Cataract is a clouding of the lens in the eye that causes vision impairment, and can be caused by aging, diabetes, smoking, trauma, and other factors. Symptoms include blurred vision, sensitivity to light, and difficulty seeing at night. Treatment options range from eyeglasses and contact lenses to surgical removal of the clouded lens and replacement with an artificial intraocular lens through procedures like phacoemulsification.
2. INTRODUCTION
Cataract is a vision-impairing disease characterized by thickening of lens.
The amount of incoming light is reduced due to cloudiness of lens that
affects vision which is often being similar looking through a waterfall or
waxed paper. Cataract is age related disorder which is the most ancient
disease to man
3. DEFINITION
A cataract is an opacification of the lens of the eye which leads to a decrease
in vision. Cataracts often develop slowly and can affect one or both eyes.
Symptoms may include faded colors, blurry or double vision, halos around
light, trouble with bright lights, and trouble seeing at night.
4. CAUSES
1. An overproduction of oxidants, which are oxygen molecules that
have been chemically altered due to normal daily life
2. Smoking
3. Ultraviolet radiation
4. The long-term use of steroids and other medications
5. Certain diseases, such as diabetes
6. Trauma
7. Radiation therapy
5. RISK FACTORS
1. Older age
2. Heavy alcohol use
3. Smoking
4. Obesity
5. High blood pressure
6. Previous eye injuries
7. A family history of cataracts
8. Too much sun exposure
9. Diabetes
10. Exposure to radiation from X-rays and cancer treatments
7. TYPES
1. Nuclear Cataracts
Also called a nuclear sclerotic cataract. They form in the center of the
lens, known as the nucleus. As they get worse, your reading vision may
actually get better at first. It's called second sight, but it's short
lived. the lens hardens and turns yellow or even brown. You have a
hard time seeing small details, colors get less rich, and you
see halos around bright objects at night.
8. 2.Cortical Cataracts
.
These take shape on the outside edge of your lens, called the cortex.
They start as white wedges, like triangles that point toward the center
of your eye. As they grw, they scatter light.
These cataracts, the main symptom is glare. may find it hard to drive at
night. They can also make your vision hazy, like you're looking through
a fog. may find it hard to tell similar colors apart or to judge how far
away an object is.
Since they can spell trouble for both near and distance vision, typically
get them removed early on.
.
9. 3.Posterior Subcapsular Cataracts
cataracts form just inside the back of the lens capsule -- the part of the
eye that surrounds the lens and holds it in place. They're directly in the
path of light as it passes through the lens.
They're quicker to come on than other cataracts, and you may get
symptoms within months. They affect your close-up vision and make it
harder to see in bright lighting.
10. 4.Anterior Subcapsular Cataracts
This type forms just inside the front of your lens capsule. An injury or
welling in your eye can lead to one. So can type of eczema called atopic
dermatitis.
11. 5.Congenital Cataracts
Congenital cataracts refers to a lens opacity present at birth. Congenital cataracts cover
broad spectrum of severity: whereas some lens opacities do not progress and are visually
insignificant, others can produce profound visual impairmentCongenital cataracts may
be unilateral
12. 6.Traumatic Cataracts
Many kinds of injuries can lead to a cataract. You can get one if you're hit inthe
eye a ball or get hurt from a burn, chemical, or splinter byThe cataract could
come on soon after the injury or not show up until years later.
13. 7.Secondary Cataracts
When another condition or a medical treatment leads to a cataract,
doctors call it secondary. Diabetes, taking steroids like prednisone, and
even cataract surgery are possible causes.
14. 8.Radiation Cataracts
From the sun's ultraviolet (UV) radiation, but it can take a toll on your eyes, too. You
can sometimes get cataracts if you spend too much time in the sun without eye
protection. People who work outdoors, like fishermen and farmers, are more likely
to get this kind of cataract. To prevent it, wear sunglasses with 100% UVA and UVB
protection.
Cataracts are also a possible side effect from radiation therapy for cancer
15. 9.Lamellar or Zonular Cataracts
This type typically shows up in younger children and in both eyes. The
genes that cause them are passed from parent to child.
These cataracts form fine white dots in the middle of the lens and may
take on a Y shape. Over time, the whole center of the lens may turn
white.
16. 10.Posterior Polar Cataracts
These on the back center of the lens, and they're often due to genes that
are pased down through your family.
Posterior polar cataracts often don't cause, which is a big plus since
they're hard to remove.
18. 12.Post-Vitrectomy Cataracts
Vitrectomy is surgery to remove the vitreous, the clear gel at the center
of your eye. The operation can help with certain eye problems but may
lead to a cataract.
19. 13.Diabetic Snowflake Cataracts
This is a rare type of cataract that can happen if you have diabetes. It gets worse
quickly and forms a gray-white pattern that looks like a snowflake.
20. 14.Christmas Tree Cataracts
A Christmas tree cataract is a rare age-related change resulting from accelerated
breakdown of membrane-associated denatured proteins induced by elevated
calcium levels. The peptides and amino acids accumulate in the lumen of the
reticular meshwork, and cysteine is concentrated beyond the level of crystallization
causing the formation of needles, that impart the fascinating appearance of a
Christmas tree in the eye. Christmas tree cataracts have also been seen in patients
with myotonic dystrophy
21. 15.Brunescent Cataracts
If don't treat a nuclear cataract, it turns very hard and brown. When that happens,
it's called brunescent
This kind of cataract makes it hard for you to tell colors apart, especially blues and
purples. Surgery to remove it is harder, longer, and riskier than when treated earlier
on.
22.
23. SIGNS AND SYMPTOMPS OF CATARACT
Clouded, blurred or dim vision
Increasing difficulty with vision at night
Sensitivity to light and glare
Need for brighter light for reading and other activities
Seeing "halos" around lights
Frequent changes in eyeglass or contact lens
prescription
Fading or yellowing of colors
Double vision in a single eye
24. MANAGEMENT
counseling the patient about cataract symptoms and how it
may affect daily activities
advising the patients about minimizing their exposure to risk
factors e.g. - cessation of smoking, control of diabetes,
alternate medications for people on oral or inhaled
corticosteroids.
prescribing spectacles or contact lenses to improve vision
using brimmed hats or sunglasses to minimize glare
25. SURGICAL MANAGEMENT
1. Phacoemulsification (phaco) is the most common technique used in
developed countries. It involves the use of a machine with an ultrasonic
handpiece equipped with a titanium or steel tip. The tip vibrates at
ultrasonic frequency (40,000 Hz) and the lens material is emulsified. A
second fine instrument (sometimes called a "cracker" or "chopper") may
be used from a side port to facilitate cracking or chopping of the nucleus
into smaller pieces. Fragmentation into smaller pieces makes
emulsification easier, as well as the aspiration of cortical material (soft
part of the lens around the nucleus). After phacoemulsification of the
lens nucleus and cortical material is completed, a dual irrigation-
aspiration (I-A) probe or a bimanual I-A system is used to aspirate out the
remaining peripheral cortical material.
26. 2.Extracapsular cataract extraction (ECCE): Extracapsular cataract extraction
involves the removal of almost the entire natural lens while the elastic lens capsule
(posterior capsule) is left intact to allow implantation of an intraocular lens] It involves
manual expression of the lens through a large (usually 10–12 mm) incision made in
the cornea or sclera. Although it requires a larger incision and the use of stitches, the
conventional method may be indicated for patients with very hard cataracts or other
situations in which phacoemulsification is problematic
3.Manual small incision cataract surgery (MSICS): This technique is an evolution of
ECCE (see below) where the entire lens is expressed out of the eye through a self-
sealing scleral tunnel wound. An appropriately constructed scleral tunnel is watertight
and does not require suturing. The "small" in the title refers to the wound being
relatively smaller than an ECCE, although it is still markedly larger than a phaco
wound. Head-to-head trials of MSICS vs phaco in dense cataracts have found no
difference in outcomes, but shorter operating time and significantly lower costs with
MSICS.
27. 4.Intracapsular cataract extraction[ICCE] involves the removal of the lens and the
surrounding lens capsule in one piece. The procedure has a relatively high rate of
complications due to the large incision required and pressure placed on the vitreous
body. It has therefore been largely superseded and is rarely performed in countries
where operating microscopes and high-technology equipment are readily available.
After lens removal, an artificial plastic lens (an intraocular lens implant) can be placed
in either the anterior chamber or sutured into the sulcus.
5.Femtosecond laser-assisted cataract surgery has been shown to have no visual,
refractive or safety benefit over manual phacoemulsification.
6.Cryoextraction is a form of ICCE that freezes the lens with a cryogenic substance
such as liquid nitrogen.In this technique, the cataract is extracted through use of
a cryoextractor — a cryoprobe whose refrigerated tip adheres to and freezes tissue of
the lens, permitting its removal. Although it is now used primarily for the removal
of subluxated lenses, it was the favored form of cataract extraction from the late 1960s
to the early 1980
28. Intraocular lenses come in three basic forms: monofocal, astigmatic (toric), and multifocal lenses
.
1.Monofocal lenses are the most commonly implanted lenses. They have the same power in all areas of
the lens. They can have a fixed focus or allow for changes in focus.
Fixed Focus Monofocal IOLs can provide excellent distance vision. However, since these lenses have a
fixed focus set for distance vision, you may need to use reading glasses for good near vision.
Accommodating Monofocal IOLs are a relatively new lens option that can be used for patients who want
both good distance and near vision without the use of eyeglasses or contact lenses. These lenses also
have a single focusing power. However, they can shift from focusing on distance objects to focusing on near
ones by physically moving inside the eye in response to the focusing action of the eye muscles. Like with all
things new, there can be a learning curve to working with specialty implants.
2.Astigmatic (toric) IOLs have astigmatism correction in them. They can be used for patients who have a
lot of astigmatism and want to reduce it.
3.Multifocal lenses are like bifocal eyeglasses. Several areas of the lens have different powers, which
allow individuals to see clearly at far, intermediate and near distances. However, these multifocal lenses are
not suitable for everyone. For some individuals, they may cause more problems with night vision and glare
than monofocal IOL lenses.
29. one week before cataract surgery, you will have an appointment with your eye
doctor to perform a few tests. These tests are painless and allow the doctor to
determine which lens implant to use during your surgery.
How to prepare for surgery
eye care provider may give you eye drops or medication to take the evening before
the surgery. Make certain you follow those instructions precisely. You will also need
to abstain from alcohol the night before your cataract surgery.
Make sure your eye care provider knows if you take other medications regularly as
certain medications may need to be taken differently. Do not eat or drink past
midnight (unless otherwise instructed by your doctor), and try to get a good night’s
rest. If you are stressed or worried about the procedure, talk to your eye care
provider and primary care physician about options available to help you relax this
night.
. Eye Drops: You will be using 3 eye drops; use is detailed below starting the day before
surgery. • Ofloxacin OR Zymar (beige cap) this is an antibiotic eye drop to help prevent
infection. • Cyclopentolate dilating drop (red cap) this drop helps ready your eye for surgery.
• Prednisolone Acetate 1%. This reduces inflammation after surgery.
30. may feel slightly gritty or scratchy for the first 24-48 hours after cataract
surgery. Your vision may be blurry due to dilation and antibiotic ointment
that is sometimes instilled directly after the operation. You will be given a
few different eye drops to use for the next couple of weeks after surgery.
These eye drops are used to prevent infection and to manage
inflammation.
After care of surgery
should avoid touching and rubbing the eye. to sleep with a protective
eye patch at night to avoid an accidental finger in your eye. For the first
few days after surgery, it is okay to use your eyes to read, write or
watch television. You should avoid bending over and lifting heavy
objects for the first week or two following surgery.
31. Complications of cataract
surgery?• Infection
• Inflammation
• Swelling
• Retinal detachment
• Posterior
capsular haze
The capsule behind the new lens implant can thicken
and become hazy following cataract surgery. A
simple laser procedure known as "Yag capsulotomy" can be
performed to remove this hazy capsule.