Singapore Eye Surgey, Eye Care Clinic - Eye Retina Surgeons

Cataract Surgery

Cataracts are opacities in the normally clear human lens which blur vision; they generally occur with advancing age or as a result of some insult eg injury, drugs, inflammation. Everybody will get a cataract if they live long enough. Here is what cataracts look like:

Fortunately, cataract surgery done properly is arguably the most successful operation in any field of surgery. No other operation has success rates as high as cataract surgery. The surgery is quick and painless and vision returns rapidly.

At Eye and Retina Surgeons, it is no longer good enough to just remove a cataract and hope for a good visual result using glasses. It is part of our practice philosophy to try and give our patients excellent vision after cataract surgery without glasses or other visual aids.

Our aim for our patients is: Good Unaided Vision!

To achieve this ideal outcome requires attention to many details prior to surgery.

1. Consultation and Assessment
2. Biometry (Precise measurements of the axial length of your eye and the corneal curvature)
3. Choice of Intraocular Lens Implant (IOL)
4. Surgical planning

Consultation and Assessment

During your consultation, your pupils will be dilated so that the density and hardness of your cataract can be assessed. This has a bearing on the choice of machine used to remove your cataract. The harder and more mature your cataract, the greater the need for the most sophisticated equipment. Your eye will be assessed for other conditions which may have a bearing on the outcome of your surgery. Eg glaucoma, diabetic retinopathy, age-related macular degeneration. Your refractive state will be assessed: myopia, hyperopia, astigmatism and presbyopia.

Your doctor will then advise you as to whether you will benefit from cataract surgery and discuss the options with you.

Biometry

Once the decision has been made that you will benefit from cataract surgery, measurements need to be taken of your eye so that we can choose the most appropriate lens implant to replace your cataractous lens. This is called biometry. Remember that if we take your cataract out, we are actually taking your lens out and we need to replace it with an artificial one to allow you to see again.

We have state of the art equipment (IOL Master, Sonomed and Alcon RXP) that will measure the length of your eyeball and the curvature of your cornea. With these measurements, we will then have all the information we need to make an informed decision on the most suitable lens for you and your lifestyle.

Choice of Intraocular Lens Implant (IOL)

Currently there are three major classes of lens implants:

Monofocal IOLs

These IOLs are the simplest and yet give excellent visual results. Because they are monofocal in nature, in general they give the best quality of vision as few compromises are made in their design. Optically speaking, all lens systems should be aspheric in design and the best of modern monofocal IOLs are aspheric designs eg the Alcon Natural IQ and the Tecnis lens:

The Alcon Natural Aspheric Lens Implant

Toric IOLs

One of the most recent and most significant lens implant developments is the toric lens implant. Toric implants can correct pre-existing corneal astigmatism. Astigmatism is present in many of us and results in blurring of vision which usually requires glasses to correct. (Astigmatism is a condition of the eye in which the transparent cornea is shaped like a part of an egg rather than a sphere).

Hitherto, nothing could be done about astigmatism after cataract surgery apart from glasses or LASIK. The Toric implant now available has shown outstanding results in giving good quality vision after cataract surgery without using glasses. It requires exquisite surgery and precise implant placement.

The Toric Lens Implant for correcting pre-existing astigmatism. Note the line of three dots on each side of the lens which shows the angle of the astigmatic correction.

Multifocal IOLs

One of the main problems after traditional cataract surgery with a monofocal lens implant is that the eye is normally 'set' for good distance vision. Reading requires reading glasses. This condition is called surgical presbyopia or 'lao hwa yen'. Physiological presbyopia occurs after the age of 40 in all patients.

A multifocal lens design called the Restor implant (because it restores the vision of youth) allows a post-cataract surgery patient to see well for far as well as near without the need for glasses at all. Dr Yeoh was an early user of the Restor multifocal lens implant when it was introduced to Singapore in 2004. Indeed Dr Yeoh is a trainer for many surgeons in the Asia-Pacific who are starting to use this lens.

Dr Yeoh found that more than 90% of his patients after the Restor lens was implanted did not need glasses at all.

The Restor multifocal lens implant: note the concentric rings in the lens which confer the power of multifocality

Patients who wish to have these more sophisticated lens implants should have healthy eyes with no other problems apart from cataract. They will then gain maximal benefit from these implants.

Some patients are unable to have a multifocal or accommodative lens implant inserted because they have high astigmatism or extreme myopia/hyperopia. For these patients, the concept of monovision may well be effective in giving a range of far and near vision. In the monovision option, the first eye that is operated is targeted for a zero degree outcome which gives excellent distance vision, but relatively poor near vision (that’s just physics at work!) The second eye that has the cataract surgery is then targeted for about -1.5D or 150 degrees myopia. With this level of myopia, a patient can have what I term ‘social reading vision’ ie computer usage, filling in forms, reading menus and importantly putting on and taking off make up! The two eyes blend the distant and near vision to give an effective range of vision. As the disparity between the two eyes is only about 1.5D or 150 degrees, the eyes and brain are quite comfortable with this arrangement. ( A difference of up to 4D or 400 degrees is tolerable)

Note that all the three implants shown above have a light yellow tint which mimics the colour of the natural human lens and offers retinal protection from potentially harmful blue light wavelengths. It is incorporated in all these lens designs for this reason.

Planning for surgery

Modern state of the art cataract surgery uses ultrasound to break up a cataract into small pieces so that it can be sucked out through a tiny 2.6mm incision. This operation is known as phacoemulsification (phaco) of cataract with insertion of a foldable lens implant.

Traditional phaco uses longitudinal movements of a metal tipped instrument (the phacotip) to break up the nucleus. Whilst this is effective, there are a few drawbacks; the back and forth movement of the phacotip results in wasted energy on the backward stroke and unwanted heat generation potentially causing damage to the eye. This movement also sometimes caused parts of the nucleus to fly away from the phacotip during the forward stroke resulting in inefficiency and potential damage to the eye.

A new and revolutionary way of removing cataracts by using a new design in which the phacotip moved from side to side was invented by leading American eyecare company Alcon. This is called Ozil or torsional Phaco. This overcame both the above problems effectively.

We will use this latest and most efficient way of removing your cataract quickly and reliably. Again, our surgeons were the first in the region to use and optimize the latest phaco machine in the removal of complicated and advanced cataracts.

The picture is showing the Phaco instrument removing a cataract

In general, your operation will take about 15 minutes and is almost always done under local anaesthesia; regional (injection) or topical (eye-drop) as day-case surgery. An anaesthetist will stand by to monitor your general condition and deal with any medical situations that may arise.

The operation is painless and you can expect to see better by the next morning.

Post-operative recovery

The eye may feel slightly uncomfortable a few hours after surgery when the anaesthetic wears off. In general, there should not be much pain. You will be given an eye shield to wear at night so that you do not rub your eyes accidentally in your sleep.

Eye drops will be given to prevent eye infection and inflammation.

After 3-4 weeks, your eye should be stable and a refraction will be done to see if you need glasses. If so, glasses can be made at this stage.

Summary

In the past, cataract surgery tended to be done only in elderly patients whose cataracts were 'ripe' and the objective was to give the cataract patient back his eye sight with the use of glasses.

This mindset has now changed because with the latest techniques of removing cataracts and the new generations of premium lens implants, cataract surgery has now become lifestyle surgery where apart from merely removing an opaque lens and replacing it with a standard lens, we can now give excellent vision to everyone with cataracts. Indeed, many patients with early cataracts often choose to undergo early cataract surgery so they do not need to wear glasses!

At ERS, we are closely linked to the market leader in cataract and IOL technology, Alcon and we pledge to use the safest and most efficient surgical techniques and lens implants available to ensure an excellent outcome for you.