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Nutrients Oct 2020Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic... (Review)
Review
Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.
Topics: Aging; Animals; Antioxidants; Ascorbic Acid; Cataract; Diabetes Complications; Dietary Supplements; Humans; Nutritional Physiological Phenomena; Oxidative Stress; Risk Factors; Vitrectomy; Vitreous Body
PubMed: 33066702
DOI: 10.3390/nu12103142 -
Blood Oct 2021Primary vitreoretinal lymphoma (PVRL) is a rare form of primary central nervous system (CNS) lymphoma (PCNSL) arising in the intraocular compartment without brain... (Review)
Review
Primary vitreoretinal lymphoma (PVRL) is a rare form of primary central nervous system (CNS) lymphoma (PCNSL) arising in the intraocular compartment without brain involvement. Despite its apparent indolent clinical course, PVRL can cause permanent vision loss and CNS relapse, the major cause of death in patients with PVRL. The pathophysiology of PVRL is unknown. As in PCNSL, the transformation of the tumor cells likely originates outside the CNS, before the cells migrate to the eye and proliferate within an immune-permissive microenvironment. PVRL exhibits a biased immunoglobulin repertoire, suggesting underlying antigen selection. The diagnosis remains challenging, requiring close coordination between ophthalmologists and cytologists. Because of their rarity and fragility in the vitreous, lymphoma cells cannot always be identified. Interleukin levels, molecular biology, and imaging are used in combination with clinical ophthalmological examination to support the diagnosis of PVRL. Multi-institutional prospective studies are urgently needed to validate the equivocal conclusions regarding treatments drawn from heterogeneous retrospective or small cohort studies. Intravitreal injection of methotrexate or rituximab or local radiotherapy is effective at clearing tumor cells within the eyes but does not prevent CNS relapse. Systemic treatment based on high-dose methotrexate chemotherapy, with or without local treatment, might reduce this risk. At relapse, intensive consolidation chemotherapy followed by stem cell transplantation can be considered. Single-agent ibrutinib, lenalidomide, and temozolomide treatments are effective in patients with relapsed PVRL and should be tested as first-line treatments. Therapeutic response assessment based on clinical examination is improved by measuring cytokine levels but still needs to be refined.
Topics: Animals; Disease Management; Humans; Retina; Retinal Neoplasms; Vitreous Body
PubMed: 34036310
DOI: 10.1182/blood.2020008235 -
Archivos de La Sociedad Espanola de... Oct 2019The Berger's space (BS) is a space located between the posterior capsule of the lens and the anterior hyaloid of the vitreous, structures that adhere in a circular...
INTRODUCTION AND OBJECTIVE
The Berger's space (BS) is a space located between the posterior capsule of the lens and the anterior hyaloid of the vitreous, structures that adhere in a circular manner by means of the Wieger ligament, for which the outer limit is defined by Egger's line. The aim of this article is to perform a review of the BS, as well as to present three cases in which this BS could be demonstrated by optical coherence tomography (OCT).
MATERIAL AND METHOD
A total of 90 patients from a general ophthalmology clinic were studied, on whom an anterior pole OCT was performed (Cirrus Lumera 700 Carl Zeiss Medicte, Dublin, California, United States). All patients were included consecutively, with an analysis being performed on the cornea, anterior chamber, iris, lens, and anterior vitreous, but excluding those in which the test could not be performed.
RESULTS
The posterior lens capsule, the anterior hyaloid, and the BS between both structures were observed in three patients. This is the first time in the current literature that three cases have been described, together with their characteristics (one phakic -case 1- and two pseudophakic, one of them vitreous destructuring -case 2- and the other with opacification of the posterior capsule of the lens -case 3-), using this previous pole OCT technique.
CONCLUSIONS
Knowledge of the BS is essential to understand the vitreo-lenticular junction and any complications in some cataract surgeries, as well as to also understand the pathological origin of pigment dispersion syndrome.
Topics: Aged; Eye Diseases; Female; Humans; Lens, Crystalline; Male; Middle Aged; Tomography, Optical Coherence; Vitreous Body
PubMed: 31378388
DOI: 10.1016/j.oftal.2019.06.006 -
Progress in Retinal and Eye Research Nov 2020Macromolecules comprise only 2% of vitreous, yet are responsible for its gel state, transparency, and physiologic function(s) within the eye. Myopia and aging alter... (Review)
Review
Macromolecules comprise only 2% of vitreous, yet are responsible for its gel state, transparency, and physiologic function(s) within the eye. Myopia and aging alter collagen and hyaluronan association causing concurrent gel liquefaction and fibrous degeneration. The resulting vitreous opacities and collapse of the vitreous body during posterior vitreous detachment are the most common causes for the visual phenomenon of vitreous floaters. Previously considered innocuous, the vitreous opacities that cause floaters sometimes impact vision by profoundly degrading contrast sensitivity function and impairing quality-of-life. While many people adapt to vitreous floaters, clinically significant cases can be diagnosed with Vision Degrading Myodesopsia based upon echographic assessment of vitreous structure and by measuring contrast sensitivity function. Perhaps due to the ubiquity of floaters, the medical profession has to date largely ignored the plight of those with Vision Degrading Myodesopsia. Improved diagnostics will enable better disease staging and more accurate identification of severe cases that merit therapy. YAG laser treatments may occasionally be slightly effective, but vitrectomy is currently the definitive cure. Future developments will usher in more informative diagnostic approaches as well as safer and more effective therapeutic strategies. Improved laser treatments, new pharmacotherapies, and possibly non-invasive optical corrections are exciting new approaches to pursue. Ultimately, enhanced understanding of the underlying pathogenesis of Vision Degrading Myodesopsia should result in prevention, the ultimate goal of modern Medicine.
Topics: Contrast Sensitivity; Humans; Myopia; Quality of Life; Visual Acuity; Vitrectomy; Vitreous Body
PubMed: 32151758
DOI: 10.1016/j.preteyeres.2020.100847 -
Retina (Philadelphia, Pa.) Jul 2021Vitreoretinal surgical techniques have evolved during the last decades because of the development and evolution of pars plana vitrectomy. The introduction of modern... (Review)
Review
BACKGROUND
Vitreoretinal surgical techniques have evolved during the last decades because of the development and evolution of pars plana vitrectomy. The introduction of modern vitrectomy is credited to Robert Machemer (1933-2009). The aim of this review is to characterize the early developments of vitreous removal.
METHODS
We used the PubMed web platform to search the terms: complications of cataract surgery, vitrectomy, vitreous body, vitreous humor, vitreous humour, vitreous tap, and vitreous transplantation. Other publications were also considered as a potential source of information when referenced in relevant articles.
RESULTS
The first description of vitreous removal for treatment of eye disorders dates the 17th century; it was conducted by a Dutch surgeon Anton Nuck (1650-1692) in a case of hydrophthalmia. In English literature, the first description of vitrectomy is attributed to the American surgeon John Collins Warren (1778-1856). This method was implemented in the spontaneous dislocation of the crystalline lens. As the fibrillar structure of the vitreous once destroyed could not be regenerated, the researchers aimed to restore the chemical composition of the vitreous. For several decades, vitreous transplantation was performed for the treatment of vitreous hemorrhages and retinal detachment.
CONCLUSION
Although the achievements of vitreoretinal surgery preceding Machemer's inventions are uncommonly reported, they have contributed to the concept and understanding of the treatment modalities.
Topics: Eye Diseases; History, 20th Century; History, 21st Century; Humans; Visual Acuity; Vitrectomy; Vitreous Body
PubMed: 33595257
DOI: 10.1097/IAE.0000000000003149 -
International Journal of Molecular... Dec 2022Several common ocular diseases are leading causes of irreversible visual impairment. Over the last decade, various mainly untargeted metabolic studies have been... (Review)
Review
Several common ocular diseases are leading causes of irreversible visual impairment. Over the last decade, various mainly untargeted metabolic studies have been performed to show that metabolic dysfunction plays an important role in the pathogenesis of ocular diseases. A number of metabolites in plasma/serum, aqueous or vitreous humor, or in tears have been found to differ between patients and controls; among them are L-carnitine and acylcarnitines, which are essential for mitochondrial fatty acid oxidation. The metabolic profile of carnitines regarding a variety of diseases has attracted researchers' interest. In this review, we present and discuss recent advances that have been made in the identification of carnitines as potential metabolic biomarkers in common ocular diseases, such as age-related macular degeneration, diabetic retinopathy, retinopathy of prematurity, central retinal vein occlusion, primary open-angle glaucoma, rhegmatogenous retinal detachment, and dry eye syndrome.
Topics: Infant, Newborn; Humans; Ophthalmology; Glaucoma, Open-Angle; Carnitine; Vitreous Body; Biomarkers
PubMed: 36555822
DOI: 10.3390/ijms232416183 -
Current Eye Research Feb 2023Intravitreal administration of drug molecules is one of the most common routes for treating posterior segment eye diseases. However, the properties of vitreous humour... (Review)
Review
Intravitreal administration of drug molecules is one of the most common routes for treating posterior segment eye diseases. However, the properties of vitreous humour changes with the time. A number of ocular complications such as liquefaction of the vitreous humour, solidification of the vitreous humour in the central vitreous cavity and detachment of the limiting membrane due to the shrinking of vitreous humour are some of the factors that can drastically affect the efficacy of therapeutics delivered via intravitreal route. Although significant research has been conducted for studying the properties of vitreous humour and its changes during the ageing process, there have been limited work to understand the effect of these changes on therapeutic efficacy of intravitreal drug delivery systems. Therefore, in this review we discussed both the coomposition and characteristics of the vitreous humour, and their subsequent influence on intravitreal drug delivery. Articles were searched on Scopus, PubMed and Web of Science up to March 2022. In this review, we discussed the biological composition and biomechanical properties of vitreous humour, methods to study the properties of vitreous humour and the changes in these properties and their relevance in ocular drug delivery field, with the aim to provide a useful insight into these aspects which can aid the process of development of novel intravitreal drug delivery systems. The composition and characteristics of the vitreous humour, and how these change during natural aging processes, directly influence intravitreal drug delivery. This review therefore highlights the importance of understanding the properties of the vitreous and identifies the need to achieve greater understanding of how changing properties of the vitreous affect the therapeutic efficacy of drugs administered for the treatment of posterior eye diseases.
Topics: Humans; Vitreous Body; Drug Delivery Systems; Eye Diseases; Pharmaceutical Preparations; Intravitreal Injections
PubMed: 36036478
DOI: 10.1080/02713683.2022.2119254 -
Translational Vision Science &... Sep 2022Vitreous substitutes are traditionally used to stabilize the retina after vitrectomy. In recent years, various approaches have been developed for using the vitreous... (Review)
Review
Vitreous substitutes are traditionally used to stabilize the retina after vitrectomy. In recent years, various approaches have been developed for using the vitreous substitute not only as a tamponade but also as a drug release system to tackle ocular diseases. This review provides an overview of the requirements for vitreous substitutes and discusses the current clinically applied as well as novel polymer-based vitreous substitutes as drug delivery systems, including their release mechanisms, efficiencies, challenges, and future perspectives.
Topics: Drug Liberation; Polymers; Retina; Vitrectomy; Vitreous Body
PubMed: 36125790
DOI: 10.1167/tvst.11.9.14 -
Experimental Eye Research Dec 2020The purpose of this research is to study the intraocular occurrence of SARS-CoV-2. In postmortem examinations, aqueous humor and the vitreous samples were collected. All... (Review)
Review
The purpose of this research is to study the intraocular occurrence of SARS-CoV-2. In postmortem examinations, aqueous humor and the vitreous samples were collected. All individuals were previously positive in nasopharyngeal swabbing and cause of death was respiratory failure due to SARS-CoV-2 infection. Testing was done using quantitative RT-PCR. We included 16 aqueous humor and 16 vitreous samples for PCR testing. None of the results was positive for SARS-CoV-2. Human GAPDH genes to verify the presence of RNA was present in all aqueous humor samples (16/16, 100%) and 15/16 (93.8%) vitreous samples. In conclusion, this case series found no evidence of SARS-CoV-2 in the intraocular milieu.
Topics: Aqueous Humor; COVID-19; COVID-19 Testing; Humans; RNA, Viral; SARS-CoV-2; Vitreous Body
PubMed: 32991885
DOI: 10.1016/j.exer.2020.108273 -
Frontiers in Immunology 2020The diseases affecting the retina or uvea (iris, ciliary body, or choroid) generate changes in the biochemical or protein composition of ocular fluids/tissues due to... (Review)
Review
The diseases affecting the retina or uvea (iris, ciliary body, or choroid) generate changes in the biochemical or protein composition of ocular fluids/tissues due to disruption of blood-retinal barrier. Ocular infections and inflammations are sight-threatening diseases associated with various infectious and non-infectious etiologies. Several etiological entities cause uveitis, a complex intraocular inflammatory disease. These causes of uveitis differ in different populations due to geographical, racial, and socioeconomic variations. While clinical appearance is sufficiently diagnostic in many diseases, some of the uveitic entities manifest nonspecific or atypical clinical presentation. Identification of biomarkers in such diseases is an important aid in their diagnostic armamentarium. Different diseases and their different severity states release varying concentrations of proteins, which can serve as biomarkers. Proteomics is a high throughput technology and a powerful screening tool for serum biomarkers in various diseases that identifies proteins by mass spectrometry and helps to improve the understanding of pathogenesis of a disease. Proteins determine the biological state of a cell. Once identified as biomarkers, they serve as future diagnostic and pharmaceutical targets. With a potential to redirect the diagnosis of idiopathic uveitis, ocular proteomics provide a new insight into the pathophysiology and therapeutics of various ocular inflammatory diseases. Tears, aqueous and vitreous humor represent potential repositories for proteomic biomarkers discovery in uveitis. With an extensive proteomics work done on animal models of uveitis, various types of human uveitis are being subjected to proteome analysis for biomarker discovery in different ocular fluids (vitreous, aqueous, or tears).
Topics: Animals; Aqueous Humor; Biomarkers; Eye; Humans; Predictive Value of Tests; Prognosis; Proteins; Proteome; Proteomics; Tears; Uveitis; Vitreous Body
PubMed: 33343583
DOI: 10.3389/fimmu.2020.610428