Any opacity in the lens or its capsule is called a cataract. However cataract is the opacity in lens preventing clear image formation on retina.
WHO/NPCB (National Programme for Control of Blindness) survey has shown that there is a backlog of over 22 million blind eyes (12 million blind people) in India, and 80.1% of these are blind due to cataract. The annual incidence of cataract blindness is about 3.8 million.
ETIOLOGY OF CATARACT
- Systemic diseases: Diabetes Mellitus, Galactosaemia, Hypoparathyroidism etc.
- Drug: Steroid
- Toxic agents: Copper, Cigarette smoking etc.
- Complicated cataract: (Cataract due other ocular disease) Iridocyclitis, Retinitis pigmentosa etc.
- Electric shock
- Blurring of vision/ diminution of vision
- White or greyish opacity
- Frequent changes of glass
- Difficulty in bright light
- Difficulty in night vision
- Coloured haloes
- Loss of contrast sensitivity
- Myopic shift( increase of minus power in aged person)
There is no medical treatment for cataract. Though, surgery (Cataract extraction & Intraocular lens implantation) is the only treatment, but in initial stages, refraction and adjustment of illumination helps.
TYPES OF SURGERY
Phacoemulsification with foldable IOL (Intra Ocular Lens) implantation is the choice of surgery. Manual small incision cataract surgery is also very popular surgery in India.
Laser Cataract Surgery: Femtosecond Laser is used to perform few steps of surgery in phacoemulsification.
The decision of cataract surgery depends on the patient’s need (visual demand) or presence of cataractous lens-induced complications.
Phacoemulsification, Manual small incision cataract surgery, and conventional extracapsular cataract extraction.
As the corneal incision size is smaller than 3mm, no suture is required and wound seals by valve action, which also provides early wound healing and early ambulation. It can substantially reduce surgically induced astigmatism and the chance of post-operative infection.
Femto cataract surgery is a Femtolaser assisted surgery for precise corneal incision, accurate capsulorhexis, and reduction in power and time of ultrasonic phaco energy to provide better visual outcome.
Cataract cannot recur once removed but, in some cases, patients may suffer with cloudy vision due to posterior capsular opacification (PCO) which can be removed by simple laser process.
On some occasions, the patients can experience halos around light or crescent-shaped shadow which cure over the period of time.
Usually, patients can continue living their normal schedule within 24hours of the surgery but, as IOL is inserted, it may take a couple of days to get accustomed to the situation and gain the desired vision.
Most cataracts develop slowly, over a length of time and affect people over the age of 50. About half of the population has a cataract by the age of 65, and nearly everyone over the age of 75 will have developed a mild cataract in one or both eyes. In rare cases, infants may have a congenital or developmental cataract.
IOLs are medical devices that are implanted inside the eye to replace the eye’s natural lens when it is removed during cataract surgery. There are two main IOLs types to consider: monofocal and multifocal intraocular lenses. Monofocal lenses correct your vision within a specified distance. Multifocal IOLs, on the other hand, may correct both distance and close-up vision. Additionally, toric lenses can be a great choice if you suffer from astigmatism.
As with any surgery, pain, infection, swelling and bleeding are possible, but very few people experience serious cataract surgery complications. In most cases, complications or side effects from the procedure can be successfully managed with medication or a follow-up procedure. To reduce your risk for problems after cataract surgery, be sure to follow the instructions by your surgeon and report any unusual occurrences immediately.
If you opt for standard cataract surgery with intraocular lens (IOL) implantation, you will need reading glasses and possibly computer glasses. There are cataract surgery options that can reduce or sometimes even eliminate your need for glasses. In particular, the premium implantable lenses such as multifocal IOL can provide excellent outcomes that enable many people to be free from spectacles for the greater part of their day.
Another option is monovision cataract surgery, by which the power of the single vision IOL is customized in each eye to expand the range of clear vision when the two eyes function in unison. In this scenario, the dominant eye provides sharper distance vision, and the non-dominant eye provides sharper near vision.
This is a misconception that is believed by some. Visual outcome depends on the quality of the surgery, not the season. In this era, phacoemulsification surgery enables smaller incision, which helps in early wound healing and ambulation. The patient can take a bath in only a few days after the surgery.