What are cataracts?
A cataract is the clouding of the eye’s inner lens, thereby not allowing the light to pass through it, causing initially diminution of the vision and later on blindness. They get worse over a period of time. The incidence of cataracts is higher in the elderly, but it has been seen in young people too.
How vision is impaired due to cataract?
The vision in the normal eye is formed when the light falls on the retina, passing through the lens. If the lens is clear the image formed is good, but the clouded lens is unable to pass light properly resulting in diminished vision as in cataract.
Symptoms of cataract?
Blurred vision: Due to cataract, the distant image formed is blurred and these people face difficulty in nighttime vision and driving.
Glare: Cataract makes it difficult to see in bright light or even in sunlight. The normal inhouse lights also seem very bright.
Double Vision: Two image formations when looking with one eye is confirmatory of cataract.
Color Changes: Color is affected by this disease. Gradually a person is unable to distinguish between blues and purples.
Second Sight: Is a phenomenon when the lens becomes so able that it improves the ability to view near distant objects. This temporarily relieves the need for spectacles (reading glasses), but gradually over time, this worsens and this improvement in near vision deteriorates.
Frequent glasses change: Due to this disease, the vision deteriorates gradually requiring frequent spectacle change.
What are the causes of cataracts?
The precise mechanism of the formation of cataracts is still not clear. Higher age is known as one of the risk factors. Others include:
- Alcohol abuse
- Diabetes mellitus
- Eye injury
- Prolonged corticosteroids use
- Extended radiation or sun exposure
How are cataracts diagnosed?
Diagnosis is made with ophthalmic eye examinations, which includes vision test and slit-lamp examination. The retina of the eye is checked after dilating the pupil.
Initially the surgeon may prescribe new spectacles with changed numbers, use of glasses which does not allow glare to fall on the eyes and use of tinted lenses. Surgeons may prescribe other things also.
In case of failure of conservative measures, surgery is the last resort left. This is selected when the diminution of vision disturbs the normal activities of living of a person.
Three common methods of cataract removal
It is the commonest cataract surgery done, which is also known as “small incision cataract surgery.” An ultrasonic high-speed vibrating device is inserted into the eye from a very small incision. Due to the ultrasonic waves the lens softens and gradually breaks into pieces, which is suctioned out. Post this procedure, the surgeon inserts an artificial lens into the eye. Sometimes the incision made is so small that no sutures are required, else only one stitch is put.
2. Extracapsular Cataract Surgery:
This is somewhat similar to earlier mentioned phacoemulsification. The only difference is that the incision made is bigger so as to enable the nucleus (central part) of the lens to be removed as single. The balance is left behind. Few disadvantages being more sutures are required, longer healing time, and may also induce astigmatism.
3. Intracapsular Cataract Surgery:
A large incision is made and the whole of lens and capsule are removed from it. This is a rare procedure, performed in cases of difficult and advanced cataracts.
Preparation before surgery
The patient has to come nil by mouth (for at least 8 hours prior to surgery). Eyedrops are advised to be used for weeks prior to planned surgery. If the patient is on other medications, how those medications are to be taken are advised by the surgeon.
What happens during the process?
This procedure is carried out under local anesthesia or topical anesthesia, which helps in both reducing the pain and as well as paralyzing the movement of the eye being operated. And then the phacoemulsification procedure as explained earlier is done. This surgery normally takes 15 minutes to 1 hour depending on many factors.
This being a day-care procedure, the patient is monitored for a few hours in the recovery area and then sent home with advice to review after 24 hours. Pain relieving medications are given.
Patient may experience discharge and also itching in the eyes, for which the patient is advised to place a warm moist cloth on the eyes for a few minutes each time. Some matter may get loose which should be removed with the help of a tissue and finger nails or tips should never be used. Dark spots may be observed by the patient, which regress over a period of few weeks.
Eye shield is given for protection of eyes from sudden bruising while asleep, along with some eye drops for prevention of infection.
Patient has to make many visits to the surgeon for examination over a period as scheduled.
Generally patients are able to return to their normal activities within a short period of time after phacoemulsification.
There is a very small incidence of complications, but they may occur. Some of the known complications are double vision, flashing or floaters, which may occur after some weeks of surgery. These should be notified immediately to the surgeon. Floater is a serious condition indicating the detachment of retina, which requires further management. Endophthalmitis, though with less incidence, but may also occur, which is infection of the eyeball.
IOL displacement may occur, but this is quite rare with the newer designs.
Glaucoma and blindness are very rare complications, but may happen.
Secondary cataract may develop over a long period of time in the left out portion of the capsule, for which YAG capsulotomy along with a laser is used for treatment.
Corrective lenses will be required for near vision after the healing.
When to contact the surgeon After surgery, if the patient experiences extreme pain, nausea or vomiting, then it should be immediately informed