WHAT IS CATARACT?

Cataract is a clouding of the eye’s natural crystalline lens and is the most common cause of vision loss in older adults. Normally, light passes through the clear lens and is focused onto the retina at the back of the eye. With age, the lens gradually becomes more and more opaque and obstructs the passage of light, leading to a decrease in vision which affects day-to-day living and quality of life. Most patients notice symptoms of cataract after the age of 60, in one or both eyes. Some people, however, develop cataract in their 50s and even their 40s.

Most cataracts develop slowly and your eyesight may not get affected in the initial stages. However, with time, the clouding of your lens will eventually interfere with your vision. When the cataract is the size of a pin head, the cloudiness affects only a small part of the lens. You may notice a slight change in your vision. As it grows larger, the cataract clouds more of your lens. This scatters and blocks the light as it passes through the lens, preventing a sharply defined image from reaching your retina. This may lead to more noticeable symptoms.

While cataracts commonly develop in both eyes, one eye may be affected before the other.  In other words, the cataract in one eye may be more advanced than the other, causing a difference in vision between eyes.

Cataract and Refractive Lens Surgery

Risk factors of cataract

Other than aging, factors that increase your risk of cataracts include a previous eye injury or inflammation, a previous eye surgery, excessive exposure to sunlight (ultraviolet-B rays), medical conditions such as diabetes and high blood pressure, genetic abnormalities, skin diseases, smoking, ionizing radiation (treatment for cancer) and prolonged use of corticosteroid medications.

Symptoms of Cataract

Symptoms of cataract include cloudy or blurred vision, distorted or double vision, sensitivity to light and glare, difficulty seeing in poor lighting conditions, difficulty in distinguishing changes in contrast, and fading of colours. People with cataract may feel as if they are living in a perpetual fog or looking through dirty eyeglasses. Everyday tasks such as driving, reading and recognizing faces is affected. If allowed to progress, cataract can also lead to loss of vision.

If you notice any unexpected changes in your vision, such as hazy, blurred or double vision, experience minor loss of night vision, faded colours, or sudden sensitivity to light and glare, see your doctor right away. If you are above the age of 60 and require brighter light for reading and other activities, see halos around lights, or need frequent changes in glasses or contact lenses, then you most probably have cataract. Even if you do not have any visible changes in vision, it is a good idea to have your eyes checked for cataract regularly if you are over the age of 50.

Rate of growth

It is not always possible to predict exactly how fast a cataract will develop as the rate of growth varies from person to person and may also vary between both eyes in a particular individual. There are many kinds of cataracts, and they can either develop very slowly or progress rapidly. Cataracts that are caused by the aging process most often progress gradually over a period of years. Cataracts that affect diabetics and young people, or cataracts that are caused due to certain injuries or use of certain medications may progress rapidly over a few months.

Classification of adult cataracts

An adult cataract can be immature, mature, or hyper-mature.

  • When there are some remaining clear areas in the lens, the cataract is considered as immature.
  • When the lens is completely opaque, the cataract is considered as mature.
  • When the cataract has a leaky fluid, it is considered as hypermature.

TYPES OF CATARACT

The different types of cataract include:

Nuclear cataract -This type of cataract forms in the center of the lens. Initially this cataract may cause a temporary improvement in your reading vision or more near-sightedness. With time, however, it turns the center of the lens yellow or even brown, leading to clouding of vision and difficulty distinguishing between shades of colour.

Cortical cataract – This type of cataract forms at the edges of the lens. It begins as whitish streaks or wedge-shaped cloudiness around the outer edge of the lens cortex and slowly extends to the center of the lens with time. This interferes with light passing through the center of the lens. People with diabetes are more prone to develop this type of cataract.

Posterior subcapsular cataract – This type of cataract affects the back of the lens and progresses much faster than other types of cataract. This cataract starts as a small, opaque area that generally forms near the back of the lens, right in the path of light. It interferes with your reading vision, reduces your vision in bright light, and causes glare or halos around lights at night. People with diabetes , Uveitis long term steroid either in the form of drops or tablets, retinitis pigmentosa  may have a higher risk of developing this type of cataract.

Congenital cataracts – This type of cataract is present at birth or develops during childhood, often in both eyes. Congenital cataracts may be genetic, or may occur due to infection, inflammation, trauma, metabolic problems or drug reactions. These cataracts may be extremely small and don’t always affect vision. However, moderate to severe cataracts that affect vision may need to be treated with cataract removal surgery at the earliest to avoid lazy eye (Ambylopia).

Traumatic cataract – This type of cataract may develop following injury to the eye while playing sports such as tennis, cricket, badminton, during an accident or due to the use of blunt force, which results in damage to the lens inside the eye. This kind of cataract may vary from minor type of opacification of the natural lens, to a profound damage to the natural lens, along with injury to outer layers of the eye and the posterior part of the eye as well.

Secondary cataract – This type of cataract is also known as posterior capsular opacification (PCO) or after-cataract. Some months or years after cataract surgery, a small percentage of people experience a decline in their eyesight. The posterior portion of the lens capsule (the part behind the natural lens) is left inside the eye during cataract surgery, and the IOL is implanted directly in front of it.This cataract makes the back surface of the lens opaque or cloudy, causing vision to become blurred again.

Radiation cataract – This type of cataract can form after a person undergoes radiation treatment for cancer. Exposure to radiation during treatment for cancer can damage the cells covering the posterior surface of the lens, leading to partial opacity or cloudiness.

Can cataract be prevented?

Presently, there are no preventative treatments for cataract, as it is a part of the natural aging process, caused by the gradual denaturation of protein in the eye’s lens. 80% of normal people after the age of 50 develop cataract. Eye drops that could be an alternative treatment to cataract surgery in the near future are being developed by scientist. However, extensive trials are still required to establish whether they can be used safely and effectively.

I have been diagnosed with cataract. What is the next step?

After being diagnosed with cataract, you need to keep track of changes to your vision. This will help your doctor calculate how mature or advanced your cataracts have become. In the initial stages, the cataract may develop at the edge of the lens and may not cause problems with vision. As it progresses, you may experience blurring or hazing of vision and become more sensitive to light and glare. Stronger lighting and eyeglasses can help you deal with these symptoms. When the cataract advances to the stage where you cannot see well enough to perform normal activities, your eye doctor may recommend cataract surgery.

 CATARACT TREATMENT

Treatment is a simple surgery where the natural cataractous (opaque) lens is removed and replaced with a clear artificial intraocular lens (IOL). Since cataract usually, occurs due to age-related changes in the lens of the eye, it is necessary for everyone over the age of 50 to have their eyes checked for cataract regularly.

If you choose to put off your cataract surgery, it would soon impact your everyday vision and overall quality of life. As it becomes severe, you could probably only distinguish between light and dark.

Cataract and Refractive Lens Surgery

TYPES OF CATARACT SURGERY

  • SICS-Small Incision cataract surgery – This is a cataract surgery wherein a 6-7 mm cut is made by the surgeon and the cataract is removed as a whole, preserving the capsule of the lens. The new rigid artificial intraocular lens is then inserted into the lens capsule through the same wound to replace the old lens. The wound is sealed and stitches are usually not required.
  • Phaco/Phacoemulsification – Phacoemulsification refers to modern cataract surgery via a small 2-3 mm cut, in which a handheld probe is used to break up and emulsify the lens into liquid using ultrasound energy. The resulting ‘emulsion’ is sucked out. After these steps, the artificial foldable intraocular lens is inserted inside the eye.
  • Femtosecond Laser Assisted Cataract Surgery Using Tm Lensx, Alcon Platform And Catalys, Amo Platform – With the advent of lasers, several steps in cataract surgery can now be performed with new levels of safety, accuracy and predictability, and the possibility of human error playing a role in the surgery has been virtually reduced to nil. The laser makes the life of a cataract surgeon simple, as a large part of the cataract surgery can be automated with a computer-controlled laser instead of hand-held instruments.
    This includes the creation of the initial surgical incisions in the cornea, the capsulotomy, and the fragmenting (breaking up) of the lens. The femtosecond laser may also produce incisions within the peripheral cornea to aid the correction of pre-existing astigmatism. The lens which has already been broken up into small bits is then removed by the surgeon and the intraocular lens is implanted. This kind of surgery is known to have lesser complications because of improved precision and repeatability of surgical steps which could enhance the results and is also a safer option for complex cataracts.

TYPES OF INTRAOCULAR LENS

  • Based on the material we have two types

RIGID – PMMA

FOLDABLE – ACRYLIC/SILICONE

  • Based on the function
  1. Monofocal Intraocular Lens – or standard IOLsare implantable lenses made of acrylic or silicone material and is a single lens used to restore vision for one area of focus, usually distance vision. You will still need to use reading glasses or bifocals for near tasks such as writing, reading, sewing, seeing mobile after surgery. Alternatively, the IOL can be set for intermediate or reading vision, but you will need to use glasses for distance vision.
  2. Multifocal Intraocular Lens – provides enhanced vision for near and far – The center of the lens provides distance focus and the periphery provides near focus. This lens is helpful if you are constantly switching distances during the day and greatly reduces the need for wearing glasses or contact lenses after surgery doesn’t give good intermediate vision.
  3. Trifocal IOL

Provides distance vision  for watching TV and other far activities.

Provides intermediate vision for working on  computers/laptops.

Provides near vision for  reading, writing, seeing mobile.

  1. Toric Intraocular Lens – are premium IOLs that can treat the cataract and also help correct or reduce the effect of pre-existing corneal astigmatism in astigmatic cataract patients. This lens is an excellent option for people with corneal astigmatism who wish to see clearly without the help of glasses. Your cataract surgeon can help you determine whether your type of astigmatism can be helped by a toric IOL.

Toric IOL can be monofocal , multifocal or trifocal.

Types of Intraocular Lenses

Monofocal IOLs are implantable lenses made of acrylic or silicone materials and placed permanently in the eye after removal of the eye’s natural lens. Monofocal lenses have a single zone of clear focus, usually set for excellent distance vision, but require the use of reading glasses for near tasks, like reading

Toric IOLs are intraocular lenses that reduce the effect of pre-existing corneal astigmatism by reducing the residual refractive cylinder and improve the quality of uncorrected distance vision.

Multifocal IOLs incorporate both distance and near powered segments in one lens. The base power bends light coming from distant objects to a single focal point on the retina. The higher power segments bend light from near objects to the same focal point on the retina. Multifocal IOLs greatly reduce the likelihood of wearing glasses or contact lenses after surgery.

Scleral Fixated IOLs (SFIOL) – Ideally, the lens is placed in the capsular cover (bag) of the lens using the support structure of the natural lens. However, there will always be instances where “in the bag” implantation isn’t possible, requiring that the IOL be sutured to the sclera with special permanent sutures. Trans-scleral suturing of Posterior Chamber IOL or Scleral Fixated Intraocular lens (SFIOL) is wellestablished and is a good option in patients with insufficient capsular support or zonular support, either as a primary or secondary implantation. The other options in these cases are Anterior Chamber IOLs and Iris Fixated IOLs. Each has its merits and demerits.

Cataract and Refractive Lens Surgery

Cataract and Refractive Lens Surgery

Which Intraocular Lens is best?

You cataract surgeon can help you decide which intraocular lens (IOL) is best for you based on your daily activities and which type of vision, near or distance focus, is required to complete those activities. Other factors to consider include pre-existing conditions such as astigmatism, glaucoma, macular degeneration, corneal disease, or other conditions which will need a specific type of lens.

How long do intraocular implants (IOLs) last?

Intraocular lens implants (IOLs) are made from materials such as acrylic or silicone, which are very durable and will last for the rest of your life. Unlike the eye’s natural lens, IOLs can neither grow cataract nor cloud up. In some cases, an IOL can dislocate (shift out of position inside the eye) as a result of trauma and result in blurred vision. In such an instance, you should contact the doctor immediately.

Can I wear my contact lenses right until the day of cataract surgery?

Depending on the type of contact lenses you wear, you will need to stop wearing them for two to four weeks prior to your cataract surgery. Since contact lenses alter the shape of the corneal surface, it may affect the preoperative measurements of the cornea that is required to determine the type of lens to be used during the cataract surgery. If you use soft lens, stop wearing them for at least one week before surgery. If you use rigid gas permeable (RGP) or hard contact lens, stop wearing them for at least 3 weeks before surgery. Failure to do so will not allow the corneal surface to return to normal. This could lead to inaccurate corneal measurements that could result in a disappointing postoperative vision outcome.

PREPARING FOR THE CATARACT SURGERY

A week or two before your cataract surgery, you will undergo a pre-operative exam to ensure that you are physically healthy enough to have the surgery. Your surgeon will do tests to measure the size and shape of your eye in order to determine the type of artificial lens (intraocular lens) that will give you good visual outcome. If you have other conditions such as astigmatism or presbyopia which affects your vision, your surgeon may suggest a replacement lens that could treat both the cataract and your pre-existing condition.


General pre-operative instructions

  • You will be informed about your pre-operative laboratory examinations and cardiopulmonary clearance schedule. The pre-operative investigation includes some blood tests and examination by the physician to determine your fitness for surgery. It also includes specialized eye tests to find out the IOL which is most suitable for your eye. It takes between 1-3 hours for the entire testing.
  • If you wish to have the examination performed elsewhere, kindly bring all the reports with you on the day of your cardiopulmonary clearance with the physician.
  • If you are diabetic, please discuss with the physician about the medication you should take before surgery.
  • Please make arrangements for a responsible adult to be with you in the hospital on the day of the surgery.

It is important for you to follow all the pre-operative instructions given to you by your doctor. Your surgeon may advise you not to eat or drink anything (especially alcohol) for 12 hours before the surgery if planned for surgery under general anaesthesia. If you are on other medications, your doctor may ask you to stop taking them or alter the timing of the medications prior to the surgery. You may be instructed to use medication or eye drops before surgery to prevent infection. A good night’s rest is important before the day of the procedure.

Day of cataract surgery

On the day of the cataract surgery, dress for your appointment in loose, comfortable clothing. Do not wear any make-up as the area around the eye needs to be as clean as possible. Avoid wearing jewellery. Try to be on time or a little early for your appointment to prevent unnecessary stress prior to the surgery. This way, you can clear any last minute questions or doubts.

CATARACT SURGERY PROCESS

While the cataract surgery itself takes about 15-30 minutes depending on the type of cataract. You can expect to be at the hospital for approximately two to four hours, taking into account the preparation and post-operative observation (recovery period), as well as postoperative instructions.

Before Surgery

Before the cataract surgery, you will be given eye drops to dilate your pupils and a mild sedative to help you relax. The surgery takes under an hour and you will be awake during the procedure. Anaesthetic (numbing) eye drops will be applied to your eye by your doctor so that you don’t feel any pain or discomfort.

During Surgery

  • The surgeon makes small cuts in the cornea (the transparent dome-shaped tissue that covers the front part of the eye) with a surgical blade or a laser to allow insertion of instruments into the eye.
  • A circular hole is then made in the lens capsule that encloses the eye’s natural lens.
  • A balanced salt solution is used to separate the cataractous (opaque) lens from the lens capsule.
  • The lens is then broken into smaller pieces with a laser or special ultrasound device and gently suctioned out.
  • A clear artificial intraocular lens (IOL) is then inserted into the lens capsule to restore vision.
  • Finally, normal pressure is restored in the eye and the incisionsare sealed. In most cases, stitches are not required to close the incisions as the eye heals quickly after surgery.

After Surgery

You will need to rest in a recovery area immediately after the surgery, until the effects of the sedation or anesthesia wear off. This usually takes about 30 minutes to an hour.After you receive instructions on how to care for your eyes at home, you can go home.

Few hours after surgery, feeling will start to return to the eye. Your vision may be cloudy, blurry or distorted after the eye shield. It can take a couple of weeks for your vision to settle as the eye needs time to adjust to the removal of the cataract and adapt to the new intraocular lens implant (IOL) used to replace the eye’s natural lens. Since each person heals differently, recovery time can vary from 24 hours, to a few days, a couple of weeks or as long as a month to experience clear vision.

It’s normal to experience dry eye or grittiness, watering, blurred or double vision and red or bloodshot eye after the cataract surgery. These symptoms usually subside as the eye heals, but it can take 4 to 6 weeks to recover fully.

Potential complications of cataract surgery


While any kind of surgery entails a certain amount of risk, cataract surgery is highly successful and generally considered as one of the safest surgeries you can have. Most complications are minor, such as swelling of the cornea or retina, increased pressure in the eye, and droopy eyelid. In general, the risk of severe visual loss is very rare, but may occur as a result of infection or bleeding inside the eye, or even retinal detachment, which may occur months or years after a perfectly successful cataract surgery. Underlying eye damage from other eye diseases such as glaucoma, diabetic retinopathy, or macular degeneration or pre existing co morbid conditions of the eye can increase your risk of complications and reduce the chance of improved vision after surgery.

POST-SURGERY INSTRUCTIONS

  • You may have to wear a protective pad or protective glasses provided at hospital over your eye when you leave the hospital to protect your eye from bright light and glare.
  • It is not safe for you to drive, so make arrangements to have someone else drive you home.
  • You can resume light activities such as reading and watching television one day after the surgery
  • Avoid washing your face and hair for 1 week after the surgery. A wet tissue or towel can be used.
  • There is no diet restriction after cataract surgery.
  • Medication for other conditions like Diabetes, Hypertension etc. if any, can be continued

Your follow up visits will be scheduled for 24 hours after the cataract surgery, one week after the surgery and one month after the surgery.