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Topic Review
Intraoperative OCT
Intraoperative OCT is an innovative and promising technology which allows anterior and posterior segment ocular surgeons to obtain a near-histologic cross-sectional and tomographic image of the tissues. Intraoperative OCT has several applications in ocular surgery which are particularly interesting in the context of corneal transplantation. Indeed, iOCT images provide a direct and meticulous visualization of the anatomy, which could guide surgical decisions. In particular, during both big-bubble and manual DALK, the visualization of the relationship between the corneal layers and instruments allows the surgeon to obtain a more desirable depth of the trephination, thus achieving more type 1 bubbles, better regularity of the plane, and a reduced risk of DM perforation. During EK procedures, iOCT supplies information about proper descemetorhexis, graft orientation, and interface quality in order to optimize the postoperative adhesion and reduce the need for re-bubbling. Finally, mushroom PK, a challenging technique for many surgeons, can be aided through the use of iOCT since it guides the correct apposition of the lamellae and their centration. The technology of iOCT is still evolving: a larger field of view could allow for the visualization of all surgical fields, and automated tracking and iOCT autofocusing guarantee the continued centration of the image.
  • 273
  • 05 May 2023
Topic Review
Canaloplasty in Corticosteroid-Induced Glaucoma
Canaloplasty should be considered as a possible alternative to filtering surgery in this form of glaucoma when medical therapy is not sufficient to maintain the intraocular pressure (IOP) within reasonable limits.
  • 272
  • 18 Apr 2023
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.
  • 270
  • 20 Apr 2023
Topic Review
Ocular Manifestations of Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is a chronic autoimmune systemic disorder of the connective tissue that does not affect only one certain organ but has a diversified effect all over the body. The etiology of SLE is may be idiopathic, genetic, hormonal, or environmental. The diagnosis of SLE is difficult and requires a series of tests and findings which can be systemic or ocular. Approximately one-third of those diagnosed with SLE experience ocular manifestations that range from mild to severe sight-threatening conditions. Ocular manifestations of SLE include keratoconjunctivitis sicca, uveitis, and posterior segment pathologic signs.
  • 270
  • 29 Feb 2024
Topic Review
Clinical Considerations for Retinal Prostheses
A retinal prosthesis, also known as a bionic eye or artificial retina, is a medical device designed to restore vision in individuals with severe vision loss or blindness caused by conditions such as retinitis pigmentosa or age-related macular degeneration (AMD). It works by bypassing the damaged photoreceptor cells and directly stimulating the remaining healthy retinal cells or the optic nerve. In recent years, numerous types of devices such as epiretinal, subretinal, and suprachoroidal ones have been developed, but the Argus II is the only FDA-approved retinal prosthesis in North America for now. Although retinal protheses show great potential, ongoing research and advancements in this field are nonetheless necessary to refine the technology and expand its applications in the future.
  • 268
  • 28 Sep 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.
  • 267
  • 18 Sep 2023
Topic Review
NLRP3 Inflammasome in Inflammatory Eye Diseases Treatment
Due to their potent immunoregulatory and angio-modulatory properties, mesenchymal stem cells (MSCs) and their exosomes (MSC-Exos) have emerged as potential game-changers in regenerative ophthalmology, particularly for the personalized treatment of inflammatory diseases. NLRP3 inflammasome, composed of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (CARD) (ASC), and pro-caspase-1 is dysregulated in almost all inflammatory eye disease. Accordingly, a large number of experimental findings suggested that this multi-protein complex could be considered an important intracellular target for MSC-based therapy of inflammatory eye disorders.
  • 265
  • 20 Oct 2023
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.
  • 264
  • 10 Jul 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.
  • 260
  • 08 Jun 2023
Topic Review
Emerging Interventions for Autosomal Recessive ABCA4-Associated Stargardt Disease
Autosomal recessive Stargardt disease (STGD1) is an inherited retinal degenerative disease associated with a mutated ATP-binding cassette, subfamily A, member 4 (ABCA4) gene. STGD1 is the most common form of juvenile macular degeneration with onset in late childhood to early or middle adulthood and causes progressive, irreversible visual impairment and blindness. 
  • 260
  • 23 Oct 2023
Topic Review
Second Tumors in Retinoblastoma Survivors after Ionizing Radiation
Retinoblastoma (RB) is the most common ocular neoplasm in children, whose development depends on two mutational events that occur in both alleles of the retinoblastoma susceptibility gene (RB1). Regarding the nature of these mutational events, RB can be classified as hereditary if the first event is a germline mutation and the second one is a somatic mutation in retina cells or nonhereditary if both mutational events occur in somatic cells. Although the rate of survival of RB is significantly elevated, the incidence of second malignant neoplasms (SMNs) is a concern, since SMNs are the main cause of death in these patients. Furthermore, evidence confirms that hereditary RB survivors are at a higher risk for SMNs than nonhereditary RB survivors. This risk seems to increase with the use of ionizing radiation in some therapeutic approaches commonly used in the treatment of RB.
  • 260
  • 20 Nov 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).
  • 257
  • 18 Aug 2023
Topic Review
Myopia, Sodium Chloride, and Vitreous Fluid Imbalance
Myopia prevalence is low in native people consuming traditional diets lacking in sodium chloride, and nutritional epidemiological evidence supports the association of rising myopia prevalence with dietary sodium intake. East Asian populations have among the highest rates of myopia associated with high dietary sodium. Similar associations of sodium and rising myopia prevalence were observed in the United States in the late 20th century.
  • 256
  • 12 Mar 2024
Topic Review
Plant-Based Diets Reducing the Main RVO Risk Factors
Retinal vein occlusion (RVO) is the second most common retinal disorder. In comparison to diabetic retinopathy or age-related macular degeneration, RVO is usually an unexpected event that carries a greater psychological impact.
  • 252
  • 26 Sep 2023
Topic Review
Multimodal Ophthalmic Imaging in Spinocerebellar Ataxia Type 7
SCA7, from an ophthalmological point of view, can be assessed through numerous multimodal imaging techniques to evaluate and manage the follow-up of patients. Visual acuity is a fundamental parameter that should be monitored, and spectral domain optical coherence tomography (SDOCT), which is a rapid and non-invasive method, should be routinely performed to evaluate ophthalmic disease progression over time. Additional exams, including NIR imaging, can indicate photoreceptor loss and disruption of the RPE that are not readily evident with color fundus photography (CFP). 
  • 250
  • 19 Jan 2024
Topic Review
Oxidative Stress Implications for Retinal Diseases
Oxidative stress plays a significant role in the pathogenesis of various retinal diseases, including diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, and retinopathy of prematurity (ROP).
  • 250
  • 29 Feb 2024
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. 
  • 249
  • 01 Mar 2024
Topic Review
Wavefront Sensors and Aberration Sensors in Ophthalmology
The wavefront sensor is one of the main elements of the adaptive vision correction system. Its task is to measure the aberrations of the wavefront and transmit the results of these measurements to the processing device. The main causes of wavefront aberrations in the eye are the shape and optical properties of the cornea, pupil and lens. In modern diagnostic devices, wave aberrations are described in terms of Zernike polynomials (OSA and ANSI standards). Nowadays, there are a wide variety of wavefront sensors.
  • 246
  • 02 Jan 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.
  • 237
  • 31 Jan 2024
Topic Review
3D Printing in Ophthalmology
Three-dimensional (3D) printing is a process in which materials are added together in a layer-by-layer manner to construct customized products. Many different techniques of 3D printing exist, which vary in materials used, cost, advantages, and drawbacks. Medicine is increasingly benefiting from this transformative technology, and the field of ophthalmology is no exception. The possible 3D printing applications in eyecare are vast and have been explored in the literature, such as 3D-printed ocular prosthetics, orbital implants, educational and anatomical models, as well as surgical planning and training. 
  • 237
  • 01 Feb 2024
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