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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 -
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 -
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 -
Macromolecular Bioscience Feb 2020Current experimental vitreous substitutes only replace the physical functions of the natural vitreous humor. Removal of the native vitreous disrupts oxygen homeostasis... (Review)
Review
Current experimental vitreous substitutes only replace the physical functions of the natural vitreous humor. Removal of the native vitreous disrupts oxygen homeostasis in the eye, causing oxidative damage to the lens that likely results in cataract formation. Neither current clinical treatments nor other experimental vitreous substitutes consider the problem of oxidative stress after vitrectomy. To address this problem, biomimetic hydrogels are prepared by free radical polymerization of poly(ethylene glycol) methacrylate and poly(ethylene glycol) diacrylate. These hydrogels have similar mechanical and optical properties to the vitreous. The hydrogels are injectable through small-gauge needles and demonstrate in vitro biocompatibility with human retinal and lens epithelial cells. The hydrogels and added vitamin C, an antioxidant, show a synergistic effect in protecting ocular cells against reactive oxygen species, which fulfills a chemical function of the natural vitreous. These hydrogels have the potential to prevent post-vitrectomy cataract formation and reduce the cost of additional surgeries.
Topics: Animals; Antioxidants; Humans; Hydrogels; Lens, Crystalline; Materials Testing; Retina; Vitreous Body
PubMed: 31846211
DOI: 10.1002/mabi.201900305 -
Journal of Analytical Toxicology Feb 2022Postmortem chemistry can be a useful ancillary technique that the forensic pathologist can use during a death investigation. In stark contrast, there is limited...
Postmortem chemistry can be a useful ancillary technique that the forensic pathologist can use during a death investigation. In stark contrast, there is limited information available for use of postmortem vitreous humor analysis in animals. In order to use postmortem vitreous humor in veterinary forensic investigations, validation of a method to analyze vitreous humor is required. The goal of this study was to determine the precision, bias, TEobs and sigma (σ) of the Element DC chemistry analyzer; assess its precision using the vitreous humor collected postmortem from dogs, cats and horses and assess the stability of postmortem vitreous humor from all the three species. Analysis of quality control material (QCM) and pooled vitreous humor samples for the three species was used to test for sodium (Na), chloride (Cl), potassium (K), magnesium (Mg), creatinine (Crea) and blood/vitreous urea nitrogen. Analysis of QCM showed that the Element DC was both precise and accurate. When analyzing the pooled vitreous humors, most within-run coefficients of variance (CVs) were found to be <5% and the between-run CVs for five out of six analytes were found to be <5% for dogs, cats and horses. In all the three species, the capped samples of vitreous humor were stable out of refrigeration for up to 5 h. The results of this study show that the Element DC can successfully be used to analyze the postmortem vitreous humor from dogs, cats and horses.
Topics: Animals; Autopsy; Body Fluids; Cats; Dogs; Horses; Postmortem Changes; Potassium; Sodium; Vitreous Body
PubMed: 33216118
DOI: 10.1093/jat/bkaa175 -
International Ophthalmology Jul 2023To research whether serum vascular endothelial growth factor (VEGF) levels could be used to evaluate diabetic retinopathy (DR) progression and to compare vitreous VEGF...
PURPOSE
To research whether serum vascular endothelial growth factor (VEGF) levels could be used to evaluate diabetic retinopathy (DR) progression and to compare vitreous VEGF levels after injections of intravitreal bevacizumab (IVB), ranibizumab (IVR), and triamcinolone acetonide (IVTA) in proliferative diabetic retinopathy (PDR).
METHODS
We enrolled a total of 91 eyes of 89 subjects (70 eyes of 68 diabetics and 21 eyes of 21 non-diabetic controls). The diabetic subjects were divided into three groups as PDR (n = 28), non-proliferative diabetic retinopathy (n = 20), and no-DR (n = 20). Eyes with PDR (n = 31) were injected with IVB (n = 7), IVR (n = 10), or IVTA (n = 6) 3 days before vitrectomy, and eight eyes did not receive an injection. Serum and vitreous samples were collected before vitrectomy and analyzed using ELISA.
RESULTS
We found the severity of retinopathy was not correlated with serum VEGF levels (P = .919, ρ = -0.011). Compared with the controls, vitreous VEGF was higher in the PDR (P < .001), whereas serum VEGF did not differ (P = .99). The controls had lower vitreous VEGF than the IVB, IVR, and no-injection subgroups (P = .01, P < .001, and P = .04, respectively). Vitreous VEGF was similar among the injected and no-injection subgroups (P = .17).
CONCLUSIONS
Serum VEGF levels may not directly reflect retinopathy progression. Neither IVB, IVR nor IVTA could eliminate vitreous VEGF levels within 3 days before vitrectomy.
Topics: Humans; Vascular Endothelial Growth Factor A; Diabetic Retinopathy; Vitreous Body; Bevacizumab; Ranibizumab; Vitrectomy; Enzyme-Linked Immunosorbent Assay; Diabetes Mellitus
PubMed: 36580154
DOI: 10.1007/s10792-022-02620-y -
Japanese Journal of Ophthalmology Jul 2016The presence of a posterior precortical vitreous pocket, referred to as a precortical pocket, implies that the vitreous cortex is formed into a collagen sheet separated... (Review)
Review
The presence of a posterior precortical vitreous pocket, referred to as a precortical pocket, implies that the vitreous cortex is formed into a collagen sheet separated from the gel in the macula. Along with strong vitreoretinal attachment at the fovea, the precortical pocket plays a role in perifoveal posterior vitreous detachments, which may lead to macular holes, premacular membranes, and ring-shaped proliferation in diabetic retinopathy. I and my colleagues published pioneer studies of the vitreous in postmortem eyes. Here, the role of the precortical pocket in various vitreoretinal interface diseases is discussed. Swept-source optical coherence tomography showed development of the precortical pocket, the connecting channel, and Cloquet's canal during early childhood. These findings raised the possibility that aqueous humor may drain into the precortical pocket. The physiologic role of the drainage route is also discussed. Crosstalk between the anterior chamber and macula is an attractive hypothesis and remains to be elucidated.
Topics: Humans; Macula Lutea; Tomography, Optical Coherence; Vitreous Body
PubMed: 27165709
DOI: 10.1007/s10384-016-0447-z -
Forensic Science, Medicine, and... Sep 2023Correctly estimating the post-mortem interval (PMI) is essential in forensic practice. In recent decades, the measurement of vitreous humor analyte concentrations -...
Correctly estimating the post-mortem interval (PMI) is essential in forensic practice. In recent decades, the measurement of vitreous humor analyte concentrations - especially of hypoxanthine and potassium - and their correlation with the PMI have returned good results. However, calculating the PMI from the data collected can be quite complex. The present paper describes a web resource ( http://modestya.usc.es:3838/Forensic/ ) that simplifies the procedure. The PMI is determined (with its 95% confidence interval) in a rapid, easy, and reliable manner based on the use of mathematical models, the biochemistry of the vitreous humor, and physical variables such as the ambient temperature, the rectal temperature, and bodyweight. The application is entirely free to use.
Topics: Humans; Postmortem Changes; Autopsy; Forensic Medicine; Models, Theoretical; Vitreous Body; Potassium
PubMed: 36199004
DOI: 10.1007/s12024-022-00537-7