Cataracts Essay Sample
A cataract refers to an eye disorder causing the eye's lens to be opaque and cloudy hence reducing the vision. The lens is the clear part which helps to focus the right rays entering the eye into the retina which is sensitive to light and is located at the back of the eye. In order to function properly, the parts that are in front of the retina have to be transparent to allow a sharp image that fall on the Retina (Andrew, 2000). For a clear resolution by the eye, all parts must coordinate appropriately so that the electrical response that is carried to the brain can be clearly interpreted. When an eye is suffering from cataracts, the lens is cloudy and the image that falls on the retina is blurred and this causes poor resolution hence a blurred vision. The extent to which the vision is blurred depends on the degree of cloudiness occurring in the lens. Cataracts show symptoms of reduced vision and affected eye appears whitish than normal. The treatment of cataracts depends on the visual requirements of every patient and sometimes may extend to surgery level.
Most cases of cataracts have been related to the age factor though other causes are possible. The disorder is more common in the elderly and statistics have proven that by the age of 80 years, more than 40% suffer from cataracts and this condition worsens as the age increases. A cataract may occur on either one of the eye or both (Andrew, 2000). Though the disorder is not contagious, individuals suffering from a one eye cataract have high chances of suffering from it on the other eye. Cataracts do not cause unusual tears in the eye and in addition to not being painful; the disorder is also not itchy. Among the aged, the disorder causes blindness if not attended to in time and with proper instruments.
Cataracts can fall under a number of classifications. Depending on its location in the lens, these may be subdivided into Lenticular, Capsular and Capsulo-lenticular which may be imperfect or confined into a portion of the eye. The extent to which clouding has occurred on the lens and also by its cause (Scott, 2005). Capsular opacity in the eye does not start in the center but at the membrane margin sometimes proceeding regularly towards the center forming a shiny satin appearance. In other cases, it may spread irregularly over the membrane surface causing a dull white opacity that is unequal in intensity. The human eye lens is round shaped and it has both the front part (anterior) and a back part (posterior) (Andrew, 2000). The central part of the lens is known as the nucleus and the outer part is the capsule. Between nucleus and the capsule lies another lens part, the cortex.
Clouding of the eye lens may happen in the nucleus only and it is termed as nuclear cataract. In situations where clouding occurs in the cortex only, it is known as a cortical cataract. If the clarity loss of the lens occurs predominantly in the capsule, it is termed as subcapsular cataract. The clouding location on the lens is also referred to as posterior or anterior, peripheral or central. It is also possible for the clouding to affect different portions simultaneously on the lens. Cataracts that are age related are referred to as senile and that affecting younger people mostly occurs in the posterior subcapsular. The degree of opacity of the lens defines the extent of the cataract as either mature or immature (Andrew, 2000).
The lens is comprised mostly of protein and water. The proteins are aligned in a specific manner keeping the lens clear and allowing light to penetrate such that a clear image is focused onto the retinal surface. Due to aging, some protein ends up clumping together clouding a small region of the lens. Continued clouding of the proteins on the lens makes it harder to see through. Also opacity of the lens may occur due to inflammation which may arise from wounds on the lens hindering the transparency that is required for a clear image to be observed. Cataracts as a result of an injury may appear and fail to increase in intensity (William, 2010).
Inflammation of the lens may also occur without resulting from wounds or injuries and this can lead to partial or complete opacity. Cerebral vessels mainly those of eye globe may also congest generally and this is a possible cause of Cataracts. Secondary cataracts may also result from changing the protein of the lens, resulting visual blurredness or complete visual loss. Surgery of the eye resulting from other conditions is a possible cause for cataracts. Exposure to ionizing radiation exemplified by X-rays and infrared radiations excessively can also lead to secondary cataracts (Andrew, 2000).
Persons suffering from diabetes are more predisposed to secondary cataracts. This is also associated with the eye inflammatory disorders like the Iritis and the Uveitis which can result to or speed cataract development in the eye involved. Also, there are genetic diseases that are associated with secondary cataract development and include the myotonic dystriophy, homocystinuria downsyndrome among others (William, 2010). Some medications, those commonly used for a wide variety of conditions, when taken for a long time may result to secondary cataracts. It is possible for a baby to be born with clouding in the lens either in one or in both eyes. This can be genetically transferred or disorders acquired during intrauterine development of the baby. Some skin diseases and membrane mucous are related with occurrence and development of cataracts.
Dimness of vision is among the initial symptoms that someone suffering from cataracts observes. This is characterized by misty and clouded figures at advanced stages. Others perceive distant objects more clearly than those that are close though this is commonly attributed to advancing years and might change. The changes in symptoms with time are associated with opacity originating from the center of the lens, such that as the pupil gets contracted. It becomes more blocked by the opaque material, while if dilated, light rays will still pass through the transparent small circumference part that enhances resolution (Scott, 2005). Normally it is difficult to notice early symptoms of cataracts. As the condition becomes intense and advanced, the clarity decreases and may exceed levels correctable by glasses. Loss of sensitivity to contrast where one observes a color being less vivid is a sign in the advanced stage. Scattering of the light in the eye may lead to observation of an uncomfortable glare.
Cataracts may form without experiencing other disease in the eye hence one is unable to arrest any symptoms and this gives the disorder a developing space and would only be discovered accidentally after the sight is impaired (Scott, 2005). Loss of capability to judge distances is a common symptom and is commonly experienced when one eye is adversely affected such that if affects vision (Andrew, 2000). Some types of cataracts cause objects to seem distorted, twisted out and irregular. However severe a cataract is, it should not encumber one from sensing light rays as opposed to total blindness. One is always in a position to distinguish light from darkness and can sense when something opaque is passed through. Cataracts however do not cause disturbances or alter the structure of the eye. People closely and frequently interacting with someone suffering from cataracts in both eyes can notice that the person is appears to have an unusual behavior in observation or is not seeing as well as previously. To a new person or an untrained observer, unless the condition has reached maturity level or the eye appears white, it is difficult to notice. In such circumstances, the pupil which normally appears to be black, will seem white or grey the observer (William, 2010).
In diagnosing different forms of cataracts, physicians who are trained in examining such conditions can detect visually diminished acuity in an affected eye or eyes. In a striated cataract, a patient’s vision is never improved by any form of dilation of the pupil. This is due to the fact that, the disorder originates from the from the edges instead of starting from the center of the lens thus making its margin most blocked from light and hence fail to transmit light rays as compared to the center. During the initial stage, the hard lenticular cataract causes the opacity to be concentrated in the central region of the lens which appears greyish in color and upon examining, it seems to lie deeper than in a normal situation due to the lens surface retaining transparency. When both the lens and the capsule are opaque, the base of the opacity reflects light rays from the surface. This causes a shiny satin like and irregularly opaque appearance. This can also be described as chalk-like though it its transparency is not completely lost and can allow the color of the lens to be identified (Scott, 2005).
In glaucoma the pupils mobility is significantly impaired if not completely. In its early stage the deeply seated opacity is usually limited to a small spot that appears to shift its location depending on the direction of light rays that are admitted into the eye. In this condition the patients is more comfortable observing in stronger light as compared to weak light rays and upon usage of a belladonna his vision becomes more impaired instead of being improved. In advanced stage the condition causes the pupil to become motionless, dilated and irregular. A characteristic opaque lens that is protruding outwards pressing the iris is observed (William, 2010). A soft cataract is characterized by uniformity in occurrence, being of lighter color than other forms, completes coverage of the eye in a much shorter time and commonly occurs at an early age unlike hard cataracts. It causes an excessively opaque margin that obscures vision even where the pupil has been dilated.
The loss of visual capability may not be fully rectified by a change in the glasses used. An Ophthalmologist has the capability to easily examine the alterations in the lens that is characterized by cataract using specially designed equipment known as the slit lamp. Usage of sunglasses and increased lighting for people with early stages of cataracts may lead to alleviated condition. A patient may also be advised to use magnifying lens for reading fine prints. Cataracts can only be treated through surgery and this depends on the visual needs for specific patients (Andrew, 2000).
Cataracts vary in symptoms and characteristics in different patients. The modes of treatment also vary as the forms of cataracts vary. Cataracts do not harm the eye and surgery should be carried out after a patient fully understands the benefits and the risks involved. If an eye suffers from other diseases causing visual impairment, cataract surgery may not in any way improve or enhance vision. In a situation where both eyes suffer from cataract and have to be operated, the second eye is operated after at least a week long period after the first operation (William, 2010). Before an operation is carried out, an artificial lens with exactly matching features to those of a natural one is necessary and should be ordered in advance. There are no known preventive measures that can be employed to prevent the development of cataracts.