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Topic Review
Non-Invasive Imaging and Proliferative Diabetic Retinopathy
Diabetic retinopathy (DR) is a leading cause of vision impairment in people aged 20–74 years. There is a trend of moving away from invasive (e.g., fundus fluorescein angiography) to non-invasive (e.g., wide-field optical coherence tomography (OCT), OCT angiography and colour fundus photography) imaging modalities to allow for more objective assessments that can be readily repeated in a time-efficient manner without compromising patient safety. Such quantitative assessments generating large amounts of data could benefit from artificial intelligence approaches to aid clinical decision making.
  • 1.2K
  • 02 Dec 2021
Topic Review
Sex Hormones and Ocular Dryness
Dry eye syndrome (DES) is strictly connected to systemic and topical sex hormones. Breast cancer treatment, the subsequent hormonal therapy, the subsequent hyperandrogenism and the early sudden menopause, may be responsible for ocular surface system failure and its clinical manifestation as dry eye disease. This local dryness is part of the breast cancer iatrogenic dryness, which affects overall mucosal tissue in the fragile population of those with breast cancer.
  • 1.2K
  • 18 Sep 2021
Topic Review
Aqueous Prostaglandin Eye Drop Formulations
Glaucoma is one of the leading causes of irreversible blindness worldwide. It is characterized by progressive optic neuropathy in association with damage to the optic nerve head and, subsequently, visual loss if it is left untreated. Among the drug classes used for the long-term treatment of open-angle glaucoma, prostaglandin analogues (PGAs) are the first-line treatment and are available as marketed eye drop formulations for intraocular pressure (IOP) reduction by increasing the trabecular and uveoscleral outflow. PGAs have low aqueous solubility and are very unstable (i.e., hydrolysis) in aqueous solutions, which may hamper their ocular bioavailability and decrease their chemical stability. Additionally, treatment with PGA in conventional eye drops is associated with adverse effects, such as conjunctival hyperemia and trichiasis. It has been a very challenging for formulation scientists to develop stable aqueous eye drop formulations that increase the PGAs’ solubility and enhance their therapeutic efficacy while simultaneously lowering their ocular side effects.
  • 1.2K
  • 28 Oct 2022
Topic Review
The Alter Retina
Alternative splicing of mRNA is an essential mechanism to regulate and increase the diversity of the transcriptome and proteome. Alternative splicing frequently occurs in a tissue- or time-specific manner, contributing to differential gene expression between cell types during development. Neural tissues present extremely complex splicing programs and display the highest number of alternative splicing events. As an extension of the central nervous system, the retina constitutes an excellent system to illustrate the high diversity of neural transcripts. The retina expresses retinal specific splicing factors and produces a large number of alternative transcripts, including exclusive tissue-specific exons, which require an exquisite regulation. In fact, a current challenge in the genetic diagnosis of inherited retinal diseases stems from the lack of information regarding alternative splicing of retinal genes, as a considerable percentage of mutations alter splicing or the relative production of alternative transcripts. Modulation of alternative splicing in the retina is also instrumental in the design of novel therapeutic approaches for retinal dystrophies, since it enables precision medicine for specific mutations.
  • 1.1K
  • 22 Sep 2021
Topic Review
Olive Pomace and Ocular Surface
Oxidative- and inflammatory-related ocular surface diseases have high prevalence and are an emerging issue in ophthalmology. Olive pomace (OP) is the olive oil’s industry main by-product, and is potentially environmentally hazardous. Nevertheless, it contains phenolic compounds with important bioactivities, like oleuropein (OL) and hydroxytyrosol (HT). The antioxidant and anti-inflammatory effects of four OP extracts (CONV, OPT(1–3)), pure OL and HT, and mixtures thereof were screened on human corneal (HCE) and conjunctival epithelial (IM-ConjEpi) cells. CONV was conventionally extracted, while OPT(1–3) were produced by pressurized liquid extraction. Thanks to their improved activity, CONV and OPT3 (HT-enriched) were selected for dose-dependent studies. Cells were stimulated with tumor necrosis factor-α or ultraviolet-B radiation, measuring interleukin (IL)-1β, IL-6, IL-8, and IL-17A as well as interferon γ-induced protein [IP]-10 secretion or intracellular ROS production, respectively. On HCE, both extracts and HT inhibited the secretion of most measured ILs, demonstrating a strong anti-inflammatory effect; while in IM-ConjEpi, all samples decreased IP-10 secretion. Moreover, HT, OL, and both extracts showed strong dose-dependent antioxidant activity in both cell lines. Compared with CONV, OPT3 was active at lower concentrations, demonstrating that intensified extraction techniques are selective towards targeted biomarkers. Hence, a high-value application as potential ocular surface therapy was proposed for the OP valorization.
  • 1.1K
  • 02 Sep 2021
Topic Review
Ocular Surface Squamous Neoplasia
Ocular surface squamous neoplasia (OSSN) encompasses a broad spectrum of neoplastic changes involving the squamous epithelium of the conjunctiva, cornea and limbus ranging from mild dysplasia, intraepithelial neoplasia (carcinoma in situ) to squamous cell carcinoma (SCC).
  • 1.1K
  • 11 Jan 2023
Topic Review
Nano-based DDS for Posterior Segment Diseases
The complex anatomy of the eye presents a major challenge in the treatment of posterior segment eye diseases, hindering the effective delivery of medications. Conventional treatments, including topical eye drops and intravitreal injections, are limited by poor bioavailability and short residence time, necessitating frequent dosing to manage the disease. Intravitreal injections can also lead to serious ocular complications. Biodegradable nano-based drug delivery systems (DDSs) have emerged as a potential solution to these limitations, offering longer residence time in ocular tissues and better penetration through ocular barriers. Furthermore, the biodegradable polymers used to create these systems are nanosized, reducing the risk of toxicity and adverse reactions.
  • 1.1K
  • 12 May 2023
Topic Review
Matrix Metalloproteinases and Glaucoma
Matrix metalloproteinases (MMPs) are enzymes that decompose extracellular matrix (ECM) proteins. MMPs are thought to play important roles in cellular processes, such as cell proliferation, differentiation, angiogenesis, migration, apoptosis, and host defense. MMPs are distributed in almost all intraocular tissues and are involved in physiological and pathological mechanisms of the eye. MMPs are also associated with glaucoma, a progressive neurodegenerative disease of the eyes. MMP activity affects intraocular pressure control and apoptosis of retinal ganglion cells, which are the pathological mechanisms of glaucoma. It also affects the risk of glaucoma development based on genetic pleomorphism. In addition, MMPs may affect the treatment outcomes of glaucoma, including the success rate of surgical treatment and side effects on the ocular surface due to glaucoma medications. Glaucoma is a neurodegenerative disorder affected by multiple factors, from which more than 60 million patients worldwide suffer. It is characterized by irreversible progressive loss of retinal ganglion cells (RGC) and distinct optic nerve head (ONH) deterioration, which is related to corresponding visual field loss.
  • 1.1K
  • 08 Oct 2022
Topic Review
Recent Advancements in Retinal Prosthesis Technology
Significant progress has been made in retinal prostheses, including material science, visual field size, and integration of artificial intelligence. These advancements reflect innovation and provide insights into the future of retinal prostheses. Retinal prostheses utilize inorganic and organic electrodes. Smaller electrodes optimize electrical signaling, but current electrodes have physical limitations. Common metals used are iridium, gold, titanium, tin, and platinum due to their inertness, electrical properties, and biocompatibility. Recent advancements aim to improve the visual field of retinal prostheses. One such example, POLYRETINA, a foldable and photovoltaic epiretinal prosthetic, addresses the limited visual field in current technology since existing prosthetics have insufficient visual angle size (VAS) for mobility and object identification tasks. Additionally, a recent study developed a wireless photovoltaic retinal implant (PRIMA) to improve central vision in atrophic age-related macular degeneration patients without affecting peripheral vision. Retinal prostheses face challenges in effectiveness, surgical complexity, patient eligibility, long-term durability, and cost/accessibility, which is why advancements in technology, surgical techniques, and understanding of retinal physiology are needed.
  • 1.1K
  • 18 Sep 2023
Topic Review
Drug Delivery Systems for Uveitis and Neuro-Ophthalmologic Conditions
To circumvent these constraints, the development of biodegradable nano-based drug delivery systems (DDS) has gained prominence. These systems promise extended residence time in ocular tissues, improved penetration through ocular barriers, and are composed of nanosized, biodegradable polymers, thereby diminishing the risk of toxicity and adverse reactions.
  • 1.1K
  • 24 Jul 2023
Topic Review
Treatment of Amblyopia
Amblyopia is the most common cause of monocular poor vision affecting up to 3.7% of the global population. Classically, the first step in treatment has been optical correction, followed by patching and/or pharmacological treatment. However, this is an evolving scenario, since researchers and clinicians are interested in new binocular treatments due to the increasing development of new technologies. In this article main, current binocular treatments as Dig Rush, falling blocks, I-BiT, Occlu-tab, Vivid Vision, and movies are reviewed for binocular amblyopia management. 
  • 1.1K
  • 05 Jul 2021
Topic Review
Ocular Barriers
Innovative and new drug delivery systems (DDSs) have been developed to vehicle treatments and drugs to the ocular posterior segment and the retina. New formulations and technological developments, such as nanotechnology, novel matrices, and non-traditional treatment strategies, open new perspectives in this field.
  • 1.1K
  • 13 Jul 2023
Topic Review
CD36 with Eye Diseases and Pathological Changes
Cluster of differentiation 36 (CD36) belongs to the B2 receptors of the scavenger receptor class B family, which is comprised of single-chain secondary transmembrane glycoproteins. It is present in a variety of cell types, including monocytes, macrophages, microvascular endothelial cells, adipocytes, hepatocytes, platelets, skeletal muscle cells, kidney cells, cardiomyocytes, taste bud cells, and a variety of other cell types. CD36 can be localized on the cell surface, mitochondria, endoplasmic reticulum, and endosomes, playing a role in lipid accumulation, oxidative stress injury, apoptosis, and inflammatory signaling. CD36 is expressed in a variety of ocular cells, including retinal pigment epithelium (RPE), retinal microvascular endothelial cells, retinal ganglion cells (RGC), Müller cells, and photoreceptor cells, playing an important role in eye diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma.
  • 1.1K
  • 31 Jan 2023
Topic Review
Dietary Antioxidants in Age-Related Macular Degeneration and Glaucoma
Age-related macular degeneration (AMD) and glaucoma are ophthalmic neurodegenerative diseases responsible for irreversible vision loss in the world population. Only a few therapies can be used to slow down the progression of these diseases and there are no available treatment strategies for reversing the degeneration of the neural retina. In AMD, the pathological process causes the malfunction and damage of the retinal pigmented epithelium and photoreceptors in the macula. In glaucoma, damage of the retinal ganglion cells and their axons is observed and treatment strategies are limited to intraocular pressure lowering. Therefore, other prophylactic and/or therapeutic methods are needed. Oxidative stress is involved in the neurodegenerative process accompanying both AMD and glaucoma; therefore, the use of antioxidant agents would clearly be beneficial, which is supported by the decreased prevalence and progression of AMD in patients adherent to a diet naturally rich in antioxidants.
  • 1.1K
  • 11 Nov 2021
Topic Review
Pathogenesis of Amblyopia
Amblyopia is a neurodevelopmental disorder caused by interocular suppression of visual input, affecting visual acuity, stereopsis, contrast sensitivity, and other visual functions. Conventional treatment comprises occlusion of the sound eye.
  • 1.1K
  • 16 Jan 2024
Topic Review
Pathophysiology of Glaucoma
Glaucoma is a progressive neurodegenerative disease which constitutes the main frequent cause of irreversible blindness. 
  • 1.1K
  • 21 Apr 2021
Topic Review
Choroidal Neovascular Membranes in Retinal and Choroidal Tumors
Choroidal neovascularizations are historically associated with exudative macular degeneration, nonetheless, they have been observed in nevus, melanoma, osteoma, and hemangioma involving the choroid and retina. 
  • 1.1K
  • 08 Feb 2023
Topic Review
Blue Light and Eye Damage
Personal digital devices, emitting high-energy light, namely in the blue wavelength, have raised concerns about possible harmful effects on users’ eyes. Scientific research history has shown a relationship between exposure to blue light and changes in ocular structures.
  • 1.1K
  • 18 May 2023
Topic Review
AS-OCT in Corneal Disorders
Anterior segment optical coherence tomography (AS-OCT) is a non-contact method of in vivo ocular imaging technology. It uses low coherence interferometry that measures the echo time delay of light backscattered from tissue structures and combines multiple axial scans into a composite B-scan image. Earlier ultrasound bio microscopy was used for anterior segment imaging, but with time AS-OCT has become a popular imaging tool for anterior segment imaging. AS-OCT is faster and provides more in-depth assessment of the anterior chamber and is repeatable and reproducible. For AS imaging, longer wavelengths (1050–1310 nm) are preferred than retinal OCT (800–900 nm) due to higher penetration and less scattering.
  • 1.1K
  • 15 Apr 2022
Topic Review
Acanthamoeba Keratitis
AK is relatively rare among corneal infections, with an estimated prevalence of 1–9 cases per 100,000. However, in Western countries, the incidence of AK has been steadily rising in direct correlation with contact lens wearing, which is the predominant risk factor.
  • 1.1K
  • 29 Mar 2021
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