The SNEC performs about 10,000 cases of cataract surgeries a year and is well known for its surgical techniques in complex cases
IT COULD be blurred vision, red eye, or myopia that worsens after 21 years of age — these are the symptoms of cataract, which clouds the eye’s natural lens and interferes with a person’s vision.
This was what Mr Mohamed Ibrahim, 65, a patient of the Singapore National Eye Centre (SNEC), experienced when he complained of blurred vision in his left eye a year ago.
He had sought treatment at SNEC for another eye condition in the past. So he thought that his hazy vision was due to his age.
It was only when he was referred to SNEC for a check-up that he realised the vision in his left eye had deteriorated sharply because of severe cataract.
Associate Professor Chee Soon Phaik, a senior consultant ophthalmic surgeon and head of Ocular Inflammation andImmunology Service, and Cataract Service at SNEC, described it as an “advanced cataract which was shaky and unstable” — a complicated case that needed immediate attention.
“In Mr Ibrahim’s case, there was no view of his retina due to the density of the cataract. In addition, vitreous gel was seen in front of his cataract when it should normally be found only behind the crystalline lens.
“These features were all suggestive of a severe loss of the support structure of his crystalline lens, causing it to wobble as he moved his eye,” says Prof Chee, a pioneer ophthalmologist at SNEC since 1991.
In cataract surgery, which takes 15 to 30 minutes to perform, the main technique used in the operation is called phacoemulsification.
An ultrasonic device is introduced through a small incision of 1.8mm to 2.65mm on the cornea to break up the cloudy crystalline lens into small pieces and remove them from the eye.
After the cataract lens is entirely removed, an artificial lens implant is inserted into the same position. In most cases, the wound does not require any stitching.
In Mr Ibrahim’s case, Prof Chee took two hours to remove the cataract and implant an artificial intraocular lens.
The cataract and the condition of his eye necessitated more steps than the usual procedure and demanded a lot of Prof Chee’s surgical skills and techniques.
“Due to the lack of supporting structures for the cataract, a modified capsular tension ring was inserted to prevent the cataract from tumbling into the vitreous cavity of the eye so that I could safely implant the artificial lens,” she explains.
This ring ensures that the artificial lens is centred and stable.
The insertion of the capsule support ring and the suturing of this to the sclera (the white outer wall of the eye) are “technically very challenging and time consuming” for any cataract surgeon, she notes.
Prof Chee successfully removed the cataract, restoring 90 per cent of Mr Ibrahim’s vision in the operated eye.
With both eyes, he can perceive depth, which was hampered previously as he had normal vision only in his right eye.
Currently, 99 per cent of cataract surgeries at SNEC use phacoemulsification or the small incision method, which ranges from 1.8mm to 2.65mm. For the past three years, Prof Chee has been performing cataract surgeries through a 1.8mm incision.
“Not many surgeons like to do this incision size because it is quite difficult to manoeuvre the forceps through a tighter incision. A smaller incision is safer as the wound heals faster and there is minimal surgically induced astigmatism,” she says.
The standard of eyecare today is about the quality of vision for the patients, she adds.
The SNEC has been successful in this regard with 99.5 per cent of its patients achieving a visual acuity of 6/12 or better after the cataract surgery.
More importantly, she notes, SNEC often gets referrals from doctors in the Asian region for complicated cataract cases, such as displaced eye lens due to trauma to the eye or developmental issues that affect the support structure of the eye.
Some 80 per cent of cataract surgeries performed by SNEC are for elderly patients.
For senior citizens, SNEC is one of the first centres in the region to evaluate cutting-edge lenses such as accommodative lens and the multifocal toric lens, which are able to correct astigmatism and presbyopia.
“Previously, we only had lenses that could correct for presbyopia if the patient had no astigmatism,” says Prof Chee.
More than half of her patients now opt for multifocal lens implant.
The SNEC is also actively involved in studying new drug delivery systems that release antibiotic and/or steroid medication to the eye after cataract surgery. This will make it unnecessary for the patient to instil eye drops after surgery.
The SNEC has also developed new innovative techniques for intra-operative complications and complicated cataract surgeries, such as the one used by Prof Chee in Mr Ibrahim’s surgery.
Prof Chee is also involved in the design of fine intraocular instruments to improve the ability of SNEC to handle complicated cases. These instruments are used in surgical procedures that are more intensive.
“The research we do widens our repertoire of surgical techniques and improves our outcomes for our patients,” she says.
This is true for Mr Ibrahim, whose vision after the surgery has improved immeasurably. “I am seeing so well that I do not need to rely on eye glasses to assist me. I am able to go back to work and I am so grateful to Prof Chee for this,” he says.