Opacification of the natural lens within the eye is called a Cataract. The lens of the eye is responsible for focusing the light onto the retina, as we age this lens which is normally clear starts becoming opaque and the cause of which there is the difficulty of light reaching up to the retina. As the light doesn’t reach the retina that is a blurring of vision that the patient faces and he is not able to perform his activities as he would perform normally.
What is the normal age at which a cataract develops?
There is no specific age at which a cataract develops, some people may develop it earlier and some could develop it later. But that is the reason we say after 40 years everybody should have a routine eye examination to rule out cataracts and also to check the pressure of the eyes.
What are the causes of the cataract?
The most common reason for developing Cataract is age, so as we age opacification of the lens causes cataracts. The other reasons for developing cataracts could be an injury to the eyes, steroid use or abuse within the eyes, systemic diseases like diabetes could cause cataracts to form faster. In our digital world radiation also could be a reason for developing early cataracts.
The most common symptoms of Cataract are an unclear image seen at a patient and it is normally not associated with pain. Some patients could have glare issues at night and they would find driving difficult. Other patients could feel that the amount of light at night is lesser and they are finding it difficult at night. There could be fading of the colors; the brightness of the colors could be lesser, the sensitivity to bright light also could be there in some patients.
It could be difficult in reading fine prints for patients who have specific posterior capsule Cataract required for the Cataract patient. A routine comprehensive examination is done wherein vision is checked followed by refraction, wherein certain specific tests which can be done like testing the glare in different lighting conditions to see if there is potential for vision improvement there could be a potential activity testing, some patients could have a drop in there contrast sensitivity, so contrast sensitivity will be able to differentiate a patient who is having a cataract vs a patient who doesn’t.
Normally before cataract surgery, a routine examination also includes checking of eye pressure and dilated examination of the retina for which drops will be needed to be instant in the patient’s eyes for dilating the pupils. For the other tests that are done before cataract, once the cataract is diagnosed and a decision for surgery is taken, an Ascan test is performed to find the power of the lens that needs to be implanted in the patient’s eyes. So there are different types of scans for the same, one is the routine Ascan wherein ultrasound is used to check the lens power. Newer advances allow us to check this same thing with laser light and that gives us a better calculation of the lens power.
So in case, the patient is opting for a specific premium lens which would include maybe a multifocal or an extended depth of focas or multifocal lens in such a situation a laser scan is important. Other tests that could be required to be done in patients who are having mature cataract could require sonography to be done to see if the retina behind is normal. In certain other situations, some specific test like ERG might be required to perform if there is suspicion of retinal disease.
Recommend for cataract surgery is surgical so it cannot be treated with medicines and the newer techniques allow us to perform the surgery without any injections or any stitches that could be required to put on the patients. It is completely painless and no injections are used.
What are the types of surgeries that are done?
A routine surgery that was done in the past was small incision cataract surgery, now we have advanced to phacoemulsification surgery, it is also called a laser by many people and now we do also have a laser used for making the cuts on the eye. But the basic surgery procedure is done by the machine called phacoemulsification and that is used to perform the cataract surgery.
What are the lenses that can be implanted in the patient’s eye?
Earlier when phacoemulsification was not available, rigid lenses were used. But now with the availability of phacoemulsification, an incision as less as 2.8 mm can allow a foldable lens to be implanted within the eyes. There are special lenses that require even smaller incisions as low as 2.8, 2.2 and 1.8 mm incisions, so the incision is as small as a dot.
Depending upon the incision there could be different lenses that could be used; most commonly used lenses are foldable lenses, the others could have multifocal lenses where the ability to focus both for distance and near is available or we could use a toric lens which also takes care of the cylindrical number.
But multifocal lenses have a small issue of glare post-operatively and that is the reason now we have extended depth of focus lenses that do not give rise to glare and give good distance and intermediate vision with our additional benefit for near as well. The other lenses are the multifocal lenses which have the capacity for both distance and near and we have trifocal lenses which can distance intermediate and near as well. The other advances are micro-incision cataract surgery or the incision is even small and almost as low as 1.8mm and there again we require special lenses for which can go through the micro incisions.
Intraocular Lens (IOL)
It is a part of the surgery to fix cataract and an intraocular lens is implanted in your eye which is an artificial lens, replaced with a natural eye lens. The intraocular lens (IOL) is made of clear acrylic material which is easily foldable and placed into the eye at the time of cataract surgery which unfolds to its real shape and size. There are many types of lenses and they are Monofocal IOL, Monofocal Aspheric IOL, Multifocal IOL, Toric IOL and Multifocal Toric IOL.
Toric Foldable Lens
Toric lenses are excellent foldable lenses that are implanted through small self-sealing incisions. Toric lens are beautifully designed to correct nearsightedness vision with astigmatism or farsightedness vision with astigmatism. Many patients receiving Toric lens implants no longer need glasses for distance vision as toric lens provide good vision for focal distance only.
Multi Focal Foldable Lens
Multi Focal Foldable Lenses are new option for patients as they are small and micro incision for cataract surgery which is manufactured by world best companies and it provides clear and trouble free vision. The Multi Focal Foldable Lens is advisable for main implantation for the visual correction in adult patients and are planned to be placed in the capsular bag. It is designed for both near and far distance vision and gives freedom from spectacle.
An accommodative lens provides vision at various distances, similar to a natural crystalline lens. It also moves inside the eye which features distance, intermediate and near vision and makes the patient less dependent on contact lenses or glasses. The accommodative lens is mostly used in patients who have cataract and presbyopia. The cataract is known as cloudiness in the natural lens of the eyes and the presbyopia is known as the loss of focusing power of the natural lens that takes place in eyes who are older than 40 years.
Tecnis® Symfony IOL - Extended Range of Vision IOL
The newest addition to the TECNIS® Family of IOLs offers new optical technology for imparting an Extended Range of Vision. For treating presbyopia traditional IOL solutions consist of Multifocals and Trifocals, which work on the principle of simultaneous vision through splitting light into multiple distinct foci and Accommodative IOLs, which change in form and power while the ciliary muscle contracts. Traditionally with these latest technologies, the correction of presbyopia is generally a concept in terms of the distinct distance for which practical imaginative and prescient is provided.