Cataract

A cataract is a condition which causes

clouding of lens in the eye resulting in blurry

vision.

The lens is situated behind the iris, the dark

portion of the eye, and is not visible. When a

cataract occurs, the lens becomes cloudy and

is seen as a white cloudy ball in the center of

the iris.

The lens is made up of mostly water and

proteins. These specific proteins provide its

transparent structure. Any structural change

in these proteins can alter the clarity of the

lens and negatively impact vision.

There are three types of cataracts classified

according to their location in the eye.

Nuclear cataract is when the cloudiness is

present in the center of the lens.

With Cortical cataract, the cloudiness is seen

in the outer peripheral region or cortical

region of the lens.

Subcapsular cataract occurs at the back of the

lens capsule or subcapsular region. This type

develops quicker and can appear more

suddenly than the nuclear and cortical

cataract.

Cataracts are also classified according to the

cause, either as age related cataract,

congenital cataract, secondary cataract or

traumatic cataract.

A cataract can occur due to many reasons.

Age As people age, changes can occur in

the structure of the lens protein leading

to cataract.

Congenital causes-Cataract can occur in

newborns as inherited disorder or can

develop in infants because of infections in

mother during pregnancy such as rubella,

herpes simplex and syphilis.

Secondary causes- Cataract can form as a

complication of other diseases such as

glaucoma and diabetes. Prolonged use of

corticosteroid inhalers and eye drops

increases the risk of cataract.

Trauma Certain injuries may result in

formation of a cataract. Cataract may also

develop years after the injury.

Other causes include excessive exposure

of the eyes to UV rays, X-rays and other

radiation during radiotherapy.

Cataracts usually develop very slowly and are

not associated with any pain or redness of the

eye. Your vision gradually becomes blurred as

if you are looking through the dirty lens of a

camera. Some patients may see a halo around

bright lights. Others find the glare from the

sun and head lights of approaching cars at

night annoying. Some patients present with

double vision in one of the eyes and the colors

appear dull or muted. In others, frequent

prescription changes for glasses or contact lens may become necessary.To assess the impact of cataract on your

vision your doctor will perform a Visual Acuity Test where the patient reads an eye chart

from particular distance with one eye at a

time.

The doctor then examines the cornea, iris,

and lens individually using an intense ray of

light from a slit lamp to detect any

abnormalities.

For the retinal exam, eye drops are added to

dilate the eye and the retina is examined for

any abnormalities using an ophthalmoscope.

a cataract develops it cannot be cured

by eye drops or medication. Patients with

mild cataracts may be helped by using strong

bifocal glasses and using appropriate light

while reading.

Surgery is the only treatment for cataract and

is recommended based on the severity of the

disease and the impact on the daily activities

of the patient. The patient usually makes the

decision to have surgery when the symptoms

negatively impact their lifestyle.

Surgery is performed on one eye at a time

with a few weeks gap in between the two

operations. Cataract surgery is done on an

outpatient basis where the patient can go

home the same day. The eye and area around

the eye is numbed using local anesthesia. The

cloudy lens is removed and replaced with a

clear plastic lens in the same lens capsule as

the natural lens.

There are three types of surgical procedures

to treat cataract:

The most common procedure used is

Phacoemulsification where your surgeon uses

an ultrasound probe to break up the lens

which is then removed by suction. The

advantage is that the incision is very small,

around 3 to 5 mm, depending on the choice of

lens, foldable or non-foldable. The incision

heals on its own and does not require any eye

patch or stitches. This surgery takes less than

30 minutes.

The second type of surgery is extracapsular

cataract surgery. This is performed when the

lens is too dense and cannot be removed by

phacoemulsification. The incision is larger as

the complete lens is removed as a single

piece. The healing process for this type of

surgery is longer and requires an eye patch

temporarily over the eye after the surgery.

Intracapsular cataract surgery is rarely

performed and only in cases of severe trauma

to the eye. The incision is even larger than in

extracapsular surgery. The whole lens is

removed along with the lens capsule. The

clear plastic lens is then placed in front of the

iris rather than in the capsule.

The intraocular plastic lens used in this type

of surgery is chosen to provide the patient with

best possible correction. Three types of

intraocular plastic lenses  monofocal, toric

and multifocal lens are used.

Following surgery your doctor will prescribe

eye drops to prevent infection and

inflammation. A follow up visit is scheduled to

monitor healing and to check for any

complications from surgery. Once complete

healing occurs glasses are ordered for optimal

vision, if required, depending on the type of

Cataract surgery is one of the safest surgeries

to undergo. Complications are rare but can

occur and need to be addressed as soon as

possible to prevent any vision loss.

Complications can include persistent

inflammation, infection, increase in

intraocular pressure, or peeling of the retina

at the back of the eye. In rare cases the

cataract seems to reappear after a few

months or years following surgery with a

cloudy appearance in the field of vision. This

occurs due to cloudiness of the capsule and

not the implanted plastic lens. It is called a

secondary cataract and can be treated by a

simple laser surgery to create a hole in the

lens capsule where the cloudiness is visible.

Cataracts may be prevented by

maintaining a healthy life style.

Fruits and vegetables are a good natural

source of vitamins and antioxidants

important in the normal growth,

functioning and prevention of age related

damage to the eye lens. A diet rich in

fruits and vegetables can help prevent

cataracts.

Not smoking or quitting if you do smoke

lowers your risk of developing cataracts.

Regular exercise and maintaining a

healthy body weight also helps to prevent

cataracts.

Increased triglycerides are a risk factor for

cataract. Keeping blood levels of

triglycerides under control through diet

restrictions helps in preventing cataracts.

Diabetes greatly increases the risk of

developing a cataract. Diabetics should

check and control blood sugar levels

regularly.

Wearing sunglasses with UV- protection

when outside protects the eyes from

damage by the sun’s harmful UV rays.

Cataracts are a slow developing disease

which normally does not get detected

early. Regular eye exams by an eye

specialist can help in early detection of

the disease.