Cataract

A cataract is a clouding of the lens in 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 vision, halos around light, trouble with bright lights and trouble seeing at night. This may result in trouble driving, reading, or recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. Cataracts cause half of all cases of blindness and 33% of visual impairment worldwide.

About 20 million people are blind due to cataracts. It is the cause of approximately 5% of blindness in the United States and nearly 60% of blindness in parts of Africa and South America. Blindness from cataracts occurs in about 10 to 40 per 100,000 children in the developed world, and 1 to 4 per 100,000 children in the developed world. Cataracts become more common with age. 

SIGNS AND SYMPTOMS

Signs and symptoms vary depending on the type of cataract, though considerable overlap occurs. People with nuclear sclerotic or brunescent cataracts often notice a reduction of vision. Those with posterior subcapsular cataracts usually complain of glare as their major symptom.

The severity of cataract formation, assuming no other eye disease is present, is judged primarily by a visual acuity test. Other symptoms include frequent changes of glasses and colored halos due to hydration of lens.

CAUSES

1.Age

Age is the most common cause. Lens proteins denature and degrade over time, and this process is accelerated by diseases such as diabetes mellitus and hypertension. Environmental factors, including toxins, radiation, and ultraviolet light, have cumulative effects, due to alterations in gene expression and chemical processes within the eye.

2.Trauma

Blunt trauma causes swelling, thickening, and whitening of the lens fibers. While the swelling normally resolves with time, the white color may remain. Blunt trauma can also result in star or petal-shaped cataracts.

3.Radiation

Cataracts can arise as an effect of exposure to various types of radiation. X-rays, one form of ionizing radiation, may damage the DNA of lens cells. Ultraviolet light, specifically UVB, has also been shown to cause cataracts, and some evidence indicates sunglasses worn at an early age can slow its development in later life.

4.Genetics

The presence of cataracts in childhood or early life can occasionally be due to a particular syndrome. Examples of chromosome abnormalities associated with cataracts include 1q21.1 deletion syndrome, cri-du-chat syndrome, Down syndrome, Patau’s syndrome, trisomy 18 (Edward’s syndrome), and Turner’s syndrome, and in the case of neurofibromatosis type 2, juvenile cataract on one or both sides may be noted.

5.Skin diseases

The skin and the lens have the same embryological origin and so can be affected by similar diseases. Those with atopic dermatitis and eczema occasionally develop shield ulcer cataracts. Ichthyosis is an autosomal recessive disorder associated with cuneiform cataracts and nuclear sclerosis. Basal-cell nevus and pemphigus have similar associations.

6.Smoking and alcohol

Cigarette smoking has been shown to double the rate of nuclear sclerotic cataracts and triple the rate of posterior subcapsular cataracts.

7.Inadequate vitamin C

Low vitamin C intake and serum levels have been associated with greater cataract rates.However, use of supplements of vitamin C has not demonstrated benefit.

8.Medications

Some medications, such as systemic, topical, or inhaled corticosteroids, may increase the risk of cataract development. Corticosteroids most commonly cause posterior subcapsular cataracts. People with schizophrenia often have risk factors for lens opacities (such as diabetes, hypertension, and poor nutrition) but antipsychotic medications are unlikely to contribute to cataract formation. Miotics and triparanol may increase the risk.

POST-OPERATIVE

Nearly every person who undergoes a vitrectomy—without ever having had cataract surgery—will experience progression of nuclear sclerosis after the operation. This may be because the native vitreous humor is different to the solutions used to replace the vitreous (vitreous substitutes), such as BSS Plus. This may also be because the native vitreous humour contains ascorbic acid which helps neutralize oxidative damage to the lens and because traditional vitreous substitutes do not contain ascorbic acid.

DIFFERENT TYPES OF CATARACTS

PREVENTION

Risk factors such as UVB exposure and smoking can be addressed. Although no means of preventing cataracts has been scientifically proven, wearing sunglasses that counteract ultraviolet light may slow their development. While adequate intake of antioxidants (such as vitamins A, C, and E) has been thought to protect against the risk of cataracts, clinical trials have shown no benefit from supplements; though evidence is mixed, but weakly positive, for a potential protective effect of the nutrients lutein and zeaxanthin. Statin use is somewhat associated with a lower risk of nuclear sclerotic cataracts.

TREATMENT

Surgical

Cataract surgery, using a temporal-approach phacoemulsification probe (in right hand) and “chopper” (in left hand) being done under operating microscope .

The appropriateness of surgery depends on a person’s particular functional and visual needs and other risk factors. Cataract removal can be performed at any stage and no longer requires ripening of the lens. Surgery is usually ‘outpatient’ and usually performed using local anesthesia.

Phacoemulsification is the most widely used cataract surgery in the developed world. This procedure uses ultrasonic energy to emulsify the cataract lens. Phacoemulsification typically comprises six steps:

• Anaesthetic – The eye is numbed with either a subtenon injection around the eye or retrobulbar block or topical anesthetic eye drops. The former also provides paralysis of the eye muscles.
• Corneal incision – Two cuts are made at the margin of the clear cornea to allow insertion of instruments into the eye.
• Capsulorhexis – A needle or small pair of forceps is used to create a circular hole in the capsule in which the lens sits.
• Phacoemulsification – A handheld ultrasonic probe is used to break up and emulsify the lens into liquid using the energy of ultrasound waves. The resulting emulsion is sucked away.
• Irrigation and aspiration – The cortex, which is the soft outer layer of the cataract, is aspirated or sucked away. Fluid removed is continually replaced with a saline solution to prevent collapse of the structure of the anterior chamber (the front part of the eye).
• Lens insertion – A plastic, foldable lens is inserted into the capsular bag that formerly contained the natural lens. Some surgeons also inject an antibiotic into the eye to reduce the risk of infection. The final step is to inject salt water into the corneal wounds to cause the area to swell and seal the incision.

PROGNOSIS

A. Postoperative care

1.       The postoperative recovery period (after removing the cataract) is   usually short. The patient is usually ambulatory on the day of surgery.

2.       It is advised to move cautiously and avoid straining or heavy lifting for about a month.

3.       The eye is usually patched on the day of surgery.

In all types of surgery, the cataractous lens is removed and replaced with an artificial lens, known as an intraocular lens, which stays in the eye permanently. Intraocular lenses are usually monofocal, correcting for either distance or near vision. Multifocal lenses may be implanted to improve near and distance vision simultaneously, but these lenses may increase the chance of unsatisfactory vision.

B. Complications

Serious complications of cataract surgery include retinal detachment and endophthalmitis. In both cases, patients notice a sudden decrease in vision. In endophthalmitis, patients often describe pain. Retinal detachment frequently presents with unilateral visual field defects, blurring of vision, flashes of light, or floating spots.

Particular risk factors are younger age, male sex, longer axial length, and complications during surgery.

The risk of endophthalmitis occurring after surgery is less than one in 1000.

Corneal edema and cystoid macular edema are less serious but more common, and occur because of persistent swelling at the front of the eye in corneal edema or back of the eye in cystoid macular edema. They are normally the result of excessive inflammation following surgery, and in both cases, patients may notice blurred, foggy vision. They normally improve with time and with application of anti-inflammatory drops. The risk of either occurring is around one in 100.

Posterior capsular opacification, also known as after-cataract, is a condition in which months or years after successful cataract surgery, vision deteriorates or problems with glare and light scattering recur, usually due to thickening of the back or posterior capsule surrounding the implanted lens, so-called ‘posterior lens capsule opacification’. Management involves cutting a small, circular area in the posterior capsule with targeted beams of energy from a laser, called Nd:YAG laser capsulotomy, after the type of laser used. This procedure leaves sufficient capsule to hold the lens in place, but removes enough to allow light to pass directly through to the retina. Serious side effects are rare. Posterior capsular opacification is common and occurs following up to one in four operations, but these rates are decreasing following the introduction of modern intraocular lenses together with a better understanding of the causes.

Vitreous touch syndrome is a possible complication of intracapsular cataract extraction.

FREQUENTLY ASKED QUESTIONS

A. CATARACT FAQs

1. Who gets cataracts?

Most people develop cataract above 60 yrs. Everyone may develop a cataract if he/she live long enough.

2. Can I prevent cataracts?

There is no medical treatment to reverse or prevent the development of cataracts. Once they form, there is only one way to achieve clear vision again, and that is to physically remove the cataract from the eye.

3. Can one wait for the surgery after diagnosis of cataract?

It depends on quality of your vision. If the decrease in vision is interfering with daily work or professional work, one should go for surgery.

4. What other options are available for cataract beside surgery?

Surgery is the only option. Medicines cannot treat cataract .

5.Can a diabetic go for cataract surgery ?

Yes, there are special IOL’s for diabetic patients but diabetes should be properly controlled.

B. PRE-OPERATIVE FAQs

1. What will happen if I donot undergo cataract operation?

You can develop glaucoma or phacoemulsification may not be possible.

2. Should  one wait for surgery & let the cataract becomes mature?

Surgery in time gives you best vision with least complication.

3. What is the life of intraocular lens?

The lens stays with you for the rest of life. There is no need to clean maintain or replace the lens after it has been implanted. The lens stays with you as long as you live. No need to replace it.

4. When can I fly after cataract surgery?

One can fly the next day. But you need to discuss it with your doctor.

5. I have mature cataract in both eyes. My vision is too much blurred. Can I get both my eyes operated the same time?

No, the operation of both eyes on same day should be avoided. The surgery for  next eye can  planned following one week

6. Can one develop cataract again?

No, only with time vision may become hazy which is known as post capsular opecification. It is treated with YAG Laser which is in OPD procedure.

7. I am a farmer. When can I work?

After 2-3 days, the lens in inside the bag and not affected by environmental condition.

8. When can I go to gym?

After 15 days, but can start walk within 2-3 days.

9. When can I watch TV?

There is no instruction in watching TV

10. When can I start reading or writing?

Depends on your comfort level but prescription for glasses will be given after one week.

11. Can I swim after surgery?

Avoid for three weeks.

12. Can I play after surgery.

After one week, but can go for the light walk even the next day.

13. Can I color my hair after surgery?

After 2 weeks.

14. When can I use eye makeup?

After 2 weeks.

15. When can I cook food after surgery?

The next day after surgery.

16. When can I weak my color contact lens?

After 2 months of surgery

C. OPERATIVE FAQs

1.  How long will I stay at AEC on the day of surgery?

You total stay at AEC will be for about four hours.

2. Can I eat before surgery in the morning?

Light food in the morning is recommended.

3. Is there any pain during the surgery?

You do not experience any pain during surgery.

4. How long does it takes for the surgery?

The surgery takes about five minutes. Inside the operation room your stay is 20min.

5. Can I have my other medicines on the day of surgery?

Yes, you should get any medicines recommended to you to the hospital and have them at proper time.

6. What is the procedure for surgery?

Your eye will be dilated with dilating drop. Area around your  eye with be cleaned after being shifted to operation theatre. Operation lasts only 5 min. Eye will be patched and you will be shifted out.

7. What all can one do the next day?

You routine work depending on your comfort.

D. POST-OPERATIVE FAQs

1.  When can I wash my face after surgery?

Avoid washing your face for 2 days. After that you just need to protect your operated eye for 2 weeks more.

2. What care do need for my operated eye after surgery?

You should not touch your eyes for one day. Avoid sleep on the side of operation for one day. Do not miss the medicine prescribed to you.

3. How many times do I need to visit the hospital?

You need two visits. The first visit is three days after surgery and the second visit is two weeks after surgery/

4 What diet should I follow after surgery?

You can resume your normal diet after the surgery. The diabetics should strictly follow recommended diet.

5. Will I need spectacles after the surgery?

Spectacles are prescribed after fifteen days. You will get good functional vision after cataract surgery without glasses. Glasses  may be required for distances in some cases. Reading glasses will be required by all cases. Even patient with Multifocal IOL may have small near vision number and may need glasses after surgery.

6.  Can I touch my eyes after surgery?

No, avoid for 1 week.

7. When can I wash my eyes after surgery?

After fifteen days with eyes closed.

8. How much time will it take to recover my vision after surgery?

Although it differs from patient to patient but most of the patients are able to see immediately after removing the bandage.

9. How long until I can return to normal activities?

Most patients can resume basic activities like reading and watching TV the day after surgery, and can usually return to work within two to seven days. Doctors typically advises against any strenuous activity for two or more weeks. Results vary by patients; therefore ask your doctor what’s best for you.

10. How much time will it take to resume my normal activities?

The day after surgery one can resuming one’s normal activities although it may vary from patient to patient.

11. When I can drive at night after surgery?

Your ability to drive at night should be significant the day after surgery. People with multifocal IOL’s may feel some glare and haloes which decrease with time.

12. Are there any precautions I should take after surgery?

Every patient is different, so be sure to ask your doctor for advice on caring for your eyes after the procedure. Oftens though, your doctor will simply ask you to retain from rubbing your eye or engaging in any strenuous activity for a few weeks after surgery.

13. What are my do’s & don’t after surgery?

Caring for my eyes, avoid rubbing of my eyes and not engaging in strenuous activity for a 2 weeks after surgery.

14. Whom should I call if I have a problem after surgery?

Consult your doctor immediately if you have any problems particularly decreased vision or pain.

15. How do I feel after surgery?

It’s mild discomfort for some time. Patient may be sensitive to light also.