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It is also called "arcus adiposus", "arcus juvenilis" (when it occurs in younger individuals), "arcus lipoides corneae" or "arcus cornealis"; sometimes a "gerontoxon".
Arcus senilis is an old age syndrome where there is a white, grey, or blue opaque ring in the corneal margin (peripheral corneal opacity), or white ring in front of the periphery of the iris. It is present at birth but then fades; however, it is quite commonly present in the elderly. It can also appear earlier in life as a result of hypercholesterolemia. Arcus senilis can be confused with the limbus sign, which reflects calcium rather than lipid deposits.
Non-surgical treatments of FCED may be used to treat symptoms of early disease. Medical management includes topical hypertonic saline, the use of a hairdryer to dehydrate the precorneal tear film, and therapeutic soft contact lenses. Hypertonic saline draws water out of the cornea through osmosis. When using a hairdryer, the patient is instructed to hold it at an arm's length or directed across the face on a cold setting, to dry out the epithelial blisters. This can be done two or three times a day. Definitive treatment, however, (especially with increased corneal edema) is surgical in the form of corneal transplantation. The most common types of surgery for FCED are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), which account for over half of corneal transplants in the United States.
More speculative future directions in the treatment of FED include in-vitro expansion of human corneal endothelial cells for transplantation, artificial corneas (keratoprosthesis) and genetic modification. Surgery where the central diseased endothelium is stripped off but not replaced with donor tissue, with subsequent Rho-Associated Kinase (ROCK) inhibition of endothelial cell division may offer a viable medical treatment.
A greater understanding of FED pathophysiology may assist in the future with the development of treatments to prevent progression of disease. Although much progress has been made in the research and treatment of FED, many questions remain to be answered. The exact causes of illness, the prediction of disease progression and delivery of an accurate prognosis, methods of prevention and effective nonsurgical treatment are all the subject of inquiries that necessitate an answer.
Increased attention must be given to research that can address the most basic questions of how the disease develops: what are the biomolecular pathways implicated in disease, and what genetic or environmental factors contribute to its progression? In addition to shaping our understanding of FED, identification of these factors would be essential for the prevention and management of this condition.
Few studies have examined the prevalence of FCED on a large scale. First assessed in a clinical setting, Fuchs himself estimated the occurrence of dystrophia epithelialis corneae to be one in every 2000 patients; a rate that is likely reflective of those who progress to advanced disease. Cross-sectional studies suggest a relatively higher prevalence of disease in European countries relative to other areas of the world. Fuchs' dystrophy rarely affects individuals under 50 years of age.
Lenticonus (/len·ti·co·nus/ (len″tĭ-ko´nus)) [lens + L. conus, cone] is a rare congenital anomaly of the eye characterized by a conical protrusion on the crystalline lens capsule and the underlying cortex. It can reach a diameter of 2 to 7 mm. The conus may occur anteriorly or posteriorly. If the bulging is spherical, instead of conical, the condition is referred to as "lentiglobus". It produces a decrease in visual acuity and irregular refraction that cannot be corrected by either spectacle or contact lenses.
Biomicroscopically "lenticonus" is characterized by a transparent, localized, sharply demarcated conical projection of the lens capsule and cortex, usually axial in localization. In an early stage, retro-illumination shows an «oil droplet» configuration. Using a narrow slit, the image of a conus is observed. In a more advanced stage associated subcapsular and cortical opacities appear. Retinoscopically the oil droplet produces a pathognomonic scissors movement of the light reflex. This phenomenon is due to the different refraction in the central and the peripheral area of the lens. Ultrasonography also can illustrate the existence of a "lenticonus". A-scan ultrasonography may reveal an increased lens thickness and B- scanultrasonography may show herniated lenticular material, suggestive of a lenticonus. Amblyopia, cataract, strabismus and loss of central fixation may be observed in association with lenticonus posterior. Cataract, flecked retinopathy, posterior polymorphous dystrophy and corneal arcus juvenilis may be encountered in association with lenticonus anterior that occurs as a part of the Alport syndrome.
Exist two distinct types of "lenticonus" based on the face of the lens affected.
The disorder is treated by strictly reducing the intake of foods rich in plant sterols (e.g., vegetable oils, olives and avocados). However, dietary therapy is often never fully sufficient to control this disease since plant sterols are constituents of all plant-based foods. Statins have been used, and while these lower cholesterol levels and may ameliorate atherosclerotic disease, plant sterol levels are insufficiently lowered by their use alone.
If dietary treatment alone is insufficient, bile acid-binding resins (e.g., cholestyramine, colestipol) could be considered. In October 2002, a new cholesterol absorption inhibitor, ezetimibe, received US Food and Drug Administration (FDA) approval for use in sitosterolemia. This drug is now the standard of care, as it blocks sterol entry and can be used in combination with bile-acid resins.
Finally, ileal bypass has been performed in select cases to decrease the levels of plant sterols in the body, though this therapy was undertaken prior to the advent of ezetimibe.
According to a survey in 2002, alternative medicine was used in an attempt to treat cholesterol by 1.1% of U.S. adults. Consistent with previous surveys, this one found the majority of individuals (55%) used it in conjunction with conventional medicine.
A review of trials of phytosterols and/or phytostanols, average dose 2.15 g/day, reported an average of 9% lowering of LDL-cholesterol. In 2000, the Food and Drug Administration approved the labeling of foods containing specified amounts of phytosterol esters or phytostanol esters as cholesterol-lowering; in 2003, an FDA Interim Health Claim Rule extended that label claim to foods or dietary supplements delivering more than 0.8 g/day of phytosterols or phytostanols. Some researchers, however, are concerned about diet supplementation with plant sterol esters and draw attention to lack of long-term safety data.
For those at high risk, a combination of lifestyle modification and statins has been shown to decrease mortality.
Homozygous FH is harder to treat. The LDL receptors are minimally functional, if at all. Only high doses of statins, often in combination with other medications, are modestly effective in improving lipid levels. If medical therapy is not successful at reducing cholesterol levels, LDL apheresis may be used; this filters LDL from the bloodstream in a process reminiscent of dialysis. Very severe cases may be considered for a liver transplant; this provides a liver with normally functional LDL receptors, and leads to rapid improvement of the cholesterol levels, but at the risk of complications from any solid organ transplant (such as rejection, infections, or side-effects of the medication required to suppress rejection). Other surgical techniques include partial ileal bypass surgery, in which part of the small bowel is bypassed to decrease the absorption of nutrients and hence cholesterol, and portacaval shunt surgery, in which the portal vein is connected to the vena cava to allow blood with nutrients from the intestine to bypass the liver.
Lomitapide, an inhibitor of the microsomal triglyceride transfer protein, was approved by the US FDA in December 2012 as an orphan drug for the treatment of homozygous familial hypercholesterolemia. In January 2013, The US FDA also approved mipomersen, which inhibits the action of the gene apolipoprotein B, for the treatment of homozygous familial hypercholesterolemia. Gene therapy is a possible future alternative.
Given that FH is present from birth and atherosclerotic changes may begin early in life, it is sometimes necessary to treat adolescents or even teenagers with agents that were originally developed for adults. Due to safety concerns, many physicians prefer to use bile acid sequestrants and fenofibrate as these are licensed in children. Nevertheless, statins seem safe and effective, and in older children may be used as in adults.
An expert panel in 2006 advised on early combination therapy with LDL apheresis, statins, and cholesterol absorption inhibitors in children with homozygous FH at the highest risk.
Around 80 cases have been reported in the literature worldwide, hence this condition appears to be relatively rare. More than likely, sitosterolemia is significantly underdiagnosed and many patients are probably misdiagnosed with hyperlipidemia.
Cystocele may be mild enough not to result in symptoms that are troubling to a woman. In this case, steps to prevent it from getting worse.These are:
- smoking cessation
- losing weight
- pelvic floor strengthening
- treatment of a chronic cough
- maintaining healthy bowel habits
- eating high fiber foods
- avoiding constipation and straining
For treatment of type II, dietary modification is the initial approach, but many patients require treatment with statins (HMG-CoA reductase inhibitors) to reduce cardiovascular risk. If the triglyceride level is markedly raised, fibrates (peroxisome proliferator-activated receptor-alpha agonists) may be preferable due to their beneficial effects. Combination treatment of statins and fibrates, while highly effective, causes a markedly increased risk of myopathy and rhabdomyolysis, so is only done under close supervision. Other agents commonly added to statins are ezetimibe, niacin, and bile acid sequestrants. Dietary supplementation with fish oil is also used to reduce elevated triglycerides, with the greatest effect occurring in patients with the greatest severity. Some evidence exists for benefit of plant sterol-containing products and omega-3 fatty acids.
Treatment options range from no treatment for a mild cystocele to surgery for a more extensive cystocele. If a cystocele is not bothersome, the clinician may only recommend avoiding heavy lifting or straining that could cause the cystocele to worsen. If symptoms are moderately bothersome, the doctor may recommend a pessary, a device placed in the vagina to hold the bladder in place. Treatment can consist of a combination of non-surgical and surgical management. Treatment choice is also related to age, desire to have children, severity of impairment, desire to continue sexual intercourse and other diseases that a woman may have.
Testing the general population under the age of 40 without symptoms is of unclear benefit.
In France, Aymé, "et al." (1989) estimated the prevalence of Fryns syndrome to be 0.7 per 10,000 births based on the diagnosis of 6 cases in a series of 112,276 consecutive births (live births and perinatal deaths).
Fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome that is usually lethal in the neonatal period. Fryns (1987) reviewed the syndrome.
Fumagillin has been used in the treatment.
Another agent used is albendazole.
Microsporidiosis is an opportunistic intestinal infection that causes diarrhea and wasting in immunocompromised individuals (HIV, for example). It results from different species of microsporidia, a group of microbial (unicellular) fungi.
In HIV infected individuals, microsporidiosis generally occurs when CD4+ T cell counts fall below 150.