ascorbic-acid and Eye-Diseases

Vitamin C is an essential dietary nutrient for the biosynthesis of collagen and a co-factor in the biosynthesis of catecholamines, L-carnitine, cholesterol, amino acids, and some peptide hormones. The lack of vitamin C causes scurvy, a pathological condition leading to blood vessel fragility and connective tissue damage due to failure in producing collagen, and, finally, to death as result of a general collapse. Vitamin C is potentially involved also in cancer and cardiovascular diseases prevention. In addition, vitamin C effects on nervous system and chronically ill patients have been also documented. This review attempts to summarize recent and well established advances in vitamin C research and its clinical implications. Since vitamin C has the potential to counteract inflammation and subsequent oxidative damage that play a major role in the initiation and progression of several chronic and acute diseases, it represents a practical tool to administer for the early prevention of these pathologic conditions.

Topics: Anticarcinogenic Agents; Ascorbic Acid; Cardiovascular Diseases; Critical Illness; Eye Diseases; Humans; Nervous System

The role of oxidation in the development of age-related eye disease has prompted interest in the use of nutritional supplementation for prevention of onset and progression. Our aim is to highlight possible contraindications and adverse reactions of isolated or high dose ocular nutritional supplements. Web of Science and PubMed database searches were carried out, followed by a manual search of the bibliographies of retrieved articles. Vitamin A should be avoided in women who may become pregnant, in those with liver disease, and in people who drink heavily. Relationships have been found between vitamin A and reduced bone mineral density, and beta-carotene and increased risk of lung cancer in smoking males. Vitamin E and Ginkgo biloba have anticoagulant and anti-platelet effects respectively, and high doses are contraindicated in those being treated for vascular disorders. Those patients with contraindications or who are considered at risk of adverse reactions should be advised to seek specialist dietary advice via their medical practitioner.

Topics: Ascorbic Acid; Carotenoids; Contraindications; Dietary Supplements; Eye Diseases; Fatty Acids, Essential; Female; Ginkgo biloba; Humans; Male; Pregnancy; Pregnancy Complications; Vitamin A; Vitamin B Complex; Vitamin E

L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (<0.01%) or in the 5% to 10% range. Calcium Ascorbate and Magnesium Ascorbate are described as antioxidants and skin conditioning agents--miscellaneous for use in cosmetics, but are not currently used. Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity. Ascorbic Acid and Sodium Ascorbate acted as a nitrosation inhibitor in several food and cosmetic product studies. No compound-related clinical signs or gross or microscopic pathological effects were observed in either mice, rats, or guinea pigs in short-term studies. Male guinea pigs fed a control basal diet and given up to 250 mg Ascorbic Acid orally for 20 weeks had similar hemoglobin, blood glucose, serum iron, liver iron, and liver glycogen levels compared to control values. Male and female

Topics: Administration, Oral; Animals; Ascorbic Acid; Carcinogenicity Tests; Chemical Phenomena; Chemistry, Physical; Cosmetics; Eye Diseases; Guinea Pigs; Humans; Irritants; Mutagenicity Tests; Primates; Rats; Reproduction; Tissue Distribution

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Eye Diseases; Health Promotion; Humans; Neoplasms; Preventive Medicine; Vitamin E

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Corneal Diseases; Diabetic Retinopathy; Drug Therapy, Combination; Eye; Eye Burns; Eye Diseases; Humans; Tuberculosis, Ocular; Vision, Ocular

Topics: Adult; Aged; Amino Acids; Animals; Aqueous Humor; Ascorbic Acid; Blood Glucose; Child; Cyclic AMP; Drug Interactions; Drug Synergism; Endophthalmitis; Eye; Eye Diseases; Glaucoma; Humans; Intraocular Pressure; Kinetics; Middle Aged; Moxisylyte; Pharmacogenetics; Prostaglandins; Rabbits; Toxicology

Topics: Ascorbic Acid; Drug Synergism; Eye Diseases; Fatty Acids, Essential; Flavonoids; Humans; Niacinamide; Pantothenic Acid; Pyridoxine; Riboflavin; Thiamine; Thiamine Pyrophosphate; Vitamin A; Vitamin A Deficiency; Vitamin B 12; Vitamin B 12 Deficiency; Vitamin B Complex; Vitamin D; Vitamin E; Vitamin K; Vitamins

Topics: Abnormalities, Drug-Induced; Animals; Ascorbic Acid; Child; Chloroquine; Enzymes; Eye Diseases; Female; Humans; Lysosomes; Pigmentation; Porphyrias; Pregnancy; Protein Biosynthesis; Psoriasis; Pyridoxine; Rabbits; Retina; Ultraviolet Rays

Topics: Alcohols; Ascorbic Acid; Carbohydrate Metabolism; Chloroquine; Erythrocytes; Eye Diseases; Glucosephosphate Dehydrogenase Deficiency; Glucosephosphates; Glutathione; Histocytochemistry; Lens, Crystalline; Lipid Metabolism; Metabolism; Methanol; Phenothiazines; Retina; Retinal Pigments; Retinitis Pigmentosa; Toxicology; Vitamin A Deficiency

Topics: Adult; Ascorbic Acid; Carbon Isotopes; Clinical Trials as Topic; Diet; Electrocardiography; Electroencephalography; Enteral Nutrition; Eye Diseases; Feces; Glucose Tolerance Test; Hematology; Hemorrhage; Humans; Keratosis; Male; Nutritional Physiological Phenomena; Nutritional Requirements; Oral Hemorrhage; Scurvy; Skin Diseases; Urine

To evaluate the stability of a model Mab1 and Fab1 under in vitro vitreal conditions in the presence of various metabolites and in the presence of light at λ > 400 nM.. A full length IgG1 monoclonal antibody (Mab1) and a fab fragment (Fab1) were formulated with various metabolites typically found in the vitreous humor and subjected to visible light treatment. Both proteins were analyzed using a variety of biochemical techniques. Furthermore, Fab1 was also tested for antigen binding ability using surface plasmon resonance.. Our data shows that some vitreal metabolites such as riboflavin and ascorbic acid affect protein stability, via formation of reactive oxygen species (ROS) and advanced glycation end products (AGE) s respectively. In contrast, metabolites such as glutathione may protect these proteins from light-induced degradation to some extent.. Ascorbic acid and riboflavin were found to photosensitize therapeutic proteins especially when exposed to light. Ascorbic acid reacted with proteins even in the absence of light. Antioxidants such as glutathione helped limit photooxidation under ambient or blue light exposure. Since antioxidant capacity in the eye decreases with age we recommend understanding long term stability, including photooxidation and photosensitization, of new candidate proteins in the context of controlled or sustained release technologies for ocular diseases.

Topics: Antibodies, Monoclonal; Antioxidants; Ascorbic Acid; Eye Diseases; Immunoglobulin Fab Fragments; Immunoglobulin G; Light; Protein Stability; Reactive Oxygen Species; Riboflavin

Limited training, high cost, and low equipment mobility leads to inaccuracies in decision making and is concerning with serious ocular injuries such as suspected ruptured globe or post-operative infections. Here, we present a novel point-of-service (POS) quantitative ascorbic acid (AA) assay with use of the OcuCheck Biosensor. The present work describes the development and clinical testing of the paper-based biosensor that measures the changes in electrical resistance of the enzyme-plated interdigitated electrodes to quantify the level of AA present in ocular fluid. We have demonstrated the proof-of-concept of the biosensor testing 16 clinical samples collected from aqueous humor of patients undergoing therapeutic anterior chamber paracentesis. Comparing with gold standard colorimetric assay for AA concentration, OcuCheck showed accuracy of >80%, sensitivity of >88% and specificity of >71%. At present, there are no FDA-approved POS tests that can directly measures AA concentration levels in ocular fluid. We envisage that the device can be realized as a handheld, battery powered instrument that will have high impact on glaucoma care and point-of-care diagnostics of penetrating ocular globe injuries.

Topics: Acrylates; Aqueous Humor; Ascorbic Acid; Biosensing Techniques; Chromatography, High Pressure Liquid; Electrochemical Techniques; Electrodes; Eye Diseases; Graphite; Humans; Mass Spectrometry; Paracentesis; Point-of-Care Systems; Polystyrenes; Sensitivity and Specificity; Spectrum Analysis, Raman

To determine whether class I ultraviolet (UV) light-blocking contact lenses prevent UV-induced pathologic changes in a rabbit model.. Twelve rabbits were assigned to 1 of 3 treatment groups (n = 4), as follows: senofilcon A (class I UV blocking) contact lenses; lotrafilcon A contact lenses (no reported UV blocking); no contact lens. The contralateral eye was patched without a contact lens. Animals received UV-B (1.667 J/cm(2)) exposure daily for 5 days. Postmortem tissue was examined as follows: in the cornea, the expression of matrix-metalloproteinases (MMPs) was evaluated by zymography, and apoptosis was evaluated by TUNEL and caspase-3 ELISA; ascorbate in the aqueous humor was evaluated by nuclear magnetic resonance spectroscopy; crystalline lens apoptosis was evaluated by TUNEL and caspase-3 ELISA.. Exposed corneas showed a significant increase in MMP-2 and -9, TUNEL-positive cells, and caspase-3 activity in the lotrafilcon A group compared with the senofilcon A group (all P = 0.03). A significant decrease in aqueous humor ascorbate was observed in the exposed lotrafilcon A lens-wearing group compared with the exposed senofilcon A lens-wearing group (P = 0.03). Exposed crystalline lenses had significantly increased caspase-3 activity in the lotrafilcon A group compared with the senofilcon A group (P = 0.03). Increased numbers of TUNEL-positive cells were noted in both the lotrafilcon A and the non-contact lens groups.. The authors show that senofilcon A class I UV-blocking contact lenses are capable of protecting the cornea, aqueous humor, and crystalline lens of rabbits from UV-induced pathologic changes.

Topics: Animals; Anterior Eye Segment; Apoptosis; Aqueous Humor; Ascorbic Acid; Caspase 3; Contact Lenses, Hydrophilic; Cornea; Enzyme-Linked Immunosorbent Assay; Eye Diseases; Hydrogels; In Situ Nick-End Labeling; Lens, Crystalline; Magnetic Resonance Spectroscopy; Matrix Metalloproteinases; Prospective Studies; Rabbits; Radiation Injuries, Experimental; Radiation Protection; Silicones; Ultraviolet Rays

Topics: Antioxidants; Ascorbic Acid; Cataract; Clinical Trials as Topic; Dietary Supplements; Eye Diseases; Glaucoma; Humans; Macular Degeneration; Risk Factors; Smoking; Vitamin E; Vitamins

This study was conducted to investigate metabolic changes in aqueous humor from rabbit eyes exposed to either UV-A or -B radiation, by using (1)H nuclear magnetic resonance (NMR) spectroscopy and unsupervised pattern recognition. methods. Both eyes of adult albino rabbits were irradiated with UV-A (366 nm, 0.589 J/cm(2)) or UV-B (312 nm, 1.667 J/cm(2)) radiation for 8 minutes, once a day for 5 days. Three days after the last irradiation, samples of aqueous humor were aspirated, and the metabolic profiles analyzed with (1)H NMR spectroscopy. The metabolic concentrations in the exposed and control materials were statistically analyzed and compared, with multivariate methods and one-way ANOVA.. UV-B radiation caused statistically significant alterations of betaine, glucose, ascorbate, valine, isoleucine, and formate in the rabbit aqueous humor. By using principal component analysis, the UV-B-irradiated samples were clearly separated from the UV-A-irradiated samples and the control group. No significant metabolic changes were detected in UV-A-irradiated samples.. This study demonstrates the potential of using unsupervised pattern recognition methods to extract valuable metabolic information from complex (1)H NMR spectra. UV-B irradiation of rabbit eyes led to significant metabolic changes in the aqueous humor detected 3 days after the last exposure.

Topics: Amino Acids; Animals; Aqueous Humor; Ascorbic Acid; Eye Diseases; Glucose; Nuclear Magnetic Resonance, Biomolecular; Rabbits; Radiation Injuries, Experimental; Ultraviolet Rays

An acute inflammatory response was initiated in the rabbit eye by an intravitreal injection of bacterial endotoxin. We examined the effect of topical corticosteroid therapy upon polymorphonuclear leukocyte (PMN) infiltration into the eye, protein leakage into aqueous humor and ascorbate level in aqueous humor. Corticosteroid therapy initiated prior to injection of endotoxin suppresses the clinical signs of inflammation, partially prevents the fall in aqueous-humor ascorbate level, has little effect upon protein leakage, but markedly reduces PMN infiltration. Corticosteroid therapy initiated after the injection of endotoxin also suppresses the clinical signs of inflammation, reduces the fall in ascorbate levels and does not influence protein leakage. However, in this case there is a marked persistence of PMN infiltration into ocular tissues. Thus the number of PMNs present in the ocular tissues is little different from that in non-steroid treated control eyes, although the clinical signs of inflammation are reduced. We suggest that in the clinical situation, the initial anti-inflammatory activity of the corticosteroids is related to an inhibitory effect upon the activity of PMNs already within the tissues, which then prevents the ensuing cascade of characteristic inflammatory events.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents; Aqueous Humor; Ascorbic Acid; Capillary Permeability; Chemotaxis, Leukocyte; Dexamethasone; Endotoxins; Eye; Eye Diseases; Eye Proteins; Female; Glucocorticoids; Inflammation; Male; Neutrophils; Prednisolone; Rabbits

During an experimentally induced inflammatory response in the rabbit eye, the decrease in the ascorbic acid concentration within the aqueous humor corresponded, in large part, to the infiltration of leukocytes into this ocular fluid. Additional in vitro studies demonstrated that activated leukocytes reacted with ascorbic acid, diminishing the concentration of this vitamin in the surrounding medium. We suggest that the very high concentrations of ascorbic acid found in the aqueous humor of a number of species affords extracellular protection for the ocular tissues against oxygen radicals and metabolites released by infiltrating leukocytes during ocular inflammation.

Topics: Animals; Aqueous Humor; Ascorbic Acid; Dose-Response Relationship, Drug; Endotoxins; Eye Diseases; Female; Hydrogen Peroxide; Inflammation; Male; Neutrophils; Oxidation-Reduction; Rabbits; Time Factors

The ocular effects of intravitreally injected copper sulfate solutions were studied in New Zealand white rabbits. These injections resulted in uveitis characterized by prolonged ocular hypotony, increased protein concentrations and decreased ascorbic acid concentrations in both the vitreous and aqueous humors, and an apparent decrease in the transport function of the anterior uvea. The extent and the duration of these effects were dose-dependent. The lower doses used, 3 or 6 micrograms of Cu as CuSO4 per eye, produced reversible inflammation. The highest dose, 30 micrograms of Cu per eye, also produced some signs of ocular chalcosis: hemorrhage, vitreous liquefaction, prolonged hypotony and local iridial ischemia. Six hours after the intravitreal injection of 6 micrograms of Cu as CuSO4 per eye, the Cu concentration in the vitreous humor increased to approximately 100 times that in the vitreous of control eyes, and began to decline only 3 days later, with a half-time of approximately 8 days. The Cu concentration in the anterior chamber of these eyes never exceeded 1 ppm and returned close to control values within 3 days. Based on these findings, factors that affect ocular trace-metal distribution and kinetics are discussed, as are reasons for the apparent difficulty in diagnosing the presence of Cu-containing intraocular foreign bodies on the basis of the Cu concentration of the aqueous humor.

Topics: Animals; Anterior Chamber; Ascorbic Acid; Copper; Copper Sulfate; Dose-Response Relationship, Drug; Eye Diseases; Eye Proteins; Female; Inflammation; Intraocular Pressure; Muscle Hypotonia; Rabbits; Time Factors; Vitreous Body

Topics: Ascorbic Acid; Eye Diseases; Female; Humans

Topics: Ascorbic Acid; Drug Therapy, Combination; Eye Diseases; Glycerol; Humans; Injections, Intravenous

The hematic level of ascorbic acid was significantly lower with respect to that of healthy subjects in 55 patients with hemorrhagic ocular diseases. Experiments on albino guinea pigs showed that an induced hypovitaminosis C (2 weeks of scorbutigenic diet followed by a maintenance dose of 0,5 mg of ascorbic acid) caused the appearance of widespread retina hemorrhages and a significant decrease of the blood ascorbate levels with respect to the control groups. The present results suggest that a prolonged insufficient dietary intake of ascorbic acid may give rise to hemorrhagic ocular pathologies in humans.

Topics: Adult; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Eye Diseases; Female; Guinea Pigs; Hemorrhage; Humans; Male; Middle Aged

Treatment of mice with 6-hydroxydopamine increased herpes simplex virus replication in the superior cervical ganglion while it decreased the subsequent prevalence of latent infection. Preganglionic neurectomy failed to block this effect. These observations suggest that intrinsic neural events modify the outcome of viral infections of the nervous system.

Topics: Animals; Ascorbic Acid; Eye Diseases; Female; Ganglia, Autonomic; Herpes Simplex; Hydroxydopamines; Immunity; Mice; Mice, Inbred BALB C; Simplexvirus

Suproachoroidal fluid (SCF) obtained at the time of the surgical evacuation of a clinically significant choroidal detachment (CD) was analyzed for its chemical and cellular components in four distinct subgroups: (1) CD following cataract surgery, (2) CD (nonhemorrhagic) following glaucoma surgery, (3) CD (hemorrhagic) following glaucoma surgery, and (4) intraoperative CD during glaucoma surgery in patients with elevated episcleral venous pressure. The fluid obtained in groups 1, 2, and 4 was clear and slightly xanthochromic and contained low-molecular-weight substances in concentrations essentially equal to serum. Proteins and other high-molecular-weight substances were present in lesser amounts than in serum. Albumin, alpha1-antitrypsin, and transferrin were present in amounts approximately equal to those in serum, whereas alpha2-macroglobulin, IgM and IgG were decreased. beta-Lipoprotein and beta-complement were absent. It is postulated that this distribution of serum proteins is a manifestation of molecular sieving and is consistent with the existence of an isoporous membrane between the intravascular and suprachoroidal space with a pore diameter of 144 A. In the intraoperative choroidal effusions, there was evidence for exclusion of more of the lower, as well as all of the higher, molecular weight proteins. This suggested that the degree of molecular sieving increased with increasing filtration rate. In the hemorrhagic SCF, the distinctive character of the fluid and the protein concentrations indicated that the integrity of the capillary membrane was mardkedly disrupted, thereby allowing higher-molecular-weight proteins and cellular elements to enter the space.

Topics: Ascorbic Acid; Blood Proteins; Capillary Permeability; Choroid; Exudates and Transudates; Eye Diseases; Eye Proteins; Humans; Potassium; Sodium

Topics: Animals; Anterior Chamber; Ascorbic Acid; Chloramphenicol; Eye Diseases; Furosemide; Male; Pneumonia; Suppuration; Turtles

Topics: Administration, Topical; Animals; Ascorbic Acid; Cornea; Cortisone; Cysteine; Eye Diseases; Rabbits; Regeneration

Topics: Animals; Ascorbic Acid; Blood; Chromatography; Eye Diseases; Hexosamines; Hyaluronoglucosaminidase; Injections; Optics and Photonics; Rabbits; Sodium Chloride; Staphylococcal Infections; Viscosity; Vitreous Body

Topics: Anti-Bacterial Agents; Ascorbic Acid; Betamethasone; Eye Diseases; Gastroenteritis; Humans; Infant; Male; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Tract Infections; Vitamin B Complex

Topics: Ascorbic Acid; Eye Diseases; Flavonoids; Fundus Oculi; Humans; Papaverine; Pyridoxine; Vascular Diseases

Topics: Ascorbic Acid; Behcet Syndrome; Chorioretinitis; Dexamethasone; Eye Diseases; Female; Humans; Injections; Male; Nitrogen; Optic Neuritis; Prednisolone; Uric Acid; Vitamin B Complex

Topics: Adult; Aqueous Humor; Ascorbic Acid; Cataract; Eye Diseases; Humans; India; Lens, Crystalline

Topics: Acute Disease; Adrenal Cortex Hormones; Ascorbic Acid; Burns, Chemical; Chronic Disease; Contact Lenses; Cornea; Corneal Injuries; Edema; Eye Diseases; Glaucoma; Glucose; Glycerol; Humans; Hypertonic Solutions; Idoxuridine; Intraocular Pressure; Keratitis, Dendritic; Keratoconus; Ophthalmic Solutions; Povidone; Silicones; Sodium Chloride; Surface-Active Agents; Tears

Topics: Ammonia; Ascorbic Acid; Eye Diseases; Fundus Oculi; Humans; Riboflavin; Thiamine; Urea; Uric Acid; Vitamin B 12; Vitamins

Topics: Ascorbic Acid; Cataract Extraction; Eye Diseases; Glaucoma; Glycerol; Humans; Intraocular Pressure; Mannitol; Osmosis; Sodium; Urea

Topics: Amyloidosis; Ascorbic Acid; Conjunctiva; Conjunctival Diseases; Conjunctivitis; Deficiency Diseases; Diagnosis; Eye Diseases; Humans; Immunoglobulin Light-chain Amyloidosis; Liver Extracts; Surgical Procedures, Operative; Triamcinolone; Vitamin A

Topics: Ascorbic Acid; Drug Therapy; Eye Diseases; Gonioscopy; Hemorrhage; Hemostatics; Humans; Iris; Vitamin K

Topics: Aqueous Humor; Ascorbic Acid; Bicarbonates; Blood Chemical Analysis; Cataract; Chemical Phenomena; Chemistry; Chlorides; Eye Diseases; Glucose; Humans; In Vitro Techniques; Lactates; Manometry

Topics: Ascorbic Acid; Eye Diseases; Humans; Intraocular Pressure; Manometry; Pharmacology; Tonometry, Ocular

Topics: Ascorbic Acid; Capillaries; Cataract Extraction; Drug Therapy; Eye Diseases; Flavonoids; Hemorrhage; Humans; Hyphema; Postoperative Complications; Postoperative Period; Preventive Medicine

Topics: Ascorbic Acid; Eye Diseases; Eye Hemorrhage; Geriatrics; Hemorrhage; Humans; Scurvy

Topics: Ascorbic Acid; Cornea; Corneal Ulcer; Eye Diseases; Penicillins; Ulcer; Vitamins