Cataract

What is a cataract?
A cataract refers to clouding of the lens which is usually clear and transparent in its healthy state. A clear lens acts like the lens of a camera, allowing light rays to pass and focusing them onto the retina, the nerve layer at the back of the eye that captures images like the film in a camera. A clouded lens impairs the transmission of light onto the retina, resulting in image blur.

What causes cataracts?
The most common cause of cataract is ageing. With time, the lens gets cloudy due to chemical changes within. This is a natural process of ageing which cannot be avoided or prevented with medications. Cataract can also be secondary to ultra-violet radiation (sunlight), heat, radio-active radiation, eye injury. diabetes, myopia, inflammatory diseases of the eye and certain drugs such as steroids. It can sometimes be congenital or developmental, appearing later in young adult life.

How do I know if I have cataracts?
Cataracts cause gradual, painless blurring of vision. Certain types of cataracts give rise to glare and difficulty with night driving and near work. There is also loss of contrast and colour saturation. It does not cause pain unless it is in an advanced stage complicated by inflammation or a sharp rise in eye pressure. When these complications occur, cataract surgery must be performed as soon as possible for pain relief. However, the chances of visual recovery following surgery for these advanced complicated cataracts are not good.

Is there a cure for cataracts?
Fortunately, the answer is a definite yes! Cataracts can be cured but only by surgery. There are currently no scientifically-proven medications that can restore the cloudy lens to its original transparent state. Surgery for cataracts has advanced rapidly over the last decade or so to provide fast visual recovery.

When should I go for cataract surgery?
The timing of cataract surgery would depend on one’s individual needs, daily activities and lifestyle. If your cataract is early but is causing symptoms and impairing your daily activities, you may opt for an operation earlier. But, if your symptoms are tolerable in relation to a more sedentary lifestyle, you may elect for surgery later. There is now no need to wait until the cataract is advanced or mature before surgery as advanced cataracts carry a higher risk of surgical complications and with these, the chances of visual recovery are poor.

How is cataract surgery performed?
Cataract surgery is performed as a day procedure with no need for overnight hospital stay. It is performed under a microscope and the patient is given sedation and numbing eye-drops to prevent pain during the operation. Tiny no-stitch incisions are made in the side of the eye so that instruments can be inserted into the eye to remove the cataract with ultra-sound energy(phacoemulsification). The operation usually takes about 15 to 30 minutes and the patient is then observed for about 1-2 hours before going home.

What are the benefits of small incision cataract surgery?
Because the incisions are very small, about 1-2mm for the microincision technique, and require no stitching, rapid visual recovery can be achieved. There is now no need to wait for large wounds to heal as in the past, which can take as long as 3 months. As stitching also distorts the eye from being round like a football to something a bit like a rugby ball, no-stitch microincision cataract surgery provides good vision the very next day. This compares with the long recovery period of 3 to 6 months when stitches were used to close larger wounds in the past.

Is there any risk to cataract surgery?
Although cataract surgery does not take long, it is still a major operation in that incisions are made for instruments to enter the eye. Any operation that entails entry into the eye carries with it a small risk of blindness from infection, in the order of 1 in 1000. Other potential risks are vitreous loss, retinal tear and/or detachment and internal bleeding, which occur in about 5% of patients.

How do we see after removal of cataracts?
Because the lens focuses light rays onto the retina, removing it causes blurring of vision as the focusing ability of the lens is lost. To correct this, an artificial lens called the intra-ocular lens(IOL) is implanted in the eye. IOLs are made of a special biocompatible plastic material which have specific powers to again focus light rays onto the retina, thus restoring vision. IOLs do not need any maintenance and usually last a lifetime. They can also correct pre-existing short-sightedness, long-sightedness or astigmatism, and all the available options can be discussed with your doctor before surgery.

Injectable Foldable IOL

How do I care for my eye after cataract surgery?
When you are fit for discharge following observation in the day ward, it is advisable that you are accompanied by someone on your way home. You should return to the clinic the next day for a review and again thereafter within a week. During this period, if there is any development of eye pain, discharge or blurring of vision, please return for an immediate review. You should not drive for about a week or engage in water or contact sports for one month while jogging or going to the gym is not a problem after the first week.

Can cataracts grow back after surgery?
No, cataracts do not grow back after surgery and as such, it is a one-time operation. However, vision may gradually become blurry over time due to clouding of a membrane behind the IOL, called the posterior capsule. This may take place several years after surgery. An out-patient laser procedure is then required to create a small window in the centre of this clouded membrane to restore vision.

What are the results of cataract surgery?
Cataract surgery is one of the most successful operations carried out today with almost 99% of patients achieving driving vision(6/12) or better following surgery. However, results may vary when there are co-existing eye conditions like glaucoma, inflammation, diabetic eye disease, macular degeneration or lazy eye.

Take-home Message
Although there is no escape for anyone from developing cataracts as a natural ageing process, microsurgery with state-of-the-art techniques today can provide rapid visual recovery to enhance the quality of life in our later years.