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Topic Review
Suprachoroidal Injections for Macular Edema
Macular edema is characterized by the accumulation of fluid in the macula, leading to vision impairment. Suprachoroidal injections can help with macular edema by delivering medication directly to the affected area, allowing for targeted treatment. Suprachoroidal injections offer several advantages in treating macular edema such as providing a more localized delivery of medication compared to other route and allowing for sustained drug release, which prolongs the duration of the therapeutic effect. This approach therefore minimizes potential side effects and systemic exposure to the medication as well as improving patient comfort. Depending on the exact etiology of macular edema, different substances can be delivered through this method, whether is is triamcinolone acetonide or corticosteroids.  
  • 567
  • 04 Dec 2023
Topic Review
Suprachoroidal Injections for Choroidal Neovascularization and Retinal Detachment
Choroidal neovascularization (CNV) is a pathological process characterized by the growth of abnormal blood vessels beneath the retina and choroid, the vascular layer located behind the retina. CNV is a common complication of various eye conditions, with age-related macular degeneration (AMD) being the most prevalent cause. In AMD, CNV is often referred to as "wet" or "neovascular" AMD, as it involves the formation of new blood vessels that are fragile and prone to leakage. These vessels disrupt the normal structure and function of the retina, leading to vision loss or distortion. CNV can also occur in other conditions like myopia, inflammatory eye diseases, and ocular trauma. The underlying cause of CNV is an imbalance of angiogenic factors, particularly vascular endothelial growth factor (VEGF). Increased levels of VEGF promote the growth of abnormal blood vessels. The new vessels are fragile, leaky, and prone to bleeding, causing damage to the surrounding tissues and impairing vision. Suprachorodal injections therefore offers a novel treatment modality for these serious and vision-altering pathologies.  
  • 565
  • 04 Dec 2023
Topic Review
The Activity of Substance P on Corneal Epithelium
In 1931, Von Euler and Gaddum isolated substance P (SP), an undecapeptide from the tachykinin family, from equine brain and intestine tissue extracts. Numerous types of cells, including neurons, astrocytes, microglia, epithelial, and endothelial cells, as well as immune cells including T-cells, dendritic cells, and eosinophils, are responsible for its production. The corneal epithelium, immune cells, keratocytes, and neurons all express the two isoforms of NK1R, which has the highest affinity for SP. 
  • 560
  • 05 May 2023
Topic Review
MicroShunt for Open-Angle Glaucoma
For moderate-to-severe glaucoma, trabeculectomy remains the “gold standard” intraocular pressure (IOP)-lowering treatment; nonetheless, this method requires extensive post-operative maintenance. Microinvasive glaucoma surgery (MIGS) treatments are designed to lessen intra- and post-operative care burden while offering an acceptable IOP decrease for individuals with mild to moderate glaucoma. The PreserFlo® MicroShunt (previously InnFocus MicroShunt) is an 8.5 mm glaucoma drainage device manufactured from poly(styrene-block-isobutylene-block-styrene) (SIBS), an extremely biocompatible and bioinert material. The lumen is narrow enough to prevent hypotony, but big enough to avoid being obstructed by sloughed cells or pigment. The device is implanted ab externo, as a stand-alone procedure or in conjunction with cataract surgery, with intraoperative mitomycin C, and a bleb is produced under the conjunctiva and Tenon’s capsule. The MicroShunt was CE-marked in 2012 and designed for primary open-angle glaucoma, the IOP of which remains uncontrolled after maximally tolerated topical treatment. Several clinical trials evaluating the MicroShunt’s long-term safety and effectiveness have been conducted, highlighting the effectiveness of the device over time, along with a tolerable safety profile.
  • 557
  • 16 Feb 2022
Topic Review
Role of Telemedicine in Diabetic Retinopathy
With the increasing prevalence of diabetic retinopathy (DR), screening is of the utmost importance to prevent vision loss for patients and reduce financial costs for the healthcare system. Telemedicine offers the opportunity to expand access to screening while reducing the economic and temporal burden associated with current in-person protocols. 
  • 545
  • 24 May 2023
Topic Review
Orbital Metastases
Orbital metastases may significantly worsen the functional status of oncological patients, leading to debilitating visual impairments. Surgical resection, orbital exenteration, and complementary therapies may result in heterogeneous clinical outcomes. Most orbital metastases occur at later stages after primary tumors, frequently showing diffuse location within the orbit and rarely invading intracranial structures. Biopsy-only techniques were more frequently preferred in view of the less invasive approaches, but surgical resection and orbital radiotherapy were related to improved clinical outcomes. Although patients with primary breast cancer and patients undergoing resection showed superior prognoses, overall survival rates were generally poor, suggesting the need to better understand orbital metastases’ microenvironments for devising optimal systemic treatment strategies.
  • 540
  • 12 Jan 2022
Topic Review
Sinonasal Orbital Apex Syndrome
Rhinosinusitis (RS) is an inflammatory disease of the nose and paranasal sinuses with a clinical picture of anterior or posterior nasal discharge, congestion, olfactory dysfunction, and facial pain or pressure. It must be confirmed with endoscopic or radiological signs of inflammation. By its duration, it is classified into acute (i.e., duration <4 weeks), subacute (4–12 weeks), and chronic RS (>12 weeks). Moreover, RS can be named according to the inflamed paranasal sinus, e.g., sphenoiditis in sphenoid sinus inflammation. RS significantly affects the patient’s quality of life due to the significant impact on personal development, sleep hygiene, mental health, physical condition, self-perception, and family relationships.
  • 539
  • 02 Aug 2023
Topic Review
Complement Dysregulation in Glaucoma Patients
Glaucoma is a progressive neurodegenerative disease characterized by damage to the optic nerve that results in irreversible vision loss. While the exact pathology of glaucoma is not well understood, emerging evidence suggests that dysregulation of the complement system, a key component of innate immunity, plays a crucial role. In glaucoma, dysregulation of the complement cascade and impaired regulation of complement factors contribute to chronic inflammation and neurodegeneration.
  • 534
  • 04 Mar 2024
Topic Review
Mitochondrial DNA Deletion/Depletion Disorders Causing Chronic Progressive External Ophthalmoplegia
Chronic progressive external ophthalmoplegia (CPEO) is the most common manifestation of mitochondrial diseases and is characterized by bilateral symmetrical progressive ptosis and reduced ocular motility. CPEO can be isolated or accompanied by a clinical feature of systemic involvement of mitochondrial dysfunction (CPEO plus syndrome). Mitochondrial disorders generally affect tissues with high metabolic demand, such as the central and peripheral nervous systems, heart, adrenal glands, renal tubules, skeletal muscles, and the eye. In CPEO, the ocular findings of ptosis and ophthalmoplegia occur due to the inability of the abnormal mitochondria to supply an adequate amount of ATP due to defective oxidative phosphorylation. The extraocular muscles are particularly susceptible due to their high mitochondrial volume and lower mutational threshold. Their susceptibility is expressed in multiple mitochondrial disorders, highlighting the significance of examining other manifestations in patients with PEO.
  • 533
  • 31 Jan 2024
Topic Review
Pathomolecular Mechanisms of Retinitis Pigmentosa
Retinitis pigmentosa, defined more properly as cone–rod dystrophy, is a paradigm of inherited diffuse retinal dystrophies, one of the rare diseases with the highest prevalence in the worldwide population and one of the main causes of low vision in the pediatric and elderly age groups. Generally speaking, the pathomolecular mechanisms of RP involve primarily genetic mutations that disrupt the normal functioning of the retina and the retinal pigment epithelium through specific and common pathways.
  • 525
  • 24 Oct 2023
Topic Review
Enhanced Diagnostics for Corneal Ectatic Diseases
There are different fundamental diagnostic strategies for patients with ectatic corneal diseases (ECDs): screening, confirmation of the diagnosis, classification of the type of ECD, severity staging, prognostic assessment, and clinical follow-up. The conscious application of such strategies enables individualized treatments. The need for improved diagnostics of ECD is related to the advent of therapeutic refractive procedures that are considered prior to keratoplasty.
  • 522
  • 12 Jan 2023
Topic Review
Types of Retinal Cell Death in Diabetic Retinopathy
Diabetic retinopathy (DR) is a major complication of diabetes and a leading cause of blindness worldwide. DR was recently defined as a neurovascular disease associated with tissue-specific neurovascular impairment of the retina in patients with diabetes. Neurovascular cell death is the main cause of neurovascular impairment in DR.
  • 518
  • 01 Sep 2023
Topic Review
Choroidal Parameters and Age-Related Macular Degeneration
The choroid is the most vascularized structure of the eye and it is fundamental for the trophism of the outer retina. Its proper functioning and homeostasis represent key points in maintaining normal retinal physiology. Choroidal alterations may be implicated in the development and progression of numerous pathologies; therefore, in-depth studies using imaging techniques can be of crucial relevance to understanding the pathophysiology of retinal-choroidal diseases. Various choroidal parameters, including the choroidal vascularity index (CVI), were found to show alterations in intermediate age-related macular degeneration (AMD).
  • 517
  • 18 Aug 2023
Topic Review
Design Principles of Retinal Prothese
MEA-based electrical stimulation activates retinal ganglion cells (RGCs), producing phosphene-based artificial vision. However, the lack of spatial selectivity in MEA stimulation leads to coarse and unreliable phosphenes. To improve selectivity, return electrodes and stimulation parameter manipulation are proposed. Patient experiences with retinal prostheses differ, resembling a "light show" rather than natural vision. The shape and strength of the electric field impact visual perception, and lateral spreading reduces selectivity. Epiretinal devices face bundle activation challenges, while subretinal prostheses exhibit variable phosphene shapes. Enhancing spatial resolution requires reliable isolated points of light. Return electrodes and stimulation parameter control are employed to achieve selectivity. Bidirectional/closed-loop systems record cell responses and optimize stimulation, while computational models aid optimization and understanding of retinal activity. These advancements aim to enhance retinal prostheses, providing a more natural and reliable visual experience.
  • 514
  • 18 Sep 2023
Topic Review
Gene Therapies and Wet  Age-Related Macular Degeneration Treatment
Age-related macular degeneration (AMD) is an eye disease and the most common cause of vision loss in the Western World. In its advanced stage, AMD occurs in two clinically distinguished forms, dry and wet, but only wet AMD is treatable. However, the treatment based on repeated injections with vascular endothelial growth factor A (VEGFA) antagonists may at best stop the disease progression and prevent or delay vision loss but without an improvement of visual dysfunction. Moreover, it is a serious mental and financial burden for patients and may be linked with some complications. 
  • 509
  • 01 Mar 2024
Topic Review
The Multifold Etiologies of Limbal Stem Cell Deficiency
A brief overview of Limbal Stem Cell Deficiency including normal limbal stem cell physiology, pathophysiology, incidence and prevalence, clinical presentation, diagnosis and treatment. Included is a comprehensive list of several genetic, acquired, and immunologic etiologies of the disease.
  • 505
  • 10 Jul 2023
Topic Review
Epigenetic Implications in Glaucoma Neurodegenerative Disease
Glaucoma, a complex and multifactorial neurodegenerative disorder, is a leading cause of irreversible blindness worldwide. Despite significant advancements in the understanding of its pathogenesis and management, early diagnosis and effective treatment of glaucoma remain major clinical challenges. Epigenetic modifications, encompassing deoxyribonucleic acid (DNA) methylation, histone modifications, and non-coding RNAs, have emerged as critical regulators of gene expression and cellular processes.
  • 495
  • 04 Mar 2024
Topic Review
Molecular Biology of Uveal Melanoma
Uveal melanoma arises from the pigment-producing cells in the iris, ciliary body, and choroid. Its annual incidence is estimated to be around 5–6 cases per million people, but is the most common primary intraocular malignancy in adults. 
  • 491
  • 21 Feb 2024
Topic Review
Canaloplasty in Pseudoexfoliation Glaucoma
Pseudoexfoliation glaucoma (PEXG) is a frequent form of secondary glaucoma due to deposits of fibrillary material in the juxtacanalicular portion of the trabecular meshwork. The research was to assess the long-term outcomes of canaloplasty surgery in pseudoexfoliation glaucoma (PEXG) patients.
  • 490
  • 20 Apr 2023
Topic Review
Mesenchymal Stem Cell-Derived Exosomes in Anterior Segment Diseases
Exosomes, which are derived from MSCs, are nanoparticle vesicles that possess therapeutic properties such as anti-inflammatory, anti-apoptotic, tissue-repairing, neuroprotective, and immunomodulatory functions, much like their parent cells. By using MSC-derived exosomes as a drug-delivery system, their potential advantages can be fully exploited. Due to their ability to penetrate the blood-brain barrier, it is inferred that they may also better penetrate biological barriers such as the blood-retinal barrier. Additionally, their cargo is protected from degradation, resulting in increased bioavailability in ocular tissues. Research suggests that utilizing MSC-derived exosomes as a treatment option could offer several benefits over traditional MSC-based therapies in the field of regenerative medicine. Exosome-based therapy provides an alternative approach that avoids potential risks associated with MSC-centered therapies, such as allogeneic immunological rejection, unwanted differentiation, and obstruction of small vessels caused by intravenous MSC injection. By circumventing these risks, treatment outcomes can be optimized.
  • 490
  • 08 Jun 2023
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