Cataract surgery is a safe, effective and common surgery that can allow some patients to be totally free of spectacles.
Cataract surgery combined with advanced technology intraocular lenses for better vision
VISUAL impairment affects a person’s life, as it significantly impacts functionality while contributing to various social, economic and psychological issues. According to the World Health Organisation, cataract is the most common cause of blindness and visual impairment.
The 2014 Malaysian National Eye Survey II revealed that cataract accounts for 58.6% of blindness in those aged above 50 years. Treatment of avoidable causes of blindness, especially cataract, has been shown to improve quality of life, boost overall cognitive health, and promote such individuals’ social and economic status.
In tandem with these observations, the development of advanced technology intraocular lenses (AT-IOLs), which include presbyopia-correcting intraocular lenses (PC-IOLs), has advanced the visual and refractive outcomes of cataract surgery for patients.
Today, patients have greater expectations for their vision outcomes and often desire spectacle independence. These can be achieved through cataract surgery with the implantation of advanced technology intraocular lenses.
Eye examinations can have a life-changing impact on the detection and prevention of vision loss and blindness.
What is a cataract?
Cataract is an opacity in the usually transparent focusing lens of the eye that interferes with clear sight as it becomes denser and cloudier.
“If one regards the eye as our precious window to the world, then a cataract will represent a cloudy, opaque windowpane that prevents us from seeing the world around us clearly,” says consultant ophthalmic surgeon Dr Cheong Fook Meng.
Cataract is an age-related condition; it becomes more prevalent with advancing age.
Dr Cheong goes on to explain that the symptoms of cataract include blurred or cloudy vision, glare and sensitivity to bright lights, double vision in one eye, poor night vision and the need for brighter light to read, frequent or sudden changes in spectacle prescription, changes in the way colours are perceived (faded, washed-out colours), or a sense that something is blocking the vision.
“Individuals with visual symptoms should consult their ophthalmologists early to check if they have cataract or other eye conditions. When vision is affected by the development of cataract, the treatment is to remove the cataract surgically and have a new intraocular lens implanted to restore vision.
“One should consider having cataract surgery when the visual impairment from cataract begins to affect the quality of life and the ability to perform routine daily activities, such as reading or driving. It should also be noted that visual impairment in the elderly increases the risk of falls, which may result in more severe complications such as fractures.
“If left untreated, the cataract will continue to progress gradually, causing further blurring of vision and leading to blindness eventually. Apart from surgery, there are currently no medications that are proven to reverse the cataract formation or to prevent it from developing,” Dr Cheong highlights.
He adds, “Cataract surgery is a safe, effective and common surgery. Recovery from cataract surgery is rapid. The patient will usually be able to appreciate the clearer and brighter vision after one or two days and resume most daily activities after a few days.”
He shares that the cost of cataract surgery depends on the severity of the cataract, the health of the eye and the types of intraocular lenses (IOL) chosen. The common types of intraocular lenses are the monofocal and multifocal (presbyopia correcting) IOLs, with or without toric correction for astigmatism.
It is best to discuss the lens options with the ophthalmologist as the operation, and the intraocular lens type are customised according to the ocular status and the patient’s lifestyle requirements.
Presbyopia
Presbyopia is the gradual loss of the eye’s ability to focus on near objects, resulting in the loss of the ability to see things up close.
Dr Cheong explains that presbyopia is a natural part of ageing and usually becomes noticeable around age 40. “It continues to worsen till age 65 when the eye loses nearly all its ability to focus on near objects.
“This is due to the progressive hardening of the ageing lens in the eye, making it less flexible and no longer able to change its shape easily to focus on close-up images.”
There are other medical conditions which increase the risk of getting presbyopia before reaching the age of 40. These include diabetes mellitus and multiple sclerosis.
“Certain medications, such as anti-depressants, anti-anxiety drugs and diuretics, are associated with early onset of presbyopia. Presbyopia can be diagnosed objectively by a thorough eye examination which includes a refraction assessment of the eyes to measure how well the eye can see at specific distances,” he shares.
Its symptoms include a tendency to hold reading materials further away to make the letters clearer, blurred vision at normal reading distance, headaches or tired eyes and a need for more light when reading.
He adds, “When presbyopia symptoms occur in the presence of developing cataract, the surgical treatment of choice would be cataract surgery with implantation of a new IOL. The eventual choice of the type of IOL to be implanted is made by the patient in consultation with the ophthalmologist based on the patient’s lifestyle requirements, visual demands and the degree of spectacle independence that the patient desires.
“The health of the eye is an important consideration as well, as not all eyes are suitable for all types of IOLs.”
Types of IOLs
The common types of IOLs available in Malaysia can be categorised into three main groups:
> Monofocal IOLs: Focus light onto a single image at a fixed distance.
> Toric IOLs: Selected when there is a significant degree of pre-existing astigmatism and are available as monofocal IOLs and multifocal IOLs.
> Multifocal IOLs (also referred to as presbyopia-correcting IOLs, or PC-IOLs): Designed to provide good vision for various distances such as far, intermediate and near.
PC-IOLs are designed to provide good vision for various distances such as far, intermediate and near, says Dr Cheong.
On the PC-IOLs, he elaborates that these technologically advanced lenses allow the patients to be spectacle free for most of their daily activities and visual needs.
Currently, the two most common types of presbyopia-correcting IOLs are the trifocal IOLs and extended depth of focus (EDOF) IOLs.
“The latest generation of non-diffractive EDOF IOLs are exciting as they work by modifying the shape of the light waves that strike the transitional elements on the anterior surface of the IOL to stretch the single good quality image formed for far distance vision towards the intermediate distance range,” he shares.
He adds, “EDOF IOLs allow the patients to extend their vision from far distance to the intermediate range without requiring spectacles, and without compromising on the quality of vision. This extended range of vision for the patient can be broadened further by targeting one eye for distance vision and the other eye to be a little short-sighted to improve the intermediate and near vision in that eye.
“Patients can have functional near vision allowing them to reduce their need for spectacles for near work activities. The advantage of the new non-diffractive EDOF IOLs is that the image quality is practically as good as that of a single focus monofocal IOL, whilst providing a broader range of vision compared to the monofocal IOLs.”
“The choice of IOLs is dependent on the patient’s visual needs, preferences and tolerance of potential visual side-effects.
“For individuals who do not want to rely on spectacles at all, many are very happy with the spectacle independence that the trifocal IOLs can provide for all their visual requirements. They may experience a bit of glare and see haloes around car headlights and streetlights when they are out at night, but they can usually adapt to it in exchange for the freedom from spectacles or contact lenses in their daily lives.”
He adds: “In contrast, patients with monofocal IOL implants do not see haloes or glare as the monofocal IOLs are single focus lenses, and they provide the best image quality. “However, patients with monofocal IOLs generally need reading glasses for detailed near work.
“Cataract surgery combined with the implantation of appropriate advanced technology intraocular lenses can improve the visual impairment caused by cataract and advancing presbyopia that develops in the ageing eye.
“Early consultations with ophthalmologists would be beneficial in detecting visually significant cataracts and addressing other refractive errors. Cataract surgery is a once-in-lifetime opportunity to restore visual vitality and reduce spectacle dependence.”
Dr Cheong Fook Meng is a Consultant Ophthalmic Surgeon at Gleneagles Kuala Lumpur. This article is brought to you by Alcon Malaysia.
