Cataract Surgery
What is a Cataract?
A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope, varying in degree from slight to complete opacity and obstructing the passage of light. Early in the development of age-related cataract the power of the lens may be increased, causing near-sightedness (myopia), and the gradual yellowing and opacification of the lens may reduce the perception of blue colors. Cataracts typically progress slowly to cause vision loss and are potentially blinding if untreated. The condition usually affects both the eyes, but almost always one eye is affected earlier than the other.[1]
A senile cataract, occurring in the aged, is characterized by an initial opacity in the lens, subsequent swelling of the lens and final shrinkage with complete loss of transparency.[2] Moreover, with time the cataract cortex liquefies to form a milky white fluid in a Morgagnian cataract, which can cause severe inflammation if the lens capsule ruptures and leaks. Untreated, the cataract can cause phacomorphic glaucoma. Very advanced cataracts with weak zonules are liable to dislocation anteriorly or posteriorly.
Causes
Cataracts develop from a variety of reasons, including long-term exposure to ultraviolet light, exposure to radiation, secondary effects of diseases such as diabetes, hypertension and advanced age, or trauma (possibly much earlier); they are usually a result of denaturation of lens protein. Genetic factors are often a cause of congenital cataracts and positive family history may also play a role in predisposing someone to cataracts at an earlier age, a phenomenon of “anticipation” in pre-senile cataracts. Cataracts may also be produced by eye injury or physical trauma.
Cataracts may be partial or complete, stationary or progressive, hard or soft.
Some drugs can induce cataract development, such as corticosteroids[3] and Seroquel.
There are various types of cataracts, e.g. nuclear, cortical, mature, and hypermature. Cataracts are also classified by their location, e.g. posterior (classically due to steroid use[3][4]) and anterior (common (senile) cataract related to aging).
Healthy Eye; Light enters the eye through the cornea and passes through the natural crystalline lens and is accuraltely focused onto the retina, creating a crisp, clear image.As the eye ages, the lens becomes cloudier, allowing less light to pass through. The light that does make it to the retina is diffused or scattered, leaving vision defocused and blurry.
