The eye is an organ that provides an organism with the ability to visualise its surroundings. It captures light and transmits the information to the brain to be processed. The eye is composed of numerous components that give rise a complex structure. These components have specific roles and ensure that the eye functions properly. However, the eye can lose its function through the degeneration of several tissues which may lead to permanent blindness, giving rise to diseases like age-related macular degeneration (AMD), Stargardt disease (SD) and Retinitis pigmentosa (RP) [12-14].
All three above mentioned diseases are generally classified as retinal degenerative diseases (RDDs) and eventually results in the damage and loss of photoreceptor(PR)
Retinitis Pigmentosa (RP) is one of such currently untreatable causes of blindness. RP, along with Age Related Macular Degeneration (AMD) are amongst the more frequent causes of blindness in the developed world (Greenwald 2009), while RP itself is the leading cause of inherited blindness (Palanker 2004).
Age-related macular degeneration (AMD) is the leading cause of blindness for people 60 years of age and older in the developed world. Vision loss is caused by the destruction of the cone photoreceptors, located in the macula, that are responsible for color/central vision. The underlying cause of AMD is the loss of the monolayer of pigmented epithelial cells located just below the photoreceptors, known as the retinal pigmentum epithelium (RPE). The main role of the RPE is to maintain the function of the photoreceptor layer by secreting nutrients, absorbing stray light, and recycling debris used during the visual cycle. As a person ages the efficiency of the RPE layer is diminished causing a build up of toxic by-products. These toxic build-ups, known as drusens, result in the separation and death of the photoreceptor and RPE layers. AMD is speculated to result from as many as 20 different genetic mutations and as a result there is no known cure for the disease (CITE), but recent advances in stem cell therapy is a hopeful step in the right direction.
Macular Degeneration is a disease of the eye that gradually causes loss of a person’s central vision. Approximately 1.75 million Americans suffer from vision loss associated with the disease (All About Vision 1). The leading cause of blindness in people over the age of 60, Macular Degeneration, exists in two types (National Eye Institute 1). Both the wet and dry versions of the disease have similarities in risk factors, but differ in symptoms and treatments.
To understand how macular degeneration affects the eye, we must first know how the eye itself functions and why it is important to have the macula intact. A heathy eye is made of different layer that helps people to see colors, movement and to see images plainly. The macula is part of the retina, the retina is
The research topic I will be introducing is Age-Related Macular Degeneration. This has been classified as a degenerative disorder that distresses the macula in one’s eye. AMD is unfortunately a common illness that individuals over 65 suffer from and that is a central cause vision loss. AMD doesn’t have a set disease pathway, in some individuals it advances slowly so that loss of vision does not arise for a long time. The disease can also advance much quicker and may lead to lack of vision in either or both eyes. The disease begins a blurry area near the center of one’s vision which grows larger and larger possibly causing a blank space in the eye (Boyd, 2013). Research is being done on AMD because it is a prevalent illness and has extreme consequences.
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
Retinitis pigmentosa is a group of inheritable diseases that is characterized by gradual deterioration of the photoreceptors in the retina. The photoreceptor cells in the retina, rod cells, are light sensitive cells that are able to sense low levels of light. The frequency of retinitis pigmentosa is one in four thousand births (Deng et al., 2015; Fahim et al., 2012; Haddad et al., 2016; Shu et al., 2012) People affected by retinitis pigmentosa will typically exhibit symptoms of night-blindness first, and this will precede a loss in the patient’s visual acuity field that starts from the outer edge and gradually moves inward resulting in a much smaller visual field and loss of peripheral vision, also known as tunnel vision (Haddad et al., 2016).
The development of the human body is an exquisite process that involves numerous complicated processes for even the smallest of body parts, including the eyes. The eyes are an extraordinarily complex organ capable of gathering information through refracted light and sending it the brain to assemble a picture. They provide the ability to see and follow a moving object and the capability to tell an approximate distance of an object. When light passes through the cornea and iris pupil, at the anterior portion of the eye, it is focused by the lens onto the retina at the back of the eye. Photoreceptor cells, which are present in the retina, detect the light and send information to interneurons which begin to sort out the information. This information is then sent to ganglion cells which transmits the final information to the brain (Sowden 199). Because the eyes have such complicated and exquisite processes, the likelihood of developmental errors occurring are possible. A large number of these developmental errors lead to congenital defects and abnormalities that effect the individual’s eye sight. Some of these defects and abnormalities can cause serious diseases and syndromes that effect more than just the eyes, but also neurological processes, facial dimorphisms, growth failure, tracheal development, and genitalia anomalies.
Glaucoma is a form of progressive optic neuropathy that has clinically visible structural damage at the ONH and RNFL that correlates to a functional VF deficit1-4. These glaucomatous structural changes include thinning or notching of the NRR, bayonetting of vessels, loss of RNFL,
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.
Glaucoma is a progressive optic neuropathy characterized by degeneration of retinal ganglion cells, cupping of the optic nerve heads and visual field defects often related to elevated intraocular pressure. Glaucoma affects 70 million people worldwide, and constitutes the second largest cause of bilateral blindness in the world [1]. Primary open angle glaucoma (POAG) is a multifactorial neurodegenerative disease. Both genetic and environmental factors are thought to contribute to the pathophysiology of the disease. Glaucoma is a complex clinical trait and its inheritance has been shown to follow both Mendelian and non-Mendelian models [2].
Inherited retinal dystrophies (IRD) are a unique group of disorders associated with the retina of the eye that manifest in various phenotypes due to underlying genetic variations. IRDs are categorized based on the retinal dysfunction’s primary locality (photoreceptor cells or retinal pigment epithelium), pattern of inheritance (autosomal dominant or recessive, X-linked,), genetic determinant and progression rate. IRDs are a highly heterogeneous group with over 250 genes studied so far (RetNet; https://sph.uth.edu/Retnet/sum-dis.htm). Due to the overlaying genetic make-up between these disorders, genes are associated to multiple phenotypes that are significantly variable. Thus, the complexity of IRD hinders definitive clinical diagnosis.1
The war against human blindness has been ongoing affair since the beginning of time. Because the origin of blindness varies from case to case, there is no single remedy and limited solutions are available to the visually impaired. However, recent technological breakthroughs have allowed scientists and doctors to test out possible solutions to a particular niche in the blindness spectrum: degenerative retinal diseases. Degenerative retinal diseases such as Retinitis Pigmentosa (RP) attack the retina exclusively. Because of that exclusivity, the other structures in the eye are typically not compromised. Therefore, the use of a retinal implant or prosthetic device to restore functional “vision” is possible. While it is important to note that retinal implants are still a pioneering technology, clinical trials such as the Argus II clinical trial, and eye health care professionals alike are reporting promising results. As such, it seems likely that retinal prosthetic devices will be a game-changer in the future treatment of degenerative retinal diseases since the devices can restore a form of vision to an otherwise blind patient.
I chose to do the retina because of two reasons. First, I have eye problems and I thought it would be interesting to learn a little-bit more about the eye because of my eye problems. Second,
Ocular manifestations in SLE are quite common and can sometimes be vision threatening. They may also often be the first manifestations of the disease.(2,3) SLE can affect any part of the eye and visual pathway. Also, some ocular manifestations can result from the use of some drugs in the treatment of SLE like hydroxychloroquine and steroids.