Cataract
Cataract are the leading cause of blindness worldwide. The World Health Organization (WHO) reports that an estimated 19.34 million people globally are blind due to age-related cataracts, accounting for 43% of all cases of blindness.1 As the population grows and lives longer, the number of blind people and the rate of cataract blindness in the world will continue to rise. Common cataract symptoms include blurred vision, glare, landscape colours becoming dull, etc. Minimally invasive phacoemulsification is the most common type of cataract surgery. It requires the implantation of IOL (monofocal lens or multifocal lens) without hospitalisation and replacement after the surgery.
1Source: World Health Organization
What is Cataract?
A cataract is a change in the protein of the lens in the eye that gradually degrades, hardens, and becomes opaque, so that vision is blurred as if covered by a foggy lens. The disease is likely to occur in one or both eyes, which, however, do not spread or infect each other. The condition varies depending on the location and degree of clouding of the lens. Vision loss also varies from person to person and can be severe enough to cause blindness.
Symptoms of Cataract
Early-stage cataracts do not show any obvious symptoms, but as the condition becomes more severe the following symptoms may occur:
Blurred vision
Glare appears
Landscape colours
become dull
Double or multiple
vision in one eye
Refractive errors get worse
(myopia, astigmatism)
Causes of Cataract
Ageing of the lens
with ageing
External Trauma
Excessive ultraviolet- /
infrared-light exposure
Metabolic diseases
(e.g. diabetes)
Drug-induced
(e.g. prolonged use of steroids)
Other eye illnesses
(e.g. high myopia)
Congenital or genetic factors
Phacoemulsification
白內障切除手術
As there are no medications that can restore clear eyesight from cloudy vision resulting from cataract, surgery is the only recognised effective treatment.
Phacoemulsification, or phaco, is the most common type of cataract surgery. It requires only local anaesthesia. The main surgical procedure is the use of ultrasound to emulsify the cloudy lens into fragments which will be aspirated from the eye. Finally, an intraocular lens will be implanted. After the surgery, when all opacified materials have been removed, light can be refocused on the retina. Vision can be restored and refractive errors corrected at the same time. The operation is not long and can be done in a day surgery centre so patient can go home directly afterwards.
Local anaesthesia
Go home on the same day
of the surgery
Surgery can be
as short as 10-20 minutes
Minimally invasive
傷口小
Refractive error can be corrected with use of different type of intraocular lens
(myopia, hyperopia, presbyopia and astigmatism)
Low risk of wound
infection and complications
Local anaesthesia
Go home on the same day of the surgery
Surgery takes only 10-20 minutes
Minimally invasive
Refractive errors corrected (myopia, hyperopia, presbyopia and astigmatism)
Low risk of wound infection and complications
Steps of Phacoemulsification
Types of Intraocular Lens (IOL):
| Monofocal Lens | Multifocal Lens (Trifocal) | Multifocal Lens (EDOF) | |
Features
|
Good vision at one distance | Good vision at multiple distances | Good vision at multiple distances + Extended depth of field |
Field of view
|
Excellent, delivers good vision at far, medium or near distances | Excellent, delivers good vision at far, medium or near distances | Excellent, delivers good vision at far, medium and near distances; continuous vision at a range of distances; less halos and glare |
Astigmatism
|
Optional | Optional | Optional |
Limitations
|
Inability to focus on near and far vision at the same time | Inappropriate for people with high vision requirements at night, such as night-shift drivers | Absence of trifocal features for near distance |
Suitability
|
|
|
|
Preparing for Cataract Surgery
- Comprehensive eye examination, including vision exam, corneal exam, etc.
- Choose the right IOL according to your doctor's recommendation
- Please follow your doctor's advice when prescribing medication for pre-operative use if necessary
- Please inform your doctor in advance if you are taking medication for a long period of time
- It is advisable to arrange for family or friends to pick up after the surgery
- You can eat and drink as usual before the operation
Postoperative Care
- Follow your doctor's instructions on the use of medication to prevent infection and reduce inflammatory response
- For 1 to 2 weeks after surgery:
- Do not rub or scratch your eyes at any time
- Do not bend over to wash your hair or shower to prevent splashing water into your eyes
- Avoid strenuous exercise, running and jumping to prevent increased intraocular pressure which may affect wound healing
- During the first week of recovery, it is recommended to wear an eye shield when sleeping to prevent unintentional contact with the wound
- Follow up on your doctor's advice to ensure you are well after surgery
Cataract Surgeries Programme
(白內障手術資助計劃)
Our ophthalmologists are among the designated doctors for the Hospital Authority's Cataract Surgeries Programme.
Eligible persons are welcome to receive cataract treatment at our Centre.
Details of the Programme can be found here.
Cataract FAQ
Should I wait until the cataract get mature?
Over clouding of the lens or over hardening of the nucleus will affect the surgeon's judgment and make the operation more difficult
The larger the lens, the larger the incision during removal and the longer the recovery time
Delayed treatment may lead to complications such as glaucoma and inflammation
Can cataract surgery alleviate other eye problems?
It can reduce refractive errors (myopia, hyperopia, presbyopia, astigmatism).
Will cataracts recur after surgery?
No, because once implanted, IOLs can be used for life without replacement unless they fail to adapt or meet daily needs.
Does cataract surgery need to be done in hospital?
No. Cataract surgery is a minimally invasive procedure. Although the patient is awake for the treatment, most patients do not feel pain and can go home the same day.