Essay On Choroidal Reflexion

For the health condition description of age-related macular degeneration I will discuss the etiology, onset, prevalence rate, body systems, body structures, and associated deficits that come and are associated with this disease. “AMD is the degradation of the cells at the center of the retina which is the layer of tissue at the back of the eye that registers light. The macula is responsible for ventral vision, which enables us to read, drive, participate in sports, and do anything else that requires focusing directly ahead. Macular degeneration distorts the heart of the vision field” (Macular degeneration, 1998). Sunlight and smoking are both influences of the onset of AMD (Age-related Macular Degeneration (AMD), 2014). It is suggested to avoid intense bright sunlight which may help reduce the retinal degeneration. Hats, sunglasses and any other accessories that can help protect the eyes from the sun are suggested. Cigarette smoking has also been linked to increasing the risk of developing AMD and it is recommended that persons should stop smoking to decrease their chance of developing AMD (Age-related Macular Degeneration (AMD), 2014). AMD does not develop until the sixth or seventh decade of life, although early

As humans, we don't always see with our eyes, but often with our imagination (Grunwald, 2016). Often times as people we never realize how useful our vision really is to us. You really don't think about something like that until it would actual happen to you. Throughout this essay, you will learn how the body is affected by Macular Degeneration (MD). Different signs and symptoms, as well as the etiology of MD, will be discussed. In the following, diagnosis tests and treatments may also be listed in order to help others who would like to know more about MD. Not to mention, you will learn the incidence and progression of MD. Furthermore, information though agencies and associations, as well as new research about MD will be given.

How does the progression of optic nerve and RGC damage translate to the clinical symptoms of glaucoma? In a study published by Harwerth and Quigley in 2006, the structure-function relationships of human glaucoma and experimental glaucoma in monkeys are compared, in order to discern a possible correlation between the progressive loss of visual field experienced by glaucoma patients and the gradual neural losses. Previous studies had suggested a large amount of variance between the well-defined relationship of experimental glaucoma and the slightly different system of clinical glaucoma, but the discrepancies could have equally resulted from different methods of data analysis, which would affect the precision of the results. The study compared

Age-related macular degeneration (AMD) is a common cause of irreversible blindness in the elderly. AMD is characterized by the progression from early to intermediate stages of the disease. The two major advanced forms are the geographic atrophy (GA) AMD and neovascular AMD. GA or “dry” AMD is characterized by loss of retinal pigment epithelium (RPE) cells and outer layers of the neurosensory retina as well as the choriocapillaris. Neovascular or "wet" AMD is characterized by the formation of choroidal neovascularization (CNV), the ingrowth of new blood vessels from the choriocapillaris through Bruch's membrane into the sub pigment epithelium or subretinal

Macular degeneration is the second most common cause of blindness in people over the age of 50, and it is frequently related to the aging process. It is a disorder of the retina where the cells of the macula degenerate until only the periphery vision remains. Women, Caucasians, and Asian Americans seem to be more vulnerable when compared to males, Mexican Americans, and Africans. Macular degeneration specifically effects individuals ability to read, recognize people’s faces, choose clothes, view pictures, and to play or view sports. Age-related macular degeneration is divided into the three categories of early, intermediate, or advanced. 70%-90% of age-related macular degeneration are caused by the early category. It is characterized by the

According to Vaughan & Ashbury’s General Ophthalmology, Glaucoma is characterized by the “optic disc cupping and visual field loss, usually associated with elevated intraocular pressure.” "In open-angle glaucoma, there is an imbalance in the production and drainage of the aqueous humor (clear fluid between the cornea and the lens) that fills the eyes anterior chamber." (Berdahl, John) In certain situations, too much aqueous is produced by the ciliary body inside the eye; and in other situations the drainage channels in the anterior chamber become impassable. Whichever the cause, the result is that the pressure inside the eye increases to perilous levels. When intraocular pressure increases, the pressure pushes harder against the nerve fibers of the optic nerve, which conveys visual information to the brain.

Patients with age-related macular degeneration may not notice any symptoms at first. The first noticeable sign is a gradual, or sudden, change in the quality of vision depending on which type of AMD is occurring. Straight lines will start to appear distorted (Kozarsky, 2017). Early dry AMD is diagnosed by the presence of drusen. This gradually can cause a dramatic loss of the center of vision. In the intermediate stage of AMD, the beginnings of vision loss are apparent, but there still may not be any other noticeable symptoms. At this time, optometrists will test for larger drusen and pigment changes in the retina (“Research into the Genetics of Macular Degeneration,” 2017). Other symptoms of age-related macular degeneration might include an

NPDR is the early stage of diabetic retinopathy. At this point, the blood vessels behind the retina have already started leaking blood or fluid, but the person may not actually notice any vision problems yet. Eventually people with NPDR can develop macular edema or macular ischemia and experience severe vision loss.

For each patient, the automated visual field tests were obtained by Humphrey Field Analyzer and optic disc images by Topcon fundus camera. Horizontal and vertical cup-to-disc ratios were calculated by a manual, planimetric technique. Mean deviation (MD) and pattern standard deviations (PSD) were documented.

According to Friedman, progress in the effort to stop or prevent AMD will be slow until the cause is learned. He claims retinal pigmant epithelium damage to be the prominant theory explaining the choroidal circulation changes that lead to AMD. Although Friedmal himself does not subscribe to this theory, other researchers do and use it as a basis for study. Grunwald, Harisprasad, Dupont, M. G. Mguire, Fine, Bruker, A.M. Maguire, and Ho compared choroidal blood flow in subjects with AMD to a control group. They used laser doppler flowmetry to asess the volume, velocity, and flow of blood in the center of the fovea. Ten subjects with no drusen (cellular debris) were compared to 20 subjects with ten or more large drusen. The average visual acuities of the two groups was very close. No significant differences between age, blood pressure, or intraocular pressure was revealed between the subjects. Spraul, G. E. Lang, Grossnik laus, and G. K. Lang questioned the validity of the study. They claim doppler flowmetry to be an imperfect method for such a study because of multiple light scattering properties of the tissue. They also

     Basically what my research is stating is that there is a major genetic component that contributes to this disease. There are three general types of hereditary Macular Degeneration. The first is called early onset. This is when you get it when you are four years of age up to seven. In this type both parents and their children can be affected. This means it is dominantly inherited. Most of the time this is called Best Disease or Viteliform Macular Degeneration.

This patient was subsequently seen on 8 occasions (over 3 decades) and, with time, the initially normal eye (OD) gradually showed signs of RP-like retinal degeneration. The purpose of this study was to evaluate which clinical modality (visual field, funduscopy or electroretinography) could have first predicted this fate. Design: Long-term longitudinal study. Subjects: 155 control subjects and this unique RP patient. Methods: Normative data was compared with the results from the patient for each modality. Z-tests were used to assess the statistical significance for each test and time point. Linear regressions were used to assess the rates of changes in both eyes. Main outcome measures: Visual field areas, retinal blood vessel diameters, amplitude and energy (wavelet analysis) of scotopic and photopic ERGs, time to reach significant outcome (in years) and rate of change. Results: At the initial visit, all tests were significantly altered (p<0.05) faster in OD. Overall (i.e. average of all the rates of change assessed), the ERG parameters degenerated 4.53 times faster in OD than OS. The progressive retinal degeneration associated with RP is known to usually cause an exponential decay (where the risk of cell death remains more or less constant or decreases

Better understanding of glaucoma, requires assessment of the different components incorporate ,retinal nerve fiber layer (RNFL), and, and visual function. On the other hand, elevated intraocular pressure, are not only risk factor of glaucoma .RNFL thickness measured by optical coherence tomography (OCT) is a reliable early marker of glaucoma[1,2]. As the pathogenesis of glaucoma involves the degeneration of axons as well as cell bodies and dendrites, The primary site of axonal damage in glaucoma is thought to be the lamina cribrosa , based on findings from previous studies [3-5] ,which thought to be via several mechanisms, including mechanical damage, [6]compromised vascular supply, [7] and increased translaminar pressure gradient[8]. The main load-bearing tissue of the eye is the sclera and its deformations due to the IOP changes are transmitted to the optic nerve head (ONH). ONH cupping in glaucoma is thought to be a combination of the two components – prelaminar and laminar cupping [9]. Clinically, glaucomatous optic nerve damage is diagnosed by the deepening and extension of the optic cup ,with dimension of the neuro-retinal rim [10]. The anterior and posterior surface of the LC is well visualized on the OCT, and this may be used in understanding glaucomatous changes [11]. Optical coherence tomography is a method of using low-coherence interferometry to scan through the layers of the retina with very high axial resolution (3 to 15 μm) , for imaging disorders affecting

With the increasing ageing population around the world, it has become a major public health concern with the number of cataract cases increasing at the same rate (Mukesh, Le, Dimitrov and Ahmed, 2006).(ref 2)

The disease has a predictable progression, advancing from the initial non-proliferative DR (NPDR), which can be asymptomatic, to the end-stage proliferative type (PDR). The rate and onset of progression is variable, as it is affected by blood pressure and blood sugar levels1. The features of NPDR include: microaneurysms, haemorrhages and exudation. Additionally PDR involves neovascularisation, resulting in vision loss. Diabetic macular oedema (DME) is also a cause of vision loss. Thickening of the retina at the macula can occur at any stage of DR, leading to blurred or distorted central vision1.