EyeWise Vision Clinic

Cataract Surgery, Complex Lens Disorders & Iris Repair in Singapore

Dr Khng is experienced in complex cataract surgical techniques, having completed overseas clinical fellowships in the US in complex lens surgery and iris repair.

What is Cataract?

A cataract is the term given to any clouding of the normally clear human natural crystalline lens. This can occur as a result of normal ageing, or may be accelerated by some medical illnesses such as diabetes. Other types of damage to the lens from trauma, eye inflammation (iritis and uveitis), or certain drugs taken for other illnesses (corticosteroids) may also cause cataracts to form. The appearances of different types of cataracts are shown in these photos.

Surgery is the typical treatment recommendation for cataracts.

About Cataract Surgery

Cataract surgery is normally a quick and safe operation, usually taking about 15 minutes by an experienced surgeon. During this process, the old cloudy yellowed lens is removed through a tiny incision, and it is replaced by a new flexible man-made lens implant which is then inserted through the same tiny incision. The optical power of the new lens is usually chosen so that the patient will have good distance vision without glasses. These lens implants also make it possible for near vision to also be perfect. Other optical problems present before surgery may also be corrected at the time of cataract surgery, such as astigmatism (cylinder), myopia, hyperopia and presbyopia (ageing sight).
Although generally safe, cataract surgery has a complication rate of 0.5-5%, depending on the difficulty of the eye and surgeon experience. Fortunately, Dr Khng has trained under several surgeons around the world in difficult and complicated cataract surgery. He frequently is referred to cases for surgical repair when some surgeons encounter cataract surgery complications, or for the more complex cataract cases (pics).

Part of his time was spent as a visiting consultant in a major eye hospital in Singapore, where he sees only complicated cataract cases, and cases requiring treatment of cataract complications. Fortunately, many of these complicated cases can be satisfactorily repaired with no or minimal visual compromise. The repair of these cases requires major experience and exposure to specialized surgical techniques and implant devices, which include standard and modified capsular tension rings, special capsular and iris hooks, specialized sutures, as well as special lens implants that can be secured by stitching them to the wall of the eye in badly injured eyes.

For more information, contact us to book an appointment at our eye care clinic in Singapore.

Frequently Asked Questions About Cataract Surgery in Singapore

A cataract is what we call any opacification in the human eye lens. The normal eye lens is clear, but with age and certain conditions like diabetes and trauma, the lens becomes cloudy, leading to cataract formation.

Many people may discover they have a cataract when they make new glasses and still cannot see well, especially if they are over the age of 50. Cataracts usually cause a gradual, progressive, painless, blurring of vision in one or both eyes. Some patients also complain of increasing glare in bright light or difficulty seeing while driving at night. Certain types of cataracts also cause progressive myopia (increased short-sightedness) with frequent changes of spectacle power. If you are noticing any such signs, you can see a cataract eye specialist for proper diagnosis.

When you are no longer happy with the vision of your eyes and are facing difficulty in performing routine work or leisure activities, you can book an appointment with our cataract specialist in Singapore. After a thorough evaluation of your vision, the ophthalmologist may prescribe cataract surgery.

This was the approach applicable for old-style cataract surgery. A cataract does not need to be ‘ripe’ or ‘mature’ before it can be removed. With modern advances in cataract surgery, the lens can now be removed from the eye at any stage of development. In fact, surgery is much easier when the cataract is not too ‘ripe’ or ‘mature’.

No, cataract surgery is not painful. Numbing eye drops are applied to the eyes, so you won’t feel any pain.

No, cataract surgery is completely risk-free. One major complication that we try very hard to prevent is post-operative infection. There is less than a 1 in 1000 risk of this happening. Even if this happens, it can usually be treated.

Ideally, your surgery should be done by a cataract specialist, who is a surgeon trained to a higher level in advanced cataract surgery. Although every eye surgeon can do cataract surgery, the level of skill and training may vary. A cataract specialist experienced in dealing with difficult cataract surgery and complex lens repair would be preferable, as he would be familiar with dealing with cataract complications. Although cataract complications are not very common, you would want a surgeon with more experience in this area, when it is your turn to have your cataract removed. You can visit our ophthalmologist in Singapore for cataract surgery or for any complex eye issues such as eye trauma, sports eye injury, or glaucoma surgery.

No, your cataract will never come back again. What sometimes happens in under 10% of patients, a few years after surgery, is thickening and haze (called an “after-cataract”) of the lens envelope (capsule) that supports the lens implant. This leads to blurred vision similar to cataract, but is easily, painlessly and safely treated at a YAG laser to restore clear vision again.

Typically in Singapore, surgery for cataract removal takes 15 minutes on average, if done by an experienced surgeon.

After cataract surgery, you can expect your vision to improve within a few days as your eye heals and adjusts.

It is not necessary to wear glasses after cataract surgery, although some people may find them helpful for reading or other activities. If you do need glasses, your doctor, or eye specialist can prescribe the appropriate type and strength for you.

The most common complication of cataract surgery is a condition called posterior capsular opacification (PCO), also referred to as after-cataract. PCO occurs when the back surface of the clear lens capsule becomes cloudy. This can happen months or even years after surgery, and if left untreated, can cause blurry vision. Fortunately, PCO is treatable with a simple laser procedure.

About Dr Christopher Khng

Dr. Christopher Khng, specialises in Complex Cataract and Anterior Segment Reconstruction Surgery, in particular, Iris Reconstruction and Surgery for Aniridia. His other areas of expertise include Complex Lens surgery, New Lens and Phacoemulsification technologies, Refractive surgery, Phakic IOLs (the Implantable Collamer Lens, ICL), and small-incision, topical anesthesia phacoemulsification cataract surgery.

He completed his first two years of medical undergraduate studies in Aberdeen University, Scotland (UK), finishing top in his medical class in both years. Because of cost, he completed his medical degrees of MBBS at National University of Singapore (NUS).

Dr. Khng served as Registrar, then Associate Consultant Ophthalmic Surgeon at the Singapore National Eye Centre (SNEC). Following his stint in SNEC, Dr. Khng was a Consultant at The Eye Institute, Tan Tock Seng Hospital, Singapore.


Dr Christopher Khng

MBBS, M.Med(Ophth), FRCS(Edin), AMS(Ophth 2003) Consultant Ophthalmologist