Physiopathology of the Eye with Cataracts - Research Paper Example

Cataracts Cataracts are normally clouding of the usually clear lens of a person’s eye. Thus for the victims of this eye anomaly, seeing through lens that are cloudy is more like looking through a window that is fogged-up or frosty. The lens is a very clear section of the eye, which assists in the focusing of an image or light onto the retina. The retina is that tissue at the back of a person’s eye that is light sensitive. In an eye that is normal, light passes via the transparent lens onto the retina. Once at the retina, light is usually converted in the form of nerve signals which are transmitted to the brain for interpretation. This therefore means that the lens must be very clear for the retina to be able to receive an image that is sharp. If however the lens is cloudy from the formation of cataract, the image seen will be blurred (Caldwell, 1988). The functioning of the eye is just like that of a camera. Thus there is passage of light rays in the eye through the cornea first and then the aqueous humor (which is a fluid that is transparent in front of the eye), and then via the pupil and finally into the lens. The light rays are then bent onto the retina which lines the back of one’s eye. From this point, the image then passes via the retinal cells, and onto the optic nerve, and eventually onto the back of the brain which finally processes the image. Cataracts will therefore occur when there is protein buildup in the lens which makes it appear cloudy. This leads to the prevention of light from passing clearly via the lens, thus leading to loss of an individual’s vision. There is formation of new lens cells outside the lens, leading to the compacting of all the older cells at the middle of the lens, which results into a cataract (WebMD Medical Reference).Most cataracts start developing when an injury or age causes a change into the tissue that forms the lens of a person’s eye. Under normal circumstances, the lens is usually positioned behind the pupil and the iris and works just like the lens of a camera. Its main function is to focus light onto the retina and at the eye’s back, where the recording of an image takes place. The lens is also responsible for the adjustment of the eye’s focus, making sure that we are able to see things clearly, both those that are far away and upclose.The lens is composed of protein and water. The protein is naturally arranged precisely in a manner that always keeps the lens in a clear form and allows passage of light through it. Old age may however cause the clumping together of the protein, which may lead to the clouding of a small portion of the lens. This therefore is the cataract, which may overtime grow bigger clouding more part of the lens and finally making it difficult to see (Caldwell, 1988). Causes of cataracts Some cataracts may result due to genetic orders that are inherited, causing other health complications and leading to an increase in the risk of cataracts. Cataracts can also be as result of other eye conditions and medical conditions such as diabetes, past surgery of the eye and trauma. Cataracts too can develop due to long-term usage of steroids. A cataract thus forms on the lens which is positioned behind the iris, which is the colored part of the eye. The lens is responsible as we said before for focusing of light that goes through the eye, leading to production of clear and sharp images at the retina which is a membrane that is light sensitive and functions just like a camera’s film. A cataract will therefore scatter the light going through the lens, which prevents a well defined image reaching the retina. This is what makes the vision to be blurred. As a person grows old, the lenses in the eyes grow less flexible, less thick and transparent. Changes related to age cause tissues within and around the lens to break down, thus clumping together and clouding tiny areas inside the lens.Surprisingly,the cataracts are not totally symmetrical which implies a cataract in one eye could be more advanced than on the other. Cataracts that are age-related usually affect an individual’s vision in the following two ways; Clumping of proteins leads to the reduction of the sharpness of the image appearing at the retina. The lens is made up of protein and water. Clumping of proteins leads to the clouding of lens leading to the reduction of light that appears at the retina. This clouding could become so severe leading to blurred vision. Majority of the age-related cataracts mostly develop from the clumping of protein. If the cataract is small, only a small section of the lens will be affected by cloudiness and a person may not even notice any change in his or her vision. Cataracts mostly tend to grow gradually and thus the vision worsens slowly. Over a period of time, the cloudy part in the lens gets larger, making the cataract to increase in size. Seeing at this point becomes very difficult and the person’s vision gets more blurred and dull. The lens may slowly change to a brownish/yellowish color, making the vision to have a brownish tint. The clear lens thus becomes gradually colored with age, leading to the vision acquiring a shade that is brownish. At the start, the tinting may be small and may not necessarily cause problem in vision. As time passes by, increased tinting makes it difficult to read and carry out other activities that are routine. This slow change in tinting does however not affect the image sharpness transported to the retina. Those that have advanced discoloration of the lens may fail to identify purples and blues (Shulman, 1995). The phrase “age-related” may be misleading a little bit. You do not necessarily have to be a senior citizen for you to get this kind of cataract. People in their 40s and 50s can have a cataract that is age-related. However during mid-age, majority of cataracts are small and don’t affect vision much. It is only after the age of 60 that most cataracts steal vision. The risk of getting cataracts thus increases as one gets older. Cataracts have got other several risk factors which include; diseases such as diabetes, personal behaviors like alcohol use and smoking and the environment where one is, such as prolonged sunlight exposure, ionizing radiation exposure such as cancer radiation therapy and X-rays, previous surgery of the eye, high blood pressure, family history of having cataracts, obesity and excessive drinking of alcohol. There are a number of cataracts which include: Cataracts affecting the center or middle of the lens/nuclear cataracts. This type of cataract causes one to become very nearsighted and even experience an improvement that is temporary in one’s reading vision. However as time goes, the lens slowly turns densely yellow further clouding one’s vision. As the cataract progresses slowly, the lens could also turn brown. Advanced browning or yellowing of the lens could make it difficult to distinguish between various shades of color. Cataracts affecting the back of the lens (posterior subcapsular cataracts).This type of cataract begins as a tiny, opaque portion that mostly forms near the back of the lens, exactly at the light’s path to the retina. This cataract causes interference with one’s reading vision, reduces one’s vision in bright light and may cause halos or glare around lights during the night. Cataracts one is born with (congenital cataracts)-some individuals may be born with cataracts or develop them while growing up. Such cataracts could be due to the mother having gotten infected while pregnant. These cataracts could also be as a result of certain conditions like galactosemia, myotonic dystrophy, and rubella or Lowe’s syndrome. Congenital cataracts do not affect vision always, however when they do, they are mostly removed immediately after being detected (Caldwell, 1988). Prevention, Risk factors, symptoms and detection of cataracts Cataracts can be prevented or delayed by wearing a hat with a brim and sunglasses to block the dangerous ultraviolet rays from the sun. Quit smoking if you are a smoker. Good nutrition can also aid in reduction of the risk of getting age-related cataract. Researchers recommend the eating of green leafy vegetables, foods containing anti-oxidants and fruits. Those over sixty should make sure that they get a comprehensive dilated exam of the eye, at least after every two years. A person’s eye care professional should check for any other signs of age-related macular degeneration, glaucoma and other related vision disorders. It is important to note that early diagnosis and treatment of several eye diseases may save one’s sight .The following are the most common known symptoms of cataract; having a blurry or, having a cloudy vision and poor night vision, seeing colors as if they are faded, getting multiple or double visions in one of the eyes, frequent changes in prescription of one’s contact lenses or sunglasses, having glares whereby lamps, sunlight and headlights appear to be very bright. These symptoms could also be an indication of various other eye conditions and problems. There are a number of comprehensive eye tests that can be done to detect a cataract. These include; Visual acuity test-this eye chart exam involves measurement of how well one sees at different distances. Dilated eye test-This involves placing drops in a person’s eyes to dilate or widen his/her pupils. The eye care professional makes use of a special magnifying lens to make an examination of one’s optic nerve and retina for any signs of injury, damage or any other eye problems. Tonometry is an instrument that measures the pressure inside of the eye. It involves use of numbing drops which may be applied to one’s eye for this particular test (Coleman, Morrison, 2005). Treatment of cataracts “Treatment of patients with both cataracts and glaucoma requires diagnostic skill and keen clinical judgement.Ophthalmologists treating these patients must decide whether to recommend surgery and, if so, they must determine the timing of the surgery, the type of procedure to perform, and details of the surgical approach. Recent experience suggests a trend toward greater use of combined cataract and glaucoma procedures in older individuals in the USA.In the US Medicare population aged 65 years or older, there were approximately 51900 combined cataract and trabeculectomy procedures performed between 1996 and 1999 compared with 28080 trabeculectomies only.” (Coleman, Morrison, 2005). Surgery thus involves the removal of the cloudy lens and having it replaced with lens that is artificial. A cataract should only be removed when the loss of vision may cause interference with one’s daily activities which may include reading, driving or even watching television. This decision can be arrived at by the patient and his or her ophthalmologist. Once the patient understands the risks and benefits of the surgery s/he can make a decision that is informed about whether surgery is the right one for him/her. There is no need of rushing into surgery. There are times when a cataract should be removed even if it does not cause any problems to one’s vision. For instance, a cataract ought to be removed if it’s preventing treatment or examination of another eye condition or problem which includes macular degeneration that is age-related or diabetic retinopathy. If a doctor discovers a cataract in an individual, it’s not a must that s/he undergoes a cataract surgery for many years. In deed someone might never even need a cataract surgery in the long run. Having one’s vision tested regularly, and having discussions ophthalmologist can determine when and if any kind of treatment is required. For those who choose surgery, their doctor could refer them to a specialist who will remove the cataract. For those who have both eyes affected by cataracts and that require surgery, their surgery can be performed on one eye per time at different periods, usually between four to eight weeks apart. Several people that require cataract surgery usually have other eye problems and conditions like macular degeneration which is age-related or glaucoma. There are usually two main kinds of cataract surgery which include; phacoemulsification, or phaco-which is a procedure that involves making of a small incision on cornea’s side which is the dome-shaped clear surface which covers the front part of the eye. The second kind of surgery is extracapsular surgery which involves the making of a longer incision on cornea’s side and removal of the cloudy core of the lens all in one piece (Coleman, Morrison, 2005). Finally the National Eye Institute is in the process of conducting and supporting several studies whose focus is factors related with development of cataracts that are age-related. These studies are the effect of exposure to sunlight, which may is related to an increased cataract risk, vitamin supplements, which have indicated varying results, delaying the progress of cataract and eventually genetic studies, which indicate promise to better understand development of cataract.Meanwhile,cataracts are not life-threatening and if detected early, somebody’s sight can be saved. Work cited Coleman L .Anne, Morrison C. John. Management of Cataracts and Glaucoma. New York: Taylor and Francis Group, 2005. Caldwell R.Delmar. Cataracts. New Orleans: Raven Press, 1988. Shulman, Julius. Cataracts:From Diagnosis to Recovery-The Complete Guide For Patients and Families. New York: St.Martins Griffin, 1995. http://www.webmd.com/eye-health/cataracts/health-cataracts-eyes http://www.mayoclinic.org/diseases-conditions/cataracts/basics/treatment/con-20015113 https://www.nei.nih.gov/health/cataract/cataract_facts.asp Read More