Age-related macular degeneration in a South Indian population, with and without diabetes

Choroidal Control Technology: New Horizons in Maculopathy and Presbyopia

OBJECTIVE

To evaluate changes in choroidal thickness in presbyopes, when reading with regular glasses versus choroidal control glasses, in patients with or without Age-Related Macular Degeneration (AMD).

METHODS

This was a pilot study on short-term axial length (AL) in 33 eyes of 24 presbyopic patients aged 60 to 80 years, assigned to two age-matched groups, with or without AMD. About them, changes in choroidal thickness were evaluated with ocular biometry through indirect measurements of axial length at baseline, after 20' of reading with conventional lenses, and after another 20' of reading with peripheral hyperopic defocus glasses. The differences in axial length between the three different times were analyzed.

RESULTS

In presbyopes without AMD there was a significant axial length shortening of -13.44 microns in the first conventional reading period, which was reversed by 90% with hyperopic defocus lenses, recovering + 12.11 microns by axial lengthening (choroidal thinning, p = 0.03). In patients with AMD, axial shortening was significantly greater than controls, -23.86 microns with conventional lenses (p < 0.001) and they, also increased their axial length with defocus, although this response was smaller in proportion (+ 15.52 microns).

CONCLUSION

Reading with positive lenses produces myopic defocus and choroidal thickening in presbyopes with and without AMD but was significantly greater in the latter. Glasses with Choroidal Control Technology reduced thickening during reading.

KEY MESSAGES

What is known • Presbyopia spectacles for near produce myopic defocus and choroidal thickening. What is new • There are differences in choroidal thickening during reading between normal subjects and those with age related macular degeneration. • Spectacles with Defocus Choroidal Control Technology reduce choroidal thickening during reading in presbyopes.

Treatment avenues for age-related macular degeneration: Breakthroughs and bottlenecks

Age-related macular degeneration (AMD) is a significant factor contributing to serious vision loss in adults above 50. The presence of posterior segment barriers serves as chief roadblocks in the delivery of drugs to treat AMD. The conventional treatment strategies use is limited due to its off-targeted distribution in the eye, shorter drug residence, poor penetration and bioavailability, fatal side effects, etc. The above-mentioned downside necessitates drug delivery using some cutting-edge technology including diverse nanoparticulate systems and microneedles (MNs) which provide the best therapeutic delivery alternative to treat AMD efficiently. Furthermore, cutting-edge treatment modalities including gene therapy and stem cell therapy can control AMD effectively by reducing the boundaries of conventional therapies with a single dose. This review discusses AMD overview, conventional therapies for AMD and their restrictions, repurposed therapeutics and their anti-AMD activity through different mechanisms, and diverse barriers in drug delivery for AMD. Various nanoparticulate-based approaches including polymeric NPs, lipidic NPs, exosomes, active targeted NPs, stimuli-sensitive NPs, cell membrane-coated NPs, inorganic NPs, and MNs are explained. Gene therapy, stem cell therapy, and therapies in clinical trials to treat AMD are also discussed. Further, bottlenecks of cutting-edge (nanoparticulate) technology-based drug delivery are briefed. In a nutshell, cutting-edge technology-based therapies can be an effective way to treat AMD.

Incidence and risk factors of age-related macular degeneration in patients with Parkinson's disease: a population-based study

Background and objective

The association between age-related macular degeneration (AMD) and Parkinson' disease (PD) remains unclear. The aim of the present study was to assess the incidence of AMD in patients with PD, elucidate differences by age and sex, and investigate potential risk factors for AMD.

Methods

Data were extracted from the Korean National Health Insurance System database, which covers 97% of the Korean population (2002 through 2019). We calculated the incidence of newly diagnosed AMD in patients with PD and used Cox proportional-hazards models to estimate risk factors for AMD, presenting adjusted hazard ratios (aHR) with 95% confidence intervals (CI).

Results

Of 172,726 patients with PD, 15,800 were newly diagnosed with AMD during the follow-up, including 5,624 men and 10,176 women. The overall incidence of AMD in patients with PD was 13.59 per 1,000 person-years. Stratified by age group and sex, the incidence was higher in women aged 40-69, and conversely higher in men aged 70-89. Risk of AMD was high in older age groups (aHR = 4.36, 95% CI: 3.74-5.09 in the 70 s), female sex (aHR = 1.07, 95% CI: 1.04-1.11), patients with diabetes mellitus (DM) (aHR = 1.14, 95% CI: 1.10-1.18), and patients with hyperlipidemia (aHR = 1.17, 95% CI: 1.13-1.21).

Conclusion

Our findings suggest that the AMD incidence is higher in patients with PD than in the general population, with varying patterns of sex differences across age groups. Particularly, old age, female sex, presence of DM, and hyperlipidemia are potential risk factors. Therefore, clinicians should pay greater attention to AMD in patients with PD.

Association of metformin use with risk of newly onset neovascular age-related macular degeneration development

PURPOSE

To investigate if metformin use reduces the odds of developing new neovascular AMD (nAMD).

METHODS

This is a case-control study of 86,930 subjects with new diagnoses of nAMD and 86,918 matched controls using the Merative™ Marketscan® Research Databases. Subjects were analyzed using multivariable conditional logistic regression to identify the risks of various exposures on developing nAMD. A subgroup analysis of 22,117 diabetic cases and 21,616 diabetic controls was also performed.

RESULTS

Metformin use was associated with reduced odds ratio (OR) of developing nAMD (OR 0.95, 95% confidence interval 0.91-0.98) in full sample and diabetic cohort particularly in patients without any diabetic retinopathy (DR) -an effect that persisted after Bonferroni correction. In the diabetic cohort without DR, reduced OR was observed at 24-month cumulative doses of 1 to 300g, 301 to 630g, and 631 to 1080g.

CONCLUSIONS

Metformin use was associated with reduced OR of nAMD, particularly in patients without DR. The protective effect was noted for 24-month cumulative doses below 1080g. Metformin may be a novel preventive strategy for nAMD.

Effects of diabetic retinopathy on longitudinal morphological changes in AMD-associated type 1 macular neovascularization

The purpose of this study was to investigate the effect of diabetic retinopathy (DR) on longitudinal morphological changes in AMD-associated type 1 macular neovascularization using optical coherence tomography angiography (OCTA). We enrolled fifty treatment-naïve eyes with a diagnosis of exudative AMD and type 1 MNV. Twenty of 50 eyes were affected by mild DR. En face OCT angiography were examined for the MNV lesion area (mm2), the MNV flow area (mm2), the central macular thickness (CMT) and the BCVA. The OCTA acquisition was performed at the following visits: (i) before the loading phase (LP) of intravitreal injection of aflibercept (T1), and (ii) 1 month after the last intravitreal injection of loading phase comprising 3 monthly injections (T2). All morpho-functional parameters showed a significantly change at T2 compared to T1 values in both groups. Furthermore, we found a greater MNV area reduction after LP in eyes without DR (P = 0.023). With regard to the remaining parameters, no significant changes were found between two groups (P > 0.05). Our analysis revealed a less MNV area reduction after loading dose of anti-VEGF therapy in eyes affected by diabetic retinopathy.

Diabetes-Related Risk Factors for Exudative Age-Related Macular Degeneration: A Nationwide Cohort Study of a Diabetic Population

Purpose

The purpose of this study was to identify diabetes-related risk factors for exudative age-related macular degeneration (AMD).

Methods

This was a nationwide population-based cohort study using authorized clinical data provided by the Korean National Health Insurance Service. A total of 1,768,018 participants with diabetes over 50 years of age participated in the Korean National Health Screening Program between 2009 and 2012. Data on covariates, including age, sex, income level, systemic comorbidities, behavioral factors, and diabetes-related parameters, including duration of diabetes, use of insulin for diabetes control, number of oral hypoglycemic agents used, and accompanying vision-threatening diabetic retinopathy, were collected from health screening results and claims data. Patients were followed up until December 2018. Incident cases of exudative AMD were identified using registered diagnostic codes from the claims data. The prospective association of diabetes-related parameters with incident exudative AMD was investigated using the multivariable-adjusted Cox proportional hazard model.

Results

During an average follow-up period of 5.93 years, 7331 patients were newly diagnosed with exudative AMD. Compared to those who had diabetes for less than 5 years, individuals with diabetes for 5 years or more had a greater risk of future exudative AMD development, with a hazard ratio (95% confidence interval) of 1.13 (1.07-1.18) in the fully adjusted model. Use of insulin for diabetes control and the presence of vision-threatening diabetic retinopathy were also associated with an increased risk of exudative AMD with a hazard ratio (95% confidence interval) of 1.16 (1.07-1.25) and 1.40 (1.23-1.61), respectively.

Conclusions

A longer duration of diabetes, administration of insulin for diabetes control, and comorbid vision-threatening diabetic retinopathy were associated with an increased risk of developing exudative AMD.

Association between Age-Related Macular Degeneration and the Risk of Diabetes Mellitus: A Nationwide Cohort Study

Age-related macular degeneration (AMD) is a degenerative and progressive disease of the macula, the part of the retina that is responsible for central vision. AMD shares some risk factors with diabetes mellitus (DM), but little is known about the risk of DM in individuals with AMD. With the goal of establishing novel perspectives, this study aimed to investigate the association between AMD and the risk of DM using the Korean Nationwide Health Insurance Database. Individuals aged ≥ 50 years who underwent a national health screening program in 2009 were enrolled. Participants were categorized by the presence of AMD and visual disability (VD). The Cox hazard regression model was used to examine hazard ratios (HRs) of DM with adjustment for potential confounders. Stratified analyses by age, sex, and comorbidities (hypertension or dyslipidemia) were also performed. During a mean follow-up of 8.61 years, there were 403,367 (11.76%) DM incidences among the final 3,430,532 participants. The crude HR (95% confidence interval (CI)) was 1.16 (1.13–1.20) for AMD. After adjusting for potential confounders, AMD was associated with a 3% decreased risk of DM (aHR 0.97, 95% CI 0.95–1.00), but no significant association with the risk of DM was found in AMD with VD (aHR 1.03, 95% CI 0.93–1.14). In summary, we did not find an increased risk of DM in individuals with AMD. A 3% decreased risk of DM in patients with AMD is not clinically meaningful. Our study suggests that the association between AMD and the risk of DM is weak, considering the potential confounders. Further studies examining this association are needed to extend our knowledge.

Association between metformin use and the risk of age-related macular degeneration in patients with type 2 diabetes: a retrospective study

OBJECTIVES

To investigate the effect of metformin on the decreased risk of developing age-related macular degeneration (AMD) in patients with type 2 diabetes mellitus (T2DM) for ≥10 years.

DESIGN

A retrospective study.

PARTICIPANTS

Patients aged ≥50 with a diagnosis of T2DM no less than 10 years were included.

METHODS

Variables predisposing to AMD were reviewed; the potential confounders related to T2DM or AMD were selected from literature records; AMD and diabetic retinopathy (DR) were diagnosed by funduscopy, optical coherence tomography and/or fluorescein angiography. The subgroup analysis was performed in early and late AMD. The protective effect of metformin was evaluated in duration-response and dose-response patterns.

RESULTS

A total of 324 patients (115 metformin non-users and 209 users) were included in the final analysis. AMD was observed in 15.8% of metformin users and 45.2% of metformin non-users (p<0.0001). The ORs for any AMD, early AMD and late AMD present in patients with DR were 0.06 (0.02-0.20), 0.03 (0.00-0.20) and 0.17 (0.04-0.75). The serum high-density lipoprotein level was positively associated with the late AMD risk (p=0.0054). When analysed by the tertiles of cumulative duration, a similarly reduced risk was observed for the second (5-9 years) (OR: 0.24, 95% CI: 0.08 to 0.75) and third tertiles (≥10 years) (OR: 0.22, 95% CI: 0.09 to 0.52) compared with the first tertile (≤4 years).

CONCLUSION

Among patients with T2DM for ≥10 years, metformin users were less likely to develop any AMD and early AMD than non-users; however, the late AMD was not significantly associated with the use of metformin. Also, AMD was less prevalent in patients with DR. The prolonged metformin treatment with a high cumulative dose enhanced the protective effect against AMD. Metformin significantly reduces the AMD risk when the cumulative duration is >5 years.

Age-related macular degeneration: Epidemiology, genetics, pathophysiology, diagnosis, and targeted therapy

Age-related macular degeneration (AMD) is a complex eye disorder and is the leading cause of incurable blindness worldwide in the elderly. Clinically, AMD initially affects the central area of retina known as the macula and it is classified as early stage to late stage (advanced AMD). The advanced AMD is classified into the nonexudative or atrophic form (dry AMD) and the exudative or neovascular form (wet AMD). More severe vision loss is typically associated with the wet form. Multiple genetic factors, lipid metabolism, oxidative stress and aging, play a role in the etiology of AMD. Dysregulation in genetic to AMD is established to 46%-71% of disease contribution, with CFH and ARMS2/HTRA1 to be the two most notable risk loci among the 103 identified AMD associated loci so far. Chronic cigarette smoking is the most proven consistently risk living habits for AMD. Deep learning algorithm has been developed based on image recognition to distinguish wet AMD and normal macula with high accuracy. Currently, anti-vascular endothelial growth factor (VEGF) therapy is highly effective at treating wet AMD. Several new generation AMD drugs and iPSC-derived RPE cell therapy are in the clinical trial stage and are promising to improve AMD treatment in the near future.

Clinical profile and magnitude of diabetic retinopathy: An electronic medical record-driven big data analytics from an eye care network in India

Purpose:

This study aimed to describe the clinical profile and magnitude of diabetic retinopathy (DR) in patients presenting to a multitier eye hospital network in India.

Methods:

This cross-sectional hospital-based study included 263,419 individuals with diabetes mellitus (DM) presenting between February 2012 and February 2021 (9-year period). The data were collected using an electronic medical record (EMR). Patients with a clinical diagnosis of DR in at least one eye were included in the analysis. Severe nonproliferative DR/proliferative DR/diabetic macular edema (DME) were considered sight-threatening DR (STDR).

Results:

In the study period, 25% (n = 66,913) were new patients diagnosed with DR. The majority of patients were males (70%). The mean age of the patients was 57 ± 10 years. The risk factors for DR were increased age: 30 to 50 years (odds ratio [OR] = 2.42), and 51 to 70 years (OR = 3.02), increased duration of DM: 6 to 10 years (OR = 2.88) and >10 years (OR = 6.52), blindness (OR = 2.42), male gender (OR = 1.36), lower socioeconomic status (OR = 1.43), and rural habitation (OR = 1.09). STDR was seen in 58% (n = 38,538) of examined patients. Risk factors for STDR were increased age 31 to 50 years (OR = 3.51), increased duration of DM: 6 to 10 years (OR = 1.23) and >10 years (OR = 1.68), blindness (OR = 3.68), male gender (OR = 1.12), and higher socioeconomic status (OR = 1.09).

Conclusion:

Every fourth person with DM was found to have DR, and every second person with DR had STDR in this study cohort. These real-world big data might provide greater insight into the current status of DR. Additional big data from similar EMR-based sources will help in planning and resource allocation.

Impact of age-related macular degeneration on diabetic retinopathy: An electronic health record based big data analysis from a tertiary eye centre in South India

Purpose:

To determine whether the presence of age-related macular degeneration (AMD) decreases the risk of diabetic retinopathy.

Methods:

This was a retrospective, case-cohort study performed in patients with a systemic diagnosis of diabetes at a tertiary health care center from May 2011 to April 2020. A total of 43,153 patients (1,024 AMD patients and 42,129 non-AMD patients) were included in the analysis. A total of 1,024 age and diabetes mellitus (DM) duration-matched controls were chosen from the non-AMD group for risk factor analysis. The severity of diabetic retinopathy was compared between the patients with AMD and the patients without AMD.

Results:

Out of the enrolled 43,153 diabetic patients, 26,906 were males and 16,247 were females. A total of 1,024 patients had AMD and 42,129 had no AMD. The mean age of the cohort was 58.60 ± 0.09 years. The overall prevalence of DR was noted to be 22.8% (9,825 out of 43,153 eyes). A significantly lower prevalence of diabetic retinopathy (DR) (23% in non-AMD, 11.4% in AMD, OR = −0.43, P < 0.001), non-proliferative diabetic retinopathy (NPDR) (12% in non-AMD, 8.2% in AMD, OR = −0.66, P < 0.001), and proliferative diabetic retinopathy (PDR) (11% in non-AMD, 3.2% in AMD, OR = −0.27, P < 0.001) was seen in the AMD patients. No significant difference was seen between the dry and wet AMD. On multivariate logistic regression analysis, the lower age, absence of AMD, and male gender were associated with a higher risk of PDR.

Conclusion:

The presence of AMD was noted to statistically reduce the risk of DR. Our results may be useful in the field of resource allocation and awareness of DR.

Untargeted metabolomics for uncovering plasma biological markers of wet age-related macular degeneration

Wet age-related macular degeneration (wAMD) causes central vision loss and represents a major health problem in elderly people. Here we have used untargeted metabolomics using UHPLC-MS to profile plasma from 127 patients with wAMD (67 choroidal neovascularization (CNV) and 60 polypoidal choroidal vasculopathy (PCV)) and 50 controls. A total of 545 biochemicals were detected. Among them, 17 metabolites presented difference between patients with wAMD and controls. Most of them were oxidized lipids (N=6, 35.29%). Comparing to controls, 28 and 18 differential metabolites were identified in patients with CNV and PCV, respectively. Two metabolites, hyodeoxycholic acid and L-tryptophanamide, were differently distributed between PCV and CNV. We first investigated the genetic association with metabolites in wet AMD (CFH rs800292 and HTRA1 rs10490924). We identified six differential metabolites between the GG and AA genotypes of CFH rs800292, five differential metabolites between the GG and AA genotypes of HTRA1 rs10490924, and four differential metabolites between the GG and GA genotypes of rs10490924. We selected four metabolites (cyclamic acid, hyodeoxycholic acid, L-tryptophanamide and O-phosphorylethanolamine) for in vitro experiments. Among them, cyclamic acid reduced the activity, inhibited the proliferation, increased the apoptosis and necrosis in human retinal pigment epithelial cells (HRPECs). L-tryptophanamide affected the proliferation, apoptosis and necrosis in HRPECs, and promoted the tube formation and migration in primary human retinal endothelial cells (HRECs). Hyodeoxycholic acid and O-phosphorylethanolamine inhibited the tube formation and migration in HRECs. The results suggested that differential metabolites have certain effects on wAMD pathogenesis-related HRPECs and HRECs.

Association of Metformin Use With Age-Related Macular Degeneration: A Case-Control Study

Importance

Age-related macular degeneration (AMD), the leading cause of irreversible blindness in older adults, appears to have no effective preventive measures. The common antidiabetic drug metformin has been shown to have protective outcomes in multiple age-associated diseases and may have the potential to protect against the development of AMD.

Objective

To determine whether metformin use is associated with reduced odds of developing AMD.

Design, Setting, and Participants

This case-control study of patients from a nationwide health insurance claims database included a population-based sample of patients. Those aged 55 years and older with newly diagnosed AMD from January 2008 to December 2017 were defined as cases and matched with control participants. Data analyses were completed from June 2019 to February 2020.

Exposures

Dosage of metformin and exposure to other prescribed medications, as identified from outpatient drug claims.

Main Outcomes and Measures

Risk of developing AMD.

Results

A total of 312 404 affected individuals were included (181 817 women [58.2%]). After matching, 312 376 control participants were included (172 459 women [55.2%]; age range, 55 to 107 years). The case group had a slightly higher percentage of participants with diabetes (81 262 participants [26.0%]) compared with the control group (79 497 participants [25.5%]). Metformin use was associated with reduced odds of developing AMD (odds ratio [OR], 0.94 [95% CI, 0.92-0.96]). This association was dose dependent, with low to moderate doses of metformin showing the greatest potential benefit (dosages over 2 years: 1-270 g, OR, 0.91 [95% CI, 0.88-0.94]; 271-600 g, OR, 0.90 [95% CI, 0.87-0.93]; 601-1080 g, OR, 0.95 [95% CI, 0.92-0.98]). Doses of more than 1080 g of metformin over 2 years did not have reduced odds of developing AMD. Both the reduction in odds ratio and the dose-dependent response were preserved in a cohort consisting only of patients with diabetes. Metformin use was associated with a decreased OR of AMD in patients with diabetes without coexisting diabetic retinopathy (OR, 0.93 [95% CI, 0.91-0.95]) but was a risk factor in patients with diabetic retinopathy (OR, 1.07 [95% CI, 1.01-1.15]).

Conclusion and Relevance

In this study, metformin use was associated with reduced odds of developing AMD. This association was dose dependent, with the greatest benefit at low to moderate doses. When looking only at patients with diabetes, we saw a preservation of the dose-dependent decrease in the odds of patients developing AMD. Metformin does not appear to be protective in patients with diabetes and coexisting diabetic retinopathy. This study suggests that metformin may be useful as a preventive therapy for AMD and provides the basis for potential prospective clinical trials.

Prevalence of age-related macular degeneration among optometric telemedicine users in Spain: a retrospective nationwide population-based study

PURPOSE

To evaluate the prevalence of AMD among optometric telemedicine users in Spain and to identify risk factors.

METHODS

Retrospective analysis of a nationwide database conducted on subjects attending to optometry centers, between January 2013 and December 2019. Fundus photographs were performed by optometrists, using non-mydriatic cameras, and evaluated by a group of 12 retina specialists.

RESULTS

Among the 119,877 subjects included, the overall prevalence of AMD was 7.6%. The prevalence of early, intermediate, and advanced AMD was 2.9%, 2.7%, and 2.0%, respectively. Of the 9129 AMD subjects, 1161 (12.7%) had geographic atrophy, and 1089 (11.9%) had neovascular AMD, either scar (4.5%) or exudative (7.4%). There was a significant association between AMD and age (per year older, adjusted odds ratio, OR 1.116; 95% CI 1.114 to 1.119, p<0.0001). Women had higher prevalence (adjusted OR 1.17; 95% CI 1.12 to 1.23, p<0.0001). Every diopter (spherical equivalent) of progress toward hyperopia was associated with a significant increase in early AMD prevalence (adjusted OR 1.02, 95 CI 1.01 to 1.04, p=0.0074). Presence of diabetes was associated with a lower AMD prevalence (p<0.0001).

CONCLUSIONS

The prevalence of AMD (any eye and any severity) was 7.6%, with a prevalence of advanced AMD of 2.0%. Older age and women were significantly associated with a higher prevalence of AMD, whereas myopia and presence of diabetes were associated with significantly lower odds of any AMD.

Age-Related Macular Degeneration and Associated Risk Factors in the Population-Based Study of Health in Pomerania (SHIP-Trend)

Background

Age-related macular degeneration (AMD) is the leading cause of visual impairment in developed countries, especially in the older population. The Study of Health in Pomerania (SHIP) is a population-based study designed to investigate risk factors and clinical disorders in the general population. In the present study, we analysed the AMD prevalence and risk factors in the north-eastern German population.

Material/Methods

From 2008 to 2012, we collected data among participants ages 29–79 years. The study population consisted of 4420 individuals. Non-mydriatic retinal photographs were taken of 3934 participants. AMD stages were graded according to the Rotterdam Classification System and the International Classification System.

Results

Photographs from 1854 participants were available for grading. The baseline examinations showed small hard drusen (<63 μm, stage 0b and 0c) were present in 10.7% of the participants (stage 0b in 7.5% and stage 0c in 3.2%). Earliest signs of AMD were detected in 28.68% (stage 0b in 7.5% and stage 1b in 21.18%). Late AMD (geographic atrophy and neovascular AMD, stages 4a and 4b) were identified in 0.43% (stage 4a in 0.16% and stage 4b 0.27%). Risk of AMD increased significantly with age and higher body mass index, waist circumference, hip circumference, and weight-waist-ratio. Smoking, sex, systolic and diastolic blood pressure, HbA1c, cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride were not associated with AMD in this study.

Conclusions

The prevalence of AMD increases with age and obesity-associated factors. These results must be verified in the follow-up. Data concerning the incidence of AMD will be available after the 5- and 10-year follow-ups.