Cataract refers to the clouding of the natural lens of the eye. The lens of the eye is similar to the lens of a camera and is responsible for making a sharp image on the retina (light sensitive part at the back of the eye).
Clouding of the lens impairs this ability and only a foggy image can be seen through a cataract affected lens. In a normal eye, the lens is a clear bag of water and protein. Cataract develops when the protein starts to clump together resulting in clouding of the lens. Initially it may involve only a part of the lens which gradually progresses and spreads to involve the entire lens resulting in significant impairment of vision and visual handicap.
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Who can get Cataract?
1. Usually seen after 40 years of age as a gradual process of aging.
2. Infrequently it can affect persons of other age groups including.
» Newborns (congenital cataract)
» Children (developmental cataract)
» Young adults (usually after trauma to the eye).
3. Other important causes include use of some drugs such as steroids, inflammation of the eye (uveitis), hereditary causes and radiation exposure.
Symptoms of Cataract:
Symptoms of cataract usually develop gradually and mainly include:
» Blurred vision.
» Increasing difficulty with vision at night.
» Sensitivity to light and glare especially from headlights during night driving.
» Halos around lights.
» The need for brighter light for reading and other activities.
» Frequent changes in power of spectacles or contact lenses.
» Fading of colours.
Cataract doesn't cause any change in the appearance of the eye or pain, redness, and watering until the cataract becomes completely white in later stages, a condition known as an overripe (hypermature) cataract. This very late stage of cataract can affect the health of the eye resulting in severe and permanent loss of vision and therefore requires urgent treatment including surgery.
When and how is Cataract treated?
Treatment of cataract depends on the stage of cataract and the level of visual impairment. In the early stages, change in the power of spectacles can help. As the lens becomes more cloudy, light cannot pass through the lens and a clear image cannot be formed. At this stage surgery is the only option to improve the vision.
When is the best time to undergo Cataract Surgery?
The decision for undergoing cataract surgery has to be jointly taken by the eye doctor and the patient.
Since the visual needs differ from person to person, the decision to undergo surgery is mainly based on the visual handicap the patient is experiencing. In some cases the doctor may prescribe cataract surgery not for visual gain but to allow the doctor to evaluate and treat retinal diseases. In these cases, the cataract blocks adequate visualization of the retina and hampers laser treatment of retinal diseases.
What are the different types of Cataract Surgeries?
Cataract surgery is a very safe and successful surgery. The technique employed most commonly these days is called phacoemulsification or 'phaco' for short.
Phaco - The surgeon makes a very small (2-3 mm) incision in the eye and inserts a thin probe. The probe dissolves and sucks the clouded internal material of the lens leaving the bag of the lens intact. A clear soft foldable artificial lens (IOL) is then placed in the same bag. Since the incision is very small, no sutures are required and the patient recovery is faster. The patient spends less than 30 minutes in the operating room and the surgery itself takes less than 15-20 minutes.
Extracapsular cataract surgery (ECCE) involves removal of the clouded lens matter as one piece leaving the bag intact. The technique therefore requires larger incision with sutures. A rigid artificial lens (IOL) is then placed in the bag. It is rarely used these days due to the large incision.
Visual recovery is often slower.
Intracapsular cataract surgery (ICCE) is the oldest technique and requires an even larger wound than ECCE. The surgeon removes the entire lens and bag as one piece. This technique is rarely used today but can be useful in special cases as in after significant eye trauma.
IOLs - How long do they last? Do I have remove and clean them daily?
The artificial lenses implanted inside the eye during cataract surgery are intended to remain permanently in place and require no maintenance or handling. They are neither felt by the patient nor noticed by others.
What is the difference between foldable and nonfoldable lenses?
Foldable lenses are made of soft material and can be implanted in the eye through the small incision of phaco surgery. Rigid lenses require larger incision for implantation during surgery and are thus used only during ECCE or ICCE.
How do I choose a lens? Which lens will be best for me?
A variety of foldable lenses are available and vary according to the material and the optics.The lenses can be made of either Hydrophobic acrylic, Hydrophilic acrylic or Silicone. There are distinct advantages and disadvantages of each material and the suitability of each type for a patient needs to be discussed with the eye surgeon.
The lenses also vary according to the optics and includes monofocal, monofocal aspheric, toric, and multifocal IOLs
How should I prepare for the surgery?The cataract surgery is done on a daycare basis and the patient is usually sent home within a couple of hours. There are no special preparations for the surgery except for a few eye drops which will be prescribed by the eye surgeon for use before surgery. Only one eye is operated at a time. There is no restriction on food before the surgery if the surgery is being planned under local anaesthesia. If the patient is taking medications for other diseases then these needs to be discussed with the doctor beforehand.
Some of the medications that can interfere with the surgery include:
» Blood thinners including heparin, warfarin, aspirin, dispirin.
» Anti prostate hypertrophy drugs.