Spasm
Spasms, Infantile
Hemifacial Spasm
Esophageal Spasm, Diffuse
Ergonovine
Angina Pectoris, Variant
Facial Muscles
Viburnum
Homeopathy
Asthma
Antigens, CD44
Glaucoma, Open-Angle
National Eye Institute (U.S.)
Ocular Hypertension
Ophthalmology
Exfoliation Syndrome
Bradykinin-induced bronchospasm in the rat in vivo: a role for nitric oxide modulation. (1/169)
Bradykinin has an important role in asthma pathogenesis, but its site of action is unclear. It was previously reported by the authors that bradykinin causes a dose-dependent reduction in dynamic compliance but little change in total lung resistance. This suggested that bradykinin may have a preferential effect in the distant lung. The purpose of the current investigation was to better characterize the effects of bradykinin on pulmonary resistance in rodents and explore the role of nitric oxide release in modulating the effect of bradykinin. Airway constriction was induced in the rats by aerosol administration of bradykinin with or without treatments with the inhaled bradykinin-2 receptor antagonist, Hoe 140 or the nitric oxide synthase inhibitors N(G)-nitro-L-arginine methylester or N(G)-monomethyl-L-arginine. Total lung resistance was partitioned into tissue and airway resistance by using the alveolar capsule method. Bradykinin induced a significant increase in both resistances. Hoe 140 abolished the response to bradykinin. The nitric oxide synthase inhibitors enhanced the bronchoconstricting response. In conclusion, the bradykinin response in the rats was not only localized to conducting airways but also involved a relatively selective tissue reaction. Bradykinin-induced bronchospasm in the rat is solely due to activation of bradykinin-2 receptor. Further, it was shown that nitric oxide significantly modulates the bronchospasm caused by bradykinin, suggesting that nitric oxide is an important modulator of airways responsiveness to bradykinin. (+info)Reduction of exercise-induced asthma in children by short, repeated warm ups. (2/169)
AIM: To study the effect of a warm up schedule on exercise-induced asthma in asthmatic children to enable them to engage in asthmogenic activities. METHOD: In the first study, peak flows during and after three short, repeated warm up schedules (SRWU 1, 2, and 3), identical in form but differing in intensity, were compared in 16 asthmatic children. In the second study the efficiency of the best of these SRWU schedules was tested on 30 young asthmatic children. Children performed on different days a 7 minute run alone (EX1) or the same run after an SRWU (EX2). RESULTS: The second study showed that for most children (24/30) the fall in peak flow after EX2 was less than that after EX1. The percentage fall in peak flow after EX2 was significantly correlated with the percentage change in peak flow induced by SRWU2 (r = 0.68). The children were divided into three subgroups according to the change in peak flow after SRWU2: (G1: increase in peak flow; G2: < 15% fall in peak flow; G3: > 15% fall in peak flow). Only the children in the G3 subgroup did not show any gain in peak flow after EX2 compared with EX1. CONCLUSION: The alteration in peak flow at the end of the SRWU period was a good predictor of the occurrence of bronchoconstriction after EX2. An SRWU reduced the decrease in peak flow for most of the children (24/30) in this series, thus reducing subsequent post-exercise deep bronchoconstriction. (+info)Reactive airways dysfunction and systemic complaints after mass exposure to bromine. (3/169)
Occasionally children are the victims of mass poisoning from an environmental contaminant that occurs due to an unexpected common point source of exposure. In many cases the contaminant is a widely used chemical generally considered to be safe. In the following case, members of a sports team visiting a community for an athletic event were exposed to chemicals while staying at a local motel. Bromine-based sanitizing agents and other chemicals such as hydrochloric acid, which were used in excess in the motel's swimming pool, may have accounted for symptoms experienced by the boy reported here and at least 16 other adolescents. Samples of pool water contained excess bromine (8.2 microg/mL; ideal pool bromine concentration is 2-4 microg/mL). Symptoms and signs attributable to bromine toxicity included irritative skin rashes; eye, nose, and throat irritation; bronchospasm; reduced exercise tolerance; fatigue; headache; gastrointestinal disturbances; and myalgias. While most of the victims recovered within a few days, the index case and several other adolescents had persistent or recurrent symptoms lasting weeks to months after the exposure. (+info)Regulation of baseline cholinergic tone in guinea-pig airway smooth muscle. (4/169)
1. We quantified baseline cholinergic tone in the trachealis of mechanically ventilated guinea-pigs and determined the influence of vagal afferent nerve activity on this parasympathetic tone. 2. There was a substantial amount of baseline cholinergic tone in the guinea-pig trachea, eliciting contractions of the trachealis that averaged 24.6 +/- 3.5 % (mean +/- s.e.m.) of the maximum attainable contraction. This tone was essentially abolished by vagotomy or ganglionic blockade, suggesting that it was dependent upon on-going pre-ganglionic input arising from the central nervous system. 3. Cholinergic tone in the trachealis could be markedly and rapidly altered (either increased or decreased) by changes in ventilation (e. g. cessation of ventilation; hyperpnoea; slow, deep breathing) and by lung distention (via positive end-expiratory pressure). These effects were not accompanied by marked alterations in blood gases and were abolished by vagotomy or atropine. By contrast, tachykinin receptor antagonists, which abolished capsaicin-induced bronchospasm, were without effect on baseline cholinergic tone. This and other evidence suggests that capsaicin-sensitive nerves have little if any influence on baseline parasympathetic tone. Likewise, while activation of afferent nerves innervating the larynx can alter airway parasympathetic nerve activity, transection of the superior laryngeal nerves was without effect on baseline cholinergic tone. 4. Cutting the vagus nerves caudal to the recurrent laryngeal nerves, thus leaving the preganglionic parasympathetic innervation of the trachealis intact but disrupting all afferent nerves innervating the lungs and intrapulmonary airways, abolished baseline cholinergic tone in the trachea. Sham vagotomy or cutting the vagi caudal to the lungs did not reduce baseline cholinergic tone. 5. The results indicate that baseline airway cholinergic nerve activity is necessarily dependent upon afferent nerve activity arising from the intrapulmonary airways and lungs. More specifically, the data are consistent with the hypothesis that on-going activity arising from the nerve terminals of intrapulmonary rapidly adapting receptors determines the level of baseline airway cholinergic tone. (+info)Bronchodilating effects of bambuterol on bronchoconstriction in guinea pigs. (5/169)
AIM: To study the effects of bambuterol (Bam) on bronchoconstriction in guinea pigs. METHODS: Bronchospasm induced by histamine aerosol, lung resistance (RL) and dynamic lung compliance (Cdyn) changes induced by ovalbumin aerosol in vivo, isolated resting lung parenchyma strips, and carbamylcholine-induced tracheal constriction in vitro in guinea pig were investigated. RESULTS: Bam dose-dependently prolonged the time to histamine-induced collapse, ED50 values (95% confidence limits) of Bam intragastric gavage (i.g.) after 1 h, 4 h, and 24 h were 0.74 (0.60-0.91), 0.75 (0.61-0.91) and 1.00 (0.77-1.30) mg.kg-1, respectively. Bam 2 or 10 mg.kg-1 i.g. 2 h before ovalbumin aerosol partly or almost completely inhibited bronchial challenge of ovalbumin-induced change of RL and Cdyn. Bam 0.1-1.0 mumol.L-1 gave a weak relaxation on isolated tracheal strips induced by carbamylcholine and failed to relax the isolated resting lung parenchyma strips in guinea pig. CONCLUSION: Bam showed a long-acting bronchodilation by its slow metabolism in vivo. (+info)Monosodium glutamate and asthma. (6/169)
Allen et al. (1987) conducted oral monosodium glutamate (MSG) challenges with 32 asthmatic volunteers and reported that 14 reacted to MSG. Another study by Moneret-Vautrin (1987) also reported MSG-induced asthma attacks in 2 of 30 asthmatic patients. Four additional studies have been conducted and none has confirmed the results of the above authors. These studies, by Schwartzstein et al. (1987), Germano (1991), Woods et al. (1998) and Woessner et al. (1999), challenged a total of 45 patients who gave a history of asthma attacks in oriental restaurants. None of these patients experienced asthmatic reactions after ingesting MSG (one-sided confidence interval of 0-0.066). Another 109 asthmatic patients, without a history of asthma in oriental restaurants, also did not react to ingestion of MSG (one-sided confidence interval of 0-0.027). With a confidence interval < 0.05 there is a >95% probability that MSG history-negative asthmatic patients are not sensitive to MSG. For the MSG history-positive asthmatics, 45 patients, in well-performed studies, underwent negative challenges to MSG, contrasting with two studies reporting positive challenges. Allen et al. (1987) and Moneret-Vautrin (1987), who reported positive MSG challenge results, performed studies with the following characteristics: 1) single blinded, conducted after discontinuing essential antiasthma medications; 2) used effort-dependent peak expiratory flow rate measurement of lung function; 3) added AM bronchodilators in some patients; 4) ignored wandering baselines on the placebo challenge days; and 5) conducted some challenges in the AM and some at night. In summary, the existence of MSG-induced asthma, even in history-positive patients, has not been established conclusively. (+info)Leukotriene-receptor antagonists. Role in asthma management. (7/169)
OBJECTIVE: To examine the role of leukotriene-receptor antagonists (LTRAs) in management of asthma. QUALITY OF EVIDENCE: Most data were derived from randomized, double-blind, controlled trials. MAIN MESSAGE: Leukotrienes appear to have an important role in the pathophysiology of asthma, including airway inflammation. Leukotriene-receptor antagonists are effective in improving asthma control end points, such as allergen, ASA, and exercise challenge, in clinical models of asthma. In chronic asthma, LTRA administration reduces asthma symptoms and rescue beta 2-agonist use, changes that are paralleled by improvements in lung function. Both zafirlukast and montelukast decrease circulating levels of eosinophils and could have other useful anti-inflammatory properties. Administration of LTRAs allows doses of inhaled corticosteroids to be reduced. Currently available LTRAs are free of serious side effects and are available as oral formulations. CONCLUSIONS: Leukotriene-receptor antagonists belong to a new class of asthma medication. While inhaled corticosteroids remain first-line therapy for managing chronic asthma, LTRAs should be considered for patients with ASA-sensitive asthma; as adjunct therapy when low to moderate doses of inhaled steroid alone provide incomplete control; or as adjunct therapy to allow reduction in doses of inhaled corticosteroids. (+info)Effects of fenoterol and ipratropium on respiratory resistance of asthmatics after tracheal intubation. (8/169)
We have studied the effects of a beta-agonist, fenoterol, and a cholinergic antagonist, ipratropium, on post-intubation total respiratory system resistance (Rrs) in asthmatics who developed increased Rrs after tracheal intubation. Sixteen stable asthmatics in whom Rrs increased after intubation were allocated randomly to receive either 10 puffs of fenoterol (group F) or 10 puffs of ipratropium (group IB) via a metered dose inhaler 5 min after intubation. Anaesthesia was induced and maintained with propofol i.v. Rrs was recorded before treatment and again 5, 15 and 30 min after treatment. Rrs decreased significantly from pretreatment values by mean 53 (SD 8)%, 53 (7)% and 58 (6)% at 5, 15 and 30 min, respectively, in group F, but declined by only 12 (6)%, 15 (4)% and 17 (5)% in group IB. At all times after treatment, patients in the fenoterol group had significantly lower Rrs values than those in the ipratropium group. We conclude that increased Rrs after tracheal intubation in asthmatics can be reduced effectively by treatment with fenoterol. A secondary finding of our study was that even after induction of anaesthesia with propofol, patients with a history of asthma may develop high Rrs. (+info)Bronchial spasm refers to a sudden constriction or tightening of the muscles in the bronchial tubes, which are the airways that lead to the lungs. This constriction can cause symptoms such as coughing, wheezing, and difficulty breathing. Bronchial spasm is often associated with respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. In these conditions, the airways are sensitive to various triggers such as allergens, irritants, or infections, which can cause the muscles in the airways to contract and narrow. This can make it difficult for air to flow in and out of the lungs, leading to symptoms such as shortness of breath, wheezing, and coughing. Bronchial spasm can be treated with medications that help to relax the muscles in the airways and open up the airways, such as bronchodilators and anti-inflammatory drugs.
A spasm is a sudden, involuntary contraction or tightening of a muscle, group of muscles, or a hollow organ such as the ureter or bronchi. Spasms can occur as a result of various factors including muscle fatigue, injury, irritation, or abnormal nerve activity. They can cause pain and discomfort, and in some cases, interfere with normal bodily functions. For example, a spasm in the bronchi can cause difficulty breathing, while a spasm in the ureter can cause severe pain and may lead to a kidney stone blockage. The treatment for spasms depends on the underlying cause and may include medication, physical therapy, or lifestyle changes.
Infantile spasms, also known as West syndrome, is a rare but serious type of epilepsy that affects infants typically between 4-8 months of age. The spasms are characterized by sudden, brief, and frequent muscle jerks or contractions, often involving the neck, trunk, and arms. These spasms usually occur in clusters and may cause the infant to bend forward or stretch out. Infantile spasms can be a symptom of various underlying neurological conditions and are often associated with developmental delays and regression. Early recognition and treatment are crucial for improving outcomes.
Hemifacial spasm is a neuromuscular disorder characterized by involuntary, irregular contractions or twitching of the muscles on one side of the face. These spasms typically begin around the eye and may progress to involve the muscles of the lower face, including those around the mouth.
The primary cause of hemifacial spasm is pressure on or irritation of the facial nerve (cranial nerve VII) as it exits the brainstem, often due to a blood vessel or tumor. This pressure can lead to abnormal electrical signals in the facial nerve, resulting in uncontrolled muscle contractions.
In some cases, hemifacial spasm may be associated with other conditions such as multiple sclerosis or Bell's palsy. Treatment options for hemifacial spasm include medications to help relax the muscles, botulinum toxin (Botox) injections to paralyze the affected muscles temporarily, and, in rare cases, surgical intervention to relieve pressure on the facial nerve.
Coronary vasospasm refers to a sudden constriction (narrowing) of the coronary arteries, which supply oxygenated blood to the heart muscle. This constriction can reduce or block blood flow, leading to symptoms such as chest pain (angina) or, in severe cases, a heart attack (myocardial infarction). Coronary vasospasm can occur spontaneously or be triggered by various factors, including stress, smoking, and certain medications. It is also associated with conditions such as coronary artery disease and variant angina. Prolonged or recurrent vasospasms can cause damage to the heart muscle and increase the risk of cardiovascular events.
Diffuse Esophageal Spasm (DES) is a motility disorder of the esophagus, which is the muscular tube that connects the throat to the stomach. In DES, the esophagus involuntarily and uncoordinately contracts, causing difficulty swallowing (dysphagia), chest pain, and sometimes regurgitation of food or liquids.
The term "diffuse" refers to the fact that these spasms can occur throughout the entire length of the esophagus, rather than being localized to a specific area. The exact cause of diffuse esophageal spasm is not known, but it may be associated with abnormalities in the nerve cells that control muscle contractions in the esophagus.
Diagnosis of DES typically involves a combination of medical history, physical examination, and specialized tests such as esophageal manometry or ambulatory 24-hour pH monitoring. Treatment options may include medications to relax the esophageal muscles, lifestyle modifications such as avoiding trigger foods, and in some cases, surgery.
Ergonovine is a medication that belongs to a class of drugs called ergot alkaloids. It is derived from the ergot fungus and is used in medical settings as a uterotonic agent, which means it causes the uterus to contract. Ergonovine is often used after childbirth to help the uterus return to its normal size and reduce bleeding.
Ergonovine works by binding to specific receptors in the smooth muscle of the uterus, causing it to contract. It has a potent effect on the uterus and can also cause vasoconstriction (narrowing of blood vessels) in other parts of the body. This is why ergonovine is sometimes used to treat severe bleeding caused by conditions such as uterine fibroids or ectopic pregnancy.
Like other ergot alkaloids, ergonovine can have serious side effects if not used carefully. It should be administered under the close supervision of a healthcare provider and should not be used in women with certain medical conditions, such as high blood pressure or heart disease. Ergonovine can also interact with other medications, so it's important to inform your healthcare provider of all medications you are taking before receiving this drug.
Angina pectoris, variant (also known as Prinzmetal's angina or vasospastic angina) is a type of chest pain that results from reduced blood flow to the heart muscle due to spasms in the coronary arteries. These spasms cause the arteries to narrow, temporarily reducing the supply of oxygen-rich blood to the heart. This can lead to symptoms such as chest pain, shortness of breath, and fatigue.
Variant angina is typically more severe than other forms of angina and can occur at rest or with minimal physical exertion. It is often treated with medications that help relax the coronary arteries and prevent spasms, such as calcium channel blockers and nitrates. In some cases, additional treatments such as angioplasty or bypass surgery may be necessary to improve blood flow to the heart.
It's important to note that chest pain can have many different causes, so it is essential to seek medical attention if you experience any symptoms of angina or other types of chest pain. A healthcare professional can help determine the cause of your symptoms and develop an appropriate treatment plan.
Facial muscles, also known as facial nerves or cranial nerve VII, are a group of muscles responsible for various expressions and movements of the face. These muscles include:
1. Orbicularis oculi: muscle that closes the eyelid and raises the upper eyelid
2. Corrugator supercilii: muscle that pulls the eyebrows down and inward, forming wrinkles on the forehead
3. Frontalis: muscle that raises the eyebrows and forms horizontal wrinkles on the forehead
4. Procerus: muscle that pulls the medial ends of the eyebrows downward, forming vertical wrinkles between the eyebrows
5. Nasalis: muscle that compresses or dilates the nostrils
6. Depressor septi: muscle that pulls down the tip of the nose
7. Levator labii superioris alaeque nasi: muscle that raises the upper lip and flares the nostrils
8. Levator labii superioris: muscle that raises the upper lip
9. Zygomaticus major: muscle that raises the corner of the mouth, producing a smile
10. Zygomaticus minor: muscle that raises the nasolabial fold and corner of the mouth
11. Risorius: muscle that pulls the angle of the mouth laterally, producing a smile
12. Depressor anguli oris: muscle that pulls down the angle of the mouth
13. Mentalis: muscle that raises the lower lip and forms wrinkles on the chin
14. Buccinator: muscle that retracts the cheek and helps with chewing
15. Platysma: muscle that depresses the corner of the mouth and wrinkles the skin of the neck.
These muscles are innervated by the facial nerve, which arises from the brainstem and exits the skull through the stylomastoid foramen. Damage to the facial nerve can result in facial paralysis or weakness on one or both sides of the face.
Blepharospasm is a medical condition characterized by involuntary spasms and contractions of the muscles around the eyelids. These spasms can cause frequent blinkings, eye closure, and even difficulty in keeping the eyes open. In some cases, the spasms may be severe enough to interfere with vision, daily activities, and quality of life.
The exact cause of blepharospasm is not fully understood, but it is believed to involve abnormal functioning of the basal ganglia, a part of the brain that controls movement. It can occur as an isolated condition (known as essential blepharospasm) or as a symptom of other neurological disorders such as Parkinson's disease or dystonia.
Treatment options for blepharospasm may include medication, botulinum toxin injections, surgery, or a combination of these approaches. The goal of treatment is to reduce the frequency and severity of the spasms, improve symptoms, and enhance the patient's quality of life.
"Viburnum" is not a medical term, but a genus of shrubs and small trees that belong to the Adoxaceae family. These plants are commonly known as "viburnums," and they have various uses in horticulture due to their attractive flowers, fruits, and foliage.
While there may be some medicinal uses for certain species of Viburnum, it is not a term that would typically appear in a medical context or definition. If you're looking for information about the medicinal properties of specific plants within the Viburnum genus, I would recommend consulting a reliable source on herbal medicine or speaking with a healthcare professional who has expertise in this area.
I'm sorry for any confusion, but "Lantana" is not a medical term. It is the name of a genus of flowering plants in the verbena family, Verbenaceae, that are native to tropical regions of the Americas and Africa. Some species of Lantana are popular ornamental plants due to their vibrant and showy flowers, but they can also be invasive in some areas.
If you have any medical concerns or questions, I would be happy to try to help you with those. Could you please provide more information about what you are looking for?
Homeopathy is a complementary and alternative medicine (CAM) system, developed in the late 18th century by Samuel Hahnemann, based on the principle of "like cures like." This concept suggests that a substance that causes symptoms in a healthy person can be used in very dilute quantities to treat similar symptoms in illness. The dilutions are so extreme that no molecules of the original substance remain, leading to significant controversy and skepticism over any potential therapeutic effect. Homeopathic remedies are typically made from plants, minerals, or animals, and are often highly individualized for each patient based on their specific symptoms, mental and emotional state, and overall constitution. Despite its widespread use, homeopathy lacks robust scientific evidence supporting its efficacy beyond placebo effects, and it is not considered a mainstream medical practice in most countries.
Asthma is a chronic respiratory disease characterized by inflammation and narrowing of the airways, leading to symptoms such as wheezing, coughing, shortness of breath, and chest tightness. The airway obstruction in asthma is usually reversible, either spontaneously or with treatment.
The underlying cause of asthma involves a combination of genetic and environmental factors that result in hypersensitivity of the airways to certain triggers, such as allergens, irritants, viruses, exercise, and emotional stress. When these triggers are encountered, the airways constrict due to smooth muscle spasm, swell due to inflammation, and produce excess mucus, leading to the characteristic symptoms of asthma.
Asthma is typically managed with a combination of medications that include bronchodilators to relax the airway muscles, corticosteroids to reduce inflammation, and leukotriene modifiers or mast cell stabilizers to prevent allergic reactions. Avoiding triggers and monitoring symptoms are also important components of asthma management.
There are several types of asthma, including allergic asthma, non-allergic asthma, exercise-induced asthma, occupational asthma, and nocturnal asthma, each with its own set of triggers and treatment approaches. Proper diagnosis and management of asthma can help prevent exacerbations, improve quality of life, and reduce the risk of long-term complications.
CD44 is a type of protein found on the surface of some cells in the human body. It is a cell adhesion molecule and is involved in various biological processes such as cell-cell interaction, lymphocyte activation, and migration of cells. CD44 also acts as a receptor for hyaluronic acid, a component of the extracellular matrix.
As an antigen, CD44 can be recognized by certain immune cells, including T cells and B cells, and can play a role in the immune response. There are several isoforms of CD44 that exist due to alternative splicing of its mRNA, leading to differences in its structure and function.
CD44 has been studied in the context of cancer, where it can contribute to tumor growth, progression, and metastasis. In some cases, high levels of CD44 have been associated with poor prognosis in certain types of cancer. However, CD44 also has potential roles in tumor suppression and immune surveillance, making its overall role in cancer complex and context-dependent.
Prescription drugs are medications that are only available to patients with a valid prescription from a licensed healthcare professional, such as a doctor or nurse practitioner. These drugs cannot be legally obtained over-the-counter and require a prescription due to their potential for misuse, abuse, or serious side effects. They are typically used to treat complex medical conditions, manage symptoms of chronic illnesses, or provide necessary pain relief in certain situations.
Prescription drugs are classified based on their active ingredients and therapeutic uses. In the United States, the Drug Enforcement Administration (DEA) categorizes them into five schedules (I-V) depending on their potential for abuse and dependence. Schedule I substances have the highest potential for abuse and no accepted medical use, while schedule V substances have a lower potential for abuse and are often used for legitimate medical purposes.
Examples of prescription drugs include opioid painkillers like oxycodone and hydrocodone, stimulants such as Adderall and Ritalin, benzodiazepines like Xanax and Ativan, and various other medications used to treat conditions such as epilepsy, depression, anxiety, and high blood pressure.
It is essential to use prescription drugs only as directed by a healthcare professional, as misuse or abuse can lead to severe health consequences, including addiction, overdose, and even death.
A drug prescription is a written or electronic order provided by a licensed healthcare professional, such as a physician, dentist, or advanced practice nurse, to a pharmacist that authorizes the preparation and dispensing of a specific medication for a patient. The prescription typically includes important information such as the patient's name and date of birth, the name and strength of the medication, the dosage regimen, the duration of treatment, and any special instructions or precautions.
Prescriptions serve several purposes, including ensuring that patients receive the appropriate medication for their medical condition, preventing medication errors, and promoting safe and effective use of medications. They also provide a legal record of the medical provider's authorization for the pharmacist to dispense the medication to the patient.
There are two main types of prescriptions: written prescriptions and electronic prescriptions. Written prescriptions are handwritten or printed on paper, while electronic prescriptions are transmitted electronically from the medical provider to the pharmacy. Electronic prescriptions are becoming increasingly common due to their convenience, accuracy, and security.
It is important for patients to follow the instructions provided on their prescription carefully and to ask their healthcare provider or pharmacist any questions they may have about their medication. Failure to follow a drug prescription can result in improper use of the medication, which can lead to adverse effects, treatment failure, or even life-threatening situations.
Open-angle glaucoma is a chronic, progressive type of glaucoma characterized by the gradual loss of optic nerve fibers and resulting in visual field defects. It is called "open-angle" because the angle where the iris meets the cornea (trabecular meshwork) appears to be normal and open on examination. The exact cause of this condition is not fully understood, but it is associated with increased resistance to the outflow of aqueous humor within the trabecular meshwork, leading to an increase in intraocular pressure (IOP). This elevated IOP can cause damage to the optic nerve and result in vision loss.
The onset of open-angle glaucoma is often asymptomatic, making regular comprehensive eye examinations crucial for early detection and management. Treatment typically involves lowering IOP using medications, laser therapy, or surgery to prevent further optic nerve damage and preserve vision.
Intraocular pressure (IOP) is the fluid pressure within the eye, specifically within the anterior chamber, which is the space between the cornea and the iris. It is measured in millimeters of mercury (mmHg). The aqueous humor, a clear fluid that fills the anterior chamber, is constantly produced and drained, maintaining a balance that determines the IOP. Normal IOP ranges from 10-21 mmHg, with average values around 15-16 mmHg. Elevated IOP is a key risk factor for glaucoma, a group of eye conditions that can lead to optic nerve damage and vision loss if not treated promptly and effectively. Regular monitoring of IOP is essential in diagnosing and managing glaucoma and other ocular health issues.
Ocular hypertension is a medical condition characterized by elevated pressure within the eye (intraocular pressure or IOP), which is higher than normal but not necessarily high enough to cause any visible damage to the optic nerve or visual field loss. It serves as a significant risk factor for developing glaucoma, a sight-threatening disease.
The normal range of intraocular pressure is typically between 10-21 mmHg (millimeters of mercury). Ocular hypertension is often defined as an IOP consistently above 21 mmHg, although some studies suggest that even pressures between 22-30 mmHg may not cause damage in all individuals. Regular monitoring and follow-up with an ophthalmologist are essential for people diagnosed with ocular hypertension to ensure early detection and management of any potential glaucomatous changes. Treatment options include medications, laser therapy, or surgery to lower the IOP and reduce the risk of glaucoma onset.
Ophthalmology is a branch of medicine that deals with the diagnosis, treatment, and prevention of diseases and disorders of the eye and visual system. It is a surgical specialty, and ophthalmologists are medical doctors who complete additional years of training to become experts in eye care. They are qualified to perform eye exams, diagnose and treat eye diseases, prescribe glasses and contact lenses, and perform eye surgery. Some subspecialties within ophthalmology include cornea and external disease, glaucoma, neuro-ophthalmology, pediatric ophthalmology, retina and vitreous, and oculoplastics.
Eye diseases are a range of conditions that affect the eye or visual system, causing damage to vision and, in some cases, leading to blindness. These diseases can be categorized into various types, including:
1. Refractive errors: These include myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia, which affect the way light is focused on the retina and can usually be corrected with glasses or contact lenses.
2. Cataracts: A clouding of the lens inside the eye that leads to blurry vision, glare, and decreased contrast sensitivity. Cataract surgery is the most common treatment for this condition.
3. Glaucoma: A group of diseases characterized by increased pressure in the eye, leading to damage to the optic nerve and potential blindness if left untreated. Treatment includes medications, laser therapy, or surgery.
4. Age-related macular degeneration (AMD): A progressive condition that affects the central part of the retina called the macula, causing blurry vision and, in advanced stages, loss of central vision. Treatment may include anti-VEGF injections, laser therapy, or nutritional supplements.
5. Diabetic retinopathy: A complication of diabetes that affects the blood vessels in the retina, leading to bleeding, leakage, and potential blindness if left untreated. Treatment includes laser therapy, anti-VEGF injections, or surgery.
6. Retinal detachment: A separation of the retina from its underlying tissue, which can lead to vision loss if not treated promptly with surgery.
7. Amblyopia (lazy eye): A condition where one eye does not develop normal vision, often due to a misalignment or refractive error in childhood. Treatment includes correcting the underlying problem and encouraging the use of the weaker eye through patching or other methods.
8. Strabismus (crossed eyes): A misalignment of the eyes that can lead to amblyopia if not treated promptly with surgery, glasses, or other methods.
9. Corneal diseases: Conditions that affect the transparent outer layer of the eye, such as keratoconus, Fuchs' dystrophy, and infectious keratitis, which can lead to vision loss if not treated promptly.
10. Uveitis: Inflammation of the middle layer of the eye, which can cause vision loss if not treated promptly with anti-inflammatory medications or surgery.
Exfoliation syndrome is a medical condition that affects the eyes. It is characterized by the progressive loss of the tissue that covers and protects the front part of the eye, called the cornea and the iris. This tissue is called the extracellular matrix, which is produced and maintained by the cells called fibroblasts. In exfoliation syndrome, these fibroblasts produce an abnormal protein that clumps together and forms white flakes that can be seen on the front surface of the eye. These flakes are made up of fibrillar extracellular matrix material, which is thought to come from the breakdown of the normal extracellular matrix. Over time, these flakes can build up and cause damage to the eye, leading to a variety of complications such as increased intraocular pressure, glaucoma, cataracts, and corneal endothelial decompensation.
Exfoliation syndrome is typically a bilateral disease, meaning that it affects both eyes, although one eye may be more severely affected than the other. It is also associated with an increased risk of developing glaucoma, which can lead to optic nerve damage and vision loss if left untreated. The exact cause of exfoliation syndrome is not fully understood, but it is thought to have a genetic component, as it has been found to cluster in families. Additionally, there are environmental factors that may increase the risk of developing exfoliation syndrome such as UV exposure, smoking and certain medications.
It's important to note that Exfoliation Syndrome can be asymptomatic at early stages, but regular eye examinations with an ophthalmologist is recommended for people over 40 years old or those who have a family history of the condition. Early detection and management of exfoliation syndrome can help prevent or slow down the progression of complications associated with it.