Cataract Surgery: Causes, Symptoms and Treatment

Overview

Once it is confirmed that the patient has cataract, the treatment is essentially surgical. Whenever the patient feels his vision has decreased to a level where it interferes with his daily activities he can get operated upon (no longer is it required for the cataract to become mature). However, in certain cases where there are associated complications or potential risks of complications, an early (even urgent) operation may be required - here the advice of your Consulting Eye Surgeon should be followed.

The operations done for cataract are the following (the list includes only established standard procedures):

Phacoemulsification with foldable IOL
Small Incision Cataract Surgery (SICS) with Intra-ocular Lens (IOL) Implantation
Conventional Surgery (Extracapsular Cataract Surgery-ECCE) is virtually obsolete now

Phacoemulsification

It is a no stitch, no injection and no bandage small incision cataract surgery. In Phacoemulsification a very small incision (only about 3 mm) is made into the clear part of the eye (Cornea) and the hard core (nucleus) of the lens is converted into a soft pulp using high frequency sound waves (NOT Laser) and sucked out. Then a foldable lens (IOL) is injected through the small incision and positioned into the capsular bag. The main advantages of this operation are early rehabilitation and decreased occurrence of astigmatism (cylindrical power in glasses). Non-foldable IOLs are not preferred as they necessitate enlarging the incision and thereby sacrificing the advantages of the small incision. All these operations are done under local or topical anaesthesia that makes the eye numb/senseless, and the patient although conscious does not feel any pain. The general anaesthesia, which has its own risks, is used only in children and uncooperative patients. The preferred method of giving anaesthesia is topical or eye drops anaesthesia. This not only helps in avoiding the painful injections and the eye bandage, but also reduces the risk associated with injection anaesthesia (e.g., retrobulbar haemorrhage, globe perforations, etc.)

Intra-ocular Lenses (IOL)

Intra-ocular Lenses (IOL) are small (5-7 mm) lenses made of a soft polymer (Silicone or Acrylic) and are implanted inside the eye in place of natural lens. The greatest advantage of IOL is a clear wide field of vision and the fact that the patient does not have to constantly wear thick glasses. However, glasses with low power may be still be required especially for reading distant and near small print, because, unlike natural lens the IOL has a fixed power (estimated by doing Ultrasound of the eye) which is usually adjusted such that the mid-range or routine viewing distances are seen clearly. Since the IOL stays in the eye throughout life, no compromise should be made on the quality of the IOL. Multifocal IOLs oer the advantage of clear distant and near vision, hence, reduce the dependence on glasses, but suer the disadvantage of lower contrast, lower color saturation and a subjective compromise in image quality.

SICS (Small Incision Cataract Surgery)

SICS has virtually replaced the conventional cataract surgery for diffcult situations. Here, although the incision made is slightly larger (5-6 mm) and the nucleus is removed using fluid pressure, yet no stitches are required and the recovery is much faster and more comfortable than the conventional surgery.

To conclude, the surgeon, the surgical technique and the quality of the IOL are not the only factors that decide the result of cataract surgery. It also depends on the condition of the eye, the cornea, the retina and the presence of systemic diseases like diabetes, hypertension, asthma, infections, etc.

The quality of the operation theatres, the ancillary and the backup facilities, the training of the support staff, etc. also have a significant influence on the success of the surgery. Ensuring good quality in all these areas leads to an increase in the surgical cost for the patient, but it must be understood that our eyes are worth a lot more.

An IOL is a clear, polymer (Silicone or Acrylic) lens that is placed in the eye during cataract surgery. It does not need any after-care. With IOL one does not need to wear glasses for most of their work and moving about. Moreover, the area of clear vision is much wider.

Before surgery, some tests are performed including tests to measure the curvature and the length of the eye ball by a special ultrasound machine. This helps in calculating the power of the IOL to be implanted. Some other tests e.g., blood, urine, ECG, etc. may have to be performed to establish general fitness of the patient.

Most people after a cataract surgery can go home the same day. It's normal to feel itching, sticky eyelids, and mild discomfort for a while after the surgery. Some fluid discharge is also common. In most cases, reasonable amount of healing will take about 4 weeks. Mild pain, irritation, redness and watering is common occurrence after cataract surgery but subsides in a few days. Problems after surgery are uncommon, but they can occur. These can include infection (in severe cases Endophthalmitis), bleeding, higher pressure inside the eye (glaucoma), inflammation (pain, redness, swelling), haziness of the cornea and detachment of the retina. Any such problem should be immediately reported to the eye surgeon especially in the event of unusual pain, loss of vision, or flashing lights.

After the surgery, you can read and watch TV almost right away, but your vision may be blurry. The healing eye needs time to adjust so that it can focus properly with the other eye, especially if the other eye has a cataract. This healing period may take many weeks. With an IOL, for example, you may notice that colors have a blue tinge, and that after you've been in bright sunlight, everything is reddish for a few hours. It doesn't take long to adjust to these changes.

Sometimes people after cataract surgery develop an opacification of the lens capsule on which the lens is placed. This is called after-cataract. This can easily be treated by a Laser called YAG Laser which makes a small opening in the capsule - YAG Capsulotomy.

Regular eye examinations after the age of 50 years are mandatory to detect eye diseases early and to institute timely treatment. Prevention of exposure to UV rays by regular use of UV protective sun glasses may confer certain degree of protection. However, any research or studies do not support this conjecture.

The word 'cataract' brings up a lot of anxiety, doubts, myths, queries and fear in the mind of the person aected by it, or his/her kin. This brochure aims to clear such doubts and myths and educate you about cataract and its current methods of treatment.

Human eye has a natural lens, which is normally transparent and forms a clear image of the outside world in the eye. When this lens develops haziness/opacity, the sight is decreased or may be even completely lost. This is called cataract.

Cataract may develop at any age - right from birth to old age - but is most commonly seen in the elderly, after the age of sixty. By the age of ninety almost 98% of the people have had some degree of cataract.

In the old age, cataract may be caused due to the normal aging process, but, at a younger age, it may occur due to a number of reasons, e.g. some eye diseases like uveitis, general diseases like diabetes, heredity, injury, radiation, infections and many more.

The most important symptom of cataract is a decrease in vision for distance and/or near objects. Other features can be decreased vision in bright or low light, decreased contrast, altered colour appreciation, seeing many images of one object, rapid changes in the number/power of glasses, or sometimes pain, redness and watering. In advanced cases there is a complete loss of vision and the pupil becomes pearly white in colour. However, none of these symptoms are seen exclusively in cataract.

The first thing a person must do on experiencing any of these symptoms is to consult an Eye Surgeon (Ophthalmologist) for a thorough eye examination. Answers to the following questions should be sought:

Do I have cataract?
Do I have any other eye disease?
What is the cause of cataract in my eye?
What are the treatment modalities available?
What treatment would be most suitable for me?
What is the expected outcome of the surgery in my case?
What are the risks involved and possible complications?
How long can I wait before I get operated?
What does the surgery involve in terms of time and expenditure?

The lens is the part of the eye that along with cornea helps focus light onto the retina. The retina is the eye's light-sensitive layer that sends visual signals to the brain. The lens is located just behind the iris, the coloured (brown, blue or green) part of the eye. In focusing (accommodation), the lens changes shape. It becomes more convex (curved) when you look at nearby objects and flatter for distant objects.

The lens is made mostly of water and protein. The protein is arranged to let light pass through and focus on the retina. Sometimes some of the protein clumps together and starts to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it hard to see.

Although researchers are learning more about cataracts, no one knows for sure what causes them. Scientists think there may be several causes, including smoking and diabetes. Or, it may be that the protein in the lens just changes as it ages. There is also some evidence that cataracts are linked to certain vitamins and minerals. Exposure to ultra-violet light has definite role in the formation of cataract.

The most common symptoms of a cataract are:

Cloudy or blurry vision
Problems with light, such as headlights that seem too bright at night, glare from lamps or the sun, or a halo or haze around lights
Colours seem faded
Double or multiple vision (this symptom goes away as the cataract grows)
Frequent changes in eye glasses or contact lenses

These symptoms can also be a sign of other eye problems. In the event of any of these symptoms please consult an eye surgeon. In early cataract one may not notice any changes in vision. Cataract tends to grow slowly, so vision worsens gradually. Some people with a cataract find that their near vision suddenly improves (phenomenon of second-sight), but this is temporary. Vision is likely to get worse again as the cataract grows.

Age-related cataract: Most cataracts are related to aging.

Congenital cataract: Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may not affect vision. If they do, they may need to be removed.

Secondary cataract: Cataracts are more likely to develop in people who have certain other health problems, such as diabetes. Also, cataracts are sometimes linked to steroid use.

Traumatic cataract: Cataracts can develop soon after an eye injury, or years later.

A comprehensive eye examination usually includes:

Visual acuity test: This eye chart test measures how well you can see at various distances.

Pupil dilation: The pupil is widened with eye-drops to allow us to see more of the retina and look for other eye problems.

Tonometry: This is a standard test to measure eye pressure. Increased pressure may cause glaucoma.

Ultrasound (Biometry) of the eye to calculate the power of the lens to be implanted. Other eye and general test may be required to establish complete diagnosis and fitness for cataract surgery.

The treatment of cataract is essentially surgical and the timing is decided by the patient's visual needs. A cataract needs to be removed only if it affects one's vision so much that it interferes with one's daily activities. Patient makes that decision himself. If you have cataracts in both eyes, the operation on the two eyes is performed preferably in an interval of one month (unless there is any emergency).

Today, cataract removal is one of the most common operations performed in India. It is also one of the safest and most effective. More than 90 percent of the people who have cataract surgery have better vision afterwards.

Currently, phacoemulsification with a foldable intraocular lens implantation through a 3 mm incision is the most preferred method of cataract surgery and has the best results, all over the world. Other types of operations are performed in special circumstances.

Currently, lasers are not commonly used to remove cataract (although some patients mistakenly use the term Laser for Phacoemulsification). Research is under way to use lasers-Dodick in cataract surgery and some success has been reported.

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