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Topic Review
Diabetic Retinopathy
Diabetic retinopathy (DR) is the most frequent microvascular complication of long-term diabetes and the most common cause of blindness, increasing morbidity in the working-age population. The most effective therapies for these complications include laser photocoagulation and anti-vascular endothelial growth factor (VEGF) intravitreal injections. However, laser and anti-VEGF drugs are untenable as a final solution as they fail to address the underlying neurovascular degeneration and ischemia. Regenerative medicine may be a more promising approach, aimed at the repair of blood vessels and reversal of retinal ischemia. Stem cell and tissue engineering therapy have introduced a novel way to reverse the underlying ischemia present in microvascular complications in diseases such as diabetes. 
  • 2.3K
  • 30 Oct 2020
Topic Review
Subretinal Injection Techniques for Retinal Disease
Inherited retinal dystrophies (IRDs) affect an estimated 1 in every 2000 people, this corresponding to nearly 2 million cases worldwide. Currently, 270 genes have been associated with IRDs, most of them altering the function of photoreceptors and retinal pigment epithelium. Gene therapy has been proposed as a potential tool for improving visual function in these patients.
  • 2.2K
  • 25 Aug 2022
Topic Review
Beneficial Effect of MOTS-c on Age-Related Retinal Diseases
Mitochondrial open reading frame of the 12S rRNA type-c (MOTS-c) is the most unearthed peptide encoded by mitochondrial DNA (mtDNA). It is an important regulator of the nuclear genome during times of stress because it promotes an adaptive stress response to maintain cellular homeostasis. Identifying MOTS-c specific binding partners may aid in deciphering the complex web of mitochondrial and nuclear-encoded signals. Mitochondrial damage and dysfunction have been linked to aging and the accelerated cell death associated with many types of retinal degenerations. Furthermore, research on MOTS-c ability to revive oxidatively stressed RPE cells has revealed a significant protective role for the molecule. Evidence suggests that senescent cells play a role in the development of age-related retinal disorders. 
  • 2.2K
  • 19 Apr 2023
Topic Review
Spermidine
Spermidine, a natural polyamine, exists in almost all human tissues, exhibiting broad properties like anti-aging, autophagy induction, anti-inflammation, anti-oxidation, cell proliferation activation, and ion channel regulation.
  • 2.1K
  • 04 Aug 2022
Topic Review
Nanotechnology for Eye Topical Drug Delivery
Topical drug delivery is one of the most challenging aspects of eye therapy. Eye drops are the most prevalent drug form because they are convenient and easy to apply by patients. However, conventional drug formulations are usually characterized by short retention time in the tear film, insufficient contact with epithelium, fast elimination, and difficulties in overcoming ocular tissue barriers. Not more than 5% of the total drug dose administered in eye drops reaches the interior ocular tissues. Drug-loaded nanoparticles/hydrogels do not enter cells via diffusion. The endocytosis pathway is related to the penetration of drug-loaded nanoparticles/hydrogels into the cell. The interactions between the nanoparticles and the cell membrane generate forces of different origins and lead to the membrane wrapping of the nanoparticles followed by cellular uptake.
  • 2.1K
  • 24 Dec 2021
Topic Review
Retinal Organization
The retinal arhitecture is similar across all vertebrates despite the morphological and functional peculiarities. The retina is composed of two main parts: the single-layred retinal pigment epithelium and the multilayred neuroretina which includes a number of neuronal and glial cell types. Homeobox genes from different classes are accepted as critical for eye field specification and retinal cells type differentiation by a broad array of loss- or gain-of-function models. Among these genes are some that are known to cause inherited retinal diseases (IRDs) that disturb the formation, function, and survival of rod and cone photoreceptors, ganglion cells, or retinal pigment epithelial cells [4,6–8]. The advances in the field of genetics and high-throughput next-generation sequencing and cell technologies allow for deepening of knowledge of the genetic basis of inherited retinal diseases (IRDs), as well as improve their diagnostics and therapy.
  • 2.1K
  • 22 Sep 2021
Topic Review
Anterior Chamber Angle Assessment Techniques
This review summarizes the last findings in Anterior Chamber Angle evaluation, focusing on new instruments and their application to the clinical practice. Special attention will be given to the comparison between these new techniques and traditional slit-lamp gonioscopy.
  • 2.1K
  • 11 Dec 2020
Topic Review
Autophagy in Eye Diseases
Autophagy is a catabolic process that ensures homeostasis in the cells of our organism. It plays a crucial role in protecting eye cells against oxidative damage and external stress factors. Ocular pathologies of high incidence, such as age-related macular degeneration, cataracts, glaucoma, and diabetic retinopathy are of multifactorial origin and are associated with genetic, environmental factors, age, and oxidative stress, among others; the latter factor is one of the most influential in ocular diseases, directly affecting the processes of autophagy activity. 
  • 1.9K
  • 23 Apr 2021
Topic Review
Age-Related Macular Degeneration (AMD)
Age-related macular degeneration (AMD) is a common irreversible sight-threatening disease characterized by progressive degeneration of the central retina, preferentially involving the retinal photoreceptors, the retinal pigment epithelium (RPE), the Bruch’s membrane (BM), or the choroidal microcirculation in the macular region.
  • 1.8K
  • 22 Sep 2021
Topic Review
Corneal Anatomy and Physiology
The cornea, known as the window of the eye, is optically transparent, including a special structure that is avascular anatomically. This dome-shaped and specialized tissue is located in the anterior part of the eye. Two major roles of the cornea are protecting the eye from harsh environments, and transmitting over 80% of light to inner portions. 
  • 1.8K
  • 22 Dec 2022
Topic Review
Femtosecond-Laser Assisted Surgery of Eye
Fs-laser technology is unique because it allows cutting tissue at very high precision inside the eye. Fs lasers are mainly used for surgery of the human cornea and lens. New areas of application in ophthalmology are on the horizon. The latest improvement is the high pulse frequency, low-energy concept; by enlarging the numerical aperture of the focusing optics, the pulse energy threshold for optical breakdown decreases, and cutting with practically no side effects is enabled.
  • 1.8K
  • 18 Feb 2021
Topic Review
TLR4 and alpha-MSH in allergy
Ocular allergic diseases are frequently seen in ophthalmological clinical practice. Immunological damage is mediated by a local Th2 inflammatory microenvironment, accompanied by changes in circulating cell subsets, with more effector cells and fewer T regulatory cells (Tregs). This study aimed to evaluate the involvement of toll-like receptor 4 (TLR4) and a-melanocyte stimulating hormone (α-MSH) in the immune regulation associated with perennial allergic conjunctivitis (PAC). We performed an Ag-specific stimulation during 72 h of culturing with or without LPS or α-MSH in peripheral blood mononuclear cells (PBMC), analyzing the cell subsets and cytokines induced by the stimuli. We also determined α-MSH in tear samples from healthy donors (HD) or PAC patients. Our findings demonstrate an immunological dysregulation characterized by an increased frequency of CD4+TLR4+ in the PBMC of patients with PAC, compared to HD. Most of these CD4+TLR4+ cells were also CD25+, and when α-MSH was added to the culture, the percentage of CD4+CD25+FoxP3+ increased significantly, while the percentage of CD69+ cells and cytokines IL-4 and IL-6 were significantly decreased. In tears, we found an increased concentration of α-MSH in PAC patients, compared with HD. These findings indicate a novel mechanism involved in controlling ocular allergic diseases, in which α-MSH diminishes the concentration of IL-6 and IL-4, restoring the frequency of Tregs and down-regulating CD4 activation. Moreover, we demonstrate the involvement of CD4+TLR4+ cells, as an effector cell subset, in ocular allergy.
  • 1.7K
  • 27 Oct 2020
Topic Review
Retinal Toxicity Induced by Chemical Agents
Vision is an important sense for humans, and visual impairment/blindness has a huge impact in daily life. The retina is a nervous tissue that is essential for visual processing since it possesses light sensors (photoreceptors) and performs a pre-processing of visual information. Thus, retinal cell dysfunction or degeneration affects visual ability and several general aspects of the day-to-day of a person’s lives. The retina has a blood–retinal barrier, which protects the tissue from a wide range of molecules or microorganisms. However, several agents, coming from systemic pathways, reach the retina and influence its function and survival. Pesticides are still used worldwide for agriculture, contaminating food with substances that could reach the retina. Natural products have also been used for therapeutic purposes and are another group of substances that can get to the retina. Finally, a wide number of medicines administered for different diseases can also affect the retina. Here gathers recent information about the hazard of these products to the retina, which could be used to encourage the search for more healthy, suitable, or less risky agents.
  • 1.7K
  • 18 Aug 2022
Topic Review
Mesenchymal Stem Cells and Exosomes in Corneal Diseases
The corneal functions (transparency, refractivity and mechanical strength) deteriorate in many corneal diseases but can be restored after corneal transplantation (penetrating and lamellar keratoplasties). Various studies have shown the differentiation of multipotent mesenchymal stem cells (MSCs) into various corneal cell types. With the unique properties of immunomodulation, anti-angiogenesis and anti-inflammation, they offer the advantages in corneal reconstruction. These effects are widely mediated by MSC differentiation and paracrine signaling via exosomes. Besides the cell-free nature of exosomes in circumventing the problems of cell-fate control and tumorigenesis, the vesicle content can be genetically modified for optimal therapeutic affinity. 
  • 1.7K
  • 20 Dec 2021
Topic Review
Corneal Infection Models: Bacterial Keratitis
Corneal infection models are tools which can be used to study host-pathogen interactions at the corneal surface. They are highly valuable in the study of bacterial keratitis, a potentially sight-threatening eye infection, localised to the cornea. During bacterial keratitis, bacteria colonise the cornea as biofilm populations which demonstrate an increased resistance to antibiotics and the host immune response. Therefore the presence or absence of biofilm is an important consideration in model development. Corneal infection models include: in vitro models (which use cell culture techniques to generate 3D corneal constructs), ex vivo models (which use whole, excised corneas) and in vivo models (which use live animals).
  • 1.6K
  • 16 Dec 2020
Topic Review
Role of Retinal Pigment Epithelium
The retinal pigment epithelium (RPE), situated upon Bruch’s membrane, plays multiple roles in the ocular system by interacting with photoreceptors and. Therefore, dysfunction of the RPE causes diseases related to vision loss, such as age-related macular degeneration (AMD). 
  • 1.6K
  • 24 Nov 2021
Topic Review
Chitosan and its Derivatives
Chitosan (CS) is a hemi-synthetic cationic linear polysaccharide produced by the deacetylation of chitin. CS is non-toxic, highly biocompatible, and biodegradable, and it has a low immunogenicity. Additionally, CS has inherent antibacterial properties and a mucoadhesive character and can disrupt epithelial tight junctions, thus acting as a permeability enhancer. As such, CS and its derivatives are well-suited for the challenging field of ocular drug delivery. In the present review article, we will discuss the properties of CS that contribute to its successful application in ocular delivery before reviewing the latest advances in the use of CS for the development of novel ophthalmic delivery systems. Colloidal nanocarriers (nanoparticles, micelles, liposomes) will be presented, followed by CS gels and lenses and ocular inserts. Finally, instances of CS coatings, aiming at conferring mucoadhesiveness to other matrixes, will be presented.
  • 1.6K
  • 31 Jul 2020
Topic Review
Dry Eye Disease
Dry eye disease (DED) is a common condition, which usually causes discomfort, but it can also be an origin of ocular pain and visual disturbances. Ocular surface inflammation is thought to be the main factor in the pathogenesis of DED. It has many overlapping causes, such as ocular surgery, environmental triggers, medication use and systemic diseases. Ophthalmic surgery may induce or worsen existing DED symptoms usually for a short-term period .
  • 1.6K
  • 05 May 2021
Topic Review
Nutrients for Eye-Related Diseases
The risk of macular degeneration can be reduced through the consumption of antioxidant-rich foods, supplements, and nutraceutical formulas. This study focuses on the antioxidants, vitamins, and minerals that have been reported for reducing the risk of macular degeneration and other eye-related diseases. Antioxidants including anthocyanins, carotenoids, flavonoids, and vitamins have been shown to reduce the risk of eye-related diseases. Anthocyanins extracted from berries are powerful antioxidants. Cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin are anthocyanin aglycones detected in berries, currants, and other colored fruits and vegetables. β-Carotene, as well as xanthophyll lutein and zeaxanthin, have been reported to reduce the risk of macular degeneration. Flavonoids from plants help in the prevention of eye-related diseases through anti-inflammatory mechanisms. A combination of these antioxidants, vitamins, and minerals possess a synergistic effect on the prevention or risk reduction of macular degeneration. Formulas have been developed as dietary supplements to cater to the high demand from consumers and patients with eye problems. 
  • 1.6K
  • 15 Sep 2021
Topic Review Peer Reviewed
Pathogenesis of Glaucoma
Glaucoma, a neurodegenerative disease, has a varied pathogenesis scenario, including elevated intraocular pressure (IOP), and hypoxic conditions in the retina. Consequently, degenerating optic axons at the optic nerve head are observed clinically when extensive damage has already occurred. Following elevated IOP, changes in retinal ganglion cells lead to apoptosis immediately followed by degeneration of their optic axons. Degradation of axons leads to cupping of the optic nerve head and visual field losses. Here we emphasize that it is the retinal ganglion cells that are initial targets of elevated IOP, and, together with hyperactivity of retinal astrocytes, create the ischemic conditions which represent the earliest sign in the pathogenesis of glaucoma.
  • 1.6K
  • 10 Mar 2023
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