Inherited Retinal Dystrophies (IRD)

Age-related macular degeneration (AMD) is a clinical condition in which there is a progressive decrease in central vision. There are two forms of macular degeneration, dry/nonexudative and wet/exudative, and these differ in fundal findings and treatment options. Dry macular degeneration is due to accumulation of drusen between the retinal pigment epithelium and Bruch’s membrane and eventually progresses to geographic atrophy. Geographic atrophy refers to loss of retinal pigment epithelium (RPE) and photoreceptors. Wet macular degeneration, comprising up to 80% of cases of macular degeneration, is due to neovascularization forming choroidal neovascular membranes, which are unstable vessels leading to an array of complications including

According to Baily and Hall, while visual impairment early in life is associated with inherited congenital disorders, abnormal fetal devepment, and problems associated with premature birth, most eye conditions are associated with aging. They claim that over 70% of the visually impaired population in the United States is over 65. Age related maculopathy, also called macular degeneration, or AMD, impairs the center of vision in older individuals. The macula is the region in the back of the retina that surrounds and includes the fovea (Goldstein 1999). It is important to understand that when this degeneration progresses enough, the condition constitutes blindness because the foveal area is what is

Three other genes make proteins that are also involved in melanin pigment formation and albinism, but the exact role of these proteins remains unknown. These genes are the P gene on chromosome 15, the Hermansky--Pudlak syndrome gene on chromosome 10, and the ocular albinism gene on the X chromosome.

     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.

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).

Genetic screening is done with RFLP analysis. RFLP stands for Restriction Fragment Length Polymorphism. RFLP analysis is used to find an identifiable pattern of fragments (an RFLP) that indicates a genetic marker. The genetic marker is unique and is inherited in all people with a disorder or disease. The RFLP comes from a strand of DNA near a suspected gene location that has been cut with a restriction enzyme into smaller pieces. The pieces of DNA are separated using gel electrophoresis into their distinctive bands. The RFLP is a distinctive pattern of the fragments in the gel. All people with the disorder or disease have the RFLP pattern, it is written in stone or in this case, DNA. DNA bands are studied to determine if a person has a disease, is a carrier, has no prior deposition to the disease, or if they will develop the disease in the future. A detailed human map is being developed by scientists worldwide who are contributing information to the human genome project. The human genome project is an attempt to map out every gene on every chromosome of the human genome. It is going slowly, but growth in knowledge of the genome is growing exponentially every year. Along with the growth, we are accumulating knowledge about more

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).

hereditary disorder of Caucasians in the United States and is the most common cause of chronic

Age-related macular degeneration also known as AMD is a disease leading to severe vision and legal blindness in the elderly population. I will address the health condition description and the disability and functional implications who suffer from this disease.

The reading shows disease and inheritance in an entirely new light. It introduces the idea that genetically inherited diseases may have been selected for, which means that they must provide certain evolutionary advantages. It reorients the reader’s perspective about a disease like hemochromatosis, which has the potential to be incredibly harmful and even deadly, establishing that it may have once provided protection from the bubonic plague, making it an advantageous trait. This brings other genetic diseases into question, examining why diseases that appear to be harmful have not been eliminated from the gene pool. The idea that a disease that is harmful and dangerous in modern times could have once been a beneficial adaptation is very interesting.

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.

screenings in multiple populations, it was concluded that the most common mutation shared between Caucasians is R864X.

Visual imparity is one of the biggest epidemics in the modern world affecting an estimated 285 million people worldwide (WHO, 2014). Of theses 285 million people, roughly 39 million of them are completely blind. Blindness is a ‘debilitating sensory impairment’ according to Lorach(2014), which can limit a person’s ability to perform everyday tasks and can hugely affect their quality of life. Most of the diseases causing visual impairments, such as cataract can be surgically treated. However, some pathologies cannot be treated with existing treatments or medications. Retinitis pigmenstosa (RP) is an example of such pathology. RP is an inherited eye disorder in which light-receiving photoreceptor cells (rods and cons) degenerate. The photoreceptor

This paper considers that focused primarily on human iris. This choice of this topic was made due to interest of wanting to provide knowledge about the factors that determine eye color. I know, like hair or skin, brown eyes are dominant over blue eye genes. I also know that a person can be identified by the retina scanners because everyone has their iris with unique structural patterns.

Prematurity is the main risk factor for RDS. Other risk factors associated with RDS include maternal diabetes, multiple gestation, elective cesarean delivery without labor, Caucasian race, male sex, precipitous delivery, and perinatal asphyxia. Factors associated with decreased risk for RDS include chronic hypertension, pre-eclampsia, chorioamnionitis, and prolonged rupture of membranes.