Cataract白內障
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What is cataract?
Cataract meanscloudiness of the eye's lens, which is crystal clear when we are young. The clouding, like graying of hair, is just part of the aging of your body.
The lens normally functions like the camera lens, and helps in focusing. An non-transparent lens prevents light from entering the eye, causing a reduction in vision.
What are the causes of cataract?
What are the symptoms if I have cataract?
Vision becomes blurred. Colours become dulll or washed out; and one becomes easily be dazzled by lights, such as those from sunlight or the light of a car's headlamp.
What are the treatments for cataract?
Cataract is irreversibleunless surgically treated. No eye drop, tablet, injection can treat it. The clouded lens has to be removed and replaced by an artificial lens or intraocular lens (IOL). Tens of thousands of people receive the surgery every year in Hong Kong.
Is cataract surgery a risky operation?
Not really. With modern cataract surgery, which uses ultrasound instead of surgical knife to remove the clouded lens, chances of severe complication is less than 1%, one of the lowest among all types of surgeries. Using micro-incision, the wound nowadays is only 3.0mm or less (less than the thickness of a Hong Kong $5 coin). The marked reduction in wound size translates directly into reduction of complications. Surgery by ultrasound typically only needs 10 to 15 minutes under local anaesthesia. Patient can choose whether to stay in a hospital or not. This is a great advance over conventional surgery, which has a big wound and requires stitches.
Should I wait till the cataract is ‘ripe’ before having the surgery?
Definitely No. This is a common misconception.
If the cataract is too mature and too hard, the ultrasound will not be able to "dissolve" it. Typically, once you notice an obvious blurring of your vision and yet you wait for several years, by the time you receive surgery, the hardness of your cataract will impose unnecessary difficulty and even danger on the operation.
Do I need to wear glasses after surgery?
In most cases it is not necessary. Removal of pre-existing short- or long-sightedness can be done by putting in an artificial lens with an appropriate power.
Do I need bed rest after the surgery?
Patient can carry out usual daily activities right after surgery, like walking, eating and watching TV. Contact sport and swimming should be avoided for a month.
In general, modern cataract surgery is quick, safe, lasting and effective. The most important thing is to avoid necessary delay, until a point that modern small wound cataract surgery cannot be done.
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什麼是白內障？
白內障是眼睛內的晶狀體出現混濁或不透明的現像。年輕時，晶狀體為透明的，隨著年歲，晶狀體會變得混濁。情況就如頭髮變白一樣。
晶狀體的作用有若相機的鏡頭，使眼睛能準確對焦。濁的晶狀體使光線無法透過，導致視力減退。
白內障成因為何？
白內障有何徵狀？
病人會感到視力減退，對色彩的敏感度亦會減低。患者會有畏光情況，特別是陽光及車頭燈。
如何治療白內障？
醫治白內障唯一方法是用手術切除，並植入人工晶體。至今並無藥物或其他方法可治療白內障。在香港，每年有超一萬人接受白內障手術。
白內障手術的風險高嗎？
白內障手術的風險並不高，嚴重併發症的機會率低於 1%，比一般外科手術要低。現今的白內障手術運用微創技術，以超聲波進行。傷口小於 3 毫米 (比一個香港 5 元硬幣的厚度小)。手術以局部麻醉完成，病人並不需要住院。比較傳統的手術，傷口較小，並不需要縫針。
白內障要熟了才動手術的嗎？
這是錯誤的觀念。白內障太硬，超聲波無法將其乳化，，返而會大大增加手術的風險。可是，一般病者往往在輪侯手術幾年後，白內障巳經變得相當硬。
手術後要帶眼鏡嗎？
多半不需。人工晶體可一併矯正度數。
手術後要卧床休息嗎？
大多數的活動，如行走、進食、看電視等都可以如常進行。首一個月應避免接觸性運動和游泳。
現代白內障手術為一快捷、安全和有效之手術。病者應避免延誤手術，以致因白內障太『熟』而無法以微創方法完成。