Age-Related Macular Degeneration and Its Risk Factors in North Africans Living in Algeria and Italy

Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina

Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.

Effect of cataract surgery on the progression of age-related macular degeneration

BACKGROUND

Cataracts and age-related macular degeneration (AMD) are common causes of decreased vision and blindness in individuals over age 50. Although surgery is the most effective treatment for cataracts, it may accelerate the progression of AMD, so this study further evaluated the influence of cataract surgery for AMD through a systematic review and meta-analysis.

METHODS

The Cochrane Systematic Evaluation method was adopted, and computer searches were conducted for the China Knowledge Network, Wanfang, Vipul, SinoMed, PubMed, SpringerLink, Clinicalkey, Medline, Cochrane Library, Web of Science, OVID, and Embase databases of cohort studies on the impact of cataract surgery on AMD, with search timeframes up to May 2022. Meta-analysis was performed using Stata/12.0.

RESULTS

A total of 8 cohort studies were included in the study. The results showed that the relative risk (RR) of AMD progression after cataract surgery was not significantly different, RR 1.194 [95% credibility interval (CI) 0.897-1.591]; the risk remained increased more than 5 years after surgery, RR 1.372 (95% CI 1.062-1.772).

CONCLUSION

There is still a significant positive correlation between cataract surgery and increase the risk of worsening of AMD progression, and faster progression of early-to-late AMD found in cataract surgery with longer follow-up of patients.

Cross-Sectional Study on Vitamin D, Zinc Oxide and Fatty Acid Status in a Population with a Moderate to High Risk of AMD Identified by the STARS® Questionnaire

INTRODUCTION

A prospective study was carried out in Belgium to determine the proportion of subjects with a moderate to high risk of developing age-related macular degeneration (AMD), identified using the STARS® (Simplified Théa AMD Risk-Assessment Scale) questionnaire, who were in need of nutritional supplementation, by assessing the vitamin D, zinc oxide and fatty acid profile status.

METHODS

This multicentre cross-sectional pilot study involved 50 Belgian subjects with no or early AMD, aged > 55 years who were at moderate to high risk for AMD. Subjects were assessed using the STARS® questionnaire, visual acuity assessment, an optical coherence tomography scan of the macula and fundus photography. Blood samples were collected, and serum analyses were performed to determine the the omega-6:omega-3 (Ω6:Ω3) ratio and the levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), zinc and cupric oxides and vitamin D.

RESULTS

Abnormal serum levels for at least one of the micronutrients was detected in 94% of the subjects. Lower than optimal vitamin D levels were found in 76% of the participants, and 68% of the subjects demonstrated at least one abnormal fatty acid profile. The Ω6:Ω3 ratio was above the reference range for normal values in 54% of the subjects; DHA and EPA levels were below the reference range in 60 and 46% of the subjects, respectively; and zinc oxide concentration was below the reference range in 50% of the subjects. Only 12% of the subjects exhibited cupric oxide deficiency.

CONCLUSION

In this study, the STARS® questionnaire was used for early identification of patients at moderate to high risk of AMD in real life. These patients presented a suboptimal nutritional status. Further research is needed to determine if specific diet modification or micronutrient supplement intake delays the onset or slows down the progression of AMD in these subjects.

TRIAL REGISTRATION

Trial registration: ClinicalTrials.Gov, identifier: NCT04482465.

Medical Compliance of Fibrate and the Decreased Risk of Age-Related Macular Degeneration in Dyslipidemia-Related Diseases: A Population-Based Cohort Study

The purpose of the current study is to evaluate the incidence of age-related macular degeneration (AMD) in dyslipidemia-related diseases with or without the use of fibrate. Patients were defined as dyslipidemia-related diseases according to the diagnostic code and lab exam arrangement, then the population was divided into those with fibrate application and those without via 1:2 ratios of propensity-score matching. The primary outcome is the development of AMD after dyslipidemia-related diseases by the Cox proportional hazard regression. Besides, the relationship between the medical compliance of fibrate, presented as medical possession ratio (MPR), and the AMD development was also analyzed. A total of 22,917 patients and 45,834 individuals were enrolled in the study and control groups. There were 572 and 1181 events of any AMD development in the study and control groups which showed identical risk of AMD (aHR: 0.94, 95% CI: 0.85–1.04). However, a reduced risk of any AMD was found in those patients reached a baseline MPR more than 20% (aHR: 0.729, 95% CI: 0.599–0.887, p = 0.0016) and overall MPR more than 5% three years after the diagnosis of dyslipidemia-related diseases (aHR: 0.712, 95% CI: 0.557–0.909, p = 0.0065). Besides, a lower risk of dry-AMD was also found in those patients with the above conditions (aHR: 0.736, 95% CI: 0.599–0.906, p = 0.0038 and aHR: 0.721, 95% CI: 0.557–0.934, p = 0.0133, respectively). In conclusion, the use of fibrate with fair initial medical compliance will decrease the incidence of AMD in patients with dyslipidemia-related diseases, especially for the development of dry-AMD.

Does Cataract Surgery Improve the Progression of Age-Related Macular Degeneration? A Meta-Analysis

Purpose

Cataract and age-related macular degeneration (AMD) are the common causes of blindness in the elderly. Although cataract surgery is the most effective treatment for cataract, some clinicians suspect that such interventions may accelerate the progression of AMD. Therefore, we carried out this meta-analysis to focus on demonstrating the effectiveness and safety of cataract surgery in eyes with AMD.

Methods

We performed a systematic literature search in the PubMed, EMBASE, and Cochrane Library databases, and the electronic databases were last searched in January 2019. We planned to include cohort trials of eyes affected by both cataract and AMD in which cataract surgery would be compared to no surgery. Two reviewers independently evaluated the search results against the inclusion and exclusion criteria. 8 trials were included for this meta-analysis.

Results

We used the Stata/12.0 to integrate the data that was extracted from the articles. Eight cohort trials with data from different study populations were included. In random effects model, the relative risk (RR) for the progression of AMD is 1.194 (95% CI 0.897–1.591). As for those grouped according to the follow-up year, the RR for longer than five years was 1.372 (95% CI 1.062–1.772).

Conclusion

We could draw out such a conclusion that there is still a positive correlation between cataract surgery and the progression of AMD, especially for the Asians. However, based on the current results, it is not possible to draw conclusions from existing studies on the impact of cataract surgery on early AMD development.

Association between sunlight exposure and risk of age-related macular degeneration: a meta-analysis

Background

A substantial number of epidemiological studies have investigated the possible associations between sunlight exposure and Age-related Macular Degeneration (AMD), but the results from studies are inconsistent. The aim of this meta-analysis was to evaluate the association between sunlight exposure and the risk of AMD.

Methods

Relevant studies were searched using databases including PubMed, EMBASE, and Web of Science database. Two authors independently extracted data and assessed study quality. The random-effects model was used to calculate the pooled covariates-adjusted odds ratio (OR). Subgroup analyses based on study design, stage of AMD, method of exposure assessment, and study latitude were carried out. The heterogeneity across the studies was tested, as was publication bias.

Results

Fourteen eligible studies including 43,934 individuals based on the inclusion criteria were analyzed. The pooled OR for sunlight exposure and AMD was 1.10 (95% CI = 0.98–1.23). In addition, similar insignificant results were observed in further subgroup analyses based on stage of AMD, method of exposure assessment, and study latitude. Sun-avoidance behavior did not decrease the risk of AMD (OR = 1.12, 95% CI = 0.76–1.67). Moderate heterogeneity was observed in most of analyses.

Conclusion

The results indicate that sunlight exposure may not be associated with increased risk of AMD based on current published data.

Pharmacogenetic Aspect of Intravitreal Ranibizumab Treatment in Neovascular Age-Related Macular Degeneration: A Five-Year Follow-Up

PURPOSE

This study aims to evaluate the role of complement factor H (CFH) in response to intravitreal ranibizumab (IVR) treatment, which is administered to patients with neovascular age-related macular degeneration (nAMD).

METHODS

In this retrospective study, 90 nAMD patients' 90 eyes were evaluated. IVR was injected once a month for three consecutive months, and then, patients were followed up for five years by using pro re nata method.

RESULTS

Average visual acuity (BCVA) values in TT group for the third, fourth and fifth years were found to be significantly higher than those in TC and CC groups, while average BCVA values in TC group were significantly higher than those in CC group (all p = .000 < .0167).

CONCLUSION

Patients with CFH TT genotype responded significantly better to treatment after third year, while patients with CC genotype had a poorer response to IVR.