Cataract is the clouding of the natural lens in the eye. The natural lens in the eye (called crystalline lens) is a convex lens made up of proteins and is transparent. Its function is to converge light rays and help to focus them on the retina (which is like a screen on which image is formed). The opacification of this lens is termed as cataract.

While cataract can occur at any age and due to a number of reasons, the majority of the cases are age related, typically seen after the age of 50 yrs. There are also other known causes of cataract like diabetes, prolonged use of steroid medication (oral or as eye drops), genetic, trauma, etc.

Morphologically Cataract can be of 3 Main Types

  1. Nuclear cataract, in which the entire lens shows change in colour to yellow-brown and an increase in density (or hardness of the cataract). This process starts in the core of the lens, hence nuclear cataract. In these patients there is an induced negative spectacle number, which can compensate for the positive number needed for near vision. This may reduce the patient’s need for near vision glasses in the early stages. However as days pass opacities appear in the lens, which blurs the vision for both distance and near.
  2. Cortical cataract, in which the outer portions of the lens become white and cloudy and there is progressive build-up of water within the lens. These water clefts in the lens can cause multiple images to form, so that the patient sometimes sees double or multiple images of a single object. With time there is progressive blurring of vision. In this type of cataract, in the advanced stages, the lens could swell with water and increase the pressure inside the eye (intra-ocular pressure). This rise of pressure could potentially damage the optic nerve of the eye and cause permanent dimness of vision.
  3. Posterior sub-capsular cataract, in which the central, back part of the lens develops white opacities. In such patients there is glare (spreading of light) typically in bright sunlight and also at night while facing the headlights of a car. They also complaint of poor near vision.

Treatment of Cataract

Irrespective of the type and cause of cataract, there is only one definitive solution to cataract which is to remove the opaque lens (cataract) surgically and replace it with an artificial one. The surgery is typically advised when the patient starts having visual complaints. Since modern technique involves removing the cataract by emulsifying it (liquefying it), it is advisable that the cataract be removed in the earlier stages when the density (hardness) of the cataract is less. This makes the surgical outcome predictable and reduces the visual recovery time.

The surgery involves making a small 2mm incision (surgical opening) in the eye, through which the procedure is performed under an operating microscope. The cataractous lens is split into pieces and each piece is emulsified and sucked out of the eye by specialised instruments. At the end, an artificial foldable lens is placed in the eye in the capsular support that originally covered the natural lens. The procedure usually takes 20 minutes and there is no need to give injection to the eye. Anaesthesia is achieved by putting eye drops. There is no need to use sutures (stitches). There is also no need to patch the eye. Black goggles are also not required. The patient is discharged immediately following surgery and no hospital stay is needed.

Frequently asked patient queries regarding cataract surgery

Can cataract be treated with eye drops or alternative medicines?

No. Cataract is permanent clouding of the natural lens. There is denaturation of proteins within the lens and these changes are irreversible. There is no known medication to ‘cure’ the cataract. No form of alternative medicines (when subjected to scientific scrutiny), have been found effective to prevent or cure cataract. With time, all cataracts progress and vision worsens. Surgical removal of the opaque lens and its replacement with an artificial lens is the only definitive treatment for cataract.

What are the precautions following cataract surgery?

There are no special precautions needed following cataract surgery except for avoiding head bath and lifting heavy weights for 3 days. Patients can go to work from the very next day. There are no visual restrictions. Patient can see television, read newspaper immediately. There are no dietary restrictions. However eye drops prescribed, will have to be instilled as per the schedule advised.

When should one get operated?

Cataract surgery is a planned procedure. The patient should consider surgery when there are visual complaints like blurred vision, glare which hamper routine activities like reading, walking on the road, climbing staircase, driving, seeing television, etc.

Will the artificial lens cause any problem?

The artificial lens is made of special materials which are inert to the eye i.e they do not induce any reactions in the eye. They are not considered as foreign objects by the eye and hence become a part of the eye. They are placed inside the eye where the cataract was present. They do not cause any heaviness, pain to the eye.

Do these artificial lenses need to be placed in all eyes during cataract surgery?

The artificial lenses are a replacement for the natural lens (cataract) of the eye. Without them, the patient would need a high spectacle power to see clearly. In almost all cases these lenses are placed in the eye during cataract surgery. However, in some special situations, like when the support (capsular cover) on which the lens is placed is weak, the doctor may decide not to implant the lens. But in all other cases, lens implantation is the norm.

Which intra-ocular lens is best suited to my eye?

There are several categories of intra-ocular lenses available. All lenses are made in such a way that they become an integral part of the eye. The basic structure of the lens offers refractive power to focus light on the retina. Apart from this basic function, there are some additional features incorporated in the different types of lenses like glare-reduction technology (reduces scattering of light), UV light filtering mechanism (prevents damage to the eye from harmful UV rays), night vision enhancement (provides better vision in dim light conditions).

The ideal lens incorporates all of these functions. The type of lens is determined by scanning tests done on the eye and other factors like presence of diabetes, high minus number, retinal problem, etc.

Will I need to wear glasses after cataract surgery in both eyes?

The artificial lens that is implanted in the eye has a primary focus for distance. So that most outdoor activities do not require glasses. However for reading (especially fine print) and in case of uneven cornea (cylindrical error), even while looking at distant objects, crisp vision is achieved by wearing glasses. Lenses in the eye do not necessarily eliminate glasses, but they eliminate the dependency on glasses and most individuals can do majority of their tasks without the glasses. On the other hand, not putting lens implant does create dependency on glasses for all activities. Today there are further refinements in lenses to reduce the need for glasses which are covered in the following questions.

What are Multi-focal lenses?

Most lenses have focus meant for distance. These are called Monofocal lenses. Their primary focus is for distance. The patient needs glasses while reading fine print or in case of cylindrical number (due to uneven corneal surface). Multifocal lenses provide for a workable near and distance vision. However these are not suited for all eyes. There are certain criteria which need to be examined and checked before advising such a lens. If the patient’s eye meets those criteria, then these lenses can give workable distance and near vision.

What are Toric lenses?

Eyes which have a significant cylindrical number, arising out of uneven outer eye surface (cornea), can benefit from these lenses. These are Monofocal lenses with built in correction for cylindrical errors.

What is Phacoemulsification?

Phacoemulsification is the modern advanced technique used for cataract surgery. The cataract is split into small pieces and emulsified by specialised instruments. Following this a foldable lens is placed inside the eye, in the capsular covering of the natural lens. And all this is done through an incision (surgical opening made in the eye) of just 2mm or less.