WHAT IS A CATARACT?
There is normally a lens in the human eye, which is responsible for focusing rays of light.
A cataract occurs when this lens loses its clarity. The opaque lens now does not permit entry of light into the eye.
WHAT IS CATARACT SURGERY?
In conventional cataract surgery, the opaque lens is simply removed. Hence, the barrier to entry of light is gone, however, the patient cannot see as the eye has lost its focusing power. Focusing now has to be done using thick glasses. .
POINTS TO NOTE REGARDING CATARACTS
1. Although cataracts usually occur in the elderly, they are also seen in babies and children and sometimes after an injury.
2. There is NO proven medication which will prevent or cure a cataract. Hence surgery is the ONLY cure.
3. There is no need to wait for the cataract to ripen for surgery. It may be removed as soon as the vision falls below a level acceptable to the patient's lifestyle. In fact, if the patient waits too long, the lens may swell and raise the pressure in the eye. This causes a lot of damage to the eye and then, even after the operation, vision may be poor.
Also, the modern method of phacoemulsification is easier and safer with early soft cataracts rather than with late hard cataracts as this technique involves breaking up of the cataract.
Therefore, do not postpone cataract surgery too long.
WHAT IS MODERN CATARACT SURGERY [Phacoemulsification]
this refers to a method of surgery (mistakenly called "laser surgery") in which the cataract is broken u by an ultrasonically vibrating tip and sucked out through an extremely small (keyhole) micro-puncture. Because of the small size of the puncture -
- No stitches are needed
- No hospitalization is required
- Visual results are better
- Recovery is faster with quicker return to normal activity
Phacoemulsification is easier and safer before the cataract becomes very advanced, and hence, early surgery, as soon as visual loss becomes unacceptable, is advisable.
WHAT ARE INTRAOCULAR LENSES ?
After cataract surgery, the eye loses its focusing power and hence the patient cannot see. Sight can be restored with the use of an external lens for focusing light ie. cataract glasses. However these cataract glasses are:
1. Thick and cosmetically unacceptable
2. Difficult for elderly patients to adjust to
3. Not optically ideal as they cause a lot of distortions in vision and blind areas. If the glasses are removed, the patient is virtually blind
A better method of focusing light after cataract surgery is to replace the opaque lens with a synthetic lens at the time of surgery. This is called an intraocular lens.
ADVANTAGES OF INTRAOCULAR LENSES
1. As the synthetic lens is placed in the same position as the natural lens, vision is better, distortion-free, and thick glasses are not needed.
2. Once inserted, then lens remains in place permanently and causes no discomfort.
Hence, the patient can see ALL the time and does not need to grope around for his glasses
3. If the vision in the other (unoperated) eye is good, it s not possible to fit cataract glasses for the operated eye. Here, intraocular lenses are particularly useful.
Intraocular lenses were originally rigid, but today they are foldable/injectable, permitting placement through the small puncture of phacoemlsification.
WHAT ARE FOLDABLE/INJECTABLE INTRAOCULAR LENSES ?
Following cataract surgery, an intraocular lens is placed in the eye to permit focusing. Conventional "rigid" lenses need the incision to be enlarged in order to accommodate their relatively large size. Foldable lenses, however, can be inserted/injected through the phacoemulsification incision, using special injection devices, without any enlargement (introduced folded, the lens then unfolds within the eye). Hence, though slightly expensive, foldable/injectable intraocular lenses permit the patient to obtain the full benefits of micropuncture surgery and today phacoemulsification with a fodable/injectable lens is considered the best and most modern way of treating cataracts.