The impact of Vision 2020 on global blindness

Accelerated Biological Aging in Exfoliation Glaucoma Assessed by Fundus-Derived Predicted Age and Advanced Glycation End Products

Glaucoma is an age-related neurodegenerative disease characterized by progressive optic nerve damage. Accelerated biological aging, assessed using predicted age derived from fundus images, may serve as a biomarker for glaucoma progression. This study aimed to examine fundus-derived age acceleration among patients with primary open-angle glaucoma (POAG), exfoliation glaucoma (EXG), and controls, and to explore its biochemical basis through advanced glycation end products (AGEs). Fundus photographs from 237 participants (79 POAG, 79 EXG, and 79 age- and sex-matched controls) were analyzed using a deep learning model (EfficientNet) previously trained to predict biological age. AGE accumulation was assessed by measuring skin autofluorescence (sAF). Multivariate regression analyses were conducted to identify factors influencing predicted age acceleration, with stratification into age tertiles to control for age-related effects. EXG patients demonstrated significant accelerated biological aging compared to controls (p = 0.006), particularly evident in younger and middle-aged tertiles. AGE scores were significantly elevated in EXG relative to both POAG (p = 0.009) and control groups (p = 0.003). Predicted age and AGE scores were more strongly correlated than chronological age and AGEs, especially in the middle tertile (p = 0.002). Accelerated biological aging detected via fundus images occurs prominently in EXG, potentially reflecting underlying AGE accumulation. Fundus-derived predicted age could serve as a non-invasive biomarker for assessing glaucoma progression risk and warrants further exploration in clinical applications.

Determinants of blindness from glaucoma among patients receiving treatment: a retrospective cohort study in Enugu, Nigeria

BACKGROUND

Irreversible blindness is the natural history of untreated glaucoma; however, a significant proportion of those receiving treatment are still blind. This study sought to identify the determinant factors responsible for blindness from glaucoma among those receiving treatment.

METHOD

This retrospective cohort study collected data via chart review of glaucoma patients (N = 231) who attended eye clinics at a large government-owned or a privately owned health facility in Enugu, Nigeria, between October and December 2023. Visual acuity was used to determine whether the eyes met the criteria for blindness. The sociodemographic and clinical characteristics of glaucoma patients who were blind (105) and patients without blindness (126) were compared. Data analysis was performed via the statistical package for social sciences (SPSS) version 26. Binary logistic regression was used to identify determinants of blindness.

RESULTS

The records of a total of 231 glaucoma patients were reviewed. One hundred and five (45.5%) patients were blind in at least one eye. The mean age was 61.1 ± 13.9 years (patients without blindness) and 63.6 ± 10.6 years (blind patients). Those living in urban areas (AOR = 0.49, 95%CI = 0.24-0.99), those with no visual impairment at presentation (AOR = 0.005, 95% CI = 0.000-0.055, p < 0.0001), those with mild to moderate visual impairment (AOR = 0.125, 95% CI = 0.06-0.277, p < 0.0001), and those with presenting IOP < 22 mmHg (AOR = 0.23, 95% CI = 0.09-0.546, p = 0.001) were significantly associated with a lower risk of blindness from glaucoma. However, being non-hypertensive was associated with a higher risk of blindness from glaucoma (AOR = 2.20, 95% CI = 1.16-4.18, p = 0.043).

CONCLUSION

Among patients receiving treatments for glaucoma, living in non-urban areas, presenting with severe visual impairments, presenting with IOP > 22 mmHg, and being non-hypertensive increased the risk of blindness. Improving access to glaucoma care in non-urban areas, increasing awareness creation on screening for early detection and patient counseling may be profitable steps towards reducing vision loss from glaucoma.

Severity of Primary Open-angle Glaucoma and Female Sexual Dysfunction among Older Adults in Malaysia

Aims and background

The objective of this study is to determine the prevalence of female sexual dysfunction (FSD) in older adults with primary open-angle glaucoma (POAG) and its correlation with the severity of visual field (VF) defects. Additionally, potential associated factors with FSD were identified.

Materials and methods

This cross-sectional study included a total of 210 female patients with POAG, aged between 40 and 80 years, from three tertiary centers in two states of Malaysia, conducted between September 2019 and 2020. FSD was assessed using the self-administered Bahasa Malaysia version of the Female Sexual Function Index-6 (MvFSFI-6), with scores of ≤19 indicating FSD. The severity of POAG was evaluated using the modified Advanced Glaucoma Intervention Study (AGIS) scoring system, predicated on two reliable consecutive VFs evaluated by two masked investigators, categorizing the condition as mild, moderate, or severe. Medical records were reviewed for POAG management and other systemic comorbidities. Sociodemographic data, including education and living status, were obtained from the participants.

Results

The participants' average age was 66.7 (7.9) years. The prevalence of FSD is 78.5%. MvFSFI-6 scores decreased with age (r = -0.88; p < 0.001) and revealed an exponential decline with increasing AGIS scores (r = -0.238, p = 0.010). Higher education was correlated with a 67% decreased possibility of experiencing FSD (OR = 0.33, 95% CI 0.12-0.88).

Conclusion

FSD is common among female patients with POAG. Sexual well-being is a crucial factor for women with POAG, particularly those with severe VF defects and lower education levels. Ophthalmologists, gerontologists, and women's health experts need to address this issue to ensure a better quality of life (QoL) for older adults.

Clinical significance

Sexual dysfunction (SD) among women with POAG increases with the severity of the disease, especially among those with lower education levels. To ensure a good QoL for these women, sexual function should be included in the comprehensive management of POAG.

How to cite this article

Chee CC, Sabah H, Yaakub A, et al. Severity of Primary Open-angle Glaucoma and Female Sexual Dysfunction among Older Adults in Malaysia. J Curr Glaucoma Pract 2024;18(4):155-161.

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

RNA-Seq Analysis Unraveling Novel Genes and Pathways Influencing Corneal Wound Healing

Purpose

Transdifferentiation of corneal fibroblasts to myofibroblasts in the stroma is a central mechanistic event in corneal wound healing. This study sought to characterize genes and pathways influencing transdifferentiation of human corneal fibroblasts (hCSFs) to human corneal myofibroblasts (hCMFs) using RNA sequencing (RNA-seq) to develop comprehensive mechanistic information and identify newer targets for corneal fibrosis management.

Methods

Primary hCSFs were derived from donor human corneas. hCMFs were generated by treating primary hCSFs with transforming growth factor β1 (TGFβ1; 5 ng/mL) for 72 hours under serum-free conditions. RNA was extracted using the RNeasy Plus Mini Kit and subjected to RNA-seq analysis after quality control testing. Differential gene expression, pathway enrichment, and protein-protein network analyses were performed using DESeq2, GSEA/PANTHER/Reactome, and Cytoscape/cytoHubba, respectively.

Results

RNA-seq analysis of hCMFs and hCSFs identified 3843 differentially expressed genes and transcripts (adjusted P < 0.05). The log(fold change) ≥ ±1.5 filter showed 816 upregulated and 739 downregulated genes between two cell types. Pathway enrichment analysis showed the highest normalized enrichment score for epithelial-to-mesenchymal transition (5.569), followed by mTORC1 signaling (2.949), angiogenesis (2.176), and TGFβ signaling (2.008). Protein-protein interaction network analysis identified the top 20 nodes influencing corneal myofibroblast development. The expression of a novel MXRA5 in corneal stroma and its association with corneal fibrosis was verified by real-time quantitative reverse transcription PCR and immunofluorescence. RNA-seq and gene count files were submitted to the NCBI Gene Expression Omnibus (GSE260476).

Conclusions

This study identified several novel genes involved in myofibroblast development, offering potential targets for developing newer therapeutic strategies for corneal fibrosis.

Association between Skin Carotenoid Levels and Cognitive Impairment Screened by Mini-Cog in Patients with Glaucoma

Carotenoids, having strong antioxidant properties, have been associated with neurodegenerative conditions like dementia and glaucoma, characterized by neuronal loss leading to cognitive and visual dysfunction. Therefore, carotenoids have attracted attention as factors predictive of the onset and progression of these neurodegenerative diseases. However, the impact of carotenoids on cognitive impairment and glaucomatous visual field defects remains unexplored. We conducted a retrospective, observational clinical study to investigate the association between skin carotenoid (SC) levels and cognitive impairment, as screened by the Mini-Cog test, in glaucoma patients. The study included 406 participants and 812 eyes were examined (average age: 69.7 ± 11.4 years; 228 men, 178 women) with various types of glaucoma: primary open angle (57.6%), exfoliation (18.6%), and other types (23.8%). SC levels were estimated via pressure-mediated reflection spectroscopy. Mixed-effects regression models were utilized to examine the relationship between SC levels, visual field defects, and Mini-Cog results. Of the participants, 28 (6.9%) tested positive on the Mini-Cog, suggesting cognitive impairment. The average SC level in the Mini-Cog positive group was significantly lower than in the negative group (269.5 ± 86.4 A.U. vs. 329.2 ± 120.4 A.U., respectively; p = 0.01). Additionally, the visual field mean deviation (MD) in the Mini-Cog positive group was notably worse than that in the negative group (-19.64 ± 9.07 dB vs. -12.46 ± 9.28 dB, respectively; p < 0.0001). The mixed-effects regression analysis revealed a significant association between Mini-Cog positivity and lower SC levels (p = 0.0006), although SC levels did not significantly correlate with MD (p = 0.3). Our findings suggest that cognitive impairment in glaucoma patients is associated with lower SC levels, underscoring the potential benefits of maintaining carotenoid levels to slow cognitive function decline. The protective role of carotenoids in glaucoma merits further investigation.

A sustainable approach to derive sheep corneal scaffolds from stored slaughterhouse waste

Aim: The escalating demand for corneal transplants significantly surpasses the available supply. To bridge this gap, we concentrated on ethical and sustainable corneal grafting sources. Our objective was to create viable corneal scaffolds from preserved slaughterhouse waste.Materials & methods: Corneas were extracted and decellularized from eyeballs that had been refrigerated for several days. These scaffolds underwent evaluation through DNA quantification, histological analysis, surface tension measurement, light propagation testing, and tensile strength assessment.Results: Both the native and acellular corneas (with ~90% DNA removed using a cost-effective and environmentally friendly surfactant) maintained essential optical and biomechanical properties for potential clinical use.Conclusion: Our method of repurposing slaughterhouse waste, stored at 4°C for several days, to develop corneal scaffolds offers a sustainable and economical alternative xenograft model.

Corneal injury repair and the potential involvement of ZEB1

The cornea, consisting of three cellular and two non-cellular layers, is the outermost part of the eyeball and frequently injured by external physical, chemical, and microbial insults. The epithelial-to-mesenchymal transition (EMT) plays a crucial role in the repair of corneal injuries. Zinc finger E-box binding homeobox 1 (ZEB1), an important transcription factor involved in EMT, is expressed in the corneal tissues. It regulates cell activities like migration, transformation, and proliferation, and thereby affects tissue inflammation, fibrosis, tumor metastasis, and necrosis by mediating various major signaling pathways, including transforming growth factor (TGF)-β. Dysfunction of ZEB1 would impair corneal tissue repair leading to epithelial healing delay, interstitial fibrosis, neovascularization, and squamous cell metaplasia. Understanding the mechanism underlying ZEB1 regulation of corneal injury repair will help us to formulate a therapeutic approach to enhance corneal injury repair.

Aqueous Humor Circulation in the Era of Minimally Invasive Surgery for Glaucoma

Glaucoma surgery with implantation of aqueous humor draining microstents may compromise long-term corneal health by disrupting aqueous humor circulation. The effect of stent numbers on this circulation was interrogated to determine the number of stents associated with minimal circulation disruption. An in vitro anterior eye model perfusion system was constructed with multiple exit ports. A 3-D model of the anterior eye was imported into ABAQUS CFD, analyzes were carried out for unsteady laminar flow and solved using Navier-Stokes equations. DT Vision Foundry was used to analyze velocity contour plot images. The field variable results output for the CFD model were fluid wall shear, fluid pressure and fluid velocity. In vitro, "aqueous" fluid flow is high through a single stent and "aqueous" stagnation is greatest in the quadrants 180° away. Increasing stent port numbers, results in an exponential decrease in the stagnant flow locations. High wall shear stress was seen in the single stent model and is markedly reduced after a second and subsequent stents are introduced. We identify two factors potentially contributing to corneal compromise post glaucoma drainage surgery: aqueous humor stagnation, remote to the stent site and higher exit flows imparting increased stent exit shear stress (particularly with a single stent). With 4 stents, there is minimal disruption of anterior chamber circulation (mimicking physiological conditions). Furthermore we propose that aqueous humor circulation disruption via the usual single-exit port approach disrupts aqueous humor circulation with long-term consequences for corneal health.

Anti-Angiogenic and Anti-Scarring Dual Effect of Galectin-3 Inhibition in Mouse Models of Corneal Wound Healing

Corneal scarring is the third leading cause of global blindness. Neovascularization of ocular tissues is a major predisposing factor in scar development. Although corneal transplantation is effective in restoring vision, some patients are at high risk for graft rejection due to the presence of blood vessels in the injured cornea. Current treatment options for controlling corneal scarring are limited, and outcomes are typically poor. In this study, topical application of a small-molecule inhibitor of galectin-3, GB1265, in mouse models of corneal wound healing, led to the reduction of the following in injured corneas: i) corneal angiogenesis; ii) corneal fibrosis; iii) infiltration of immune cells; and iv) expression of the proinflammatory cytokine IL-1β. Four independent techniques (RNA sequencing, NanoString, real-time quantitative RT-PCR, and Western blot analysis) determined that decreased corneal opacity in the galectin-3 inhibitor-treated corneas was associated with decreases in the numbers of genes and signaling pathways known to promote fibrosis. These findings allowed for a high level of confidence in the conclusion that galectin-3 inhibition by the small-molecule inhibitor GB1265 has dual anti-angiogenic and anti-scarring effects. Targeting galectin-3 by GB1265 is, thus, attractive for the development of innovative therapies for a myriad of ocular and nonocular diseases characterized by pathologic angiogenesis and fibrosis.

Trends in the Ophthalmic Workforce and Eye Care Infrastructure in South India: Cross-Sectional Questionnaire Study

BACKGROUND

This study is part of broad-based research to determine the impact of blindness control activities in general and with special reference to the Andhra Pradesh Right to Sight Society (APRTSS) activities in the southern Indian states of Andhra Pradesh and Telangana. As part of the global "VISION 2020: The Right to Sight" initiative, the APRTSS was established in the undivided state of Andhra Pradesh in 2002. Since then, the APRTSS has been actively implementing the strategies of VISION 2020 to reduce visual impairment and blindness in the state.

OBJECTIVE

The availability and distribution of the eye care workforce are essential to reach the goals of VISION 2020: The Right to Sight, the global initiative to eliminate avoidable blindness. This study assessed the trends in the availability and distribution of eye health professionals and eye care infrastructure in 2 southern Indian states: Andhra Pradesh and Telangana.

METHODS

This cross-sectional study used a pretested questionnaire to gather data for the year from 2012 to 2013. Data for 2002 to 2003 were collected from available historical records. The questionnaires were pretested in a pilot study conducted before the main survey. Pretested questionnaires were administered to all eye care professionals-ophthalmologists (n=1712) and midlevel ophthalmic personnel (MLOP; n=1250)-eye care facilities with ≥10 inpatient beds or performing ≥100 cataract surgeries per annum (n=640), local nongovernmental eye care organizations (n=182), and international eye care organizations (n=10). Data were collected for 2 different time periods: the baseline year of 2002 to 2003 and the target year of 2012 to 2013. Data analysis was conducted using SPSS version 19.0.

RESULTS

The response rates were 81.1% (519/640) for eye care facilities, 96.1% (1645/1712) for ophthalmologists, and 67.6% (845/1250) for MLOP. From 2002-2003 to 2012-2013, there has been an increase in eye care facilities, from 234 to 519 (121.8%); ophthalmologists, from 935 to 1712 (83.1%); and MLOP, from 767 to 1250 (63%). The ophthalmologist:population ratio improved from 1:88,260 in 2002-2003 to 1:51,468 in 2012-2013. The MLOP:population ratio improved from 1:168,283 in 2002-2003 to 1:138,117 in 2012-2013 but still falls short of the ideal number.

CONCLUSIONS

Both southern Indian states are able to meet the requirements for ophthalmologists and eyecare infrastructure as per the goals of VISION 2020. However, the number of MLOP falls short of the ideal ratio for the population. This study has some limitations. For example, most of the data collected through questionnaires were based on self-report, which might introduce bias due to memory recall or over or under-reporting of certain information. However, this was addressed by cross-checking the collected data with information from supplementary sources.

Dysregulation of histone deacetylases in ocular diseases

Ocular diseases are a growing global concern and have a significant impact on the quality of life. Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the most prevalent ocular diseases. Their prevalence and the global market size are also increasing. However, the available pharmacotherapy is currently limited. These diseases share common pathophysiological features, including neovascularization, inflammation, and/or neurodegeneration. Histone deacetylases (HDACs) are a class of enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. HDACs are crucial for regulating various cellular processes, such as gene expression, protein stability, localization, and function. They have also been studied in various research fields, including cancer, inflammatory diseases, neurological disorders, and vascular diseases. Our study aimed to investigate the relationship between HDACs and ocular diseases, to identify a new strategy for pharmacotherapy. This review article explores the role of HDACs in ocular diseases, specifically focusing on diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity, as well as optic nerve disorders, such as glaucoma and optic neuropathy. Additionally, we explore the interplay between HDACs and key regulators of fibrosis and angiogenesis, such as TGF-β and VEGF, highlighting the potential of targeting HDAC as novel therapeutic strategies for ocular diseases.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

Review of smartphone funduscopy for diabetic retinopathy screening

I detail advances in funduscopy diagnostic systems integrating smartphones. Smartphone funduscopy devices are comprised of lens devices connecting with smartphones and software applications to be used for mobile retinal image capturing and diagnosis of diabetic retinopathy. This is particularly beneficial to automate and mobilize retinopathy screening techniques and methods in remote and rural areas as those diabetes patients are often not meeting the required regular screening for diabetic retinopathy. Smartphone retinal image grading systems enable retinopathy to be screened remotely as teleophthalmology or as a stand-alone point-of-care-testing system. Smartphone funduscopy aims to avoid the need for patients to be seen by expert ophthalmologists, which can reduce patient travel, time taken for images to be processed, appointment backlog, health service overhead costs, and the workload burden for expert ophthalmologists.

Qualitative and quantitative endothelium changes after cataract surgery: ultrasound phacoemulsification vs. nanolaser technique

Purpose

The aim of this study was to evaluate corneal endothelial cell density and morphology, central corneal thickness, and best visual acuity using ultrasound (US) phacoemulsification or nanosecond laser technique.

Setting

Department of ophthalmology, Nabeul, Tunisia.

Design

Prospective cohort study.

Methods

This study included eyes with nuclear cataracts with a density grade of 1, 2, 3, or 4 according to LOCS III, divided into two groups; group 1 had conventional US, and group 2 had nanosecond laser. The endothelial cell density (ECD), coefficient of variation (CoV) in cell size, percentage of hexagonal cells, central corneal thickness (CCT) and best visual acuity (VA) were evaluated during 24 months.

Results

Seventy-four eyes had uneventful surgery, 40 in group 1, 34 in group 2. Three procedures in group 2 required conversion to standard phacoemulsification. The mean ECD decreased from 2616.4 ± 194.6 cells/mm2 in group 1 preoperatively to 2088.4 ± 229.9 after 2 years. In group 2, it decreased from 2611.8 ± 186.5 cells/mm2 to 2276.4 ± 163.8 after 2 years. The change was statistically significant in both groups. The decline of the mean ECD in group 2 was significantly less important than in group 1 (p = <10-2). The mean percentage of hexagonal cells was 45.18 ± 4.9 preoperatively and 43.5% ± 6.6 after 2 years in group 1. In group 2, it remained almost stable with 45.6 ± 5.1 and 45.4% ± 6.6 preoperatively and after 2 years, respectively. Preoperatively, the mean CoV was 0.39 ± 0.037 in group 1 and 0.38 ± 0.04 in group 2. After 2 years, it was 0.38 ± 0.04 and 0.37 ± 0.038 in group 1 and group 2, respectively. The changes of the mean CoV and the mean percentage of hexagonal cells were significant in both groups, but the difference between the groups was significant only during the six first months postoperatively. In preoperative, the mean corneal central thickness was 509.7 ± 19.5 in group 1 and 510.3 ± 20.4 in group 2. In both groups, the mean corneal thickness increased on D1 postoperatively to 550.9 in group 1, and 528.2 in group 2. The mean corneal thickness decreased more rapidly after 1 week in group 2, to find the initial values. Visual acuity improved from 0.76 Log Mar ± 0.5 at enrolment to 0.45 Log Mar ± 0.2, and 0.033 Log Mar ± 0.086 in group 1 at 1 day post-operative and after 24 months, respectively and from 0.58 Log Mar ± 0.28 to 0.2 Log Mar ± 0.09 and 0.035 Log Mar ± 0.083, respectively in group 2. There was no significant difference in VA at each follow-up between groups except for day 1.

Conclusion

Our study showed lower corneal tissue trauma, and lower endothelial cell loss in the laser cataract surgery compared to phacoemulsification.Clinical trial registration: (https://classic.clinicaltrials.gov/ct2/show/NCT05886283), identifier NCT05886283.

Intraocular nano-microscale drug delivery systems for glaucoma treatment: design strategies and recent progress

Glaucoma is a leading cause of irreversible visual impairment and blindness, affecting over 76.0 million people worldwide in 2020, with a predicted increase to 111.8 million by 2040. Hypotensive eye drops remain the gold standard for glaucoma treatment, while inadequate patient adherence to medication regimens and poor bioavailability of drugs to target tissues are major obstacles to effective treatment outcomes. Nano/micro-pharmaceuticals, with diverse spectra and abilities, may represent a hope of removing these obstacles. This review describes a set of intraocular nano/micro drug delivery systems involved in glaucoma treatment. Particularly, it investigates the structures, properties, and preclinical evidence supporting the use of these systems in glaucoma, followed by discussing the route of administration, the design of systems, and factors affecting in vivo performance. Finally, it concludes by highlighting the emerging notion as an attractive approach to address the unmet needs for managing glaucoma.

Heparan sulfate proteoglycans (HSPGs) of the ocular lens

Heparan sulfate proteoglycans (HSPGs) reside in most cells; on their surface, in the pericellular milieu and/or extracellular matrix. In the eye, HSPGs can orchestrate the activity of key signalling molecules found in the ocular environment that promote its development and homeostasis. To date, our understanding of the specific roles played by individual HSPG family members, and the heterogeneity of their associated sulfated HS chains, is in its infancy. The crystalline lens is a relatively simple and well characterised ocular tissue that provides an ideal stage to showcase and model the expression and unique roles of individual HSPGs. Individual HSPG core proteins are differentially localised to eye tissues in a temporal and spatial developmental- and cell-type specific manner, and their loss or functional disruption results in unique phenotypic outcomes for the lens, and other ocular tissues. More recent work has found that different HS sulfation enzymes are also presented in a cell- and tissue-specific manner, and that disruption of these different sulfation patterns affects specific HS-protein interactions. Not surprisingly, these sulfated HS chains have also been reported to be required for lens and eye development, with dysregulation of HS chain structure and function leading to pathogenesis and eye-related phenotypes. In the lens, HSPGs undergo significant and specific changes in expression and function that can drive pathology, or in some cases, promote tissue repair. As master signalling regulators, HSPGs may one day serve as valuable biomarkers, and even as putative targets for the development of novel therapeutics, not only for the eye but for many other systemic pathologies.

Significance of Singlet Oxygen Molecule in Pathologies

Reactive oxygen species, including singlet oxygen, play an important role in the onset and progression of disease, as well as in aging. Singlet oxygen can be formed non-enzymatically by chemical, photochemical, and electron transfer reactions, or as a byproduct of endogenous enzymatic reactions in phagocytosis during inflammation. The imbalance of antioxidant enzymes and antioxidant networks with the generation of singlet oxygen increases oxidative stress, resulting in the undesirable oxidation and modification of biomolecules, such as proteins, DNA, and lipids. This review describes the molecular mechanisms of singlet oxygen production in vivo and methods for the evaluation of damage induced by singlet oxygen. The involvement of singlet oxygen in the pathogenesis of skin and eye diseases is also discussed from the biomolecular perspective. We also present our findings on lipid oxidation products derived from singlet oxygen-mediated oxidation in glaucoma, early diabetes patients, and a mouse model of bronchial asthma. Even in these diseases, oxidation products due to singlet oxygen have not been measured clinically. This review discusses their potential as biomarkers for diagnosis. Recent developments in singlet oxygen scavengers such as carotenoids, which can be utilized to prevent the onset and progression of disease, are also described.

Role of Oxidative Stress in Ocular Diseases: A Balancing Act

Redox homeostasis is a delicate balancing act of maintaining appropriate levels of antioxidant defense mechanisms and reactive oxidizing oxygen and nitrogen species. Any disruption of this balance leads to oxidative stress, which is a key pathogenic factor in several ocular diseases. In this review, we present the current evidence for oxidative stress and mitochondrial dysfunction in conditions affecting both the anterior segment (e.g., dry eye disease, keratoconus, cataract) and posterior segment (age-related macular degeneration, proliferative vitreoretinopathy, diabetic retinopathy, glaucoma) of the human eye. We posit that further development of therapeutic interventions to promote pro-regenerative responses and maintenance of the redox balance may delay or prevent the progression of these major ocular pathologies. Continued efforts in this field will not only yield a better understanding of the molecular mechanisms underlying the pathogenesis of ocular diseases but also enable the identification of novel druggable redox targets and antioxidant therapies.

Prevalence and patterns of refractive error among adults in Sagamu, South-West Nigeria

Background: The study was part of community-based research towards strengthening the provision of optical services within a local governmental area in Nigeria.Aim: To describe the prevalence of refractive errors in the southwestern Nigerian adult population.Setting: Adults of age 30 years and above who were regular residents of the local governmental area.Methods: A multistage stratified random cluster sampling method was used to select the subjects. The sampling unit was the different households. A random sample of them were refracted and then refractive errors were analysed. Analyses excluded participants with history of cataract surgery. Associations with myopia (−0.50 dioptres [D] or more) and hyperopia (≥ 0.50 D) were evaluated in logistic regression analyses.Results: The prevalence of refractive error in the study sample was 33.8% (95% confidence level [CI]: 27.1–34.4) using study participants with 6/9 presenting visual acuity but improvement by at least a line with pin hole. The prevalence of hyperopia was 46.9% and higher in women (51.8%), while that of myopia was 21.9% but higher in men (25.0%). The prevalence of hyperopia increased from 29% for 40–49 years of age to 65% for 50–59 years of age and tended to decline thereafter. Prevalence of myopia decreased from 17% in persons 40–49 years of age to 11% in those 50–59 years of age but increased after 60 years of age. A higher prevalence of myopia was positively associated (p  0.05) with lifetime occupations requiring near work, nuclear opacities, posterior subcapsular opacities and glaucoma. Factors associated with hyperopia were the same as for myopia, except for occupation, and in the opposite direction.Conclusion: The high prevalence of refractive errors strongly supports the need for an affordable and accessible optical service in the local government.

Evaluation of CRISPR/Cas9 mediated TGIF gene editing to inhibit corneal fibrosis in vitro

Corneal wound healing is influenced by many factors including transcriptional co-repressors and co-activators. Interactions of co-activators and co-repressors with Smads influence mechanistic loop facilitating transcription of alpha-smooth muscle actin (α-SMA), a key profibrotic gene, in corneal repair. The role of a transcriptional repressor, 5'TG3'-interacting factor (TGIF), in the regulation of α-SMA and myofibroblast formation in the cornea was shown previously by our group. This study tested a hypothesis if TGIF1 gene editing via CRISPR/Cas9 can ease myofibroblast formation in the cornea using an in vitro model. Primary human corneal stromal fibroblasts (hCSFs) generated from donor corneas received gene-editing plasmid facilitating loss (CRISPR/Cas9 knockout) or gain (CRISPR activation) of TGIF function by UltraCruz transfection reagent. Phase-contrast microscopy, immunoblotting, immunocytochemistry and quantitative polymerase chain reaction (qPCR) were used to measure levels of myofibroblast profibrotic genes (α-SMA, fibronectin, Collagen-I, and Collagen-IV) in hCSFs lacking or overexpressing TGIF1 after growing them in± transforming growth factor beta1 (TGF-β1) under serum-free conditions. The CRISPR-assisted TGIF1 activation (gain of function) in hCSFs demonstrated significantly decreased myofibroblast formation and messenger ribonucleic acid (mRNA) and protein levels of profibrotic genes. Conversely, CRISPR/Cas9-assisted TGIF knockdown (loss of function) in hCSFs demonstrated no significant change in the levels of myofibroblast formation or profibrotic genes under similar conditions. These results suggest that TGIF gene-editing approach can be employed to modulate the transcriptional activity of α-SMA in controlling pathological and promoting physiological wound healing in an injured cornea.

Fingertip-Measured Skin Carotenoids and Advanced Glycation End Product Levels in Glaucoma

Carotenoids have antioxidant properties, and the accumulation of advanced glycation end products (AGEs) is associated with reactive oxygen species production; they have attracted attention as factors predictive of the onset and progression in glaucoma. Fingertip measurement is applicable for carotenoids and AGEs due to its noninvasiveness and simplicity. The study included 663 eyes of 663 Japanese subjects (357 males, 306 females). The mean age was 69.9 years with a standard deviation of 11.0. The study population comprised participants with primary open-angle glaucoma (PG) (n = 358), exfoliation glaucoma (EG) (n = 168), and controls (n = 137). Multivariate models suggested that lower skin carotenoid (SC) levels were associated with male gender (standard β = −0.14), AGE scores (−0.24), and a history of intraocular surgery (−0.22). Higher SC levels were associated with higher vegetable intake scores (0.21 for score 3) and diabetes (0.10). However, no association was seen between SCs and glaucoma type. AGEs levels were negatively associated with carotenoid scores (−0.25), PG (−0.15), and smoking habits (−0.26) and positively correlated with EG (0.14). SCs and AGEs were negatively correlated in the single regression analysis (r = −0.20, p < 0.0001). In conclusion, higher levels of AGEs may be candidates for systemic biomarkers of glaucoma associated with the exfoliation syndrome. SC levels can reflect self-reported daily vegetable intake.

Uncorrected refractive error in a university community

Aims and Background

To determine the prevalence and pattern of uncorrected refractive error among staff of a Nigerian university.

Patient and Methods

A cross-sectional study of consecutive staff of the University of Nigeria, Nsukka, Nigeria who presented for a 10-day free eye screening program. Demographic data and data on eye care awareness and knowledge were obtained with a combination of self-administered and interviewer-administered questionnaires in the English language. Clinical examinations included visual acuity taken at 6 m with Snellen's chart; noncontact tonometry; pen-torch eye examination; and direct ophthalmoscopy; autorefraction and subjective refraction.

Results

One thousand and eighty-three subjects aged 18-82 years (mean = 44.1 ± 12.15 years) comprising 568 females (52.4%) and 515 males (47.6%) were screened. Eighty-nine subjects (8.3%) were visually impaired and five subjects (0.5%) were blind. Three hundred and fifty-six subjects were diagnosed with refractive error (356/1083; 32.9%), out of which 149 subjects (41.9%) were uncorrected. The prevalence of uncorrected refractive error in this study population was 13.8%. Astigmatism was the commonest refractive error, whereas hypermetropia and hypermetropic astigmatism were the commonest spherical and astigmatic errors, respectively.

Conclusion

A significant proportion of the staff of this Nigerian university still lives with uncorrected refractive error with its attendant consequences. Regular eye checks should be done by the staff of our universities and effort should be intensified in eye care awareness creation among the populace, including the apparently enlightened communities.

Comparisons between retinal vessel calibers and various optic disc morphologic parameters with different optic disc appearances: The Glaucoma Stereo Analysis Study

The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. This study evaluated the retinal vessel calibers and correlations using GSAS fundus photographs between retinal vessels and 38 optic nerve head (ONH) morphologic parameters comprehensively. In all 240 eyes, the mean central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were 138.4 and 216.5 μm, respectively; the CRAE correlated with age, visual field scores and 19 ONH parameters and CRVE correlated with age, intraocular pressure, visual field scores and 11 ONH parameters. Among the different optic disc appearances including focal ischemia (FI) (n = 53, 22%), generalized enlargement (GE) (n = 53, 22%), myopic glaucoma (MY) (n = 112, 47%), and senile sclerosis (SS) (n = 22, 9%), the CRAE did not differ significantly; CRVE was significantly narrower in SS than in FI and MY. In FI, GE, MY, and SS disc types, CRAE correlated with 3, 14, 9, and 2 ONH parameters, respectively, and CRVE corelated with 9, 0, 12, and 6 ONH parameters, respectively. We confirmed previous observations on the effect of retinal vessel narrowing on glaucomatous changes in the ONH and visual field. The associations between retinal vessel caliber and ONH morphologic parameters vary among different optic disc appearances, suggesting different effects of vascular changes in each disc type.

The Effect of Dietary Antioxidant Supplementation in Patients with Glaucoma

Purpose

Oxidative stress may be a risk factor for glaucoma, and many previous reports have suggested that antioxidants could be a promising treatment. Here, we investigated the effects of a novel supplement containing three food-derived antioxidants (hesperidin, crocetin, and Tamarindus indica) on markers of oxidative stress in patients with glaucoma.

Patients and Methods

This study had a prospective, single arm design. Thirty Japanese glaucoma patients were recruited and given 4 tablets with ample water twice a day for 8 weeks. The treatment was stopped, and the subjects were followed for an additional 8 weeks. We measured biological antioxidant potential (BAP) with a free radical analyzer. We also measured urinary 8-hydroxy-2ʹ-deoxyguanosine (8-OHdG; a marker of oxidative DNA damage). Clinical laboratory data were measured in venous blood samples. Clinical parameters were also recorded. Comparisons used a one-way analysis of variance (ANOVA) followed by Dunnett’s test.

Results

The 8-OHdG level was not reduced. We also divided the patients into groups with high or low oxidative stress. In patients with relatively high oxidative stress, the 8-OHdG level was significantly reduced at weeks 4, 8, 12, and 16 (P < 0.001, P < 0.01, P < 0.01, P < 0.01), and BAP was significantly elevated at weeks 8 and 12 (P = 0.03, P = 0.04). In patients with relatively low oxidative stress, the 8-OHdG level was not significantly reduced during supplement intake but was significantly elevated at weeks 12 and 16 (P =0.03, P = 0.04), while BAP was not significantly elevated.

Conclusion

An 8-week oral course of antioxidant supplementation was effective in patients with a high oxidative stress level. Dietary supplementation could hold promise in the treatment of systemic oxidative stress-related diseases.

Improving productivity, costs and environmental impact in International Eye Health Services: using the 'Eyefficiency' cataract surgical services auditing tool to assess the value of cataract surgical services

Objective

Though one of the most common surgeries, there is limited information on variability of practices in cataract surgeries. ‘Eyefficiency’ is a cataract surgical services auditing tool to help global units improve their surgical productivity and reduce their costs, waste generation and carbon footprint. The aim of the present research is to identify variability and efficiency opportunities in cataract surgical practices globally.

Methods and Analysis

9 global cataract surgical facilities used the Eyefficiency tool to collect facility-level data (staffing, pathway steps, costs of supplies and energy use), and live time-and-motion data. A point person from each site gathered and reported data on 1 week or 30 consecutive cataract surgeries. Environmental life cycle assessment and descriptive statistics were used to quantify productivity, costs and carbon footprint. The main outcomes were estimates of productivity, costs, greenhouse gas emissions, and solid waste generation per-case at each site.

Results

Nine participating sites recorded 475 cataract extractions (a mix of phacoemulsification and manual small incision). Cases per hour ranged from 1.7 to 4.48 at single-bed sites and 1.47 to 4.25 at dual-bed sites. Average per-case expenditures ranged between £31.55 and £399.34, with a majority of costs attributable to medical equipment and supplies. Average solid waste ranged between 0.19 kg and 4.27 kg per phacoemulsification, and greenhouse gases ranged from 41 kg carbon dioxide equivalents (CO2e) to 130 kg CO2e per phacoemulsification.

Conclusion

Results demonstrate the global diversity of cataract surgical services and non-clinical metrics. Eyefficiency supports local decision-making for resource efficiency and could help identify regional or global best practices for optimising productivity, costs and environmental impact of cataract surgery.

Fellow-Eye Comparison between Phaco-Microhook Ab-Interno Trabeculotomy and Phaco-iStent Trabecular Micro-Bypass Stent

The aim of this study is to compare the surgical efficacy and safety between microhook ab-interno trabeculotomy (µLOT) and iStent trabecular micro-bypass stent implantation when both were combined with cataract surgery in both eyes of patients. Sixty-four glaucomatous eyes (32 participants; mean age, 75.9 ± 7.6 years; 15 men, 17 women) were included retrospectively. Intraocular pressure (IOP), number of antiglaucoma medications, best-corrected visual acuity (BCVA), anterior chamber flare (ACF) and corneal endothelial cell density (CECD) were evaluated preoperatively, as well as 2, 3, 6, and 12 months postoperatively. Surgical complications and interventions were compared between the procedures. The preoperative IOP and medications with µLOT (18.8 ± 5.7 mmHg and 3.0 ± 1.2, respectively) were higher than with the iStent (15.5 ± 3.4 mmHg and 2.7 ± 1.2, respectively) (p = 0.0001 and p = 0.0437, respectively). At 12 months, the µLOT values (12.6 ± 2.3 mmHg and 2.3 ± 0.9, respectively) were identical to iStent (12.8 ± 2.5 mmHg and 2.3 ± 0.9, respectively) (p = 0.0934 and p = 0.3251, respectively). At 12 months, the IOP decreased more with µLOT (6.2 mmHg, 29.5%) than iStent (2.7 mmHg, 15.6%) (p = 0.0003). The decrease in medications was greater with µLOT (0.7) than iStent (0.4) (p = 0.0437). Survival rate of IOP control ≤15 mmHg and IOP reduction ≥20% was significantly higher after µLOT (40.6% at 12 months) than iStent (18.8%) (p = 0.0277). The frequency of layered hyphema was significantly greater with µLOT (8 eyes, 25%) than iStent (0 eyes, 0%) (p = 0.0048). The increase in the ACF at 2 weeks postoperatively was significantly greater with µLOT than iStent (p = 0.0156), while changes in the BCVA and CECD were identical between groups. The fellow-eye comparison showed that the IOP reduction was greater with µLOT than iStent when combined with cataract surgery.

Uptake of Trachoma Trichiasis Surgery and Associated Factors Among Trichiasis-Diagnosed Clients in Southern Tigray, Ethiopia

BACKGROUND

Trachoma is the most common infectious cause of blindness in the globe. Trichiasis surgery is the best treatment option for this disease. Despite efforts done to eliminate blinding trachoma, there is limited evidence on the surgical uptake of trachoma trichiasis in Ethiopia. This study was aimed to assess the uptake of trachoma trichiasis surgery in Southern Tigray, Ethiopia.

METHODS

Mixed cross-sectional study was employed among 409 participants. Study participants were selected using a consecutive sampling technique. Pretested and interviewer-administered data were collected using a structured questionnaire. Binary and multivariable logistic regression was done to identify associated factors. Adjusted odds ratios 95% CI was estimated to show the strength and direction. Variables with p-values <0.05 were considered statistically significant. For qualitative data, 4 focus group discussions were conducted with 40 participants and described by thematic analysis then triangulated with quantitative findings.

RESULTS

About 234 (57.9%, 95% CI: (53.2, 62.9)) participants utilized trachoma trichiasis surgery (TT). History of trachoma trichiasis (TT) for >2 years [AOR: 0.4, 95% CI: (0.22, 0.72)], informed about surgery program by health workers [AOR: 0.3, 95% CI: (0.13, 0.71)], history of TT surgery [AOR: 0.18, 95% CI: (0.05, 0.6)], absence of someone to care the family [AOR: 14, 95% CI: (6.9, 28.6)], companion [AOR: 8.9, 95% CI: (4.3, 18.3)], nearby health facility [AOR: 2.4, 95% CI: (1.1, 5.4)], work load [AOR: 8.8, 95% CI: (4.6, 17)], fear [AOR: 4.3, 95% CI: (1.8, 10)], and believing eye drop can treat TT [AOR: 3.9, 95% CI: (1.4, 11)] were significantly associated factors.

CONCLUSION

More than half of the participants accepted the TT surgical uptake. Strengthening community awareness on proper eye care, and effective treatment options, and addressing the negative attitude towards surgical treatment in the community are important measures to achieve the elimination target of trachoma.

Topical administration of the kappa opioid receptor agonist nalfurafine suppresses corneal neovascularization and inflammation

Corneal neovascularization (CNV) causes higher-order aberrations, corneal edema, ocular inflammation, and corneal transplant rejection, thereby decreasing visual acuity. In this study, we investigated the effects of topical administration of the kappa opioid receptor agonist nalfurafine (TRK-820) on CNV. To induce CNV, intrastromal corneal sutures were placed on the corneal stroma of BALB/c mice for 2 weeks. Nalfurafine (0.1 µg/2 μL/eye) was topically administered to the cornea once or twice daily after CNV induction. The CNV score, immune cell infiltration, and mRNA levels of angiogenic and pro-inflammatory factors in neovascularized corneas were evaluated using slit-lamp microscopy, immunohistochemistry, flow cytometry, and polymerase chain reaction. The mRNA expression of the kappa opioid receptor gene Oprk1 was significantly upregulated following CNV induction. Topical administration of nalfurafine twice daily significantly suppressed CNV and lymphangiogenesis, as well as reduced the mRNA levels of angiogenic and pro-inflammatory factors in the neovascularized corneas. Moreover, nalfurafine administration twice daily reduced the numbers of infiltrating leukocytes, neutrophils, macrophages, and interferon-γ-producing CD4⁺ T cells in the neovascularized corneas. In this study, we demonstrated that topical administration of nalfurafine suppressed local CNV in a mouse model along with the activation of KOR, suggesting that nalfurafine may prevent and control CNV in humans.

Correlation Analysis between Macular Choroidal Thickness and Visual Field Mean Defect in Primary Open-Angle Glaucoma

Purpose

To evaluate the differences in macular choroidal thickness and volume between patients with primary open-angle glaucoma (POAG) and healthy controls to assess the correlation between macular choroidal thickness and visual field mean defect (MD).

Methods

Case-control study. A total of 101 patients (101 eyes) with POAG who were hospitalized in our hospital and 102 healthy subjects (102 eyes) matched by age, sex, and axial length were consecutively selected as the POAG group and the control group, respectively. The macular choroidal thickness and volume in nine regions were measured in all subjects by enhanced-depth imaging optical coherence tomography (EDI-OCT).

Results

The mean thicknesses of the choroid in the macular area in the POAG group and healthy group were 207.97 ± 62.83 µm and 208.24 ± 47.97 µm, and the mean volumes were 0.63 ± 0.19 µm³ and 0.64 ± 0.14 µm³. There were no significant differences in macular choroidal thickness, volumes of various macular regions, or mean choroidal thickness or volume between the POAG and healthy groups (all p > 0.05). The macular choroidal thickness of various macular regions was not correlated with visual field MD in the POAG group (all p > 0.05).

Conclusion

The macular choroidal thicknesses and volumes in POAG patients were not significantly different from those in healthy individuals. The macular choroidal thickness was not correlated with MD in POAG patients. Therefore, macular choroidal thickness is not an appropriate parameter to evaluate damage caused by POAG, and the role of the macular choroid thickness in POAG needs to be further investigated.

MicroRNA-191-5p ameliorates amyloid-β1-40 -mediated retinal pigment epithelium cell injury by suppressing the NLRP3 inflammasome pathway

Amyloid β (Aβ) is a crucial component of drusen, the hallmark of the early stage of age-related macular degeneration (AMD), and can cause retinal pigment epithelium (RPE) cell damage through activation of the inflammatory response. MicroRNAs play a critical role in inflammation. However, the mechanism underlying the effect of microRNAs on the NLRP3 inflammasome induced by Aβ remains poorly understood. In the present study, we demonstrated that Aβ_1-40 -mediated RPE damage by inducing a decrease in endogenous miR-191-5p expression. This led to the upregulation of its target gene, C/EBPβ. C/EBPβ acts as a transcription factor for NLRP3, promotes its transcription, and upregulates the downstream inflammatory factors Caspase-1 and IL-1β. Correspondingly, overexpression of miR-191-5p alleviated RPE cell injury by suppressing inflammation. The present study elucidates a novel transcriptional regulatory mechanism of the NLRP3 inflammasome. Our findings suggest an anti-inflammatory effect of miR-191-5p in Aβ_1-40 -induced RPE impairment, shedding light on novel preventive or therapeutic approaches for AMD-associated RPE impairment.

Phacoemulsification with Goniosynechialysis versus Phacoemulsification Alone in Angle-Closure Glaucoma: A Meta-Analysis of Randomized Controlled Trials

Purpose

This meta-analysis aimed to compare the efficacy and safety of phacoemulsification with goniosynechialysis (Phaco-GSL) with those of phacoemulsification alone (Phaco-alone) in patients with angle-closure glaucoma and cataract.

Methods

Randomized controlled trials (RCTs) were selected through a search of electronic databases. Trial eligibility and risk of bias were assessed using Cochrane review methods. Primary measures included the intraocular pressure (IOP), number of antiglaucoma medications, peripheral anterior adhesion (PAS) extent, and their pre- and postoperative changes. For continuous parameters, we calculated weighted mean differences and 95% confidence intervals. Statistical analysis was performed using RevMan 5.3 software.

Results

Eight RCTs were included, where 224 and 236 eyes were in the Phaco-GSL and Phaco-alone groups, respectively. Both postoperative IOP and number of medications were not significantly different between the study groups at the six- and twelve-month follow-up. However, the 12-month postoperative PAS extent was significantly smaller in the Phaco-GSL group than in the Phaco-alone group. Similarly, changes from the preoperative to 12-month postoperative PAS extent were significantly greater in the Phaco-GSL group than in the Phaco-alone group, but IOP and the number of medication changes were not different.

Conclusions

Our results provide evidence that Phaco-GSL provides advantages over Phaco-alone treatment regarding PAS reduction. In terms of IOP and medication reduction, both groups were comparable. Thus, Phaco-GSL can be considered for the treatment of patients with angle-closure glaucoma and cataract due to its ease, safety, and potential benefit for the anterior chamber angle.

Simultaneous optical coherence tomography and Scheimpflug imaging using the same incident light

For any single anterior chamber cross-sectional (tomographic) imaging method, there is a practical compromise between image size and image resolution. In order to obtain large field-of-view cross-sectional images of the whole anterior chamber and high-resolution cross-sectional images of the fine corneal layers, measurements by multiple devices are currently required. This paper presents a novel raster scanning tomographic imaging device that acquires simultaneous large field-of-view Scheimpflug (12.5 mm image depth, 50 μm axial resolution in air) and high-resolution spectral domain optical coherence tomography (SD-OCT) (2 mm image depth, 3.7μm axial resolution in air) using the same illuminating photons. For the novel raster scanning 3D Scheimpflug imaging, a tunable lens system together with numerical methods for correcting refraction distortion were used. To demonstrate the capability of simultaneous measurement of both fine corneal layers and whole anterior chambers topology, ex vivo measurements on 12 porcine and 12 bovine eyes were carried out. There is a reasonable agreement in the overall central corneal thicknesses (CCT) obtained from the simultaneous SD-OCT and Scheimpflug measurements. In addition, because the same infrared light beam was used to illuminate the sample, both OCT and Scheimpflug images were taken at the exact same location of a sample simultaneously in a single measurement. This provides a unique method for measuring both the thickness and the refractive index of a sample.

Evaluation of Redox Profiles of the Serum and Aqueous Humor in Patients with Primary Open-Angle Glaucoma and Exfoliation Glaucoma

Oxidative stress is thought to play a significant role in the development of glaucoma. However, the association between systemic and local oxidative stresses in different types of glaucoma has not been assessed fully. The current study compared the redox status in the aqueous humor (AH) and blood samples among eyes with primary open-angle glaucoma (POAG), exfoliation glaucoma (EXG), and non-glaucomatous controls to evaluate the relationship among systemic redox status, intraocular oxidative stress, and clinical backgrounds. AH and blood samples were obtained from 45 eyes of 45 Japanese subjects (15 POAG, 15 EXG, and 15 control eyes). The serum levels of lipid peroxides, ferric-reducing activity, and thiol antioxidant activity were measured by diacron reactive oxygen metabolites (dROM), biologic antioxidant potential (BAP), and sulfhydryl (SH) tests, respectively, using a free radical analyzer. The activities of cytosolic and mitochondrial forms of the superoxide dismutase (SOD) isoforms, i.e., SOD1 and SOD2, respectively, in AH and serum were measured using a multiplex bead immunoassay. In AH, SOD1 in subjects with EXG and SOD2 in those with POAG and EXG were significantly higher than in control eyes. In serum, compared to control subjects, BAP in subjects with POAG and EXG was significantly lower; SOD1 in those with EXG and SOD2 in those with POAG and EXG were significantly higher. dROM and SH did not differ significantly among the groups. The BAP values were correlated negatively with the SOD1 concentrations in AH and serum, SOD2 in the AH, intraocular pressure, and number of antiglaucoma medications. In conclusion, lower systemic antioxidant capacity accompanies up-regulation of higher local antioxidant enzymes, suggesting increased oxidative stress in eyes with OAG, especially in EXG. Determination of the systemic BAP values may help predict the redox status in AH.

Association of Postfungal Keratitis Corneal Scar Features With Visual Acuity

Importance

Corneal opacity is a leading cause of visual impairment worldwide; however, the specific features of corneal scars, which decrease visual acuity, have not been well characterized.

Objective

To investigate which features of a postfungal keratitis corneal scar contribute to decreased visual acuity after an episode of infectious keratitis and evaluate whether any corneal features may be used as outcomes for clinical trials.

Design, Setting, and Participants

In this ancillary, prospective cross-sectional study, a subset of study participants treated for fungal keratitis (n = 71) as part of the Mycotic Ulcer Treatment Trial I (MUTT I) underwent best spectacle-corrected visual acuity (BSCVA) and best contact lens-corrected visual acuity examination, Scheimpflug imaging, and anterior segment optical coherence tomography at a referral hospital in India approximately 2 years after enrollment. Data were collected from December 3, 2012, to December 19, 2012, and analyses were performed from December 2, 2013, to October 2, 2019.

Main Outcomes and Measures

Linear regression models were used to evaluate the importance of various corneal features for BSCVA and to assess whether these features could be used to differentiate the 2 treatment arms of the MUTT I trial.

Results

Seventy-one patients (42 men [59.1%]; median age, 48 [range, 39-60] years) were examined at a median (IQR) time of 1.8 (1.4-2.2) years after enrollment. The mean (SD) logMAR BSCVA was 0.17 (0.19) (Snellen equivalent, 20/32). In multivariable linear regression models, BSCVA was most associated with irregular astigmatism (1.0 line of worse BSCVA per 1-line difference between BSCVA and contact lens visual acuity; 95% CI, 0.6-1.4) and corneal scar density (1.5 lines of worse vision per 10-unit increase in the mean central corneal density; 95% CI, 0.8-2.3). The thinnest point of the cornea was the metric that best discriminated between the natamycin- and voriconazole-treated ulcers in MUTT I, with 29.3 μm (95% CI, 7.1-51.6 μm) less thinning in natamycin-treated eyes.

Conclusions and Relevance

Both irregular astigmatism and corneal scar density may be important risk factors for BSCVA in a population with relatively mild, healed fungal corneal ulcers. The thinnest point of the corneal scar may be a cornea-specific outcome that could be used to evaluate treatments for corneal ulcers.

Novel immunotherapeutic effects of topically administered ripasudil (K-115) on corneal allograft survival

Corneal allograft survival is mediated by the variety of immunological reactions and wound healing process. Our aim was to explore the effects of topical administration of ripasudil, a selective Rho-associated coiled-coil protein kinase inhibitor, on corneal allograft survival. Ripasudil was administered to mice thrice a day after allogeneic corneal transplantation. Corneal graft survival, opacity, neovascularization, re-epithelization, immune cell infiltration, and mRNA levels of angiogenic and pro-inflammatory factors in the grafted cornea and draining lymph nodes (dLNs) were evaluated with slit-lamp microscopy, immunohistochemistry, flow cytometry, and polymerase chain reaction. Graft survival was significantly prolonged with lower graft opacity and neovascularization scores in 0.4% and 2.0% ripasudil-treated groups, and mRNA levels of angiogenic and pro-inflammatory factors in ripasudil-treated grafted corneas were reduced. Moreover, 0.4% and 2.0% ripasudil reduced CD45⁺-infiltrated leukocyte frequency, Cd11b and Cd11c mRNA levels, and the frequencies of mature dendritic cells, IFNγ-, and IL-17- producing CD4⁺T cells in the dLNs of recipients. Re-epithelization rate of the grafted cornea was significantly higher in the 0.4% and 2.0% ripasudil groups than in the control. Topically applied ripasudil prolonged graft survival by downregulating neovascularization and inflammation factors, while promoting corneal re-epithelization, suggesting that ripasudil may be useful for suppressing immunological rejection in corneal transplantation.

Can Polyphenols in Eye Drops Be Useful for Trabecular Protection from Oxidative Damage?

Polyphenols, with anti-oxidant properties, counteract oxidative stress effects. Increasing evidence has found oxidative stressto be the main risk factor for trabecular meshwork (TM) damage, leading to high-tension glaucoma. Topical anti-oxidants could represent a new target for glaucoma treatment. Our aim is to investigate the protective mechanisms on a human TM culture of a patented polyphenol and fatty acid (iTRAB®)formulation in response to oxidative stress using an advanced invitromodel consisting of 3D-human TM cells, embedded in a natural hydrogel, and a milli-scaled multi-organ device model for constantdynamic conditions. The 3D-human TM cells(3D-HTMCs) were treated daily with 500 µM H2O2or 500 µM H2O2and 0.15% iTRAB®(m/v) for 72 h, and molecular differences in the intracellular reactive oxygen species (iROS), state of the cells, activation of the apoptosis pathway and NF-kB and the expression ofinflammatory and fibrotic markers wereanalyzed at different time-points.Concomitant exposure significantly reduced iROS and restored TM viability, iTRAB® having a significant inhibitory effect on the apoptotic pathway, activation of NF-κB, induction of pro-inflammatory (IL-1α, IL-1ß and TNFα) and pro-fibrotic (TGFβ) cytokines and the matrix metalloproteinase expressions. It is clear that this specific anti-oxidant provides a valid TM protection, suggesting iTRAB® could be an adjuvant therapy in primary open-angle glaucoma (POAG).

CNS axonal degeneration and transport deficits at the optic nerve head precede structural and functional loss of retinal ganglion cells in a mouse model of glaucoma

BACKGROUND

Glaucoma is a leading neurodegenerative disease affecting over 70 million individuals worldwide. Early pathological events of axonal degeneration and retinopathy in response to elevated intraocular pressure (IOP) are limited and not well-defined due to the lack of appropriate animal models that faithfully replicate all the phenotypes of primary open angle glaucoma (POAG), the most common form of glaucoma. Glucocorticoid (GC)-induced ocular hypertension (OHT) and its associated iatrogenic open-angle glaucoma share many features with POAG. Here, we characterized a novel mouse model of GC-induced OHT for glaucomatous neurodegeneration and further explored early pathological events of axonal degeneration in response to elevated IOP.

METHODS

C57BL/6 J mice were periocularly injected with either vehicle or the potent GC, dexamethasone 21-acetate (Dex) once a week for 10 weeks. Glaucoma phenotypes including IOP, outflow facility, structural and functional loss of retinal ganglion cells (RGCs), optic nerve (ON) degeneration, gliosis, and anterograde axonal transport deficits were examined at various stages of OHT.

RESULTS

Prolonged treatment with Dex leads to glaucoma in mice similar to POAG patients including IOP elevation due to reduced outflow facility and dysfunction of trabecular meshwork, progressive ON degeneration and structural and functional loss of RGCs. Lowering of IOP rescued Dex-induced ON degeneration and RGC loss, suggesting that glaucomatous neurodegeneration is IOP dependent. Also, Dex-induced neurodegeneration was associated with activation of astrocytes, axonal transport deficits, ON demyelination, mitochondrial accumulation and immune cell infiltration in the optic nerve head (ONH) region. Our studies further show that ON degeneration precedes structural and functional loss of RGCs in Dex-treated mice. Axonal damage and transport deficits initiate at the ONH and progress toward the distal end of ON and target regions in the brain (i.e. superior colliculus). Most of anterograde transport was preserved during initial stages of axonal degeneration (30% loss) and complete transport deficits were only observed at the ONH during later stages of severe axonal degeneration (50% loss).

CONCLUSIONS

These findings indicate that ON degeneration and transport deficits at the ONH precede RGC structural and functional loss and provide a new potential therapeutic window for rescuing neuronal loss and restoring health of damaged axons in glaucoma.

Advanced Glycation End Product Accumulation in Subjects with Open-Angle Glaucoma with and without Exfoliation

Advanced glycation end products (AGEs), which are the products of a non-enzymatic reaction between reducing sugars and other macromolecules, are critical in aging, as well as metabolic and degenerative diseases. To assess the involvement of AGEs in glaucoma, skin autofluorescence (sAF) level, which is a measurement of AGEs' accumulation, was compared among Japanese patients with glaucoma (316 with primary open-angle glaucoma (PG) and 127 exfoliation syndrome and glaucoma (EG)) and controls (133 nonglaucomatous controls) (mean age 71.6 ± 12.8 years, 254 men and 322 women). The sAF values were estimated from the middle fingertip using a 365 nm light-emitting diode for excitation and detection at 440 nm emission light. The estimated AGE values (arbitrary unit) were 0.56 ± 0.15, 0.56 ± 0.11, and 0.61 ± 0.11 in the control, PG, and EG groups, respectively (p < 0.0001, analysis of variance); and were significantly higher in the EG group than the control (p = 0.0007) and PG (p < 0.0001) groups. After adjustment for various demographic parameters by multivariate analyses, male sex (standard β = 0.23), EG (0.19), and diabetes (0.09) were associated with higher AGE levels; PG (-0.18) and smoking (-0.19) were associated with lower AGE levels. Age, visual acuity, intraocular pressure, glaucoma medications, lens status, and systemic hypertension were not associated with AGEs. The high AGE level in EG suggested that specific oxidation and glycation mechanisms underlie the glaucoma pathogenesis associated with pseudoexfoliation syndrome.

Stem cell therapies for retinal diseases: from bench to bedside

As the human retina has no regenerative ability, stem cell interventions represent potential therapies for various blinding retinal diseases. This type of therapy has been extensively studied in the human eyes through decades of preclinical studies. The safety profiles shown in clinical trials thus far have indicated that these strategies should be further explored. There are still challenges with regard to cell source, cell delivery, immuno-related adverse events and long-term maintenance of the therapeutic effects. Retinal stem cell therapy is likely to be most successful with a combination of multiple technologies, such as gene therapy. The purpose of this review is to present a synthetical and systematic coverage of stem cell therapies that target retinal diseases from bench to bedside, intending to appeal to both junior specialists and the broader community of clinical investigators alike. This review will only focus on therapies that have already been studied in clinical trials. This review summarizes key concepts, highlights the main studies in human patients and discusses the current challenges and potential methods to reduce safety concerns while enhancing the therapeutic effects.

Effects of French maritime pine bark/bilberry fruit extracts on intraocular pressure for primary open-angle glaucoma

We tested oral French maritime pine bark (40 mg)/bilberry fruit extract (90 mg) supplements for intraocular pressure-lowering effects in Japanese subjects with primary open-angle glaucoma. Eighteen subjects (29 eyes) were recruited with intraocular pressure of ≥15 mmHg who used one to three bottles of antiglaucoma medications. After a 2-week observation (period 1), subjects ingested a tablet/day of Sante^® Glagenox for 4 weeks (period 2). The mean intraocular pressure (17.2 ± 2.3 mmHg) decreased significantly to 15.7 ± 1.9 mmHg (8.7% reduction) at week 4 (p = 0.0046). The mean morning intraocular pressure (14.1 ± 3.1 mmHg) self-measured using the iCare HOME tonometer during period 1 decreased significantly to 13.3 ± 2.9 mmHg (5.7% reduction) during period 2 (p = 0.0291). Blood redox parameters, diacron reactive oxygen metabolites, biologic antioxidant potential, and sulfhydryl tests were unchanged after 4-week supplementation. Intra-subject comparisons, compared to period 1, showed pooled, self-measured, period-2 intraocular pressures was significantly lower in nine subjects (50%), unchanged in six subjects (33%), and elevated in three subjects (17%), suggesting some non-responders. Four-week supplementation with French maritime pine bark/bilberry fruit extracts can further reduce intraocular pressure even in Japanese patients with controlled primary open-angle glaucoma. Further study should confirm the intraocular pressure-lowering effects and mechanisms of this supplement in glaucoma management. The study was registered in UMIN (ID: UMIN000033200).

Performance of Plusoptix A09 Photo Screener in Refractive Error Screening in School Children Aged between 5 and 15 Years in the Southern Part of India

Purpose:

To evaluate the performance of Plusoptix A09 in detecting ametropia, warranted against frequently-used technique of retinoscopy in children attending school (5–15 years) and its probability as a screening tool.

Methods:

This study was the subset of a larger epidemiological study visual acuity refractive error squint conducted in schools to determine the prevalence of ocular morbidity among the 5–15 years' school children population. Every 7^th student in the class (each school had mean value of 100 students) was randomly selected for this study after ascertaining their eligibility as per the inclusion criteria. A cohort of a total of 150 children within the age group of 5–15 (mean, 10.21 ± 2.83) years were recruited from 11 schools of Udupi district. Students with best corrected visual acuity of 20/20, refractive error within ±5.00 diopter (D), without any eccentric fixation, and no history of ocular pathology or seizures were recruited. Refractive error was tested by Plusoptix photorefractor followed by non-cycloplegic and cycloplegic retinoscopic techniques. The examiners performing these tests were masked and unware of the findings. Bland Altman plotted the agreement between the techniques, followed by the receiver operating characteristic curve (ROC), and sensitivity of Plusoptix.

Results:

One-way analysis of variance calculated statistical differences among Plusoptix, objective retinoscopy, and cycloplegic retinoscopy for mean spherical value (1.12 ± 1.16 D, 0.65 ± 0.69 D, and 0.8 ± 0.82 D), cylindrical value (−0.83 D ± 1.27, −0.32 D ± 0.86, and −0.34 D ± −0.93), and spherical equivalent value (0.71 D ± 1.06, 0.45 D ± 0.7, and 0.61 D ± 0.81), with P = 0.0001, 0.0001, and 0.097, respectively. Bland Altman plots showed good agreement for spherical equivalent values of Plusoptix and objective retinoscopy. However, the area under the ROC curve (0.386) suggests that lower diagnostic ability of this device in this age group population in comparison to retinoscopy (0.575) with the sensitivity and specificity of Plusoptix was 69.2% and 84.8%.

Conclusions:

This study fails to report ideal sensitivity mandated for a screening tool, although good specificity and agreement are observed. Along with retinoscopy, this tool will be effective in screening a children's population aged between the age group of 5 and 15 years.

Comparison of the diurnal efficacy and safety of cyclocryocoagulation and cyclophotocoagulation in patients with refractory glaucoma

PURPOSE

To compare the diurnal IOP-lowering efficacy and safety of cyclocryocoagulation (CCC) and cyclophotocoagulation (CPC) in patients with refractory glaucoma.

METHODS

Forty eyes of 40 Caucasian patients with advanced primary or secondary glaucoma with only tunnel vision left were included in this retrospective, comparative interventional case series. Twenty eyes treated with CCC were compared with 20 eyes treated with CPC. Primary endpoint was the reduction of 24 h mean diurnal intraocular pressure (IOP; mean of 6 measurements), peak IOP and diurnal IOP fluctuations 3 and 6 months post-treatment. Secondary outcomes were the occurrence of postoperative complications and the identification of factors influencing the postoperative IOP reduction.

RESULTS

In the CCC group (mean age 70.6 ± 13.4 years), mean diurnal IOP was significantly reduced from 20.0 ± 4.5 mmHg to 14.7 ± 2.5 (p < 0.001) at 3 months and 13.9 ± 3.34 mmHg at 6-month follow-up (p < 0.001). In the CPC group (mean age 74.9 ± 9.0 years), mean diurnal IOP significantly decreased from 18.2 ± 3.1 mmHg to 13.2 ± 2.2 (p < 0.001) at 3 months and 13.1 ± 2.6 mmHg (p < 0.001) at 6 months. At 6 months, 75% of the CCC and 63% of the CPC group had mean diurnal IOP reductions of 20% or more. The most frequent complication (25%) was a transient IOP increase during the first days after CCC. A higher preoperative mean diurnal IOP was recognized as the only factor influencing the postoperative IOP reduction after CCC and CPC.

CONCLUSIONS

Both cyclodestructive methods seem to be reasonably safe and effective in lowering 24 h mean diurnal IOP in the perspective of 6 months in patients with refractory glaucoma. The IOP-lowering effect after CCC was better but not statistically significantly different compared to CPC. A higher rate of complications was observed in the CCC group, however.

Capacity building for universal eye health coverage in South East Asia beyond 2020

BACKGROUND

The World Report on Vision suggests that universal eye health coverage (UEHC) can be achieved through an integrated people-centered eye care (IPCEC) delivery. This study provides an estimation of capacity building of facilities and workforce to attain UEHC through IPCEC in South East Asia (SEA) beyond 2020.

METHODS

The data sources on the magnitude of blindness and visual impairment in the SEA region included reports of the Vision Loss Expert Group, most recent population-based studies from the member states and unpublished data from the study teams. The model is based on the estimated or projected population of the member states in 2020 and 2030.

RESULTS

Data from the ten member states of the World Health Organization (WHO) SEA show that the magnitude of blindness and moderate to severe visual impairment (MSVI) has decreased between 1990 and 2015, but still higher than global average. Cataract and uncorrected refractive errors were the common causes of blindness and MSVI, respectively. The estimated WHO SEA region share of world population is likely to increase from 38.39% in 2020 to 44.32% in 2030, and so also will be the visually impaired people. By adopting the IPCEC the WHO SEA countries would require at least 429,802 community workers, 164,784 allied ophthalmic personnel and 10,744 ophthalmologists in the public facilities in 2030.

CONCLUSION

In order to attain UEHC and use the IPCEC model, each country in the region should invest substantially more in structured eye care delivery and workforce.

Involvement of free radical-mediated oxidation in the pathogenesis of pseudoexfoliation syndrome detected based on specific hydroxylinoleate isomers

We reported previously that enzymatic and singlet oxygen-mediated fatty acid oxidation may be major oxidation pathways in subjects with primary open angle glaucoma, based on measurement of serum levels of hydroxylinoleate (HODE) and hydroxyarachidonate (HETE) isomers after reduction and saponification. In this study, we measured serum levels of HODE and HETE isomers to investigate the pathogenesis of exfoliation syndrome (EX). In total, 311 Japanese subjects comprising EX patients (n = 192) and non-glaucomatous control subjects (n = 119) were included in this study. Patients with EX (n = 192) were divided into EX with glaucoma (EXG) and EX without glaucoma (EXS) groups (n = 128 and n = 64, respectively) depending on the intraocular pressure. Total HODE (/linoleic acid) serum levels were significantly (p = 0.0426) higher in the EX group (202.7 ± 153.2 μmol/mol) than in the controls (167.1 ± 105.3 μmol/mol). Among the HODE isomers, the levels of 9-(E,E)-HODEs (p < 0.0001) and 13-(E,E)-HODEs (p < 0.0001), both free radical-mediated oxidation products, were higher in the EX and EXG groups than in the controls, whereas no significant difference was observed between EXS and controls. After adjusting for differences in demographic parameters, multivariate analyses confirmed the association between 9- and 13-(E,E)-HODEs and EX. This is the first report of a dramatic increase in free radical-mediated oxidation products related to the pathogenesis of EX, and our findings suggest that free radical-mediated oxidation can be one of the causes of deterioration in EX.

The myofibroblast, biological activities and roles in eye repair and fibrosis. A focus on healing mechanisms in avascular cornea

Tissue healing is one of the mysteries of modern medicine. Healing involves complex processes and many cellular types, amongst which the myofibroblast plays a major role. In the eye, when needed, myofibroblasts can be found from the cornea to the retina, derived from a wide variety of different cells, and aimed at effectively repairing tissue damage. Myofibroblast differentiation requires transforming growth factor (TGF)-β1, the presence of specific extracellular matrix components such as the ED-A domain of fibronectin, and mechanical tension. Control of this process may, in some cases, be abnormal leading to development of fibrotic tissue, which alters and compromises the integrity of the original tissue. The eye is no exception to this rule with normal visual function, a highly demanding process, only possible in a fully integrated organ. The cornea, a transparent protective tissue and first dioptre of the eye, has the particularity of being entirely avascular and very richly innervated under normal physiological conditions. However, these anatomical features do not prevent it from developing myofibroblasts in the event of a deep corneal lesion. Activated by growth factors such as TGF-β1 and platelet-derived growth factor from the aqueous humour, tears or corneal epithelial cells, myofibroblasts can cause corneal scarring, sometimes with devastating consequences. Understanding the factors involved in healing and its signalling pathways, will potentially enable us to control corneal healing in the future, and thus avoid fibrotic ocular surface disease and the blindness that this may induce. Currently, this issue is the subject of very active research and development with the aim of discovering new antifibrotic therapies.

Prevalence, Causes, and Factors Associated with Visual Impairment and Blindness among Registered Pensioners in Ghana

Purpose

To determine the prevalence, causes, and factors associated with presenting visual impairment and blindness among pensioners.

Design

A nationwide cross-sectional study. This study was part of the analysis on data obtained in the pensioners' medical survey conducted among members of the National Pensioners Association in Ghana.

Method

(i) Setting: it was a multicenter study involving thirteen centers throughout Ghana with a center in each regional capital. (ii) Study population: the study involved 4813 pensioners. (iii) Observation procedures: data were captured through the use of questionnaires, physical examinations including eye examinations, and urine and blood sample analysis. (iv) Main outcome measure: presenting visual impairment and blindness (as defined by the WHO ICD-10 classification).

Results

The overall prevalence of blindness among pensioners in Ghana was 3.8% (95% CI = 3.2–4.4), while the prevalence of moderate and severe visual impairment was 21.7% (95% CI = 20.5–23.0). The prevalence of blindness was lowest in the 60–65-year-old age group (2.1% (95% CI = 1.3–2.8)) and highest in the above 80-year-old age group (12.2% (95% CI = 6.6–17.8)). Cataract was the leading cause of blindness (62.4%) and moderate and severe visual impairment (55.7%). Factors significantly associated with blindness and visual impairment include educational status, vegetarianism, arthritis, and having proteins in urine.

Conclusion

There is a high prevalence of visual impairment and blindness among the pensioners in Ghana. Sadly, the greatest cause was cataract, which is correctable. Increase in formal education status will be important in the prevention of blindness and visual impairment.

In vivo characterization of the deformation of the human optic nerve head using optical coherence tomography and digital volume correlation

We developed a method to measure the 3-dimensional (3D) strain field in the optic nerve head (ONH) in vivo between two intraocular pressures (IOP). Radial optical coherence tomography (OCT) scans were taken of the ONH of 5 eyes from 5 glaucoma patients before and after IOP-lowering surgery and from 5 eyes from 3 glaucoma suspect patients before and after raising IOP by wearing tight-fitting swimming goggles. Scans taken at higher and lower IOP were compared using a custom digital volume correlation (DVC) algorithm to calculate strains in the anterior lamina cribrosa (ALC), retina, and choroid. Changes in anterior lamina depth (ALD) relative to Bruch's membrane were also analyzed. Average displacement error was estimated to be subpixel and strain errors were smaller than 0.37%. Suturelysis decreased IOP by 9-20 mmHg and decreased compressive anterior-posterior strain Ezz in the ALC by 0.76% (p=0.002,n=5). Goggle-wearing increased IOP by 3-4 mmHg and produced compressive Ezz in the ALC (-0.32%,p=0.001,n=5). Greater IOP decrease was associated with greater ALD change (p=0.047,n=10) and greater strains in the ALC (Ezz:p=0.002,n=10). A deepening of ALD was associated with lower IOP and greater ALC strains (p⩽0.045,n=10). A DVC-based method to measure strains from OCT images caused by IOP changes as small as 2.3 mmHg provides preliminary evidence that ALD is shallower and ALC strains are less compressive at higher IOP and that ALD change is associated with ALC strains. STATEMENT OF SIGNIFICANCE: Glaucoma causes vision loss through progressive damage of the retinal ganglion axons at the lamina cribrosa, a connective tissue structure in the optic nerve head that supports the axons as they pass through the eye wall. It is hypothesized that strains caused by intraocular pressure (IOP) may initiate this damage, but few studies have measured the strain response to pressure of the optic nerve head in patients. We present a method to measure the 3D displacement and strain field in the optic nerve head caused by IOP alteration in glaucoma patients using clinically available images. We used this method to measure strain within the optic nerve head from IOP changes caused by glaucoma surgery and wearing tight-fitting swimming goggles.

Increased Plasma Levels of 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in Patients with Pseudoexfoliation Glaucoma

Purpose

To investigate systemic oxidative stress-induced DNA damage in patients with pseudoexfoliation glaucoma (PXG), we estimated plasma levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG) as a marker for oxidative DNA damage in comparison to controls. In addition, we also examined a combined effect of lysyl oxidase-like 1 (LOXL1) polymorphism status and 8-OHdG levels on PXG risk.

Materials and Methods

A retrospective case-control study was performed to estimate plasma levels of 8-OHdG in 41 PXG patients and 45 nonglaucomatous controls using the enzyme-linked immunosorbent assay (ELISA). The assay was performed in duplicate on an automated ELISA analyzer. Two common polymorphisms (rs1048661 and rs3835942) in LOXL1 gene were genotyped by Sanger sequencing.

Results

The mean and median levels of 8-OHdG were significantly increased in the PXG cases (p=0.032) and male subjects (p=0.041). Subjects with levels greater than the third quartile (75% percentile) exhibited a significant increased risk of PXG (odds ratio = 4.06, 95% confidence interval (CI = 1.11–14.80, p=0.029)). Within- and between-group comparisons showed that the mean levels were higher in individuals carrying the LOXL1 risk variant (G/G), but not statistically significant. In logistic regression analysis, both 8-OHdG (p=0.044) and rs3835942 (p=0.012) showed a statistically significant effect on the PXG outcome. However, the effect was lost when age, sex, and rs1048661 were included. A significant positive correlation was observed between 8-OHdG levels and intraocular pressure (R=0.284, p=0.008) and cup/disc ratio (R=0.233, p=0.031). Furthermore, in receiver operating characteristic analysis, the area under the curve was statistically significant (p=0.032) with a value of 0.635 (95% CI = 0.518–0.751).

Conclusion

The study demonstrates an association of increased plasma levels of 8-OHdG in patients with PXG, supporting the role of oxidative stress, and increased oxidative DNA damage in PXG development.

Enhanced EGF receptor-signaling potentiates TGFβ-induced lens epithelial-mesenchymal transition

The ocular lens is exposed to numerous growth factors that influence its behavior in diverse ways. While many of these, such as FGF and EGF promote normal cell behavior, TGFβ is unique in that it can also induce lens cell pathology, namely, the epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) leading to fibrotic cataract formation. The present study explores how EGF impacts on TGFβ-induced EMT in the lens. LECs in explants prepared from 21-day-old Wistar rats were treated with either 200 pg/ml TGFβ2, 5 ng/ml EGF, or a combination of these, with or without a 2-h pre-treatment of an EGFR inhibitor (PD153035), MEK inhibitor (U0126) or Smad3 inhibitor (SIS3). Co-treatment of LECs with TGFβ2 and EGF, compared with TGFβ2 alone, resulted in a more pronounced elongation and transdifferentiation of the LECs into myofibroblastic cells, with higher protein levels of mesenchymal cell markers (α-SMA and tropomyosin). Combining EGF with a less potent lower dose of TGFβ2 (50 pg/ml) induced LECs to undergo EMT equivalent to treatment with a higher dose of TGFβ2 (200 pg/ml) within 5 days of culture. EGF alone, nor the lower dose of TGFβ2, were able to induce EMT in LECs within 5 days. Co-treatment of LECs with EGF and TGFβ2 induced a temporal shift in the phosphorylation levels of Smad2/3, ERK1/2 and EGFR and changed the expression patterns of downstream EMT target genes, compared to treatment of LECs with either growth factor alone. Inhibition of EGFR-signaling with PD153035 blocked the EMT response induced by co-treatment with EGF and TGFβ2. Taken together, our data demonstrate that EGF can potentiate TGFβ2 activity to enhance EMT in LECs, further highlighting the importance of EGFR-signaling in cataract formation. By directly blocking EGFR signaling, the activity of both EGF and TGFβ2 can be simultaneously reduced, thereby serving as a potential target for cataract prevention.