The promise of neuroprotection by dietary restriction in glaucoma

Age-related driving mechanisms of retinal diseases and neuroprotection by transcription factor EB-targeted therapy

Retinal aging has been recognized as a significant risk factor for various retinal disorders, including diabetic retinopathy, age-related macular degeneration, and glaucoma, following a growing understanding of the molecular underpinnings of their development. This comprehensive review explores the mechanisms of retinal aging and investigates potential neuroprotective approaches, focusing on the activation of transcription factor EB. Recent meta-analyses have demonstrated promising outcomes of transcription factor EB-targeted strategies, such as exercise, calorie restriction, rapamycin, and metformin, in patients and animal models of these common retinal diseases. The review critically assesses the role of transcription factor EB in retinal biology during aging, its neuroprotective effects, and its therapeutic potential for retinal disorders. The impact of transcription factor EB on retinal aging is cell-specific, influencing metabolic reprogramming and energy homeostasis in retinal neurons through the regulation of mitochondrial quality control and nutrient-sensing pathways. In vascular endothelial cells, transcription factor EB controls important processes, including endothelial cell proliferation, endothelial tube formation, and nitric oxide levels, thereby influencing the inner blood-retinal barrier, angiogenesis, and retinal microvasculature. Additionally, transcription factor EB affects vascular smooth muscle cells, inhibiting vascular calcification and atherogenesis. In retinal pigment epithelial cells, transcription factor EB modulates functions such as autophagy, lysosomal dynamics, and clearance of the aging pigment lipofuscin, thereby promoting photoreceptor survival and regulating vascular endothelial growth factor A expression involved in neovascularization. These cell-specific functions of transcription factor EB significantly impact retinal aging mechanisms encompassing proteostasis, neuronal synapse plasticity, energy metabolism, microvasculature, and inflammation, ultimately offering protection against retinal aging and diseases. The review emphasizes transcription factor EB as a potential therapeutic target for retinal diseases. Therefore, it is imperative to obtain well-controlled direct experimental evidence to confirm the efficacy of transcription factor EB modulation in retinal diseases while minimizing its risk of adverse effects.

Evaluating the impact of caloric restriction, body mass index and exercise on primary open-angle glaucoma: A review

This literature review evaluates any possible links between primary open-angle glaucoma (POAG) and caloric restriction (CR), body mass index (BMI), and exercise, aiming to map the extent of the literature. Its primary objective is to recognise the nature and breadth of research evidence, identify possible gaps in these topics and develop future studies. The databases searched were MEDLINE (PudMed), Scopus and ScienceDirect, in April 2023 for articles published in English, with no date restriction. A total of 447 search results were retrieved. Of these, 73 were related to CR, 249 to BMI, and 125 to exercise. Records identified included systematic reviews, meta-analyses, randomised controlled trials, cohort studies and animal studies. CR has been shown to halt the degeneration of retinal ganglion cells and protect against various glaucomatous processes in animal models. Low BMI has been shown to be associated with an increased risk of POAG and a faster rate of visual field deterioration in POAG. However, the association between high BMI and POAG is not consistent. Exercise has been shown to cause mechanical, vascular, and neurobiological changes affecting the pathophysiology of POAG. The present review helps identify key characteristics and factors relating to the impacts of CR, BMI, or exercise on POAG.

Epigenome-metabolism nexus in the retina: implications for aging and disease

Intimate links between epigenome modifications and metabolites allude to a crucial role of cellular metabolism in transcriptional regulation. Retina, being a highly metabolic tissue, adapts by integrating inputs from genetic, epigenetic, and extracellular signals. Precise global epigenomic signatures guide development and homeostasis of the intricate retinal structure and function. Epigenomic and metabolic realignment are hallmarks of aging and highlight a link of the epigenome-metabolism nexus with aging-associated multifactorial traits affecting the retina, including age-related macular degeneration and glaucoma. Here, we focus on emerging principles of epigenomic and metabolic control of retinal gene regulation, with emphasis on their contribution to human disease. In addition, we discuss potential mitigation strategies involving lifestyle changes that target the epigenome-metabolome relationship for maintaining retinal function.

Is Ultra-Processed Food Intake Associated with a Higher Risk of Glaucoma? A Prospective Cohort Study including 19,255 Participants from the SUN Project

OBJECTIVE

The aim of this study was to examine the relationship of ultra-processed food (UPF) intake with the incidence of glaucoma in a large sample of Spanish university graduates followed prospectively.

METHODS

Prospective cohort study using data from the SUN Project. A final sample of 19,225 participants (60.1% women) was included in this study, with a mean age of 38.2 years (standard deviation (SD) = 12.4). Participants were followed-up for a mean time of 12.9 years (SD = 5.4). Dietary intake was measured using a 136-item semiquantitative food-frequency questionnaire. UPFs were defined based on the NOVA classification system. Glaucoma diagnosis was determined by asking the participants if they had ever been diagnosed with glaucoma by an ophthalmologist. This self-reported diagnosis of glaucoma has been previously validated.

RESULTS

After adjusting for several covariates, participants with the highest UPF consumption were at higher risk of glaucoma (hazard ratio (HR) = 1.83; 95% confidence interval (CI) 1.06 to 3.17) when compared to participants in the lowest category of UPF consumption. Regarding subgroup analyses, a significant multiplicative interaction was found for age (p = 0.004) and omega 3:6 ratio (p = 0.040). However, an association between UPF consumption and glaucoma was only found in older participants (aged ≥ 55 years), in men, in the most physically active group, in the group of non- or former smokers, in those with a lower omega 3:6 ratio, and in those with a lower energy intake. Regarding the contribution of each type of UPF group, UPF coming from sweets showed a significant risky effect (HR = 1.51; CI 95% 1.07 to 2.12).

CONCLUSIONS

This prospective cohort study shows that participants with a greater UPF consumption have a higher risk of developing glaucoma when compared to participants with a lower consumption. Our findings emphasize the relevance of monitoring and limiting the consumption of UPFs as a means of preventing glaucoma incidence.

A novel fixed-combination timolol-netarsudil-latanoprost ophthalmic solution for the treatment of glaucoma and ocular hypertension

Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration, poor efficacy and side effects. Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution (FC-TNL) has the ability to treat glaucoma by lowering the intraocular pressure (IOP) with great efficacy and improving patient compliance. However, the commercialized netarsudil dimesylate precipitated when the pH of the solution was above 5.4, or when maleic acid, the salt of commercial timolol maleate, was mixed with netarsudil dimesylate. Consequently, the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in pH 4.8-5.2 solution by synthesizing timolol mesylate. Next, the morphology of timolol mesylate was observed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction. The prepared FC-TNL showed good stability during refrigeration storage. Additionally, FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study. Importantly, once-daily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells. The FC-TNL was stable, safe and effective, being a promising glaucoma therapeutic.

A Review on Peripheral Tinnitus, Causes, and Treatments from the Perspective of Autophagy

Tinnitus is the perception of phantom noise without any external auditory sources. The degeneration of the function or activity of the peripheral or central auditory nervous systems is one of the causes of tinnitus. This damage has numerous causes, such as loud noise, aging, and ototoxicity. All these sources excite the cells of the auditory pathway, producing reactive oxygen species that leads to the death of sensory neural hair cells. This causes involuntary movement of the tectorial membrane, resulting in the buzzing noise characteristic of tinnitus. Autophagy is an evolutionarily conserved catabolic scavenging activity inside a cell that has evolved as a cell survival mechanism. Numerous studies have demonstrated the effect of autophagy against oxidative stress, which is one of the reasons for cell excitation. This review compiles several studies that highlight the role of autophagy in protecting sensory neural hair cells against oxidative stress-induced damage. This could facilitate the development of strategies to treat tinnitus by activating autophagy.

Intermittent Fasting to the Eye: A New Dimension Involved in Physiological and Pathological Changes

Intermittent fasting (IF) is gaining popularity as a therapeutic dietary strategy that regulates metabolism and can alter the development of metabolic disorders. An increasing amount of research has connected ocular diseases to IF and discovered that it has a direct and indirect effect on the eye’s physiological structure and pathological alterations. This article summarizes the progress of research on IF in regulating the physiological structures of the ocular vasculature, the anterior segment of the eye, the retina, and the choroid. We explored the therapeutic potential of IF for various common ocular diseases. In the future, a comprehensive study into the fundamental processes of IF will provide a direct and rigorous approach to eye disease prevention and therapy.