DEGENERACION MACULAR PDF
La degeneración macular asociada a la edad —también llamada degeneración macular, DMAE o DMA— constituye el deterioro de la mácula, que es la. Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the. Esta publicación es para las personas con degeneración macular relacionada con la edad y para sus familiares y amigos. Ofrece información sobre la.
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Macular degenerationalso known as age-related macular degeneration AMD or ARMDis a medical condition degenerzcion may result in blurred or no vision in the center of the visual field. Macular degeneration typically occurs in older people. Preventive efforts include exercising, eating well, and not smoking. In it affected 6. Macular degeneration by itself will not lead to total blindness. For that matter, only a small number of people with visual impairment are totally blind.
In almost all cases, some vision remains, mainly peripheral. Other complicating conditions may lead to such an acute condition severe stroke or trauma, untreated glaucoma, etc. The area of the macula comprises only about degensracion. Even though the macula provides such a small fraction of the visual field, almost half of the visual cortex is devoted to processing macular information. The loss of central vision profoundly affects visual functioning.
It is quite difficult, for example, to read without central vision. Pictures that attempt to depict the central visual loss of macular degeneration with a black spot do not do justice to the devastating nature of the visual loss.
This mcaular be demonstrated by printing letters six inches high on a piece of paper and attempting to identify them while looking straight ahead and holding the paper slightly to the side. Most people find this difficult to do. In addition, people with dry macular degeneration often do not experience any symptoms but can experience gradual onset of blurry vision in one or both eyes.
Recurrence ratios for siblings of an affected individual are three- to sixfold higher than in the general dfgeneracion. These genes have roles regulating the immune response, inflammatory processes and homeostasis of the retina. Variants of these genes give rise to different kinds of dysfunction in these processes. Over time, this results in accumulation of intracellular and extracellular metabolic debris.
This can cause scarring of the retina or breakdown of its vascularization. Genetic tests are available for some of these gene variations.
However, pathogenesis of macular degeneration is a complex interaction between genetics, environment and lifestyle, and presence of unfavorable genetic factors doesn’t necessarily predict progression to disease. The three loci where identified gene variants are found are designated:. The pathogenesis of age-related macular degeneration is not well known, although some theories have been put forward, including oxidative stress, mitochondrial dysfunction, and inflammatory processes.
The imbalance between the production of damaged cellular components and degradation leads to the accumulation of harmful products, for example, intracellular lipofuscin and extracellular drusen.
Incipient atrophy is demarcated by areas of retinal pigment epithelium RPE thinning or depigmentation that precede geographic atrophy in the early stages of AMD. In the dry nonexudative form, cellular debris called drusen accumulates between the retina and the choroid macullar, causing atrophy and scarring to the fegeneracion. In the wet exudative form, which is more severe, blood vessels grow up from the choroid neovascularization behind the retina which can leak exudate and fluid and also cause hemorrhaging.
Early work demonstrated a family of immune mediators was plentiful in drusen.
Other gene markers of progression risk includes tissue inhibitor of metalloproteinase 3 TIMP3suggesting a role for extracellular matrix metabolism in AMD progression. The early stigmata of disease, drusen, are rich in cholesterol, offering face validity to the results of genome-wide association studies. In AMD there is a progressive accumulation of characteristic yellow deposits, called drusen buildup of extracellular proteins and lipidsin the macula a part of the retinabetween the retinal pigment epithelium and the underlying choroid which is believed to damage the retina over time.
Amyloid degeneraciowhich builds up in Alzheimer’s disease brains, is one of the proteins that accumulate in AMD, which is a reason why AMD is sometimes called “Alzheimer’s of the eye” or “Alzheimer’s of the retina”. AMD-like pathology begins with small yellow deposits drusen in the macula, between the retinal pigment epithelium and the underlying choroid.
Most people with these early changes referred to as age-related maculopathy still have good vision. People with drusen may or may not develop AMD, in fact, the majority of people over age 60 have drusen with no adverse effects. The risk of developing maculad is higher when the drusen are large and numerous and associated with the disturbance in the pigmented cell layer under the macula.
Large and soft drusen are thought to be related to elevated cholesterol deposits. Early AMD is diagnosed based on the presence of medium-sized drusen, about the width of an average human hair.
Early AMD is usually asymptomatic. In late AMD, enough retinal damage occurs that people have symptomatic central vision loss in addition to drusen. The damage can either be the development of atrophy or the onset of neovascular disease. Late AMD is further divided into two subtypes degeneraciom on the types of damage: This includes early and intermediate forms of AMD, as well as the advanced form of dry AMD known as geographic atrophy. Dry AMD patients tend to have minimal symptoms in the earlier stages; visual function loss occurs more often if the condition advances to geographic atrophy.
Geographic atrophy also called atrophic AMD is an advanced form of AMD in which progressive and irreversible loss of retinal cells leads to a loss of visual function.
Neovascular or exudative AMD, the “wet” form of advanced AMD, causes deegeneracion loss due to abnormal blood vessel growth choroidal neovascularization in the choriocapillaristhrough Bruch’s membrane. It is usually, but not always, preceded by the dry form of AMD. The proliferation of edgeneracion blood vessels in the dsgeneracion is stimulated by vascular endothelial growth factor VEGF. Unfortunately, because these blood vessels are abnormal, these new vessels are fragile, ultimately leading to blood and protein leakage below the macula.
Bleeding, leaking, maculr scarring from these blood vessels eventually cause irreversible damage to the photoreceptors and rapid vision loss if left untreated.
Age-related accumulation of low-molecular-weight, phototoxic, pro-oxidant melanin oligomers within lysosomes in the retinal pigment epithelium RPE may be partly responsible for decreasing the digestive rate of photoreceptor outer rod segments POS by the RPE — autophagy. A decrease in the digestive rate of POS has been shown to be associated with lipofuscin formation — a classic sign associated with AMD. The role of retinal oxidative stress in the cause of AMD by resulting in further inflammation of the macula is suggested by the dgeeneracion rate of disease in smokers and those exposed to UV irradiation.
Mitochondrial dysfunction may play a role. Diagnosis of age-related macular degeneration depends on signs in the maculanot necessarily vision.
Additionally, early diagnosis of wet AMD can prevent further visual deterioration and potentially improve vision. Diagnosis of dry or early stage AMD may include the following clinical examinations as well as procedures and tests:. A Cochrane review found the use of vitamin and mineral supplements, alone or in combination, by the general population degenerwcion not affect whether or not AMD started.
Treatment of AMD varies depending on the category of the disease at the time of diagnosis. In general, treatment is aimed at slowing down the progression of AMD. A randomized control trial found that bevacizumab and ranibizumab had similar efficacy, and reported no significant increase in adverse events with bevacizumab. A controversy in the UK involved the off-label use of cheaper bevacizumab over the approved, but expensive, ranibizumab.
Other approved antiangiogenic drugs for the treatment of neo-vascular AMD include pegaptanib  and aflibercept. The American Academy maculae Ophthalmology practice guidelines do not recommend laser coagulation therapy for macular degeneration, but state that it may be useful in people with new blood vessels in the choroid outside of the fovea who don’t respond to drug treatment.
Photodynamic therapy has also been used to treat wet AMD. This activates the verteporfin destroying the vessels. Cataract surgery could improve visual outcomes for people with AMD, though there have been concerns about surgery increasing the progression of AMD.
A randomized controlled trial found that people who underwent immediate cataract surgery within two weeks had improved visual acuity and better quality of life outcomes than those who underwent delayed cataract surgery 6 months. Because peripheral vision is not affected, people with macular degeneration can learn to use their remaining vision to partially compensate.
Adaptive devices can help people read.
Wet macular degeneration – Symptoms and causes – Mayo Clinic
These include magnifying glasses, special eyeglass lenses, computer screen readers, and TV systems that enlarge reading the material. Also, Apple devices provide a wide range of features voice-over, screen readers, Braille etc. Video cameras can be fed into standard or special-purpose computer monitors, and the image can be zoomed in and magnified. These systems often include a movable table to move the macylar material. Accessible publishing provides larger fonts for printed books, patterns to make tracking easier, audiobooks and DAISY books with both text and audio.
The prevalence any age-related macular degeneration is higher in Europeans than in Asians and Africans. This suggests that similar pathways may be involved in the etiologies dgeeneracion AMD and other age-related diseases.
A practical application of AMD-associated genetic markers is in the prediction of progression of AMD from early stages of the disease to neovascularization.
Cell based therapies using bone marrow stem cells as well as retinal pigment epithelial transplantation are being studied. Degeheracion are a few other rare kinds of macular degeneration with similar symptoms but unrelated in etiology to Wet or Dry age-related macular degeneration.
They are all genetic disorders that may occur in childhood or middle age.
Una Mirada a la Degeneración Macular
Similar symptoms with a very different etiology and different treatment can be caused by epiretinal membrane or macular pucker or any other condition affecting the macula, such as central serous retinopathy. From Wikipedia, the free encyclopedia. Macular degeneration Synonyms Age-related macular degeneration Picture of the back of the eye showing intermediate vegeneracion macular degeneration Specialty Ophthalmology Symptoms Blurred or no vision in the center of the visual field  Complications Visual hallucinations  Usual onset Older people  Types Early, intermediate, late  Causes Damage to the macula of the retina  Mavular factors Maacular, smoking  Diagnostic method Eye examination  Prevention Exercising, eating well, not smoking  Treatment Anti-VEGF medication injected into the eye, laser coagulationphotodynamic therapy  Frequency 6.
Adeno associated virus and gene therapy of the human retina. Archived from the original on 22 December Retrieved 21 December The Cochrane Database of Systematic Reviews. Retrieved 5 November American Academy of Ophthalmology.
Clinical Interventions in Aging. American Journal of Epidemiology. Archived from the original on May 23, The New England Journal of Medicine. Archived from the original on Nacular 11, Nicholas Weedon M, ed.
A targeted inhibitor of the complement alternative pathway reduces RPE injury and angiogenesis in models of age-related macular degeneration.