The study proposed herein aims to accomplish the following: To determine the optimal exposure, gamma, contrast, and brightness corrections necessary to increase the perceived contrast of images by individuals affected by Retinitis Pigmentosa (RP) and to determine the optimal image overlay of input signals corrected at both high and low thresholds such that perceived contrast is maximized. Additionally, this study will develop an I/O system of minimal necessary size responsible for image processing following image acquisition from micro cameras that will output post-processed image data onto small, high resolution LCD/LED screens contained in a wearable binocular device similar to commercially available home theater glasses. Lastly, this study aims to expose a cohort of individuals affected with Retinitis Pigmentosa to a series of images, environments, and scenes typically difficult for RP affected individuals to observe and distinguish due to color similarities and decreased contrast and brightness; and subsequently assess the effectiveness of the wearable prosthesis based on the accuracy of object identification both with and without the device.
SIGNIFICANCE:
Vision loss affects millions of people worldwide. According to a 2002 survey by the World Health Organization (WHO), approximately 37 million individuals worldwide are totally blind, with 124 million having low vision. The WHO defines low vision and blindness as varying degrees of loss of visual acuity and visual field loss, relative to the better eye, with optimal correction. Blindness affects both genders, with individuals over 50 comprising 82% of the blind population. Causes of blindness vary, with approximately 60% being due to cataract and refractive errors which are...
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...and RP1 (Ziviello 2005). More complex mechanisms for RP development have been suggested, such as mutations in carbonic anhydrases. Because photoreceptors have high metabolic needs, acidic metabolites resulting from aerobic and anaerobic respiration, such as lactic acid, are produced in large quantities by these cells, and as such necessitate removal to maintain pH homeostasis (Alvarez 2007). This is inherently troublesome due to the avascular nature of the retina. This function is instead performed by the choriocapilaris, and is reliant upon the activity of multiple enzymes such as carbonic anhydrase four (CA4). CA4 thereby helps to maintain pH homeostasis which is critical to the health and proper functioning of the photoreceptors, with CA4 mutations compromising this regulatory ability, resulting in photoreceptor degeneration, and subsequently RP (Alvarez 2007).
Optometrists have accepted vision therapy, which is a medical treatment for optical muscle disabilities, as a feasible treatment used for eye related problems; claiming the treatment can strengthen vision and give the patient the opportunity to understand visuals quicker and clearer (Press). Vision therapy originated in the 1950s and over the past 25 years, has gained popularity, mainly because of new technological innovations in the field of treatment. Generally, vision therapy is prescribed as a measure mainly for people between the ages of 3 and 18. With the results from a comprehensive series of eye tests, the optometrist can work with the patient using special instruments—prisms, filters, occluders, and eye lenses—and strengthen the eye muscles, thus improving sight. According to optometrists in favor of vision therapy, these methods of treatment using these instruments function as safer routes to repair eye disabilities. Although vision therapy can yield favorable results, the practice as a treatment for innate eye disabilities has been in hot debate lately; as it can exceed $8000 and insurance companies do not cover the treatment. For decades, insurance companies have refused to accept vision therapy as a legitimate method for repairing eyesight (Boink). Concomitant with lack of insurance, the cost for a full treatment can exceed $8000, and doctors cannot guarantee a successful outcome. Recently, parents of children with eye related disabilities, such as amblyopia (lazy eye) and strabismus (cross-eye), and doctors have attempted to cooperate with public schools to allow families access to school-funded doctors to practice vision therapy. With a tight budget, most schools cannot afford to supply vision therapy, and a...
Rett syndrome is a postnatal neurodevelopmental disorder that mainly affects girls but is rarely found in boys as well. Rett syndrome strikes all racial and ethnic groups, and occurs worldwide in 1 of every 10,000 female births. It was first identified by Dr. Andreas Rett, an Austrian physician who described it in an article published in 1966. Even though Rett described the disorder in his 1966 article it went another 17 years until being generally recognized after Swedish researcher Dr. Bengt Hagberg published an article about the disorder in 1983 (Rett Syndrome Fact Sheet).
Age related macular degeneration (AMD) is the leading cause of blindness in people over the age of 50. Every ten years after the age of 50 the prevalence of this disease increases exponentially. Many different factors contribute to the development of AMD including genetic, environment, and metabolic functions. Aside from smoking, abnormal blood pressure, and an unhealthy diet low in fruits and vegetables, many more studies are concluding that similar inflammatory and oxidative processes seen in other age related diseases are also playing a key role in the development of AMD. This disease affects the central areas of the retina and choroid. In return central vision is impaired while peripheral vision is usually not lost. AMD is seen in two different forms, the earlier nonneovascular (dry) type and the more advanced neovascular (wet) type. Each form has its own specific pathology and unique characteristics that set them apart. Fatty, protein deposits called drusens may be the key risk factor in understanding dry AMD pathology, progression, and treatment. Once the more advanced wet AMD is diagnosed, pathology and treatment are targeted around the formation and destruction of abnormal blood vessels, characteristic of the wet AMD eye. The increasing prevalence of AMD has influenced more investigation into what factors can be modulated to prevent the onset or to stop the progression of AMD. Early diagnosis is very important because this is when an eye doctor can spot the early signs of the disease through ultrasound or angiography. This text will discuss the pathology of drusens and the role of inflammation and oxidation in the aged eye. By better understanding these processes more effective treatment approaches and preventive...
Results suggested that subjects who were hyperopic had the most limited lateral peripheral vision. Their average range was 20.25 degrees less than the average 20/20 control of 150 degrees. (Figure 1). Myopic subjects also had less range but not to the same extent. The average range was 12 degrees less than the control. This indicates that myopic and hyperopic subjects do not have the same range of peripheral vision as the average 20/20 vision human, hyperopia most significantly.
Retinitis pigmentosa is caused by damage to the retina of the eye. The retina is the light sensitive layer of tissue at the back of the eye. The retina focuses images in the brain and then sends them via electrical signals up to the brain. The retina is a very important part of the eye to help a person see. What is affected in the retina from this disorder are the rods in the eye. The rods allow a person to see in the dark. Retinitis pigmentosa slowly causes the rods in the eye to deteriorate over time. Retinitis pigmentosa also can cause the cones in people’s eyes to deteriorate. If a person’s cones deteriorate first, then the person first develops blindness in the center of their eye and they lose some of their color vision. This form of retinitis pigmentosa is much rarer than the form that deteriorates the rods in the eyes.
Rett syndrome is a progressive neurological disorder that affects almost exclusively in females. The most basic symptoms include decreased speech, cognitive disabilities, severe lack of muscle control, small head size, and unusual hand movements. A woman with a mutation in her MECP2 gene, has a 50% risk with any pregnancy to pass on her X chromosome with the mutation. It is not common for women with Rett syndrome to have children because the severity of the disorder. The mutated gene on the X chromosome that is responsible for causing Rett syndrome is the methyl CpG-binding protein 2, MECP2 gene. The gene makes a protein that controls other genes. When a mutation occurs in the MECP2, the protein it makes does not work properly. This is thought to counteract normal neuron, nerve cell development. The severity of the syndrome in females is related to the type of mutation in the MECP2 gene and the percentage of cells that carry a normal copy of the MECP2 gene. Rett syndrome is believed to affect all ethnic groups and nationalities with an equal frequency of about 1 case for every 10,000 to 15,000 live female births.
The paper that I’m writing is on Rett Syndrome. Rett is a rare and severe ‘girls only” form of autism. What is Rett you ask? Well it is neurodevelopment that is found in girls. If you are diagnosed with it they can feel overwhelmed, there is no cure for this disease. You are normally diagnosed with it in the early years (first 2 years of life). There are 4 stages of Rett 1 being the least dramatic case and 4 being the severe. The disorder was identified by Dr. Andreas Rett in 1966, but was not until 1983 when it was started to be researched by Dr. Bengt Hagberg. Apraxia is perhaps the most severely disability of Rett Syndrome that interfering with movement and speech, and eye sight.
The high percentages of individuals who endure this impairment justifies and practically demands future research because the causes are not fully understood. The need for future research can be better emphasized if those with normal vision try to empathize with victims of macular degeneration. One can only imagine how frustrating it must be to receive sensatrions only in the periphery of the retina. Because the macula encompassed the cone rich fovea, which is used to focus on objects, the fovea degenerates as well. This occurence inables individuals to interpret the sensations they experience. Reading, ...
Rett syndrome is a neurological disorder that mainly affects females. According to “The Molecular Pathology of Rett syndrome: Synopsis and Update”, it states that the disorder starts to be recognizable when the child is between six to eighteen months of age. The affected child will loose their ability to speak and hand movements. Through research, MECP2 is in the X chromosome gene (2006). An estimate of females that suffer from Rett syndrome is 1 in 1,000 and in the United States, it is approximately 16,000 young and adult females that are affected (Rett Syndrome, 2008). In my paper, I will give a brief history of how Rett syndrome was first noticed, discuss the dysfunction in the brain, the development and behavior, and possible treatments.
Life revolves around being able to see things. Although individuals who are blind can lead a full and happy life, someone with excellent vision who suddenly loses theirs or notices a decrease in their visual acuity over time may find it difficult to adapt. Thankfully, with the help of an optometrist, individuals can actively work to preserve their vision for as long as possible. Phoenix Eye Care must be a priority for all, as advanced technology allows threats to the eyes to be detected as the earliest stage. The right treatment can help to slow or stop the progression before major issues develop. For this reason, every individual needs to undergo routine eye exams.
Optic nerve atrophy is a debilitating condition that in almost all cases leads to blindness or near blindness. According to the American Association for Pediatric Ophthalmology and Strabismus (2014), the disease is classified as “mild to severe damage to the optic nerve that can adversely affect central vision and color vision” (“Optic nerve atrophy,” para. 2). What is even more devastating is that there is no known cure for the disease – the damage caused to the eye by optic nerve atrophy cannot be undone. In order to treat the disease, the only option is “limiting further optic nerve damage (if possible),” (“Optic nerve atrophy,” para. 5). For those with optic nerve damage as a result of the disease, if vision has not been completely lost, co...
Glaucoma is a group of eye disorders that cause blindness by hurting the optic nerve, which is the large nerve that is responsible for vision. In glaucoma, the optic nerve damage is related to a change in the fluid pressure that circulates around the eyeball. In many cases, Glaucoma occurs when the eye's fluid pressure is high, but it can also occur when the pressure is measured as normal.
Robert, a 65 year-old male, has trouble reading fine detail, especially out of his central vision. He complains that his vision is blurred and that it is harder to see while operating a motor vehicle. In addition, sometimes objects appear wavy or crooked, which impairs his vision. His worst symptoms were that he occasionally lost the ability to distinguish between the features of familiar faces and he had a localized blind spot. Robert is not alone; many people suffer from symptoms related to loss and distortion of the visual field. He suffers from macular degeneration, the leading cause of decreased vision loss in the United States, especially for people over the age of 50 (Philippi, 2000).
Bowser and Reed [1995] as cited by Bryant et al [1998] argue that as a child progresses through the Education System, their requirements change and this may necessitate a need for different devices. This is not limited to those children with a physical disability but is relevant to all children with SEN as they progress and the Education System places additional burdens upon them. For children with a visual impairment ICT can provide support in various ways; tools to support communication, to improve access to information and as a means of producing learning materials in alternative. There is a wide range of devices and software, which can