Effects of eye drops containing a mixture of 3% diquafosol sodium and tocopherol acetate (vitamin E) on the ocular surface of murine dry eye

Therapeutic Potential of Combined 5% Lifitegrast and Tocopherol Eye Drops in Managing Inflammation and Oxidative Stress in Murine Dry Eye

Background/Objectives: This study aimed to evaluate the therapeutic effects of combined 5% lifitegrast (LF) and tocopherol (TCP) eye drops in a murine experimental dry eye (EDE) model. Methods: Female C57BL/6 were divided into seven groups: untreated controls, EDE control, EDE + 0.05% cyclosporin A (CsA), EDE + tocopherol (TCP), EDE + 5% LF, EDE + 5% LF + TCP (once daily), and EDE + 5% LF + TCP (twice daily). Clinical parameters (tear volume, tear break-up time (TBUT), corneal fluorescein staining score (CFSS), tear film lipid layer grade (TFLLG)) were assessed on days 7 and 14. Goblet cell density in the conjunctiva, CD4+ IFN-γ+ T cells, interleukin levels, reactive oxygen species (ROS) levels, and corneal apoptotic cells were analyzed on day 14. Results: Monotherapy with 0.05% CsA and LF showed improvements in all clinical parameters compared to the EDE control (p < 0.05). Combination therapy groups demonstrated superior improvements in clinical parameters compared to the EDE control, 0.05% CsA, and 5% LF groups. CD4+ IFN-γ+ T cell percentages and ROS levels in the cornea and conjunctiva were markedly reduced in the combination groups compared with the 0.05% CsA and 5% LF groups (p < 0.01). Furthermore, corneal apoptotic cells significantly decreased in the combination groups compared to the 0.05% CsA and TCP groups (p < 0.05). Conclusions: Combined 5% LF and TCP eye drops improved tear film parameters and reduced inflammatory and oxidative stress markers. The combination therapy can mitigate ocular surface damage by managing inflammation and oxidative stress in dry eye.

Innovative formulations for the ocular delivery of coenzyme Q10

Coenzyme Q10 (CoQ10) is a lipophilic antioxidant agent that plays a crucial role in the mitochondrial electron transport chain. The neuroprotective role of CoQ10, countering mitochondrial dysfunction and oxidative stress, suggests its potential as an adjuvant for ocular neurodegenerative diseases linked to retinal cell loss. However, despite its promising properties, ocular barriers pose challenges for effective delivery. Therefore, the present work aimed to identify new ocular delivery strategies to improve the therapeutic potential of CoQ10 by increasing its ocular bioavailability at the posterior segment and supporting its controlled release. Polymeric micelles of D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) were selected as carriers for the loading of CoQ10, increasing its solubility and promoting its penetration through ocular tissues. After their characterization by dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS), loaded micelles were applied to porcine sclera and choroid to confirm their ex vivo retention and permeation capacity. To ensure a controlled release, they were then loaded into a crosslinked polymer film, which was characterized in terms of mechanical properties, swelling degree and release profiles of TPGS and CoQ10. The biocompatibility of this platform was tested by the HET-CAM assay, and ex vivo studies confirmed its ocular potential.

Nutrition and diet for dry eye disease: Insights toward holistic management

Dry eye disease (DED) is one of the most common eye problems in the aging population. Hyperosmolarity triggers the immune response in DED and consequently activates the self-perpetuating immune cycle, leading to chronic damage of the ocular surface. This event causes symptoms such as a burning sensation, irritation, redness, photophobia, and blurred vision in DED patients. Subsequently, the quality of life gets significantly affected. The rising demand for DED management and treatment solutions, and the desirable outcomes from innovative therapies that draw global interest provide evidence to demonstrate the role of diet and nutrition in DED. Nutritional deficiency and a Westernized diet contribute to the chronic systemic progression of DED symptoms. It has been revealed in several published studies that the use of nutrients and dietary supplements improves the ocular surface and acts as a protective factor against DED. - We reviewed nutrition and dietary aspects in managing DED and its associated consequences, based on published studies, and reached an evidence-based conclusion.

A sterilizable platform based on crosslinked xanthan gum for controlled-release of polymeric micelles: Ocular application for the delivery of neuroprotective compounds to the posterior eye segment

TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) polymeric micelles show interesting properties for ocular administration thanks to their solubilization capability, nanometric size and tissue penetration ability. However, micelles formulations are generally characterized by low viscosity, poor adhesion and very short retention time at the administration site. Therefore, the idea behind this work is the preparation and characterization of a crosslinked film based on xanthan gum that contains TPGS micelles and is capable of controlling their release. The system was loaded with melatonin and cyclosporin A, neuroprotective compounds to be delivered to the posterior eye segment. Citric acid and heating at different times and temperatures were exploited as crosslinking approach, giving the possibility to tune swelling, micelles release and drug release. The biocompatibility of the platform was confirmed by HET-CAM assay. Ex vivo studies on isolated porcine ocular tissues, conducted using Franz cells and two-photon microscopy, demonstrated the potential of the xanthan gum-based platform and enlightened micelles penetration mechanism. Finally, the sterilization step was approached, and a process to simultaneously crosslink and sterilize the platform was developed.

Nutritional Factors: Benefits in Glaucoma and Ophthalmologic Pathologies

Glaucoma is a chronic optic neuropathy that can lead to irreversible functional and morphological damage if left untreated. The gold standard therapeutic approaches in managing patients with glaucoma and limiting progression include local drops, laser, and/or surgery, which are all geared at reducing intraocular pressure (IOP). Nutrients, antioxidants, vitamins, organic compounds, and micronutrients have been gaining increasing interest in the past decade as integrative IOP-independent strategies to delay or halt glaucomatous retinal ganglion cell degeneration. In our minireview, we examine the various nutrients and compounds proposed in the current literature for the management of ophthalmology diseases, especially for glaucoma. With respect to each substance considered, this minireview reports the molecular and biological characteristics, neuroprotective activities, antioxidant properties, beneficial mechanisms, and clinical studies published in the past decade in the field of general medicine. This study highlights the potential benefits of these substances in glaucoma and other ophthalmologic pathologies. Nutritional supplementation can thus be useful as integrative IOP-independent strategies in the management of glaucoma and in other ophthalmologic pathologies. Large multicenter clinical trials based on functional and morphologic data collected over long follow-up periods in patients with IOP-independent treatments can pave the way for alternative and/or coadjutant therapeutic options in the management of glaucoma and other ocular pathologies.

Potential Properties of Natural Nutraceuticals and Antioxidants in Age-Related Eye Disorders

Eye health is crucial, and the onset of diseases can reduce vision and affect the quality of life of patients. The main causes of progressive and irreversible vision loss include various pathologies, such as cataracts, ocular atrophy, corneal opacity, age-related macular degeneration, uncorrected refractive error, posterior capsular opacification, uveitis, glaucoma, diabetic retinopathy, retinal detachment, undetermined disease and other disorders involving oxidative stress and inflammation. The eyes are constantly exposed to the external environment and, for this reason, must be protected from damage from the outside. Many drugs, including cortisonics and antinflammatory drugs have widely been used to counteract eye disorders. However, recent advances have been obtained via supplementation with natural antioxidants and nutraceuticals for patients. In particular, evidence has accumulated that polyphenols (mostly deriving from Citrus Bergamia) represent a reliable source of antioxidants able to counteract oxidative stress accompanying early stages of eye diseases. Luteolin in particular has been found to protect photoreceptors, thereby improving vision in many disease states. Moreover, a consistent anti-inflammatory response was found to occur when curcumin is used alone or in combination with other nutraceuticals. Additionally, Coenzyme Q10 has been demonstrated to produce a consistent effect in reducing ocular pressure, thereby leading to protection in patients undergoing glaucoma. Finally, both grape seed extract, rich in anthocyanosides, and polynsatured fatty acids seem to contribute to the prevention of retinal disorders. Thus, a combination of nutraceuticals and antioxidants may represent the right solution for a multi-action activity in eye protection, in association with current drug therapies, and this will be of potential interest in early stages of eye disorders.

Ocular Surface Ion Transport and Dry Eye Disease

Purpose of Review

To review the role of ocular surface epithelial (corneal and conjunctival) ion transporters in the pathogenesis and treatment of dry eye disease (DED).

Recent Findings

Currently, anti-inflammatory agents are the mainstay of DED treatment, though there are several agents in development that target ion transport proteins on the ocular surface, acting by pro-secretory or anti-absorptive mechanisms to increase the tear fluid Film volume. Activation or inhibition of selected ion transporters can alter tear fluid osmolality, driving water transport onto the ocular surface via osmosis. Several ion transporters have been proposed as potential therapeutic targets for DED, including the cystic fibrosis transmembrane conductance regulator (CFTR), calcium-activated chloride channels (CaCCs), and the epithelial sodium channel (ENaC).

Summary

Ocular surface epithelial cell ion transporters are promising targets for pro-secretory and anti-absorptive therapies of DED.

Nutraceuticals: A Promising Therapeutic Approach in Ophthalmology

Oxidative stress represents one of the main factors driving the pathophysiology of multiple ophthalmic conditions including presbyopia, cataracts, dry eye disease (DED), glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). Currently, different studies have demonstrated the role of orally administered nutraceuticals in these diseases. For instance, they have demonstrated to improve lens accommodation in presbyopia, reduce protein aggregation in cataracts, ameliorate tear film stability, break up time, and tear production in dry eye, and participate in the avoidance of retinal neuronal damage and a decrease in intraocular pressure in glaucoma, contribute to the delayed progression of AMD, or in the prevention or treatment of neuronal death in diabetic retinopathy. In this review, we summarized the nutraceuticals which have presented a positive impact in ocular disorders, emphasizing the clinical assays. The characteristics of the different types of nutraceuticals are specified along with the nutraceutical concentration used to achieve a therapeutic outcome in ocular diseases.

Fullerenol protects cornea from ultraviolet B exposure

The eyes are highly susceptible to the oxidative stress induced by ultraviolet B (UVB, wavelength between 280 ∼ 320 nm), which could cause severe damage to the cornea. Fullerenols are effective antioxidants to alleviate UVB-induced injury, while their application for the eyes is still rare. In present study, we investigated the protective performance and mechanism of fullerenols on cornea under UVB radiation in vivo and in vitro. The synthesized fullerenols exhibited broad-spectrum free radical scavenging properties (applicable to both reactive oxygen species (ROS) and reactive nitrogen species (RNS)) and photo-stability. When compared with another widely used antioxidant glutathione (GSH), the administration of fullerenols markedly decreased the injured area, corneal edema, cell death, and increased the cell proliferation in UVB-induced rat cornea. The effects of fullerenols were confirmed in UVB-exposed human corneal epithelial cells (hCECs), where elevated cell viability and proliferation, decreased oxidative free radical production, repaired mitochondrial dysfunction and DNA lesions were observed. RNA sequencing (RNA-Seq) analysis demonstrated that fullerenol alleviated UVB-induced corneal injury through down-regulation of oxidative stress-related genes and up-regulation of proliferation-associated genes. Our results demonstrate the suitability of fullerenols as a potential exogenous treatment in ameliorating UVB-induced cornea damage.

Dry Eye Disease and Vitamins: A Narrative Literature Review

Dry eye disease (DED) is a major public health problem worldwide that seriously impairs the quality of life, reduces work productivity, and poses significant economic burden. In DED, tear film instability or hyperosmolarity activates a self-perpetuating vicious cycle that may aggravate ocular surface inflammation and damage. Thus, treatment approaches should focus on interrupting this cycle and ameliorating inflammation. In addition to anti-inflammatory medications, such as corticosteroids, cyclosporine, and lifitegrast, nutrients with anti-inflammatory and anti-oxidative properties may also be effective for the treatment of DED. Evidence indicates that vitamin deficiencies may be associated with an increased risk of DED and that vitamin supplementation can be an effective treatment for DED. In the present review, we introduce the results of clinical and experimental studies on the association between vitamin deficiencies and DED. The potential efficacy of systemic and topical supplementation in the treatment of DED is also discussed.