CATARACT

CATARACT – Risk Factors and Etiology, Pathophysiology, Signs and Symptoms, Diagnostic Evaluation and Management

A cataract is a clouding or opacity of the normally clear lens of eye. The patient may have a cataract in one or both the eyes. Cataract is the third leading cause of preventable blindness.

RISK FACTORS AND ETIOLOGY

• Increasing age
• Diabetes
• Drinking excessive amounts of alcohol
• Excessive exposure to sunlight
• Exposure to ionizing radiation, such as that used in X-rays and  cancer radiation therapy
• Family history of cataracts
• High blood pressure
• Obesity
• Previous eye injury or inflammation
• Previous eye surgery
• Prolonged use of corticosteroid medications
• Smoking

PATHOPHYSIOLOGY

Following are the various mechanisms involves in the occurrence of cataract:

• Caused by degeneration and opacification of existing lens fibers, formation of aberrant fibers or deposition of other material in their place.
• Loss of transparency occurs because of abnormalities of lens protein and consequent disorganization of the lens fibers
• Any factor that disturbs the critical intra and extra-cellular equilibrium of water and electrolytes, the colloid system within the fibers causing opacification
• Fibrous metaplasia of lens fibers occurs in complicated cataract
• Epithelial cell necrosis occurring in angle closure glaucoma leads to focal opacification of the lens epithelium
• Abnormal products of metabolism, drugs or metals can be deposited in storage diseases, metabolic diseases and toxic reactions

Three biochemical factors are evident in cataract formation:

1. Hydration: seen particularly in rapidly developing forms. Actual fluid droplets collect under the capsule forming lacunae between fibers, the entire tissue may swell and becomes opaque, and this process is reversible in early stage, as in juvenile insulin dependent diabetes. Hydration maybe due to osmotic changes in the lens or due to changes in the semipermeability of the capsule
2. Denaturation of lens protein: if the proteins are denatured with an increase in insoluble protein, a dense opacity is produced. This stage is irreversible and opacity does not clear, this change is seen in young lens or the cortex of the adult nucleus where metabolism is active
3. Sclerosis: inactive fibers of the nucleus suffer from degenerative change of slow sclerosis

Altered the metabolic process within lens —- reduction in oxygen uptake —- increase in water content followed by dehydration —- protein in the lens undergoes numerous age related changes —- causes the formation of cataract

TYPES OF CATARACT

• Nuclear cataracts: a nuclear cataract may at first causes more nearsighted. But with time, the lens gradually turns more densely yellow and further cloudy. As the cataract slowly progresses, the lens may even turn brown. Advanced yellowing or browning of the lens can lead to difficulty distinguishing between shades of color.
• Cortical cataracts: a cortical cataract begins as whitish, wedge-shaped opacities or steaks on the outer edge of the lens cortex
• Posterior subcapsular cataracts: a posterior subcapsular cataract starts as a small, opaque area that usually forms near the back of the lens, right in the path of light on its way to the retina
• Congenital cataracts (Aphakia): some people are born with cataracts or develop them during childhood. Such cataracts maybe the result of the mother having an infection during pregnancy
• Hypermature shrunken cataract: when cortex disintegrates and transform into mass. The lens become inspissated and shrunken, the anterior capsule becomes thickened
• Morgagnian Hypermature Cataract: sometimes cortex becomes liquefies and nucleus sink into the bottom. The liquefied cortex become milky and nucleus is seen as brown mass, visible as semicircular line in pupillary area altering its position with change in position of the head

SIGNS AND SYMTPOMS

• Clouded, blurred or dim vision
• Increasing difficulty with vision at night
• Sensitivity to light and glare
• Seeing ‘halos’ around lights
• Frequent changes in eyeglass or contact lens prescription
• Fading or yellowing of colors
• Double vision in a single eye

DIAGNOSTIC EVALUATION

• Visual acuity test: a visual acuity test uses an eye chart to measure how well an eye can read a series of letters
• Slit-lamp examination: with this examination, the eye can be visualizing at large scale by magnifying the eye. The microscope is called a slit lamp; it uses an intense line of light, a slit, to illuminate cornea, iris, lens and the space between iris and cornea
• Retinal examination: to visualize the retina

Other tests:

• Snellen visual acuity test
• Opthalmoscopy
• Slit lamp bimicroscopic examination
• Glare testing
• Keratometry
• Ocular examination
• Perimetry: to determine the scope of visual fields

MANAGEMENT

Objective of Cataract Surgery

• The objective of cataract surgery is to remove the opacified lens
• Successful treatment of acute attack and prompt alleviation of manifestations
• Prevention of complications and further attacks
• Rehabilitation and education of the clients and significant others

Pharmacologic Therapy

• Beta carotene
• Vitamin C and E
• Antioxidant supplements
• Selenium
• Multivitamin supplements
• Contact lenses
• Strong bifocals
• Glasses
• Mydriatics: Phenylephrine HCL acid
• Cyloplegics: Tropicamide
• Homatropine
• Atropine

Surgical Management

• Phacoemulsification: in this method, surgery can usually be performed in less than 30 minutes and usually requires only minimal sedation. Numbing eyedrops or an injection around the eye is used and, in general, no stitches are used to close the wound, and often no eye patch is required after surgery
• Extracapsular cataract extraction surgery: this procedure is used mainly for very advanced cataracts where the lens is too dense to dissolve into fragments. This technique requires a larger incision so that the cataract can be removed in one piece without being fragmented inside the eye. An artificial lens is placed in the same capsular bag as with the phacoemulsification technique. This surgical technique requires a various number of sutures to close the larger wound, and visual recovery is often slower. Extra capsular cataract extraction usually requires an injection of numbing medication around the eye and an eye patch after surgery
• Intracapsular cataract surgery: this surgical technique requires an even larger wound than extracapsular surgery, and the surgeon removes the entire lens and the surrounding capsule together. This technique requires the intraocular lens to be placed in a different location, in front of the iris
• Aphakia: (absence of the lens) is corrected by the use of eyeglasses, contact lenses

NURSING MANAGEMENT

Nursing Assessment

• Assess knowledge level regarding procedure

Assess the level of fear and anxiety

Determine visual limitations

Postoperative Assessment

• Assess pain level

Sudden onset: maybe due to ruptured vessel or suture and may lead to hemorrhage

Severe pain: accompanied by nausea and vomiting maybe caused by intraocular pressure

Assess visual acuity in unoperated eye

Assess patient’s ability to ambulate

Assess patient’s level of independence

Nursing Diagnoses

• Self-care deficit related to visual deficit
• Anxiety related to lack of knowledge about the surgical and postoperative experience
• Risk for injury related to blurred vision
• Risk for infection related to trauma to incision
• Acute pain related to trauma to incision

Nursing Intervention

Relieving Pain

• Give medication to reduce pain as analgesics
• Give cold compression demand for blunt trauma
• Encourage to the use of sunglasses in strong light
• Vital signs must assess frequently
• Physical rest in bed with backrest elevated to provide comfort

Relieving Anxiety

• Assess the degree and duration of visual impairment
• Orient the patient to new environment
• Explain the preoperative routines
• Push to perform daily living habits when able
• Encourage the participation of family

Prevention of Injury

• Provided a comfortable position to the patient
• Help the patient to set the environment
• Orient the patient in a room
• Discuss the need for use of goggles when instructed
• Do not put pressure over the affected eye trauma
• Used the proper procedures when providing eye drugs

Promoting Self-Care

• Cleared the all doubts of patient regarding the disease condition
• Maintained good IPR with the patient
• Provided calm cool environment to the patient
• Music therapy and pet therapy given to patient
• Relaxation therapy also provided to relieve the anxiety of patient

Improving Knowledge

• Provided adequate knowledge about a disease condition
• Provided the sunglasses to patient during exposure to sunlight
• Provided medications to patient on proper time
• Advised the patient to talk with doctor
• Followed the recommendations that ensure regular eye checkup by the ophthalmologist

Health Education

• Advised the patient to wear sunglasses during exposure
• Advised the patient to take analgesics to reduce pain
• Advised the patient to take proper diet
• Advised the patient to take care of eyes after surgery
• Advised patient to prevent eyes from dirt and dust
• Advised patient to preventing eyes from trauma
• Advised patient to report to doctor for early complications
• Advise patient to increase activities gradually as directed by health care provider
• Caution against activities that cause patient to strain
• Instruct patient and family in proper use of medications
• Advise patient to apply plastic shield over the eye at night to avoid accidental injury during sleep
• Infirm about fitting temporary corrective lenses for the first 6 weeks

COMPLICATIONS

• Capsular rupture
• Vitreous loss
• Endothalemitis
• Pseudoexfoliation
• Myopia

After Care

Before the patient goes home, may receive the following:

• A patch to wear over eye until the follow-up exam
• Eyedrops to prevent infection, treat inflammation, and help with healing
• Wear dark sunglasses outside after removing the patch
• Wash hands well before and after using eye drops and touching eye. Try not to get soap and water in eye when are bathing or showering for the few days