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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.
  • 1.0K
  • 10 Mar 2023
Topic Review
Glaucoma
Glaucoma is defined as a progressive loss of the innermost nerve cells of the retina, the retinal ganglion cells, with a simultaneous characteristic loss of the peripheral visual field. The underlying cause for glaucoma remains unclear and the condition has been recognized as multifactorial with a potential important systemic involvement.
  • 971
  • 12 Feb 2021
Topic Review
Therapeutic Ophthalmic Lenses
The increase of public awareness on ocular conditions leads to an early diagnosis and treatment, as well as an increased demand for more effective and minimally invasive solutions for the treatment of both the anterior and posterior segments of the eye. Despite being the most common route of ophthalmic drug administration, eye drops are associated with compliance issues, drug wastage by lacrimation, and low bioavailability due to the ocular barriers. In order to overcome these problems, the design of drug-eluting ophthalmic lenses constitutes a non-invasive and patient-friendly approach for the sustained drug delivery to the eye. Several examples of therapeutic contact lenses and intraocular lenses have been developed, by means of different strategies of drug loading, leading to promising results. 
  • 967
  • 12 Feb 2021
Topic Review
Experimental Autoimmune Uveitis
Reactive oxygen species (ROS) are produced by host phagocytes and play an important role in antimicrobial actions against various pathogens. Autoimmune uveitis causes blindness and severe visual impairment in humans at all ages worldwide. However, the role of ROS in autoimmune uveitis remains unclear. We used ROS-deficient (Ncf1-/-) mice to investigate the role of ROS in experimental autoimmune uveitis (EAU). Besides, we also used the antioxidant N-acetylcysteine treatment to evaluate the effect of suppression of ROS on EAU in mice. The EAU disease scores of Ncf1-/- mice were significantly lower than those of wild-type mice. EAU induction increased the levels of cytokines (IL-1α, IL-1β, IL-4, IL-6, IL-12, IL-17, and TNF-α) and chemokines (MCP-1) in the retinas of wild-type mice but not in those of Ncf1-/- mice. EAU induction enhanced the level of NF-κB activity in wild-type mice. However, the level of NF-κB activity in Ncf1-/- mice with EAU induction was low. Treatment with the antioxidant N-acetylcysteine also decreased the severity of EAU in mice with reduced levels of oxidative stress, inflammatory mediators, and NF-κB activation in the retina. We successfully revealed a novel role of ROS in the pathogenesis of EAU and suggest a potential antioxidant role for the treatment of autoimmune uveitis in the future.
  • 960
  • 30 Oct 2020
Topic Review
Sickle Cell Retinopathy
This work provides a complete review on sickle cell retinopathy (SCR), the most representative ophtalmologic complication of sickle cell disease (SCD), a hemoglobinopathy affecting both adults and children. It extensively relates the classification, epidemiology, clinical manifestations, risk factors, diagnosis, prevention and therapeutic options for SCR. It also highlights the need of a multidisciplinary theranostic approach.
  • 926
  • 14 Dec 2020
Topic Review
Glaucoma Patients with Flammer Syndrome
Flammer syndrome (FS) describes a phenotype characterized by the presence of primary vascular dysregulation along with a number of symptoms and signs. Although most people with FS are healthy, FS favors the occurrence of certain diseases, such as normal tension glaucoma. This is because disturbed autoregulation makes the eye more sensitive to intraocular pressure (IOP) spikes or blood pressure drops. Treatment of FS is generally appropriate when patients either suffer greatly from their symptoms or if we can assume that it has contributed to a disease. In glaucoma, this may be the case if the glaucoma damage progresses despite well-controlled IOP. Both the still sparse scientific studies and our long clinical experience suggest that FS-targeted therapy not only relieves the symptoms of FS but also slows the progression of glaucoma damage in selected cases. This description is intended not only to help affected patients but to also motivate clinicians and researchers to conduct therapy studies to confirm or refute our observations. 
  • 924
  • 08 Oct 2021
Topic Review
Normal-Pressure Hydrocephalus
Normal-pressure hydrocephalus (NPH) is a neurological disease characterized by enlarged cerebral ventricles and clinical features of gait disturbance, urinary incontinence, and cognitive decline.
  • 923
  • 23 Mar 2021
Topic Review
Endophthalmitis
Exogenous fungal endophthalmitis (EXFE) represents a rare complication after penetrating ocular trauma of previously unresolved keratitis or iatrogenic infections, following intraocular surgery such as cataract surgery.
  • 913
  • 22 Sep 2021
Topic Review
Visual Training in Amblyopia
Active vision therapy using perceptual learning and/or dichoptic or binocular environments has shown its potential effectiveness in amblyopia, but some doubts remain about the type of stimuli and the mode and sequence of presentation that should be used. 
  • 904
  • 04 Jan 2021
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.
  • 901
  • 04 Aug 2022
Topic Review
Magnification of Iris in Ocular Prosthesis
The ocular prostheses, used for the prosthetic rehabilitation of ocular defects, are generally made from acrylic resin. As the thickness of clear acrylic over the iris is increased on the ocular prosthesis, the size of the iris is also increased, due to magnification through the clear resin.
  • 893
  • 22 Mar 2022
Topic Review
Neurodegeneration in Diabetic Retinopathy
Diabetic retinopathy (DR) remains a critical global burden, with 103.12 million individuals affected and an estimated increase to 160.5 million by 2045. It represents a common and preventable complication of both type 1 and type 2 diabetes affecting the adult working population. Neurodegeneration is a critical element of diabetic retinopathy pathogenesis. The neuronal cells’ apoptosis contributes to microvascular impairment and blood–retinal barrier breakdown.
  • 892
  • 03 Mar 2022
Topic Review
Histamine in Glaucoma
Glaucoma is an optic neuropathy characterized by high intra-ocular pressure (IOP) and  progressive degeneration of retinal ganglionic cells (RGCs). Increased IOP and short-term IOP fluctuation are two of the most critical risk factors in glaucoma progression which can lead to visual field impairment and loss of visual function as a consequence of the damage of optic nerve. Histamine is produced within mast cell and neurons in the Central Nervous System (CNS) and it is a well-characterized neuromodulator.  The secretion of histamine  follows a circadian rhythm, regulates IOP and modulates retinal circuits and vision.
  • 889
  • 02 Nov 2021
Topic Review
Molecular Therapeutics for Corneal Scar Treatment
The process of corneal wound healing is complex and induces scar formation. Corneal scarring is a leading cause of blindness worldwide. The fibrotic healing of a major ocular wound disrupts the highly organized fibrillar collagen arrangement of the corneal stroma, rendering it opaque. The process of regaining this organized extracellular matrix (ECM) arrangement of the stromal layer to restore corneal transparency is complicated. The surface retention capacity of ocular drugs is poor, and there is a large gap between suitable corneal donors and clinical requirements. 
  • 883
  • 04 Nov 2022
Topic Review
Negative Dysphotopsia after Cataract Surgery
Dysphotopsias are unwanted visual phenomena that occur after cataract surgery. They represent some of the most common reasons for patient dissatisfaction after uncomplicated surgery for cataract phacoemulsification with in-the-bag intraocular lens (IOL) implantation. Depending on the form of the optical phenomenon and the effect it poses on vision, dysphotopsias are divided into positive and negative type. Positive dysphotopsias are usually described by patients as glare, light streaks, starbursts, light arcs, rings, haloes, or flashes of light. Negative dysphotopsias (ND) are manifested as an arc-shaped shadow or line usually located in the temporal part of the visual field, similar to a temporal scotoma. ND is evoked by an external light source that is typically temporally oriented. Patients most commonly experience this phenomenon in photopic conditions when the pupil is narrow. ND is a diagnosis of exclusion where other possible ocular and neuro-ophthalmological pathologies should be excluded. The etiology of ND is not clearly defined, and the cause seems to be multifactorial. Holladay and Simpson categorized the risk factors for ND development into three groups: anatomic characteristics (pupil size, hyperopia, and angle kappa), IOL properties (IOL surface steepness, edge design, dioptricpower, and refraction index), and surgical technique for cataract removal (optic–haptic junction orientation and position of nasal anterior capsule to the IOL surface).
  • 882
  • 28 Jan 2023
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.
  • 877
  • 18 Aug 2022
Topic Review
Central Serous Chorioretinopathy
Central serous chorioretinopathy (CSC) is a complex and not entirely understood retinal disease.
  • 861
  • 22 Sep 2021
Topic Review
Measuring Intraocular Pressure for Various Tonometers
Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients, and patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients, and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The research describes the various devices currently in use for the measurement of intraocular pressure (IOP), highlight the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.
  • 861
  • 18 Apr 2023
Topic Review
Optical Coherence Tomography in Myopia and Pathologic Myopia
Myopia represents a growing and significantly global public health problem, with a prevalence of over two billion people (28.3% of the global population), including 277 million individuals (4.0%) with high myopia. Pathologic myopia is defined by the presence of myopic lesions in the posterior segment of the eye (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Advances in imaging with optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) technology, including the development of swept source OCT/OCTA, widefield or ultra-widefield systems, have greatly improved the understanding, diagnosis, and treatment of myopia and myopia-related complications.
  • 860
  • 17 Jun 2022
Topic Review
Sorsby‘s Fundus Dystrophy
Sorsby‘s fundus dystrophy (SFD) is a rare, autosomal dominant inherited retinal disease with complete penetrance affecting both genders similarly, typically becoming symptomatic after the second decade of life, with an average onset in the 4th to 5th decade of life, leading to severe bilateral vision loss and blindness if left untreated.
  • 847
  • 22 Jun 2021
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