Blue Light Exposure: Ocular Hazards and Prevention-A Narrative Review.

INTRODUCTION: Exposure to blue light has seriously increased in our environment since the arrival of light emitting diodes (LEDs) and, in recent years, the proliferation of digital devices rich in blue light. This raises some questions about its potential deleterious effects on eye health. The aim of this narrative review is to provide an update on the ocular effects of blue light and to discuss the efficiency of methods of protection and prevention against potential blue light-induced ocular injury. METHODS: The search of relevant English articles was conducted in PubMed, Medline, and Google Scholar databases until December 2022. RESULTS: Blue light exposure provokes photochemical reactions in most eye tissues, in particular the cornea, the lens, and the retina. In vitro and in vivo studies have shown that certain exposures to blue light (depending on the wavelength or intensity) can cause temporary or permanent damage to some structures of the eye, especially the retina. However, currently, there is no evidence that screen use and LEDs in normal use are deleterious to the human retina. Regarding protection, there is currently no evidence of a beneficial effect of blue blocking lenses for the prevention of eye diseases, in particular age-related macular degeneration (AMD). In humans, macular pigments (composed of lutein and zeaxanthin) represent a natural protection by filtering blue light, and can be increased through increased intake from foods or food supplements. These nutrients are associated with lower risk for AMD and cataract. Antioxidants such as vitamins C, E, or zinc might also contribute to the prevention of photochemical ocular damage by preventing oxidative stress. CONCLUSION: Currently, there is no evidence that LEDs in normal use at domestic intensity levels or in screen devices are retinotoxic to the human eye. However, the potential toxicity of long-term cumulative exposure and the dose-response effect are currently unknown.

Real-world outcomes with ranibizumab in branch retinal vein occlusion: The prospective, global, LUMINOUS study.

OBJECTIVE: To evaluate the effectiveness, safety, and treatment patterns of ranibizumab 0.5 mg in treatment-naïve patients with branch retinal vein occlusion (BRVO) enrolled in the LUMINOUS™ study. STUDY DESIGN: A 5-year, global, prospective, multicenter, observational, open-label study conducted in a clinical practice (real-world) setting at outpatient ophthalmology clinics that recruited 30,138 consenting adult patients from all approved indications for ranibizumab across 42 countries. Patients with BRVO were treated according to the local ranibizumab label of the participating countries. Mean change in visual acuity (VA) in Early Treatment Diabetic Retinopathy Study letters from baseline to Year 1, treatment exposure during Year 1, and adverse events (AEs) over 5 years were assessed. RESULTS: Of the 1366 recruited BRVO patients, 405 were treatment-naïve at baseline with a mean (standard deviation [SD]) age of 67.9 (12.5) years, 57.5% were female, and 71.8% were White. At Year 1 (n = 189), the mean (SD) VA gain was 11.9 (17.66) letters from a baseline of 49.2 (±20.32) letters with a mean (SD) of 5.0 (2.34) injections. VA gains were higher in patients (n = 83) who received 6-9 injections (13.6 [20.16] letters) than in those who received 2-5 injections (n = 92, 11.7 [15.43] letters), or 1 injection (n = 14, 3.6 [13.72] letters). Patients with baseline VA <23 letters had numerically highest VA gains (n = 20, 31.1 [24.48] letters). Over 5 years, the rate of ocular/non-ocular AEs was 7.4%/9.1% and serious AEs was 0.3%/4.4% in treatment-naïve BRVO patients (n = 405). CONCLUSIONS: One year results from the LUMINOUS real-world study showed a clinically meaningful VA improvement with ranibizumab in treatment-naïve patients with BRVO; numerically higher VA gains were achieved in patients who received more injections and those with poor baseline VA. No new safety signals were observed.

The Role of Diet, Micronutrients and the Gut Microbiota in Age-Related Macular Degeneration: New Perspectives from the Gut⁻Retina Axis.

Age-related macular degeneration (AMD) is a complex multifactorial disease and the primary cause of legal and irreversible blindness among individuals aged ≥65 years in developed countries. Globally, it affects 30⁻50 million individuals, with an estimated increase of approximately 200 million by 2020 and approximately 300 million by 2040. Currently, the neovascular form may be able to be treated with the use of anti-VEGF drugs, while no effective treatments are available for the dry form. Many studies, such as the randomized controlled trials (RCTs) Age-Related Eye Disease Study (AREDS) and AREDS 2, have shown a potential role of micronutrient supplementation in lowering the risk of progression of the early stages of AMD. Recently, low-grade inflammation, sustained by dysbiosis and a leaky gut, has been shown to contribute to the development of AMD. Given the ascertained influence of the gut microbiota in systemic low-grade inflammation and its potential modulation by macro- and micro-nutrients, a potential role of diet in AMD has been proposed. This review discusses the role of the gut microbiota in the development of AMD. Using PubMed, Web of Science and Scopus, we searched for recent scientific evidence discussing the impact of dietary habits (high-fat and high-glucose or -fructose diets), micronutrients (vitamins C, E, and D, zinc, beta-carotene, lutein and zeaxanthin) and omega-3 fatty acids on the modulation of the gut microbiota and their relationship with AMD risk and progression.

Functional effect of Saffron supplementation and risk genotypes in early age-related macular degeneration: a preliminary report.

BACKGROUND: To determine whether the functional effects of oral supplementation with Saffron, a natural compound that proved to be neuroprotective in early age-related macular degeneration, are influenced by complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) risk genotypes. METHODS: Thirty-three early AMD patients, screened for CFH (rs1061170) and ARMS2 (rs10490924) polymorphisms and receiving Saffron oral supplementation (20 mg/day) over an average period of treatment of 11 months (range, 6-12), were longitudinally evaluated by clinical examination and focal electroretinogram (fERG)-derived macular (18°) flicker sensitivity estimate. fERG amplitude and macular sensitivity, the reciprocal value of the estimated fERG amplitude threshold, were the main outcome measures. RESULTS: After three months of supplementation, mean fERG amplitude and fERG sensitivity improved significantly when compared to baseline values (p < 0.01). These changes were stable throughout the follow-up period. No significant differences in clinical and fERG improvements were observed across different CFH or ARMS2 genotypes. CONCLUSIONS: The present results indicate that the functional effect of Saffron supplementation in individual AMD patients is not related to the major risk genotypes of disease.

Occipital porencephaly in a child with gyrate atrophy of the choroid and retina.

A 4-year-old girl was hospitalized for psychomotor delay, low vision, and horizontal nystagmus. She was found to have bilateral chorioretinal atrophic scars and 2 large occipital porencephalic cavities. High plasma ornithine levels led to the presumed diagnosis of gyrate atrophy of the choroid and retina. After 6 months of arginine-restricted diet and high-dose pyridoxine (300 mg/d), there was no change of plasma ornithine level or ocular findings. To our knowledge, this is the first report showing an association of porencephaly with gyrate atrophy of the choroid and retina.