What is Cataract ?
The crystalline lens of the eye is transparent and colourless in young individuals. Its primary function is to focus parallel rays of light from infinity on the retina. The imprint formed by these light rays is sent to the brain through the optic nerve, and an image is formed. This is how we are able to perceive objects.
The lens tends to become opaque as age progresses. This clouding of the normally clear lens is called “Cataract”. The word cataract literally means “waterfall” in Greek. This is related to the fact that patients with cataract perceive objects hazily as through a waterfall. The rays of light are obstructed by the opacity within the lens, as a result of which, objects appear blurred.
How Common is Cataract ?
Cataract is an important cause of preventable cause of blindness. Cataract has been reported to be responsible for 50-80% of the bilaterally blind in the country. Three out of every four individuals [aged older than 60 years] in this country develops a cataract.
What Causes Cataract ?
The most common cause of cataract is related to ageing changes in the eye. The lens tends to lose its clarity with age. Other causes of cataract include :
- Family history of cataracts
- Medical problems such as diabetes
- Injury to the eye
- Medications, especially steroids
- Radiation exposure
- Smoking
- Surgery for another eye problem
- Too much exposure to ultraviolet light (sunlight)
- In many cases, cause is unknown
What are the symptoms of cataract ?
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Gradual and painless vision loss. Progressive blurring of objects is classical of developing cataracts.
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Frequent change of glasses can also be a sign of progressing cataract. Often, people who needed reading glasses are able to read without any glasses.
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Being sensitive to glare at night
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Cloudy, fuzzy, foggy, or filmy vision
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Difficulty seeing at night or in dim light
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Double vision
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Loss of color intensity
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Problems seeing shapes against a background or the difference between shades of colors
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Seeing halos around lights
By performing a detailed slit-lamp examination of the eye, your doctor can detect the cataract
How is Cataract Treated ?
Cataract Surgery is the only way a cataract can be removed.
Your doctor can examine you and tell you when you need surgery for cataract.
Replacing it with an artificial intraocular lens at the time of cataract surgery helps in restoring vision to normal. No medications, exercises or dietary supplements have been shown to prevent or reduce cataracts.
Catarct surgery should be planned when cataract cause enough loss of vision to interfere with daily activities. It is not advisable to postpone surgery too long, as it can cause hardening of cataract. Sometimes, the cataract may become hypermature and can lead to complications in the eye.
About Cataract Surgery
Cataract surgery through phacoemulsification is the most modern and advanced method for performing cataract surgery.
Is Cataract Surgery Safe ?
Modern Cataract surgery is now very safe, and can be done on an outpatient basis.
There is no need for admission into the hospital. It is a day care surgery, and involves staying in the hospital for 2 to 3 hours.
What Preoperative Evaluations are required before cataract surgery ?
You will be called for a preoperative evaluation before your surgery. This is usually done 2 days prior to your surgery.
You will undergo following examinations during your preoperative checkup
* IOL Master : It takes measurements that provide the power (dioptre) of the intraocular lens to be implanted
* Corneal Topography : It gives an estimate about the size, shape and power of the cornea (astigmatism)
* Specular microscopy : It gives inference about the health of the cornea and function of the cells lining the cornea
* Fundus examination : It includes examination of the posterior segment of the eye i.e. the macula, the optic nerve, retina and vitreous
* Medical checkup : Complete physical examination for diabetes, blood pressure, heart problems or other systemic conditions is done
Apart from this, you will undergo several other tests prior to your surgery
Phacoemulsification
Phacoemulsification through a small incision is the most advanced method and allows safe and predictable surgery. A small instrument called the phaco probe is introduced within the eye. Ultrasonic vibrations generated within the probe break the cataract into multiple small pieces (emulsification), which are then removed using a suction device through the same probe. After removing the cataract, a foldable intraocular lens (IOL) is implanted in the eye through this small incision. No stitches, bandage or dark glasses are required for healing of the wound.
Raghudeep Eye Clinic is one of the pioneers worldwide of the ultramodern “micro-incision phacoemulsification “ technique. The devices and disposables used here are those recommended by the US FDA. Only the latest and very best in technology is employed here. There is no compromise in quality at any step before, during or after surgery.
Intraocular Lens (IOL)
It is an artificial lens that is implanted during cataract surgery. It is made up of acrylic material and can be folded and inserted into the eye. Once inside the eye, the IOL unfolds to its original size and shape.
Following are the types of IOLs available :
With this lens, the patient is required to wear spectacles selectively for distance and near vision to obtain clear vision as this IOL has only one point of focus. However, the asphericity of the IOL leads to improved contrast sensitivity and sharpness of vision.
It is meant for patients with existing corneal astigmatism (cydlindrical numbers). It gives good quality distance vision with less dependance on glasses; patients will still require glasses for tasks such as reading or working at the computer.
It is designed to give full range of clear vision, near to far, and everywhere in between with minimal dependance on spectacles.
This lens has unique properties of multifocality as well as toricity. It offeres minimal dependence on glasses to patients who have pre-existing corneal astigmatism, thus allowing a full range of distance, intermediate, and near vision
Your doctor will suggest which IOL is suitable for your eye condition and your visual requirement.
Is there any restriction in acitivities after Cataract Surgery ?
After phacoemulsification, the patient is not required to restrict normal daily activities. From the next day of surgery, the patient can resume normal work and linving. Eye drops need to be continued for 4-6 weeks after surgery. Oral medicines may be necessary in some cases. Most patients have improved vision soon after surgery, but sight may continue to improve for several days or weeks.
The notion that glasses are not required after IOL implantation is not correct for all types of IOLs. The IOL is unable to expand and contract, unlike the normal crystalline lens. Depending on the type of IOL implanted in your eye, there will be a selective need for glasses for distance and / or near. Spectacles are prescribed around 2 weeks after surgery.
During cataract surgery, the capsule of the lens is left intact to hold the IOL in place. In the long term, this capsule can thicken and cause blurring of vision. This is called capsule opacification (Chhari). The onset of this thickening varies from person to person. It may occur earlier in young individuals. This opacification can be removed successfully with YAG laser.
Cataract is not a disease. It is a normal part of the ageing process. With advances in science and technology, cataract surgery is now safer and more predictable than ever.
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