Cataract:: Causes, Diagnosis, Management

Cataract:

Cataract means clouding or opacity of the crystalline lens. In general cataract may be classified into :-

1        Senile Cataract     :  Commonly occurs and associated with aging.           

2        Congenital Cataract       :         Occurs at birth

3        Traumatic Cataract        :         Occurs after injury

4        Aphakia      :         Absence of crystalline lens.

Etiology :

1.     It is caused by chemical changes in the portion of the lens because of slow degenerative changes of aging person.

2.     Infant whose mother with german measles during first trimister of pregnancy.

3.     Aging above 80 years 80% of the people are affected.

Signs and symptoms:

1.     Blurred or distorted vision

2.     Glare from bright light

3.     Gradual and painless loss of vision

Previously dark pupil may appear milky or white.

Diagnosis: 

1.     SLIT lamp Examinations : To provide magnification  

2.     Tonometry : To determine Intra ocular pressure

3.     Direct and Indirect opthalmoscopy

4.     Occular examinations

5.     Perimetry to determine the scope of the visual field

Management:

General instructions / Information:

1.     Operative treatment is the only satisfactory treatment for cataract.

2.     A patient with one cataract usually manages without surgery, but if it is in both eyes, surgery is recommended.

3.     Surgery is done on only one eye at a time.

4.     Cataract surgery is done usually under local anesthesia

5.     Pre-operative medication procedure decreased response to pain and lessened motor activity (neuro leptic analgesics)

6.     Oral medications are given to reduce T.O.P. [Intra ocular pressure]

7.     Intra - Occular lens are usually implanted at the time of cataract extraction.

8.     In some instances after lens extraction and the healing process the patient may be fitted with appropriate eyeglasses or cataract lenses to correct refractions.

Surgical management :

There are two types of extracts in this procedure

Intra Capsular extraction : The lens as well as the capsule are removed through the small incision.

Extra Capsular Extraction : In this procedure, the lens capsule is incised and the nucleus, cortex and anterior capsule are extracted.

Two types of procedures for extracts are :

1 Cryosurgery : It is special technique in which the pencil like instrument with a metal tip is super cooled (-35oC) then is touched to the exposed lens, freezing to it so that the lens is easily lifted out.

2 Phaco : It is the mechanical breaking of Emulsification (emulsifying) of the lens by a hollow needle vibrating at ultrasonic speed. This action is coupled with irrigation and aspiration of the emulsified particles from the anterior chamber.

Nursing management:

Pre -operation:

Orient the patient and explain the procedure and plan of care to decrease anxiety.

1.     Instruct not to touch the eyes to decrease contaminations.

2.     Administer pre-op medication as prescribed

Post -operation:

1.     Medicate for pain as prescribed to promote comfort

2.     Administer medication to control nausea and vomiting

3.     Caution the patient against coughing or sneezing to prevent increased Intra-ocular pressure.

4.     Avoid taped movements or bending from the waist to minimizing the Intra-ocular pressure.

5.     Allow patient to ambulate as soon as possible.

6.     Encourage patient to wear eye shield at night to protect the operated eye for injury while sleeping.