2. What is Cataract?
• Cataracts are changes in clarity of the
natural lens inside the eye that gradually
degrade visual quality.
• Clouding that develops in the crystalline
lens of the eye or in its envelope (lens
capsule), varying in degree from slight to
complete opacity and obstructing the passage
of light
3.
4. Cause
• The lens is made mostly of water and protein.
Specific proteins within the lens are
responsible for maintaining its clarity. But as
we age, some of the protein may clump
together and start to cloud a small area of the
lens. This is a cataract, and over time, it may
grow larger and cloud more of the
lens, making it harder to see. The following
causes are...
5. • Ultraviolet radiation from sunlight and other sources
-Sunlight consists of ultraviolet (referred to as UVA or UVB)
radiation, which penetrates the layers of the skin. Both UVA and UVB have
destructive properties that can promote cataracts. The eyes are protected
from the sun by eyelids and the structure of the face (overhanging
brows, prominent cheekbones, and the nose). Long-term exposure to
sunlight, however, can overcome these defenses.
• Diabetes
-High blood sugar in diabetes causes the lens of the eye to
swell, which changes your ability to see. To correct this kind of eye
problem, you need to get your blood sugar back into the target range (90-
130 milligrams per deciliter or mg/dL before meals, and less than 180
mg/dL one to two hours after a meal). It may take as long as three months
after your blood sugar is well controlled for your vision to fully get back to
normal.
• Hypertension
6. • Obesity
• Smoking
-Cigarette smoking is a definite risk factor for cataracts and it is dose related
- the more you smoke and the longer the duration of smoking, the greater the
cataract risk.
• Prolonged use of corticosteroid medications
-Because oral corticosteroids affect your entire body instead of just a
particular area, this form is the most likely to cause significant side effects. Side
effects depend on the dose of medication you receive.
- Corticosteroids mimic the effects of hormones your body produces
naturally in your adrenal glands, which sit atop your kidneys. When prescribed in
doses that exceed your body's usual levels, corticosteroids suppress
inflammation, which can reduce the signs and symptoms of inflammatory
conditions, such as arthritis and asthma.
• Statin medicines used to reduce cholesterol
-"Statins" is a class of drugs that lowers the level of cholesterol in the blood
by reducing the production of cholesterol by the liver. (The other source of
cholesterol in the blood is dietary cholesterol.) Statins block the enzyme in the
liver that is responsible for making cholesterol.
• Previous eye injury ,Inflammation or Previous eye surgery
• Hormone replacement therapy
• Significant alcohol consumption
• High myopia
• Family history
7. Types of Cataract
• A subcapsular cataract occurs at the back of the lens.
People with diabetes or those taking high doses of
steroid medications have a greater risk of developing a
subcapsular cataract.
• A nuclear cataract forms deep in the central zone
(nucleus) of the lens. Nuclear cataracts usually are
associated with aging.
• A cortical cataract is characterized by white, wedge-
like opacities that start in the periphery of the lens and
work their way to the center in a spoke-like fashion.
This type of cataract occurs in the lens cortex, which is
the part of the lens that surrounds the central nucleus.
8. Who usually gets affected by Cataract?
• While cataracts are often associated with
aging, there is no hard and fast rule as to who
gets them. They can form in adults as early as
age 40. They can also affect babies and small
children. In some cases, they are hereditary.
9. How to prevent getting Cataract?
• The standard cataract surgical procedure is typically
performed in either a hospital or in an ambulatory surgery
center. The most common form of cataract surgery today is
a process called phacoemulsification. With the use of an
operating microscope, your surgeon will make a very small
incision in the surface of the eye in or near the cornea. A
thin ultrasound probe is inserted into the eye that uses
ultrasonic vibrations to dissolve (phacoemulsify) the
clouded lens. These tiny fragmented pieces are then
suctioned out through the same ultrasound probe. Once
the cataract is removed, an artificial lens is placed into the
same thin capsular bag that the cataract occupied.
This intraocular lens is essential to help your eye focus after
surgery.
10. There are three basic techniques for cataract surgery:
• Phacoemulsification: This is the most common form of cataract removal as
explained above. In this most modern method, cataract surgery can usually be
performed in less than 30 minutes and usually requires only minimal sedation
and numbing drops, no stitches to close the wound, and no eye patch after
surgery.
• Extracapsular cataract surgery: This procedure is used mainly for very
advanced cataracts where the lens is too dense to dissolve into fragments
(phacoemulsify) or in facilities that do not have phacoemulsification
technology. This technique requires a larger incision so that the cataract can be
removed in one piece without being fragmented inside the eye. An artificial
lens is placed in the same capsular bag as with the phacoemulsification
technique. This surgical technique requires a various number of sutures to
close the larger wound, and visual recovery is often slower. Extracapsular
cataract extraction usually requires an injection of numbing medication around
the eye and an eye patch after surgery.
• Intracapsular cataract surgery: This surgical technique requires an even larger
wound than extracapsular surgery, and the surgeon removes the entire lens
and the surrounding capsule together. This technique requires the intraocular
lens to be placed in a different location, in front of the iris. This method is
rarely used today but can be still be useful in cases of significant trauma.
11. Complications of Cataract Surgery
• While cataract surgery is one of the safest procedures available with a high rate of
success, rare complications can arise. Your ophthalmologist will discuss the specific
potential complications of the procedure that are unique to your eye prior to
having you sign a consent form. The most common difficulties arising after surgery
are persistent inflammation, changes in eye pressure, infection, or swelling of the
retina at the back of the eye, and retinal detachment. If the delicate bag the lens
sits in is injured, then the artificial lens may need to be placed in a different
location. In very rare cases, the intraocular lens moves or does not function
properly and may need to be repositioned, exchanged, or removed. All of these
complications are extremely rare but can lead to significant visual loss if left
untreated; thus, close follow-up is required after surgery.
• In some cases, within months to years after surgery the thin lens capsule may
become cloudy, and you may have the sensation that the cataract is returning
because your vision is becoming blurry again. This process is termed posterior
capsule opacification, or a "secondary cataract." To restore vision, a laser is used in
the office to painlessly create a hole in the cloudy bag. This procedure takes only a
few minutes in the office, and vision usually improves rapidly.
12. How to avoid/ Prevention of Cataract
• At present, there is no real effective way to prevent the
formation of cataracts, so secondary prevention involves
controlling other eye diseases that can cause cataracts and
minimizing exposure to factors that promote cataracts...
• Wearing sunglasses outside during the day might reduce
your chances of developing cataracts or having problems
with the retina. Some sunglasses can filter out UV
light, reducing exposure to harmful UV radiation and might
slow the progression of cataracts.
13. • Some people take vitamins, minerals, and herbal
extracts to decrease cataract formation. No scientific
data prove that these remedies are effective. No
topical or oral medications or supplements are proven
to decrease the chance of developing cataracts.
• A healthy lifestyle might help, just as a healthy lifestyle
helps prevent other diseases in the body. Eat a proper
diet, get regular exercise and rest, and do not smoke.
• If you have diabetes, tight blood-sugar control can
delay the otherwise accelerated development of
cataracts.
