Retinitis Pigmentosa Essay

A medical definition of vision impairment is a sine qua non that prohibits 20/20 vision in one or both eyes (Bowman, Bowman, Dutton & Royal National Institute for the Blind, 2001; Vision Australia, 2015; Webster & Roe, 1998). Examples of vision impairment include, cataracts, which has the lens inside the eye increasingly cloudy; albinism, which is passed down genetically affecting clear vision and causes sensitivity to bright light; optic nerve damage, which affects field of vision as those nerves controlling vision are disrupted; macular degeneration, where parts of the retina that control colour and fine details are affected; retinitis pigmentosa, which is an ongoing reduction of the field of vision available and nystagmus, where the eye flickers involuntary (Bowman, Bowman, Dutton & Royal National Institute for the Blind, 2001; American Foundation for the Blind, 2015; Vision Australia, 2015 ; Baton Rouge Regional Eye Bank, 2015). John suffers from retinitis

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.

Roi1 is also known as rough eye and it is a dominant mutation which causes abnormal patterns and genomic inversions in the D.melanogaster eye (Chanut et al. 2002). The recombination map location of the Roi1 is 2-54.7. The gl3 is an allele and the Gl1 is a protein for the gl gene, also known as glass, both are located at 3-63.1. The gl gene is known to reduce the size of the adult D. melanogaster eye. Even though the gl3 is a weak allele for the glass gene it produces a really pigmented eye ( Ma et al. 1996). The rh1 gene is known as rhodopsin; the recombination map location is at 3.66.4. Rh1 causes degeneration of the D. melanogaster retina (Kristaponyete et al. 2012). Rho1 also known as the rhomboid gene, is closely related to the roughed (ru); which happens to be a recessive eye mutation (Wasserman

To understand the diverse causes of RP, a basic understanding of visual perception is required. Phototransduction (conversion of light to electrical signals) occurs first, which is initiated by two types of photoreceptors: rods and cones. These two types vary in their function as rods are primarily responsible for night vision and lack sensitivity to color while cones function in color vision. Light contacts these photoreceptors, and isomerizes a retinaldehydechromophore (retinal) which is bound to varying types of opsin proteins corresponding in their reactivity to different wavelengths of light. Upon absorption of a photon of light, the chromophore 11-cis-retinal is isomerized to the all-trans confirmation, which subsequently causes a series of molecular interactions which ultimately result in the electrical response of the photoreceptors (Vugler 2010). As 11-cis-retinal is required to absorb photons of light, this compound must be regenerated, a function that is performed with the aid of nearby cells of the retinal pigment epithelium

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.

Rett syndrome is considered one of the autism spectrum disorders. Rett syndrome is a developmental disability disorder resulting in severe mental and physical deficits in female children. Rett syndrome is grouped as a pervasive developmental disorder (PDD) in which conditions are severe and pervasive, and that begin in early life and influence multiple areas of development. Rett syndrome, including the age of onset and the severity of symptoms, varies from child to child. Before the symptoms begin, however, the child generally appears to grow and develop normally, although there are often subtle abnormalities even in early infancy, such as loss of muscle tone (hypotonia), difficulty feeding, and jerkiness in

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

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.

Couple 3 comes into your office. The husband is color blind; the wife is heterozygous for the color-blindness allele.

Red-green colorblindness is usually inherited in an X-linked recessive way and it affects an approximated 6 percent of men in the world. This means that, the disorder is usually passed to the affected persons through the X chromosomes thus making the condition to be experienced more by men than

     Macular Degeneration is a problem in the part of the eye that controls your sharpest central vision. It is a group of diseases that result in a loss of detailed vision. The brain will not just leave the spot empty, so it learns to fill it in with spotty macular cell damage. People most of the time don't tell their doctors (opthalmologists) about it until it is well in advance.

The gene carrying the defect that produces albinism is recessive, which means that both parents must carry this recessive gene in order to produce a child with the condition. When both parents carry the gene (and neither has albinism), there is a one in four chance with each pregnancy that their child will have albinism. The inheritance pattern of ocular albinism is alittle different. This condition is X-linked, meaning that the recessive gene for ocular albinism is located on the X chromosome. X-linked ocular albinism appears just about only in males who inherit the condition from their mothers.

Patients with retinitis-pigmentosa are implanted with electrode arrays, which, when stimulated, create the perception of vision. Initially, I test to screen candidates for eligibility based on their light perception ability. If deemed eligible, I carry out device calibration and visual-function testing post-implantation. Active communication within the team is imperative throughout this process. Initially, the research coordinator identifies candidates and establishes a project timeline.

Small lentigines ≤ 5 mm well defined, brown to black in color and could be widely distributed

4. Retinitis pigmentosa is a visual disorder that affects the photoreceptors in your brain. This disease refers to a group of inherited diseases that affect the photoreceptor cells responsible for capturing images from the visual field. These cells line the back of the eye in the region known as the retina. People with this disease experience their vision beginning to fade; because the two types of photoreceptor cells - rod and cone cells - die. Rod cells are found all throughout the retina, and they also aide in night vision. Cone cells can also be found throughout the retina, however they are concentrated in the center of the retina and are used for things like reading and seeing color.