A cataract is an opacity of the eye’s normally clear, transparent crystalline lens. It is commonly associated with aging (senile cataracts) but can develop at any age. It may also be associated with blunt or penetrating trauma, long-term corticosteroid use, systemic disease such as diabetes mellitus, hypoparathyroidism, radiation exposure, expose to long hours of bright sunlight (ultraviolet), or other eye disorders. Vision impairment depends on the size, density, and location in the lens.
· Diminished visual acuity, disabling sensitivity to glare, painless, dimmed or blurred vision with distortion of images, poor night vision. Other effects include myopic shift, astigmatism, monocular diplopia (double vision), color shift (aging lens becomes progressively more absorbent at the blue end of the spectrum), brunescence (color values shift to yellow brown), and reduced light transmission.
· Yellowish, gray, or white pupil
· Develops gradually over a period of years; as the cataract worsens, stronger glasses no longer improve sight
· May develop in both eyes, although one is more compromised than the other
ASSESSMENT AND DIAGNOSTIC METHODS
· Degree of visual acuity is directly proportionate to density of the cataract.
· Snellen visual acuity test
· Slit-lamp biomicroscopic examination
· A-scan ultrasonography
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.
Two surgical techniques are available: intracapsular cataract extraction (ICCE) and extracapsular cataract extraction (ECCE) including phacoemulsification. Less than 15% of people with cataracts require surgery.
Indications for surgery are loss of vision that interferes with normal activities or a cataract that is causing glaucoma. Cataracts are removed under local anesthesia on an outpatient basis. Lens replacement may involve aphakic eyeglasses, contact lens, and intraocular lens (IOL) implants. When both eyes have cataracts, one eye is surgically treated at a time.
· Because surgery is performed on an outpatients basis, instruct patient to make arrangements for transportation home, care that evening, and a follow-up visit to the surgeon the next day.
· Withhold any anticoagulants the patient is receiving, if medically appropriate. Aspirin should be withheld for 5 to 7 days, nonsteroidal anti-inflammatory drugs (NSAIDs) for 3 to 5 days, and warfarin (Coumadin) until the prothrombin time of 1.5 is almost reached.
· Administer dilating drops every 10 minutes for four doses at least 1 hour before surgery. Antibiotic, corticosteroid, and NSAID drops may be administered prophylactically to prevent postoperative infection and inflammation.
· Instruct patient to wear a protective eye patch for 24 hours after surgery to prevent accidental rubbing or poking of the eye. After 24 hours, eyeglasses (sunglasses in bright light) should be worn during the day and a metal shield worn at night for 1 to 4 weeks.
· Provide postoperative discharge teaching concerning eye medications, cleansing and protection, activity level and restrictions, diet, pain control, positioning, office appointments, expected postoperative course, and symptoms to report immediately to the surgeon.
· Instruct patient to restrict bending and lifting heavy objects.
· Caution patient that vision may blur for several days to weeks.
· Inform patient that vision gradually improves as the eye heals; IOL implants improve vision faster than glasses or contact lenses.
· Reinforce that vision correction is usually needed for remaining visual acuity deficit.