Cataract and Surgery

Next week my mother would undergo Cataract Surgery. I find the little facts as general knowledge....

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 colours. 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.

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. 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. Such spontaneous posterior dislocations (akin to the historical surgical procedure of couching) in ancient times were regarded as a blessing from the heavens, because some perception of light was restored in the cataractous patients.

Cataract Surgery

Cataract surgery is considered one of the most effective medical procedures today. In fact, more than 3 million cataract surgeries are performed each year in the United States alone, with more than 981 percent of first-time cataract procedures considered "successes," meaning no complications. 

Artificial Intraocular Lens Standard Cataract Surgery
Standard cataract surgery involves replacing the natural lens of the eye with an artificial intraocular lens (IOL). This is a permanent solution to restore vision, although patients may still need to wear glasses for astigmatism and presbyopia.

Artificial Intraocular Lens Custom Cataract Surgery

There is also a custom artificial intraocular lens cataract surgery which uses advanced technology to produce what is considered to be premium lenses. These premium lenses can eliminate or greatly reduce astigmatism and presbyopia. Patients can see better than they have in years.

Cataract Laser Surgery

Standard cataract surgeries were performed manually by surgeons using a blade for some parts of the procedure. There is always a margin of error using this type of surgery. There is now new technology which allows eye surgeons to use a laser to create incisions which are up to ten times more precise than using blades. The LenSx is the first FDA cleared custom cataract laser.

Surgical Guidance System

There is a new system referred to as ORA (Optiwave Refractive Analysis). This system is used in custom cataract surgery to analyze the power and position of the implanted IOLs. In the past, eye surgeons took measurements before the procedure. They were often not as precise because of unknown factors that happened during the surgery. The ORA system fine tunes the lens prescription during the procedure.


Risks and Complications of Cataract Surgery

The following list, while not comprehensive, provides some of the potential complications which could occur. These may develop during or after cataract surgery while you are still under your doctor's care and would be addressed immediately. If any of these issues arise after your surgery, contact your doctor right away.

Secondary cataract.
Occurring after about 30 percent of surgeries,1 a secondary cataract happens when cells have grown under the lens and the posterior capsule holding the IOL has become cloudy, blurring your vision. Your doctor will then use a YAG laser to create a small hole in the membrane for light to pass through. This is a painless outpatient procedure your doctor can perform quickly.

Tearing of the posterior capsule.
During cataract surgery, the natural lens is removed from the posterior capsule and replaced with an artificial IOL. The capsule can sometimes tear during this process. When this happens, the physician will repair the vitreous body that has leaked into the capsular bag,   capsular bag: A thin membrane that holds the eye's natural lens.   and seal it off.

Inflammation.
Swelling inside the eye that is unrelated to infection is usually minor and can easily be treated with anti-inflammatory drops after surgery.

Incision leak.
Sometimes a small leak in the incision in the cornea can occur. Such a leak increases the chances of infection, and your doctor may apply a contact lens or pressure bandage over your eye to decrease the chance of infection. In some cases, the incision must be closed with a stitch.

Visual effects.
As a result of the multifocality, some visual effects (halos or radial lines around point sources of light at night) may also be expected due to the superposition of focused and unfocused multiple images. A reduction in contrast sensitivity may also be experienced by some patients, especially in low lighting conditions such as driving at night.

Cystoid macular edema.
 As long as 3 months after cataract surgery, or as soon as a few weeks, the tissues of the macula may swell. If this happens, your central vision will be blurry, and your doctor will most likely give you a non-steroidal anti-inflammatory drug.

Bleeding.
Bleeding inside the eye during cataract surgery is extremely rare, because the incision is placed on the edge of the cornea, which contains no blood vessels. If it does occur, it will likely occur on the surface of the eye. In this case, the surgeon will usually cauterize the area and the bleeding stops.

Intraocular Infection.
Developing an infection after cataract surgery is extremely rare, occurring only once in several thousand surgeries.1 Most cataract surgeons administer antibiotic drops before, during, and after surgery to minimize the risk. Endophthalmitis, an inflammation of the eye triggered by infection, is also very rare and more common in people with compromised immune systems, which includes patients with diabetes. For tips on managing diabetes, click here.

Pronounced astigmatism.
Sometimes swelling of the cornea or tight stitches (if stitches are used) can distort the shape of the cornea, causing astigmatism. Swelling will reduce during healing, and the astigmatism will generally go away on its own. Or if stitches were used, once they are removed, the cornea will usually relax back to its natural shape.

Retinal detachment.
If you are extremely nearsighted, you may be more prone to retinal detachment during cataract or any other eye surgery. Symptoms include flashing lights, new floaters, gradual shading of vision as though a curtain was being drawn, and quick detachment of your sharp, central vision. If you experience any of these symptoms, call your doctor immediately.

Glaucoma.
An extremely small number of cataract surgery patients develop secondary glaucoma after cataract surgery. Secondary glaucoma is usually temporary and can develop when inflammation or bleeding occurs during the surgery. In most cases, glaucoma medications can be used to help control the increased intraocular pressure, but sometimes, laser or other surgery is required.

Bruising or black eye.
If your doctor used an injection to numb your eye, it is possible that you may experience some bruising around your eye. This is temporary and will go away on its own.

Decentered intraocular lens.
Rarely, the IOL placed in the eye can become displaced a week to a month later. If this happens, you would experience blurred vision, glare, double vision, or fluctuating vision (when the eye sees the edge of the IOL, causing focused and unfocused images). This is sometimes due to torn zonules during surgery or through an accident involving the eye. Your doctor will either reposition the lens or remove and replace it with another.

Other adverse reactions that have been associated with the implantation of intraocular lenses are: hypopyon, acute corneal decompensation, pupillary block, and secondary surgical intervention (including but not limited to lens repositioning, biometry error, visual disturbances or patient dissatisfaction).
 
Source of knowledge:
http://surgery.about.com/
http://www.reclaimyourvision.com
http://www.alcon.com
http://www.medpagetoday.com
http://www.listmyfive.com
http://www.news-medical.net