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PostHeaderIcon Cataracts in Adults

A normal lens is clear. It lets light pass to the back of the eye and helps with focussing. A cataract is a cloudy area in the lens inside the eye, which blocks some of the light. As a cataract develops, it becomes harder for a person to see.

eye-anatomy

Cataracts are a normal part of aging. About50% of the US population aged between 65 and 74 have some cataract. About 70 percent of those 75 and over have this condition.

Most people with cataracts have a cataract in both eyes. However, one eye may be worse than the other because each cataract develops at a different rate. Some people with a cataract don't even know it. Their cataract may be small, or the changes in their vision may not bother them very much. Other people who have cataracts cannot see well enough to do the things they need or want to do. Cataracts may mean that a patient’s vision fails to meet legal driving standards.

SOME SYMPTOMS OF CATARACT

  • Cloudy, fuzzy, foggy, or filmy vision.
  • Difficulty reading
  • Changes in the way you see colors.
  • Problems with glare from car headlights, or the sun.
  • Frequent changes in your glasses prescription (increasing short-sightedness).

These symptoms also can be signs of other eye problems.

HOW IS A CATARACT TREATED?
A change in your glasses, brighter lighting, stronger bifocals, or the use of magnifying lenses may temporarily help improve your vision. Usually though surgery is necessary to remove the lens and replace it with an artificial intra-ocular lens (IOL) implant. This is one of the most common and most successful surgeries performed in the US today.

Just because you have a cataract does not mean it must be removed immediately. Cataract surgery can almost always be put off until you are unhappy with the way you see. Your ophthalmologist will tell you whether you are one of a small number of people who must have surgery. For example, your ophthalmologist may need to see or treat an eye problem that is behind the cataract. Or surgery may be required because a cataract is so large it could cause damage to other parts of the eye or could become more difficult to remove if left for much longer.

WHAT SHOULD YOU KNOW ABOUT THE SURGERY?
It doesn’t hurt.
Cataract surgery is performed in the operating room, but most people do not need to stay overnight in a hospital. However, you will need a friend or family member to take you home, as you may be given sedative medication during the surgery.

Painless Cataract Surgery
Cataract surgery is a painless experience. People usually stay awake during their surgery and can resume their normal activities shortly afterwards. Two kinds of Anesthesia are used to numb the eye: Topical Anesthesia and Regional Anesthesia.

Topical Anesthesia is very popular because injections around the eye are not required. Instead, drops are used to numb the eye. The anesthesiologist may give a sedative injection into the back of the hand to settle any “nerves”. No eye patches are needed, and people usually notice improved vision immediately after surgery.

Regional Anesthesia involves gently injecting numbing medications into the tissues around the eye. This mean the eye cannot see, move or blink during the operation. Regional anesthesia gradually wears off 2 to 4 hours after the surgery. The eye is patched for the first day and night and people begin to notice their improved vision by the next day. There are advantages to each kind of anesthesia, so the specific needs of each surgery patient will be carefully considered by the anethesiologist and surgeon in selecting the most suitable method of anesthesia. General anesthesia may rarely be used.

Removing and Replacing The Lens: No-Stitch Surgery
Your ophthalmologist uses phacoemulsification, an advanced technique that allows the cataract to be removed through a tiny, secure opening 2-3 mm long. The lens is removed by a small ultrasonic probe inserted through the incision. He also uses intraocular lenses which can be folded to fit through the same small incision. They then unfold within the eye. Once the lens is inside the eye is stays in position permanently.

This type of surgery means your recovery period is dramatically shortened and your eye recovers much quicker than previously. Normal activities such as driving, walking and sports can usually be resumed within a few days.

One of the side benefits of cataract surgery is an improvement in the focus of the eye after surgery. Often patients see much better in the distance. Reading glasses may be needed, and are usually prescribed by the Optometrist about 3 or 4 weeks after surgery. Some newer IOLs (see below) are able to give good vision for both distance and near vision, and less need for glasses. Tell your ophthalmologist if this interests you.

Before surgery the eye is precisely measured so an individual lens implant can be chosen for you. Your ophthalmologist uses the latest technology to determine the implant strength needed to give you the best possible vision.

CAN A CATARACT RETURN?
A cataract cannot return because the lens has been removed. However, in about 5% of all people who have phacoemulsification, the lens capsule later becomes cloudy. It causes the same vision problems as a cataract does. The treatment for this condition is an office procedure called YAG capsulotomy. Your ophthalmologist uses a laser to make an opening in the membrane behind the implant, immediately improving vision. This is done painlessly in the office with anesthetic drops, takes just a few minutes and does not require a hospital stay. Most people see better after YAG capsulotomy, but, as with cataract surgery, complications can occur. Your ophthalmologist will discuss the risks with you. YAG capsulotomies are not performed as a preventative measure.

IS CATARACT SURGERY RIGHT FOR ME?
Most people who have a cataract recover from surgery with no problems and improved vision. In fact, serious complications are very rare with modern cataract surgery. This type of surgery has a success rate of 95% in patients with otherwise healthy eyes. But no surgery is risk free. Although serious complications are extremely rare, when they occur they could result in loss of vision (see below).

If you have a cataract in both eyes, it is usual to wait two to three weeks until your first eye heals before having surgery on the second eye. If the eye that has a cataract is your only good eye, your ophthalmologist will weigh very carefully the benefits and risks of cataract surgery.

You will be able to make the right decision for yourself if you know the facts. Ask your ophthalmologist to explain anything you do not understand. There is no such thing as a "dumb" question when it comes to your health. You may wish to write down questions to ask your ophthalmologist to help you make an informed decision about treatment.

CATARACT SURGERY -THE OPERATION
The procedure is:

  • Drops will be put into your eye to dilate (enlarge) the pupil.
  • When you arrive in the operative suite, you will be given a mild sedative.
  • A painless anaesthetic will be administered.
  • The skin around the eye will be cleaned. Sterile drapes will be placed around your head and face. Your ophthalmologist’s specialist anesthetist will monitor you continuously to ensure your safety and comfort. A microscope will be positioned over your eye and you will be asked to look up towards the light of the microscope. The actual surgery usually takes about 20 minutes. Your ophthalmologist will stabilize your eye with a device to keep your eyelids open. You will feel no pain, only slight pressure on your eye and face. All you have to do is to relax and hold still.
  • The doctors will talk to you during the surgery to tell you what is going on. If you have any problems during the surgery, or you need to cough, you must speak up and tell your doctor.
  • After surgery you rest for a while. Most patients are able to leave within an hour.

OFFICE VISITS
Usually visits are scheduled at Day 1 or 2 after the surgery, and then a few days later, and then at week 3. If at any time you wish to see your doctor, however, you simply need to telephone for an appointment.

BENEFITS AND RISKS OF CATARACT SURGERY

Benefits: Improvements in Activities

  • Everyday activities: driving, working, reading
  • Moving around, safety (less risk of falls), independence
  • Social activities, hobbies
  • Less dependence on glasses

Risks: Possible Complications (all rare)

  • High pressure in the eye
  • Loss of cataract material into the back of the eye (may require further surgery)
  • Artificial lens damage or dislocation (may require further surgery)
  • Drooping eyelid (may require further surgery)
  • Infection inside the eye - can cause loss of vision (Occurs in about 1 in 2000 cases, and may require further surgery).
  • Retinal detachment or swelling (may require further surgery)
  • Severe bleeding inside the eye (may require further surgery)
  • Swelling or clouding of the cornea (may require further surgery)
  • Blindness (very, very rare)
  • Loss of the eye (extremely rare, but possible)

Cataract surgery is the most commonly performed type of eye surgery. The vast majority of cases, approximately 99% of the time, the surgery is uncomplicated. Cataract surgery usually results in improved vision and a well-satisfied patient. However, cataract surgery should never be trivialised. In a small percentage of patients, events occur which can lead to less than ideal results. Most of these events are known risks of the surgery itself and can occur even if the operation is performed well by an experienced surgeon. The occurrence of these events is often unpredictable. Patients should be aware of such possibilities when they decide to proceed with surgery. All risks associated with your cataract surgery are rare but treatable, and have already been carefully considered by your ophthalmologist before he recommends surgery to you. Your ophthalmologist will be happy to discuss any concerns you may have in further detail.

OPTIONS FOR FOCUS AND INTRA-OCULAR LENS (IOL) CHOICE

Until recently the only intraocular lens choice for most people has been a monofocal (single focus) lens with the focus set for distance vision. This means that reading glasses are required for near vision for that eye.

Blended Vision
Another option is to leave the second eye with near focus when that eye has its cataract surgery. This is called blended vision or monovision, where one eye is set for distance focus and the other for near focus. However, this means that the distance vision in the near focus eye without a spectacle lens is not as sharp as it could be. Many people (30%) find this situation very useful and some find it intolerable. This is how we give older patients (45 years or more) reading vision after laser refractive surgery. We can usually test for this tolerance before surgery, or between surgeries for each eye.

In recent years newer IOLs have been produced which partially mimic natural vision and allow simultaneous focusing at far and near, making reading glasses less necessary.

The Simultaneous Bifocal Intraocular Lenses
These Bifocal IOLs can potentially restore a dual range of vision for cataract patients. They provide the ability to simultaneously focus on faraway objects, and on objects that are near. The result is increased spectacle independence across a range of distances. Previously long-sighted patients find this lens most suitable. Short-sighted patients are not as happy with it.

Smudgy vision and haloes around car headlights at night (see diagram next page) are common annoying side effects with this type of lens, but this tends to improve after a month or two. A small percentage of patients (2% in US Clinical Studies) have been dissatisfied to the point of requesting replacement of the lens. Removal/replacement of the lens is more risky than the original surgery.

Vision under low light conditions is less sensitive than with monofocal IOLs.

The Simultaneous Bifocal lenses are reasonably good for reading. Intermediate (1m) focus is not clear, and computer glasses may be needed.

If the pupil of the eye is very small (less than 2. 5 mm) such as in bright sunlight, the near vision with these lenses may not be better than with a monofocal lens, and reading glasses may be needed.

Pseudo-accommodative IOLs
These lenses have a higher degree of flexibility than monofocal lenses. When the internal eye muscles act on them there is a change in their shape which can enable improved reading ability compared to monofocal lenses. However the reading vision obtained is not as great as with Simultaneous Bifocal IOLs, and a blended vision approach is often used with these lenses

Note: These options are not suitable for all patients. Your Doctor will discuss and recommend the most appropriate lens for your specific circumstances.


halo-effectHALOS:

The top image represents a night scene with a monofocal IOL, the middle one is said to represent the same scene through a diffractive IOL such as the Tecnis. However some patients with the ReSTOR and Tecnis do describe haloes as bad as the lower image.

The Simultaneous Bifocal lenses are more expensive and are not covered by most insurers. The surgery fee is often higher because of the greater complexity of assessing patients for the use of these lenses, and the extra tests that need to be done. About 10% of the time, fine tuning of the focus using the excimer laser is required to optimize vision. This is not included in the surgical fee.

Discuss with your ophthalmologist if you are interested in these lenses.


INTEROCULAR SURGERY RISKS

WHAT ARE THE RISKS ASSOCIATED WITH INTRAOCULAR SURGERY?
Cataract surgery is the most commonly performed type of eye surgery. The vast majority of cases, approximately 95% of the time, the surgery is uncomplicated. Cataract surgery usually results in improved vision and a well-satisfied patient. However, cataract surgery should never be trivialised. In a small percentage of patients, events occur which can lead to less than ideal results. Most of these events are known risks of the surgery itself and can occur even if the operation is performed well by an experienced surgeon. The occurrence of these events is often unpredictable. Patients should be aware of such possibilities when they decide to proceed with surgery. Some of the most common risks are reviewed in this article.

• Serious Infection (Endophthalmitis)

Ophthalmic surgeons normally make great efforts at the time of surgery to reduce the possibility of intraocular infection, which is called “endophthalmitis”. Patients usually receive topical antibiotic eye drops starting days before surgery. Just before surgery, the surface of the eye and the skin around the eye are cleaned with antiseptics, and the patients face except the eye is covered with sterile drapes. All instruments used are sterile, as in all modern surgeries. After the surgery is completed, topical antibiotic eye drops are used again. Nonetheless, even with these precautions, an intraocular infection, called endophthalmitis, occurs in approximately one out of 5,000 cases. Symptoms and signs of endophthalmitis include excessive eye redness, pain, light sensitivity, and worsening vision. In some cases, the patients may be fairly comfortable on the first day or so after surgery, but then worsen in terms of pain, vision, and light sensitivity several days later. Patients who undergo cataract surgery must call their ophthalmologist immediately if they worsen in these ways. If a patient develops endophthalmitis, antibiotics are often injected into the eye to treat the infection. Sometimes an additional surgery (vitrectomy) is performed to remove the jelly-like substance of the eye; this may control the infection. However about half of all eyes that develop endophthalmitis have severe visual loss.

• Cystoid Macular Edema

The retina is the nerve tissue which lines the entire inside of the back part the eye. The very center of the retina is called the macula, which is responsible for clear central vision. After cataract surgery, inflammation can sometimes cause retinal blood vessels to leak fluid, which accumulates in the macula, causing blurred vision. This swelling is referred to as “cystoid macular edema”. When vision is affected by macular edema, the ophthalmologist may recommend a specialized test in order to determine the extent of swelling. Ophthalmologists often treat macular edema with topical steroid eye drops and non-steroidal anti-inflammatory eye drops which help quiet any inflammation, often improving the situation over weeks or months. Sometimes injections of steroids behind the eye, or even intra-ocular vitrectomy surgery are useful in improving the vision.

• Corneal Edema

The cornea is the clear window on the front of the eye. Sometimes, following intraocular surgery, the cornea can become water-logged and hazy for a time, leading to a decrease in the clarity of the vision. Usually, but not always, the clarity will return after a week or two. Occasionally the cornea may remain cloudy. This is called pseudophakic bullous keratopathy. This can be remedied by means of another surgery; corneal transplantation. This problem is more common in people who have weakened corneas prior to surgery, such as those with Fuch’s corneal endothelial dystrophy, a premature degeneration of the cornea.

• Retinal Detachment

A retinal detachment occurs when eye fluid gets under the retina through a fine tear allowing it to separate abnormally from the back wall of the eye. A retinal detachment may cause a curtain across part or all of the vision of the eye. Retinal detachments can occur in patients who have not had any prior eye surgery, especially in patients who are highly myopic (short-sighted), and require surgery. However, cataract surgery increases the risk of retinal detachment. After cataract surgery, retinal detachments occur in approximately 0.5% of patients. You should contact your ophthalmologist immediately if you develop a curtain blocking the vision, flashes of light like lightning streaks, or new floating spots in your vision. These symptoms can sometimes indicate a retinal detachment.

• Posteriorly Dislocated Lens Material

In some instances, lens material can fall into the back cavity (vitreous cavity) of the eye. Often small pieces of posteriorly dislocated lens material are well tolerated by the eye without problems. When larger pieces are dislocated, the ophthalmologist may recommend a second surgery, called a vitrectomy and lensectomy, to remove the lens material. This removal prevents excessive inflammation and pressure from developing.

• Choroidal Hemorrhage

Rarely and unpredictably during cataract surgery, acute bleeding can occur in the choroid, which is the delicate pattern of blood vessels underlying and nourishing the retina. Although this complication, called “choroidal hemorrhage” is more common among elderly patients with high blood pressure, it is truly unpredictable. In some cases of choroidal hemorrhage, the bleeding is localized, and patients do well. In more severe cases of choroidal hemorrhage, visual loss can be substantial.

This article has been reproduced with the permission of Dr. Laurence Sullivan of Bayside Eye Specialists in Australia.