Description, Causes and Risk Factors:
A cataract occurring spontaneously in the elderly; mainly a cuneiform cataract, nuclear cataract, or posterior subcapsular cataract, alone or in combination.
Senile cataracts are a clouding of the lens in the eye that develops with aging. More than 70 percent of people over age 75 have some degree of lens clouding. Senile cataracts can occur in any of three areas of the lens: the nucleus, cortex or capsule. Cataracts are not painful but can obscure vision; one eye or both may have cataracts, and more than one type of senile cataract can occur in an eye.
Senile cataract can be classified into 3 main types: nuclear cataract, cortical cataract, and posterior subcapsular cataract (PSCC or PSC). Nuclear cataracts result from excessive nuclear sclerosis and yellowing, with consequent formation of a central lenticular opacity. In some instances, the nucleus can become very opaque and brown, termed a brunescent nuclear cataract. Changes in the ionic composition of the lens cortex and the eventual change in hydration of the lens fibers produce a cortical cataract. Formation of granular and plaquelike opacities in the posterior subcapsular cortex often heralds the formation of posterior subcapsular cataracts.
The cause is not entirely clear. There seems to be a change to the structure of the proteins in the lens. This may be caused by a disturbance in the way fluids and nutrients get to the lens as you become older. Some of the proteins may then clump together in places within the lens. This causes tiny areas of cloudiness. Each tiny area of cloudiness blocks a bit of light getting past to the retina. The severity of the senile cataract depends on the number of areas of cloudiness that develop in the affected lens.
Numerous studies have been conducted to identify risk factors for development of senile cataracts. Various culprits have been implicated, including environmental conditions, systemic diseases, diet, and age.
West and Valmadrid stated that senile cataract is a multifactorial disease with different risk factors associated to the different cataract types. In addition, they stated that cortical and posterior subcapsular cataracts were related closely to environmental stresses, such as ultraviolet (UV) exposure, diabetes, and drug ingestion. However, nuclear cataracts seem to have a correlation with smoking. Alcohol has been associated with all cataract types.
A similar analysis was completed by Miglior et al. They found that cortical cataracts were associated with the presence of diabetes for more than 5 years and increased serum potassium and sodium levels. A history of surgery under general anesthesia and the use of sedative drugs were associated with reduced risks of senile cortical cataracts. Posterior subcapsular cataracts were associated with steroid use and diabetes, while nuclear cataracts had significant correlations with calcitonin and milk intake. Mixed cataracts were linked with a history of surgery under general anesthesia.
Most affected people develop a senile cataract for no apparent reason. Other factors that may increase the chance of developing senile cataracts may include:
Being exposed to a lot of ultraviolet light.
Having a family history of cataracts.
Having a poor diet.
At first you may notice your vision becoming a bit blurred. With time, you may notice some of the following:
Seeing halos around bright lights; for example, street lights.
Not being able to see as well in brightly lit rooms or in sunshine.
Becoming easily dazzled by bright lights such as the headlights of an oncoming car.
Your color vision may become washed out or faded.
Over the years your vision may gradually become worse and cannot be corrected by glasses.
Depending on the severity of the cataract, the effect on your sight can range from vision being slightly blurred to complete blindness in the affected eye.
Having spots in your vision.
Diagnosis of senile cataract is made basically after a thorough history and physical examination are performed. Laboratory tests are requested as part of the preoperative screening process to detect coexisting diseases (eg, diabetes mellitus, hypertension, cardiac anomalies). Studies have shown that thrombocytopenia may lead to increased perioperative bleeding and, as such, should be properly detected and managed before surgery.
Ocular imaging studies are requested when a posterior pole pathology is suspected and an adequate view of the back of the eye is obscured by the dense cataract. This is helpful in planning out the surgical management and in providing a more guarded postoperative prognosis for the visual recovery of the patient.
In patients with dense cataracts that preclude adequate visualization of the fundus, a Maddox rod test (a glass rod, or a series of parallel glass rods, that converts the image of a light source into a streak of light perpendicular to the axis of the rod. The position of this streak in relation to the image of the light source seen by the fellow eye indicates the presence and amount of heterophoria) can be used to grossly evaluate macular function with detection of a large scotoma, represented as a loss of the red line, a sign suggestive of a macular pathology.
No time-tested and proven medical treatment exists to delay, prevent, or reverse the development of senile cataracts.
The definitive management for senile cataract is lens extraction. Over the years, various surgical techniques have evolved from the ancient method of couching to the present-day technique of phacoemulsification. Phacoemulsification offers the advantage of a smaller incision size at the time of cataract surgery. Almost parallel is the evolution of the IOLs being used, which vary in ocular location, material, and manner of implantation. Depending on the integrity of the posterior lens capsule, the 2 main types of lens surgery are the intracapsular cataract extraction (ICCE) and the extracapsular cataract extraction (ECCE).
Aldose reductase inhibitors, which are believed to inhibit the conversion of glucose to sorbitol, have shown promising results in preventing sugar cataracts in animals. Other anticataract medications being investigated include sorbitol-lowering agents, aspirin, glutathione-raising agents, and antioxidant vitamins C and E.
NOTE: The above information is for processing purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
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