017). Summary statistics were used to describe the participants and logistic regression was used to perform the bivariate and multivariate analyses. The analyses were performed using Stata version 14 and the complex survey design of the datasets was accounted for using the ‘svyset’ command.

Results

Gendered differences were observed for vision difficulties. More women than men reported vision difficulties in Ghana (men: 14.67% vs women: 23.45%) and Togo (men: 14.86% vs women: 23.61%), but more men than women reported vision difficulties in Gambia (men: 11.64% vs women: 9.76%). We also observed gender differences in how age, education, marital status, and region of residence were significantly associated with reported vision difficulties. The direction and magnitude of these relationships were different among men and women across the survey data in Ghana, Gambia, and Togo.

Conclusion

The findings imply the need to tackle the existing gender inequities that are associated with vision difficulties to promote the quality of life of individuals, especially among older adults.

Polymeric long-acting drug delivery systems (LADDS) for treatment of chronic diseases: Inserts, patches, wafers, and implants

Non-oral long-acting drug delivery systems (LADDS) encompass a range of technologies for precisely delivering drug molecules into target tissues either through the systemic circulation or via localized injections for treating chronic diseases like diabetes, cancer, and brain disorders as well as for age-related eye diseases. LADDS have been shown to prolong drug release from 24 h up to 3 years depending on characteristics of the drug and delivery system. LADDS can offer potentially safer, more effective, and patient friendly treatment options compared to more invasive modes of drug administration such as repeated injections or minor surgical intervention. Whilst there is no single technology or definition that can comprehensively embrace LADDS; for the purposes of this review, these systems include solid implants, inserts, transdermal patches, wafers and in situ forming delivery systems. This review covers common chronic illnesses, where candidate drugs have been incorporated into LADDS, examples of marketed long-acting pharmaceuticals, as well as newly emerging technologies, used in the fabrication of LADDS.

The killifish visual system as an in vivo model to study brain aging and rejuvenation

Worldwide, people are getting older, and this prolonged lifespan unfortunately also results in an increased prevalence of age-related neurodegenerative diseases, contributing to a diminished life quality of elderly. Age-associated neuropathies typically include diseases leading to dementia (Alzheimer's and Parkinson's disease), as well as eye diseases such as glaucoma and age-related macular degeneration. Despite many research attempts aiming to unravel aging processes and their involvement in neurodegeneration and functional decline, achieving healthy brain aging remains a challenge. The African turquoise killifish (Nothobranchius furzeri) is the shortest-lived reported vertebrate that can be bred in captivity and displays many of the aging hallmarks that have been described for human aging, which makes it a very promising biogerontology model. As vision decline is an important hallmark of aging as well as a manifestation of many neurodegenerative diseases, we performed a comprehensive characterization of this fish's aging visual system. Our work reveals several aging hallmarks in the killifish retina and brain that eventually result in a diminished visual performance. Moreover, we found evidence for the occurrence of neurodegenerative events in the old killifish retina. Altogether, we introduce the visual system of the fast-aging killifish as a valuable model to understand the cellular and molecular mechanisms underlying aging in the vertebrate central nervous system. These findings put forward the killifish for target validation as well as drug discovery for rejuvenating or neuroprotective therapies ensuring healthy aging.