Cataract & IOL Surgery

Before understanding cataract, it is important to know how a normal eye works. The eye is like a camera. The lens in a camera allows light to pass through and focuses that light on the film at the back of the camera for a clear picture.

The eye works in a similar way. The lens of the eye is normally clear and allows light to pass through. The light is focused on a thin film-like retina, which is situated at the back part of the eye. This is how we see.

It is a cloudiness of the normally clear lens in the eye. It prevents the lens from focusing light onto the retina and hence causes unclear vision. As the cataract advances, this cloudiness of vision increases over a period of time until the vision is completely impaired.

Cataract development is part of the normal ageing process. Almost all people above the age of 60 years have cataract of a variable degree, although it can occur at an earlier age also. In some people cataract development is aggravated by an eye injury, presence of diabetes, use of medications or other eye diseases. Rarely cataract may be present in the newborn as a developmental defect.

Because cataracts form in different ways, the symptoms of cataracts are variable. Most people notice that their vision gradually deteriorates and objects may begin to look yellow, hazy, blurred or distorted. Some people report double vision, or polyopia (objects appearing multiple). Many people also find that they need more light to see clearly, or that they experience glare or haloes from lights at night. A common problem encountered is increasing nearsightedness. In advanced cases, the cataract may be visible as a whitish-looking pupil.

Cataracts that occur due to the ageing process cannot be prevented as the ageing process itself cannot be prevented. Using the eyes for reading and similar activities has nothing to do with cataract formation. Avoiding the use of eyes will not prevent cataract.

Till date as per all authentic medical research no medication exists to prevent or cure a cataract. The only known treatment for cataract is surgery.

Cataract surgery can be performed as soon as the patient feels handicapped in performing routine activities at work and leisure. It is not advisable to wait for the cataract to mature as unnecessary delay can make surgery difficult and prone to complications. Modern cataract surgery can be performed successfully in any season including summers and the rainy season.

Modern cataract surgery is one of the safest and most successful forms of surgery. It requires a very short hospital stay and is generally performed under local or topical anesthesia. The patient is awake during surgery but does not feel any discomfort or pain. Patients are ambulatory immediately after surgery and are discharged on the same day. Cataract surgery at Saraswati Nethralaya is performed with sophisticated operating microscopes. A micro incision of 1.8 to 2.5 mm is first made in the eyeball (Step 1). A smooth round opening is then made in the front part of the lens capsule, which is a thin membrane enclosing the entire lens (Step 2). All cloudy lens material within the lens capsule is then removed through the same incision by the procedure of phacoemulsification using a thin titanium probe that emits high-speed ultrasound waves, vibrating at 40,000 times per second. This breaks the cataract into tiny pieces, which are then suctioned out of the eye through the same probe (Step 3). In the final step, a Foldable Intraocular Lens (IOL) is introduced through the small incision, and placed within the capsule of the lens where it unfolds and stays in place securely (Step 4).

Micro incisions such as those used in phacoemulsification seal themselves immediately after surgery and heal very quickly and allow one to return to normal work and activities within a few days. This is currently the most effective method for removing cataracts.

Great strides have been made in phacoemulsification technology. All top-of-of-the-line phacoemulsification machines currently available have the capability to deliver Cold Phaco which has the advantage of significantly reducing the ultrasonic energy to break up the cataract resulting in safer surgery and less damage to the eye, resulting in crystal clear corneas after surgery and faster visual recovery even in hard cataracts. These include Torsional Phaco (OZil IP Technology) available in the latest state-of-the-art Infiniti Vision System from Alcon, The WhiteStar Signature with Ellips FX from AMO, and The Stellaris Vision Enhancement System from Bausch & Lomb, which are all available at Saraswati Nethralaya for the benefit of cataract patients.

 

Your eye surgeon will be the best judge to decide whether you can undergo microincision phaco-surgery. Each patient undergoing cataract surgery at our centre is examined in detail to assess the endothelial count of the cornea . If the endothelial cell count is low we are using BSS Plus and Viscoat, which are imported medicines, to minimize loss of the already depleted endothelial cell counts during surgery.

 

1) Monofocal IOLs : These lenses provide good distance vision and most patients are not dependent on their distance glasses for daily activities. However, patients implanted with monofocal IOLs typically require reading glasses after cataract surgery.

In the recent years, monofocal lenses have been designed with aspheric surfaces. These state-of-the-art FDA approved aspheric or aberration-free IOLs greatly improve image quality by enhancing contrast, eliminating glare and haloes, and improving night vision.

2) Toric IOLs : These special lenses correct high cylindrical powers reducing the patient’s dependence on distance glasses.

3) Multifocal IOLs and Accommodative IOLs : These lenses are designed to provide good unaided distance and near vision with less dependence on glasses.

IOL power calculations at Saraswati Nethralaya are done by trained personnel and every endeavor is made so as to get very minimal post-operative power in the distance glasses. This is done using immersion ultrasound biometry for measuring the eye accurately before the operation. A new device called the IOLMaster is available at the centre which is capable of extremely accurate measurement of the eye and calculation of the IOL power.

 

Once the IOL is implanted in the eye, it remains in place for the remainder of one's lifetime.

Fortunately, the technological advances in IOL manufacture and surgery have made it quite safe. Complications are rare and similar ones can occur with conventional surgery without an IOL implantation. All patients irrespective of other general illnesses like diabetes, hypertension etc. can have IOL surgery. If there is any reason why you should not have an IOL your ophthalmologist will explain.

Until a few years ago cataract could not be removed with lasers. Surgery done by phacoemulsification was commonly termed Laser Surgery by layman people. Now, some of the steps of cataract surgery can be performed by Femtosecond Laser which has significantly improved the precision of some of the most critical steps that were traditionally performed manually. The femtosecond laser is a special laser which allows the surgeon to create high precision incisions. The femtosecond laser technology has already been in use in the recent years for creating precise flaps in bladeless LASIK with more predictable outcomes and increased safety.

More recently, the femtosecond laser is being utilized to assist or replace several aspects of the manual cataract surgery. These include the creation of the surgical incisions in the cornea, circular opening on the lens surface (capsulotomy), and breaking up (fragmentation) of the lens. The femtosecond laser can also be used to make incisions in the peripheral cornea to aid the correction of pre-existing astigmatism (cylindrical power).

 

In conventional phacoemulsification surgery, the surgeon makes the corneal incisions with a metallic blade, and manually creates an opening in the front of the lens capsule to gain access to the cataract, and then divides the cataract with a hand held ultrasonic probe.

In bladeless cataract surgery, the Femtosecond laser is used for these three critical steps of cataract surgery, i.e. to make the incisions, the opening in the lens capsule, and to divide the lens into fragments. Thereafter, the lens fragments are removed by the surgeon using the ultrasonic probe.

 

In both traditional cataract surgery and bladeless laser cataract surgery, microsurgical instruments are used in the operating room to remove the cloudy lens from the eye. The back membrane of the lens (called the posterior capsule) is left in place. An intraocular lens is placed inside the eye to replace the natural lens that was removed.

No surgeon in the world can perform a surgery with guaranteed results. However, almost all the patients regain good vision following cataract surgery. In certain cases, eye disease or problems in the cornea, retina or optic nerve may limit the potential for clear vision even when the cataract surgery itself has been successful. However, it might not be possible to evaluate the condition of the retina, optic nerve, in advanced cataracts.

 

Modern microsurgical techniques for cataract removal are highly successful procedures. The few complications that exist are becoming even more remote, with newer developments in surgical techniques and anesthesia.

Some minor complications that can occur include a slight drooping of the eyelid, swelling around the eye, corneal haze, reflections or slight distortion from the lens implant, which are usually temporary. The chances for serious complications are negligible. Possible serious complications include infection, severe inflammation, and hemorrhage.

In a majority of cases these complications can be treated successfully or may resolve on their own with a good final restoration of vision. The above list is however not exhaustive.

However, in a certain number of patients undergoing cataract surgery, the back part of the lens capsule may thicken over a period of time causing blurred vision. This is known as Posterior Capsular Opacification (PCO), secondary cataract or “After Cataract”. This is not a complication. The condition is treated with a R20;YAG Laser CapsulotomyR21; with full restoration of vision

There are numerous benefits of cataract surgery, many of which cannot be measured statistically. These include: 

• Improved colour vision  colours are brighter and more vivid
• Greater clarity of vision  vision is crisper and sharper
• Improved quality of life  studies have repeatedly shown that people enjoy an improved quality of life after successful cataract surgery. Many people can resume driving, reading, writing, watching television, sewing, household work and using a computer immediately after.

 

Even when retinal diseases or other problems prevent a total restoration of vision, the remaining vision is usually improved by cataract surgery.