Jackson, Jefferson, Klecka, Castillo Retinitis Pigmentosa Jackson, Jefferson, Klecka, Castillo

Retinitis Pigementosa (RP) RP refers to a group of inherited disease causing retinal degeneration. Retinal degeneration

Symptoms Decreased vision or in low light Loss of side (peripheral) vision, causing “tunnel vision” Loss of central vision (in advanced cases) Symptoms often first appear in childhood, but serve lost do usually develop until early childhood.

Decreased vision at night Night Vision Problems: Halos, Blurred vision, and Night Blindness

Peripheral vision

Loss of central vision

Causes RP can run in families Disorder can be caused by genetic defects Cells controlling night vision are called “rods” Retinal cone cells are damaged the most The eye contains two types of Photoreceptors. Rods and cones, Rod are the most numerous of the photoreceptors some 120 million, are not sensitive to color. They are responsible for our dark-adapted, or scotopic vision. Rods are incredibly efficient photoreceptors be triggered by individual photons under optimal conditions. Optimum dark adapted vision s obtained only after a considerable period of darkness, say 30 minutes or longer, because rod adaptation process is much slower than that of cones. Rod sensitivity is shifted toward shorter wavelengths compared to daylight vision accounting for the growing apparent brightness of green leaves in twilight. Rods are better motion sensors. Predominate in the peripheral vision, that peripheral vision is more light sensitive, enabling you to see dimmer objects in your peripheral vision. Cones: 6 to 7 million cones can be divided into “red” cones 64%, “green” cones 32%, and blue cones (2%) They provided the eye’s color sensitivity The green and red cones are concentrated in the fovea centralis The blue cone have the highest sensitivity and are mostly found outside the fovea, leading to some distinctions in the eye’s blue perception Cones are less sensitive to light than the rods, as a typical day night comparison. The daylight (cone vision) adapts much more rapidly to changing light levels, adjusting to a change like coming indoors out of sunlight in a few seconds. Like all neurons, the cones fire to produce an electrical impulse on the nerve fiber and then must reset to fire again. The light adaption I though to occur by adjusting their reset time. Cones are responsible for all high resolution vision. The eye moves continually to keep the light from the object of interest falling on the fovea centralis where the bulk of the cones reside

Exams and test Color vision Retina by ophthalmoscopy after pupils been dilated Fluorescein angiography Intraocular pressure Measurement of electrical activity (electroretinogram) Pupil reflex test Retinal photography Refraction test Retinal Photography Side vision test (visual field test) Slit lam examination Visual acuity Ophthalmoscopy is an examination of back part of the eye (fundus), which includes the retina, optic disc, choroid, and blood vessels. Fluorescein angiography is an ye test that uses a special dye and camera to look at blood flow in the retina and choroid the two layers in the back of the eye. Electroretinogram is a test to measure the electrical response of the eye’s light-sensitive cells, called rod and cones, These cells are part of the retina (the back part of the eye) Refraction test is an eye exam that measures a person's prescription for eyeglasses or contact lenses Retinal photography by taking a high – resolution pictures inside the eye, we can use a digital imaging system to record a detailed photo of the retina. Side vision test the visual field refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point. Slit lamp examination looks at structures that are at the front of the eye. Visual acuity is used to determine the smallest letters you can read on a standardized chart (snellen chart) or a card held 20 feet away. Special charts are used when testing at distances shorter than 20 feet. Test can be found one medlineplus medical encyclopedia

Treatments Gene Therapy Stem cell research Eye implants Pharmacology and medicines Docosahexaenoic acid (DHA) Vitamin A antioxidants Gene therapy theory behind gene therapy is to treat the disease by repairing the abnormal gene. This is achieved by replacing the disease causing faulty gene with a “normal” copy into an individual’s cells. The most successful method to deliver the gene to the cells s by using a virus that has been genetically modified to carry human DNA. The eye has proven to be an ideal organ for gene therapy as it is well protected from the body’s immune response, and these early successes will pave the way in the near future for treatments for both inherited and non - inherited forms of blindness. Stem cell research stem cells are produced in the body that have the remarkable potential to develop into many different cell types in the body during early life and growth, in addition, in many tissues they serve as sort of internal repair systems, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential either to remain s stem cell or become another type of cell with a more specialized function, such a muscle cell, a red blood cell, or a brain cell. Eye implants implant technology involves the use of microelectronics and microchip electrodes surgically implanted into the back of the eye 9reina0 to restore the function of the damaged light-activated cell found there. These photoreceptors cells respond to light and convert it to an electrical single which is passed to nerve cells in the eye, and then ultimately to the brain where is it perceived as vison. Pharmacology and medicines Neuroprotection Anti – Apoptotic Agents Anti- Oxidants Anti – Vascular agents All treaments listed above can be found at fightingblindness.ie Docosahexaenoic acid (DHA) which is a long chain omega 3 fatty acid commonly found in fish to slow the progression of the disease. Vitamin A may slow diease by taking in high dose of vitamin A can cause serious liver problems.

Genetic mutations that could cause RP Autosomal recessive Autosomal dominant X linked Autosomal recessive parents carry the gene but have no symptoms themselves. They could have some children who are affected and others who are not, Autosomal dominant an affected parent could have affected and unaffected children. X link only the males are affected, the females carry the gentic trail but do not experience serious vision losss