Information - Cataract Surgery

The lens of the eye is normally transparent. If a cloudy area develops in the lens, it is called a cataract. When the amount of light that passes through the lens is reduced and scattered by the cataract, images are not focussed properly on the retina at the back of the eye. The result is that vision becomes increasingly poor.

 

 

 

 

 The lens is contained within a clear membrane called the lens capsule which separates the lens from the iris and the transparent, thick fluid called the vitreous body.

 

 

 

 

Cataracts affect only the lens of the eye and will often worsen to the point where surgery is needed to remove the cloudy lens and replace it with a permanent artificial lens. If the eye is healthy, the likelihood is that cataract surgery will restore good vision.

With older surgical methods, both the lens and the capsule were removed. With modern methods, however, the capsule is preserved. This is a significant advance in surgical technique because:

·        The capsule is used to position the artificial lens.

·        Risks of surgery are fewer.

·        Vision following surgery is usually better.

Causes and Symptoms

Cataracts develop as a normal part of the ageing process. Diabetes, various chronic eye diseases, eye injury or excessive ultra-violet light may also cause cataracts. Cataracts usually develop slowly at a different rate within each eye. One of the earliest symptoms is glare and sensitivity to bright light. Later, as the cataract continues to worsen, haloes may appear around lights and colours often become duller and darker. Vision typically becomes more blurred, hazy and foggy, though near vision without glasses can improve.

 

Diagnosis and Treatment

Removal of a cataract may be necessary when vision has worsened to the point where daily activities are affected, or if personal safety is at risk. If vision is unaffected or only slightly affected by a cataract, no treatment is necessary. Cataracts cannot be cured by any type of medication, eye exercise, alternative therapy, diet or glasses – surgery is the only way to remove a cataract.

Your optometrist will:

·        Examine the external and internal structures of both eyes.

·        Assess your vision to determine how much vision has been affected.

·        Determine whether the cataract can be removed safely and successfully and refer you to the appropriate Ophthalmologist for this simple procedure.

·        Determine whether any other eye conditions or diseases are present and need treatment.

Preparation for Surgery

After you have discussed the treatment plan with your optometrist/ophthalmologist and have decided to have cataract surgery, other tests may be required. You will need to have your eyes examined to determine the optical power of the artificial lens that will replace the cloudy lens. This is called biometric analysis. You may also be asked to use eye drops for use before and after surgery.

About Artificial Lens Implants

The artificial lens is also called an “intraocular lens implant”. It is a transparent plastic disc with a shape similar to the neutral lens. Two plastic extensions press against the capsule and lock the lens in place in the back portion of the lens capsule.

Usually, the focus of the lens implant is fixed and can’t change. In some cases, the refractive result after surgery may be outside the intended range. Most people fitted with modern intraocular lenses won’t need spectacles for distance vision. However, others may require glasses for both distance vision and close vision.

The quality and safety of artificial lenses has almost eliminated the need for thick cataract glasses and contact lenses. Most lenses are made of silicone or acrylic, but other materials are under development. While these materials are safe and effective, if you think you may have sensitivity to any of them then let us know.

 

Surgical Techniques for the Removal of Cataracts

There are 3 different methods to remove a cataract.

1.     Phacoemulsification: The most common surgical technique where viewing the eye through a high-powered microscope placed above the patient, the surgeon makes a 3mm incision at the junction where the cornea meets the sclera. A small probe, which vibrates at high frequencies, is inserted to divide the cloudy lens into small pieces. The pieces are gently suctioned away from the lens capsule through the incision. The artificial lens is usually inserted into the lens capsule, the incision is normally so small that it often requires no stitches and after surgery, the eye is covered with a shield for protection.

 

 

2.     Extracapsular Cataract Extraction: This technique is less common. It is effective though, for those patients whose lens nucleus is too hard to remove using other techniques. The surgeon makes a 10-12mm incision at the border of the cornea and the sclera. The front of the capsule is opened, and the lens is removed. An intraocular lens is inserted and fixed in position.

 

 

3.     Intracapsular Extraction: This technique is rarely used, where your eye doctor removes the entire lens and lens capsule. If both lenses are affected by cataracts, your doctor will usually wait until the first eye has healed before operating on your second eye. Even if the surgery is successful in such patients, there is a possibility that vision will be improved only slightly or not at all.

 

 

Recovery from Cataract Surgery

For the 24 hours after surgery, don’t:

·        Drive or operate heavy machinery.

·        Make important decisions or sign legal documents.

·        Drink alcohol.

It’s best to have someone help you for a few days as you recover from the surgery. Your optometrist or nurse may give you additional after-care instructions. Most patients get sufficient relief from pain and discomfort by using pain-relieving medicines. Tell your ophthalmic surgeon or optometrist if you need stronger pain relief.

Within a few days of the surgery, your optometrist will want to examine your eye and check on your progress. So that your eye can be monitored and examined, visit your optometrist as scheduled. Recovery is usually quick. Soon after surgery, most people notice that their vision has improved. Glasses are still needed for reading. After the shield over your eye is removed, wear sunglasses if light becomes too bright.

Be careful that you:

·        Use eye drops as directed.

·        Don’t jar or stress the eye.

·        Don’t press on the eye or rub it.

After the eye has healed and adjusted to the intraocular lenses for several weeks, your eye will need to be tested again. You may need glasses and be given a new prescription.

Possible Complications of Cataract Surgery

·        Infection inside the eye.

·        Bleeding and blood collection within the eye.

·        Excessive inflammation.

·        High pressure within the eye.

·        Retained piece of cataract in the eye.

·        Damage to, or dislocation of, the artificial lens.

·        Detachment of the retina.

·        Drooping eyelid.

·        Swelling and clouding of the cornea.

·        Rarely, blindness and loss of the operated eye.

·        Further surgery.

 

Signs and Symptoms after Surgery

Tell you optometrist if you have any of the following signs or symptoms:

·        Fever more than normal body temperature.

·        Chills.

·        Increasing redness of the eye.

·        Increasingly blurred or disturbed vision.

·        Nausea or vomiting.

·        Excessive coughing.

·        Pain that is not relieved by non-prescription medications.

·        Any other concerns regarding your surgery.

Cloudy Vision after Surgery

Once the natural lens has been removed, a cataract can’t come back. However, in a few patients, vision after surgery may again become cloudy and hazy. This is due to clouding of the lens capsule behind the intraocular lens. An optometrist can quickly detect the problem and send you back to the surgeon who can correct this via a laser beam to create an opening in the cloudy capsule which will once again allow light to pass easily. This procedure is called a capsulotomy. If you need a capsulotomy, ask your optometrist to discuss its benefits, risks and limitations.