All About Cataracts

All About Cataracts

What is cataract?

Cataract is the clouding or opacification of the lens inside the eye, which happens gradually, leading to progressive loss of vision. It commonly affects the older age group although any age group can be affected.

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Cataract

What are the causes for cataract?

Age is the most common cause for cataract. It is related to the degradation and metabolic changes in the lens’ proteins over time, which leads to the opacification of the initially clear lens. Environmental factors such as UV light exposure, radiation, tobacco and toxins may have cumulative effects towards the worsening of the process. It may also be accelerated by certain diseases such as diabetes mellitus. Other causes include trauma, secondary to certain medication such as corticosteroids and secondary to other eye diseases or eye surgeries. There is another group called congenital cataract which is mainly due to genetics, intrauterine infections and metabolic diseases.

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Picture showing the location of lens and cataractous lens

Is cataract preventable?

While we cannot stop the process of aging, prevention of UV light exposure by wearing sunglasses and smoking cessation may help slow down the development of cataracts.

What are the symptoms of cataract?

The main symptom is the gradual worsening of blurred vision. Some may have an increase in myopia in the early stage which can be corrected by glasses. Certain types of cataract may cause more night glare especially when the patient drives at night facing oncoming headlights.

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Comparison between a normal eye and an eye with cataract (patient’s right eye has cataract)

How do we treat cataract?

In early cataracts, symptoms may be improved with change of glasses, anti-glare sunglasses, or brighter lighting. However, if these methods do not help, surgery is the only effective method to remove the cataract. Generally, a cataract needs to be removed only when the symptoms interfere with patient’s daily activities, such as driving, working and reading. It is a decision to be made after weighing the benefits verses the risks of surgery.

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How cataract surgery is done

How is cataract surgery performed?

Modern cataract surgery is performed through phacoemulsification followed by implantation of an artificial intraocular lens. Phacoemulsification is a process where the lens is emulsified with an ultrasonic handpiece and aspirated from the eye. It involves the use of a machine with microprocessor-controlled fluid dynamics. Firstly, one or more small incisions (about 1.8mm-2.75mm) are made in the eye to allow the introduction of surgical instruments. After that, an opening is then made in the anterior capsule. The lens fibres, which form the nucleus and cortex of the cataract, are then removed leaving the posterior capsule to hold the new artificial lens. The surgery is assisted with the use of viscoelastic agents and balanced salt solution to maintain the anterior chamber and to protect the cornea. Before the advent of phacoemulsification machine, cataract extraction surgery involved manual nuclear expression.

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Dr Ong Ming Jew
Ophthalmologist
Regency Specialist Hospital Sdn Bhd

Will I feel pain during the surgery?

Majority of cataract cases are performed under local anesthesia. Some surgeons may use topical anaesthesia only. Some surgeons may give a little injection at the outer coating of the eyeball. You may feel a slight pain during the injection. After that, you shouldn’t feel any pain during the whole process of surgery. If you do feel pain, you can inform the surgeon and local anaesthesia can be added. You are aware of the whole process if surgery is done under local anaesthesia. A small percentage of patients may opt to do the surgery under general anaesthesia, for example patients with extreme anxiety and patients who are unable to follow instruction during surgery. You can always discuss with your doctor regarding the options before deciding on the surgery.

What are the risks involved in cataract surgery?

Although the risk for cataract surgery is low, it does involve the risk of partial to total vision loss if complication occurs. Some complications can be treated and vision loss reversed, but in certain cases, vision loss may be permanent. Complications that may occur with cataract surgery include infection in the eye (endophthalmitis), swelling in the centre of the retina (cystoid macular edema), swelling of the clear covering of the eye (corneal edema), bleeding in the anterior chamber of the eye (hyphema), detachment of the nerve layer of the eye (retinal detachment), dislocation of intraocular lens and opacification of posterior capsule. You should always ask your doctor regarding the risks before you decide on surgery.

Will I get cataract again after the surgery?

You will not get cataract again after you have had cataract surgery done. The intraocular lens is to be there permanently. The explantation of intraocular lens is very rarely done. If you have blurring of vision after the cataract surgery, you may need to refer to your doctor to look out for any complications.

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