Glaucoma is traditionally classified as an ocular disease characterized by progressive retinal ganglion cell (RGC) loss and optic nerve damage. However, emerging evidence suggests that its pathophysiology may extend beyond the eye, involving trans-synaptic neurodegeneration along the visual pathway and structural changes within central brain regions, including the lateral geniculate nucleus and visual cortex. In this narrative review, we have used the phrase ‘brain involvement’ to underscore central changes that accompany or follow retinal ganglion cell loss; we have not intended to redefine glaucoma as a primary cerebral disorder. Neuroimaging studies and neurocognitive assessments in adult glaucoma patients, primarily older individuals with primary open-angle glaucoma reveal that glaucoma patients may exhibit alterations in brain connectivity and cortical thinning, aligning it more closely with neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. This evolving neurocentric perspective raises important questions regarding shared mechanisms—such as mitochondrial dysfunction, chronic inflammation, and impaired axonal transport—that may link glaucomatous optic neuropathy to central nervous system (CNS) pathology. These insights open promising therapeutic avenues, including the repurposing of neuroprotective and neuroregenerative agents, targeting not only intraocular pressure (IOP) but also broader CNS pathways. Furthermore, neuroimaging biomarkers and brain-targeted interventions may play a future role in diagnosis, prognosis, and individualized treatment. This review synthesizes current evidence supporting glaucoma as a CNS disease, explores the mechanistic overlap with neurodegeneration, and discusses the potential clinical implications of glaucoma within a neuro-ophthalmologic paradigm.

Pericytes, specialized mural cells surrounding microvessels, play a crucial role in maintaining vascular homeostasis and function across various organs, including the eye. These versatile cells regulate blood flow, support the integrity of the blood–retinal barrier, and contribute to angiogenesis. Recent advancements in molecular and cellular biology have revealed the heterogeneity of pericytes and their critical involvement in ocular physiology and pathology. This review provides a comprehensive analysis of pericyte functions in ocular health and their implications in diseases such as diabetic retinopathy, age-related macular degeneration, glaucoma, and retinal vein occlusion. Pericyte dysfunction is implicated in vascular instability, neurovascular coupling failure, inflammation, and pathological neovascularization, contributing to vision-threatening disorders. The review further explores recent findings on pericyte-targeted therapies, including pharmacological agents, gene therapy, and cell-based approaches, aiming to restore pericyte function and preserve ocular health.

Mitochondrial dysfunction represents a central hallmark of aging and a broad spectrum of chronic diseases, ranging from metabolic to neurodegenerative and ocular disorders. Nicotinamide riboside (NR), a vitamin B₃ derivative and efficient precursor of NAD⁺ (nicotinamide adenine dinucleotide), and berberine (BBR), an isoquinoline alkaloid widely investigated in metabolic regulation, have independently emerged as promising mitochondrial modulators. NR enhances cellular NAD⁺ pools, thereby activating sirtuin-dependent pathways, stimulating PGC-1α–mediated mitochondrial biogenesis, and triggering the mitochondrial unfolded protein response (UPR^mt). BBR, by contrast, primarily activates AMPK (AMP-activated protein kinase) and interacts with respiratory complex I, improving bioenergetics, reducing mitochondrial reactive oxygen species, and promoting mitophagy and organelle quality control. Importantly, despite distinct upstream mechanisms, NR and BBR converge on shared signaling pathways that support mitochondrial health, including redox balance, metabolic flexibility, and immunometabolic regulation. Unlike previous reviews addressing these compounds separately, this article integrates current preclinical and clinical findings to provide a unified perspective on their converging actions. We critically discuss translational opportunities as well as limitations, including heterogeneous clinical outcomes and the need for robust biomarkers of mitochondrial function. By outlining overlapping and complementary mechanisms, we highlight NR and BBR as rational combinatorial strategies to restore mitochondrial resilience. This integrative perspective may guide the design of next-generation clinical trials and advance precision approaches in mitochondrial medicine.

Corneal diseases, which can result in substantial visual impairment and loss of vision, are an important worldwide health issue. The aim of this review was to investigate the novel application of bioscaffolds in stem cell and regenerative treatments for the treatment of corneal disorders. The current literature reports that organic and artificial substances create bioscaffolds that imitate the inherent structure of the cornea, facilitating the attachment, growth, and specialization of stem cells. Sophisticated methods such as electrospinning, 3D bioprinting, and surface modification have been reported to enhance the characteristics of the scaffold. These bioscaffolds have been shown to greatly improve the survival of stem cells and facilitate the regrowth of corneal tissue in both laboratory and live animal experiments. In addition, the incorporation of growth factors and bioactive compounds within the scaffolds can promote a favorable milieu for corneal regeneration. To summarize, the advancement of these groundbreaking bioscaffolds presents a hopeful treatment strategy for the regeneration of the cornea, which has the potential to enhance the results for individuals suffering from corneal disorders. This study highlights the possibility of utilizing the fields of biomaterials science and stem cell treatment to tackle medical demands that have not yet been satisfied in the field of ophthalmology.

Cataract formation remains a significant cause of global visual impairment. Increasing attention has been directed toward antioxidant-based interventions as potential non-surgical strategies to delay or prevent cataractogenesis, particularly in the age-related and diabetic contexts. This review summarizes recent preclinical evidence on nutritional antioxidants for the prevention of age-related and diabetic cataracts. Agents such as trimetazidine, Moringa oleifera stem extract, ginsenoside Rg1, lanosterol nanoparticles, β-casomorphin-7, and cerium oxide-based nanotherapies have been shown to mitigate oxidative damage, modulate redox signaling pathways, and preserve lens clarity. Advances in drug delivery, including topical formulations, nanoparticle carriers, and intravitreal injections, have been proposed to overcome the anatomical and pharmacokinetic barriers associated with the avascular lens. The new data support ongoing translational research to maximize the clinical use of antioxidants and highlight their therapeutic potential in the prevention of age-related and diabetic cataracts.

Background: Glaucoma is a chronic neurodegenerative disorder characterized by the selective vulnerability of retinal ganglion cells (RGCs), in which mitochondrial dysfunction, redox imbalance, and impaired bioenergetic signaling play central pathogenetic roles. Mitochondrial homeostasis in RGCs critically depends on maintaining intracellular NAD⁺ pools, which support oxidative phosphorylation, sirtuin-mediated deacetylation, and antioxidant gene expression. Nicotinamide riboside (NR), a potent NAD⁺ precursor, and berberine (BBR), an AMPK activator derived from Berberis aristata, have recently emerged as synergistic modulators of mitochondrial metabolism and oxidative stress resistance. Methods: This study retrospectively assessed clinical outcomes associated with combined nutraceutical supplementation of nicotinamide riboside (NR) and berberine (BBR) in patients with primary open-angle glaucoma undergoing stable topical hypotensive therapy. We have included a narrative review in the current literature regarding NAD⁺ biology, AMPK–sirtuin signaling, and oxidative stress responses in retinal ganglion cell (RGC) degeneration. Due to the absence of comparator groups receiving only NR or only berberine in this retrospective cohort, the combined supplementation has been regarded as a biologically complementary strategy, and the potential for synergistic efficacy remains a subject for further investigation. Results: Translationally, a retrospective clinical cohort receiving combined NR and BBR supplementation showed functional stabilization of the visual field and structural preservation of the retinal nerve fiber layer over a six-month follow-up, in line with the proposed mitochondrial protective mechanisms. Conclusions: The clinical trends identified in this retrospective cohort have substantiated the translational significance of NR + BBR supplementation as a potential adjunctive approach in glaucoma management. NAD⁺ repletion and engagement of the AMPK–SIRT–NRF2 pathway may enhance mitochondrial resilience in RGCs. Collectively, these findings offer initial clinical evidence advocating for additional controlled studies on NR + berberine supplementation, while mechanistic interpretations have been derived from the existing literature and are hypothesis-generating.