Cataract is a condition of the eye wherein the eye lens becomes progressively cloudy or opaque. This decreases or blurs vision over time and may even cause blindness.
There are many causes of cataract but aging is the most common factor. Cataract mostly affects those who are above 40 years of age.
Signs and symptoms
People with cataract commonly experience difficulty appreciating colors and differentiating changes in contrasts. Difficulty in driving, reading, recognizing faces and coping with glare from bright lights are other common symptoms of cataract. Moreover, the color of your pupil may also undergo some change.
Cataract can be treated by conventional surgery. The main aim of the surgery is to remove the natural cataractous lens (the foggy one) and replace it with an artificial clear lens called IOL (Intra Ocular Lens).
MICS: One of the modern techniques uses a specialized 'Phaco' machine to send a probe through a 1.8 mm incision close to the eye and removes the cataract. This procedure is called the MICS (Micro Incisional Cataract Surgery).
Small Incision Cataract Surgery (SICS) is a keyhole surgery technique used to manually squeeze out the cataract through a small incision. The size of the incision varies from 6 mm to 7.5 mm depending on the magnitude of the cataract. As the incision size is larger compared to the one used in the Phaco machine procedure, it requires a couple of sutures for faster wound healing and better vision. However, the patients would have to rest for a longer time and take extra care as a larger incision takes more time to heal.
The size of the incision in SICS is at least 6 mm and therefore uses a 6 mm rigid lenses which is cheaper and fits better instead of an expensive injectable lens which a requires a smaller incision and may not fit properly. Though this makes SICS a bit cheaper than the computerized machine phaco procedure, it has its own disadvantages as mentioned above.
MICS ( micro incision cataract surgery) enables the implantation of third generation ultra-thin, foldable Intra ocular lens called MIL (Micro incision Intraocular Lens) through a 1.6 mm - 1.8 mm fissure. This uses the most advanced cataract removal system in the world - "
MICS makes this procedure very safe and absolutely painless. It takes less time and is highly accurate. The vision improves instantly in a matter of minutes and no padding or bandaging is required after the surgery. In fact, you may even be able to drive back on your own and recommence your daily routine on the same day (or the next day at most).
IOLs (Intra Ocular Lens) are artificial lenses which are surgically implanted in the eye, replacing the eye's natural lens removed during cataract surgery. These lenses help your eye regain both the focusing and refractive ability. These IOLs may be used to treat myopia, hyperopia and presbyopia allowing less reliance on visual aids like eyeglasses and contact lenses to help you see clearly.
The IOL performs all the basic functions of the natural eye lens:
- Transparency: Providing a clear medium through which light can pass and reach your retina
- Optical: Focusing a sharp image of an object onto the retina.
- Anatomic: Creating a functional barrier between the front (anterior) and back (posterior) segments of the eye.
- Accommodation:Varying the eye's refractive power, providing clear images of objects over a wide range of near, far and intermediate distances.
Mainly, there are two types of IOL available - Non-foldable & Foldable
Non-foldable Lenses :These are made of a hard material and are bigger than the foldable ones. A bigger incision is needed to insert them.
Foldable Lenses :A soft acrylic material is used to make these lenses foldable which offer considerable advantages over the non-foldable ones.
Advantages of Foldable IOLs
- Need very small incision for insertion, usually as small as 2.6 mm
- Does not require stitches
- Very short healing time, generally not extending beyond 4-5 days
- Minimal chances of infection
Foldable lenses can further be categorized into two types - Monofocal & Multifocal.
Monofocal Lenses:A Monofocal lens implant can fix your vision for only one distance. These are designed to provide patients with enhanced distance vision but they would still require glasses for near vision. The implant cannot change shape like your original lens. Thus, the patient has no ability to focus in or out and will be dependent on progressive bifocals for near vision.
Multifocal Lenses:They have revolutionized existing state-of-the-art cataract surgery. Multifocal IOL helps to achieve the ultimate goal of total independence from glasses.Also available are Accommodative IOLS. An accommodative IOL is hinged to work in coordination with the eye muscles. The design allows the accommodative lens to move forward as the eye focuses on near objects and move backward as it focuses on distant objects.
Q1. How long will I have to wait for treatment?
Ans. According to Dr Setiya hospital data the average wait for cataract surgery in 2003/4 was 190 days, but in todays day you can get the surgery done sucessfuly if all preoperative tests are normal.
Q2. Can I be treated as a day case?
Ans. Best practice is to perform this operation as a day case. You get to go home straight after the operation, which patients often find more convenient. However, some hospitals are better than others at managing to do this. Dr Setiyas statistics show that the best hospitals treat all patients as day cases l.
Q3. How many operations have you done?
Ans. A number of studies have made an association between the volume of procedures carried out by surgeon or hospital and the outcome, suggesting that practice makes perfect. Cataract surgery is one of the most commonly performed operations at JJN . Some non-specialist hospital trusts conduct up to 6515 operations a year, while others carry out as few as 18. Find out how experienced your surgeon and hospital is in this procedure.
Q4. Do you specialise in cataract surgery?
Ans. Make sure you see someone that specializes in the surgery you are undergoing. In some cases a junior surgeon may assist, but less experienced surgeons should not be performing the operation on their own so find out what kind of supervision there will be.
Q5. What is your complication rate?
Ans. Cataract surgery has one of the highest success rates and according to the Royal College of Ophthalmologists fewer than 2 per cent of patients have serious, unforeseen complications. One of the most common is a thickening of the lens casing, but this can easily be corrected with laser treatment. Check how the surgeons carrying out your operation compare - there could be three or four members in the surgical team. If some operations they carried out had complications, ask them to explain what they were and why they occurred.
Q6. What kind of anaesthetic will be used?
Ans. A local anaesthetic is usually used, but a general anaesthetic might be appropriate depending on your circumstances. You should tell your consultant if you don't want a sharp-needle anaesthetic. A sub-Tenon's local anaesthetic is highly effective at pain relief and is much safer. Topical anaesthetic is good in skilled hands, but is associated with more perception of what is going on. If undergoing a general anaesthetic, your life is in the anaesthetist's hands even in what is otherwise a routine surgical procedure, so try to find out what qualifications and experience they have and try to meet them before the operation.
Q7. What is your accuracy of biometry?
Ans. Biometry is the process that uses either laser or ultrasound to predict the correct lens implant power and getting it right is a key part of a successful operation. Consultants should adhere to the guidelines from the Royal College of Ophthalmologists. Ask whether your hospital audits the accuracy of biometry and find out what kind of results your surgeon has had.
Q8. Are you going to try anything on me that is new to you?
Ans. New lens technology is being developed that neutralises various aberrations, but you need to consider the possible long-term dangers of something that hasn't got a long track record of success. Although new implants might be shown to be both safe and advantageous over time, some ophthalmologists are still wary about new types of lens and lens materials.
Q9. Will you be providing a multifocal lens?
Ans.While it's possible that multifocal lenses can improve your vision for distance and for reading so that no further correction is required, in practice this is not always achieved. Contrast is reduced by certain types of multifocals and biometry has to be very accurate to get good results. There is also a period of adjustment required on the part of the patient to a diffraction type of multifocal lens. In a recent survey by the United Kingdom and Ireland Society of Cataract and Refractive Surgeons, only 5% of its members had used multifocal lenses.
Q10. What is your attitude to complementary therapies?
Ans. One Spanish study shows that Lutein - available as a supplement or found in spinach or kale - may improve sight for people with age-related cataracts. If you are interested in complementary treatments, you should assess your consultant's attitude towards them and ask what they suggest in your case.
Q11.And finally - is surgery really necessary?
Ans. Unnecessary cataract operations could result in a worsening of vision. The first question to ask the surgeon is whether you definitely need surgery. In general, surgery should be considered if your eyesight interferes with your daily life and affects your ability to read or work. If you drive, you must reach the required standard set by the DVLA, so you might need the cataract removed if you want to keep your licence.