A PRESENTATION AT THE NONA ANNUAL SCIENTIFIC CONFERENCE HELD AT GOMBE 2ND OCTOBER, 2017
A cataract is opacity of the lens that distorts image projected onto the retina and that can progress to blindness. The lens opacity reduces visual acuity. In that, the lens loses water and increases in size and density, causing compression of lens fibers.
A cataract then forms as oxygen uptake is reduced, water content decreases, calcium content increases, and soluble protein becomes insoluble. Over time, compression of lens fibers causes a painless, progressive loss of transparency that is often bilateral. Surgical removal of the opacified lens is the only cure for cataracts.
Intervention is indicated when visual acuity has been reduced to a level that the client finds to be unacceptable or adversely affects lifestyle.
This Paper seeks to:
Explain the causes of Cataract
Highlight on the clinical manifestations of Cataract
Briefly explain the Medical/Surgical Management of Cataract and
Discuss the Nursing Care of a Patient with Cataract.
Definition of Cataract
A cataract is a lens opacity or cloudiness. On visual inspection, the lens appears gray or milky and it is one of the most common eye disorders. According to the World Health Organization, cataract is the leading cause of blindness in the world. Almost one in five people between the ages of 65 and 74 develop cataract severe enough to reduce vision.
Cataracts have several causes and may be:
Age-related, the most common cataract (senile cataract).
Present at birth (hereditary),
Trauma (develops after a foreign body injures the lens).
Complicated cataracts develop as secondary effects in patients with metabolic disorders (e.g., diabetes mellitus),
Radiation damage (x-ray or sunlight),
Eye inflammation or disease (e.g., glaucoma, retinitis pigmentosa, detached retina, recurrent uveitis).
Exposure to a toxic substance e.g from drug e.g steroids or chemical toxicity.
Congenital cataract due to maternal infection (e.g., German measles, mumps, hepatitis) during the first trimester of pregnancy.
Lifestyle. Factors that increase the risk of cataracts include cigarette smoking, obesity, high-triglyceride levels in men e.t.c.
Low socio-economic status: Recent studies have linked cataract risk to lower income and educational level.
Opaque or cloudy white pupil
Gradual loss of vision
Decreased color perception: increasing density of the lens tissue results in its yellowing, and this can lead to loss of some colour perception - objects appear more yellow and less blue than they did.
Vision that is better in dim light with pupil dilation
‘Ghosting’ of images (where one distinct image is seen with the shadow of another next to it) and the patient may interpret this as ‘double’ vision.
Absence of the red reflex
Glare: Glare refers to the pain felt when the patient looks directly into the light.
Halos: Halos are formed when the patient looks at a bright light and there is still the vision of the light after looking away.
Assessment and Diagnostic Findings
Diagnosis is made by:
Visual acuity test, and
Direct ophthalmoscope or
Slit lamp examination: Ophthalmoscope or slit lamp examination allows detailed visualization of anterior segment of the eye to identify lens opacities and other eye abnormalities.
History and Physical Examination
Snellen’s visual acuity test: measures the degree of visual acuity in the patient.
Ophthalmoscope: is used to view the extent of cataract.
Slit-lamp biomicroscopic examination: is used to establish the degree of cataract formation.
There is no medical treatment for cataracts, although use of vitamin C and E and beta-carotene is being investigated.
Glasses or contact, bifocal, or magnifying lenses may improve vision.
Mydriatics can be used short term, but glare is increased.
In fact no nonsurgical treatment cures cataracts or prevents age-related cataracts.
Surgical removal of the opacified lens is the only cure for cataracts. Cataracts occur bilaterally, the more advanced cataract is removed first.
Extracapsular cataract extraction: the most common procedure, removes the anterior lens capsule and cortex, leaving the posterior capsule intact.
A posterior chamber intraocular lens is implanted where the patient’s own lens used to be.
Intracapsular cataract extraction: removes the entire lens within the intact capsule.
An intraocular lens is implanted in either the anterior or the posterior chamber, or the visual deficit is corrected with contact lenses or cataract glasses.
Phacoemulsification: has become a preferred technique.
It involves making a small incision (2-3mm) at the limbus into the anterior chamber, or a little further away from the cornea, in the sclera.
Through this, a tunnel is formed, diagonally, into the anterior chamber.
Next, a single continuous circular tear is made in the anterior capsule (capsulorrhexis).
The ‘phaco’ probe is then directed through the incision and the lens nucleus is emulsified and removed from the eye by an irrigation/aspiration technique.
Finally, a small or foldable lens is placed in the remaining capsular ‘bag’ of the lens.
Preoperative Nursing Care of the Patient undergoing Cataract Surgery:
The eye is a delicate and important organ, and its care and protection are of the utmost importance. The patient with cataract should receive the usual preoperative care for ambulatory surgical patients undergoing eye surgery.
The patient will require a thorough orientation to his immediate hospital environment.
This is done to help the patient during the postoperative period, since he may be temporarily blind as a result of the surgery.
Assist the patient to learn details of his room such as the location of furniture, doors, windows, and so forth.
Familiarize the patient with the voices of those who will care for him after surgery.
Familiarize him with the daily sounds and noises in the environment, since he will be more aware of sound without his vision.
The patient should be observed for tendencies to cough or sneeze (smoker's cough, allergies, and so forth).
Such observations should be reported to the professional nurse for consideration in the plan of care.
Such violent movements of the head during the postoperative course may cause increased intraocular pressure, leading to hemorrhage or rupture of incisions.
The patient must receive a thorough education about the postoperative course of events and his responsibilities and restrictions.
During surgery patients need to be able to lie still and must be aware that they cannot move their heads or their eyes.
They also need to be prepared for their faces to be covered, because this can be a very frightening experience initially.
A member of the theatre staff who acts as a liaison between the patient and the surgical team usually supports patients undergoing cataract surgery under local anaesthesia.
The patient must understand the objective of resting the eyes and avoiding actions that increase intraocular pressure. Thus,
The head must be kept very still.
No showers, no shampooing, no tub baths.
No bending over at the waist.
No lifting of heavy objects.
No sleeping on the operative side.
A bowel preparation is done the evening prior to surgery to prevent the patient from straining at stool during the immediate post-op period.
Cutting of eyelashes, and shaving of face should be done prior to surgery.
After the patient has been taken to surgery, prepare a post-op bed, ensuring that the bed is equipped with side rails.
Sand bags should be made available for use in immobilizing the head.
Often, if the patient must be kept absolutely still or will be temporarily blinded after surgery, a member of the family may be asked to stay with the patient.
If this is the case, the family member should receive the same orientation and education given to the patient.