Cataract

By : Mohammad khalil Abu Abd Allah

Basem El Najry

structure of the lens : The lens is biconvex , transparent , avascular structure with no nerve supply.

part of the anterior segment of the eye a long with the cornea , behind the iris in front of the vitreous humour

suspended in place by the suspensory ligament ( zonules )

The lens measures 9mm in diameter and 4 mm thick ,

The lens measures 9mm in diameter and 4 mm thick ,

Anatomy and physiology of the eye lens:

Lens anatomy-

Lens anatomy-

lens capsule subcapsular epithelium the cortex

lens layers:

lens composition and function :lens composed of 65% water and 35% protein and it also contain a trace of minerals Na , K , Ca.the function of the lens is to focus lights rays on the retina by accommodation

Lens layer

it is an opacity or cloudiness of the normally clear , crystalline lens

cataract

Changing in lens color

lens remain transparent until the age of 40 years Lens fibers produced inside the lens through out

the life pushing toward the center ( nuclei ) By aging the ability to arrange denatured protein

fibers this lead change in transparency of the lens the lens become more dense and the color

changed from clear to yellow or brown that's by the age of 70 years the lens become sufficiently cloudy to obstruct

also the enzymatic and antioxidant protection of lens ( which protect the lens from the ultra violet rays) decreased with age

pathophysiology of cataract

according to locations : anterior pole cataract , posterior pole cataract, nuclear cataract, cortical and lamellar cataract

according to the degree : immature , mature and hyper mature.

classification of opacity:

Types of cataractage related TraumaticToxiccongenital secondary to existing eye disease associated with systemic disease

poor central vision frequent changes in eyeglass prescription changes in color vision increased glare from lights, especially oncoming

headlights when driving at night "second sight" improvement in near vision (no longer

needing reading glasses), but a decrease in distance vision poor vision in sunlight presence of a milky whiteness in the pupil as the cataract

progresses.

Signs and symptoms :

Cataracts are easily diagnosed from the reporting of symptoms, a visual acuity exam, refraction test , and by examination of the eye itself by slit lamp.

Diagnosis:

If a cataract is not bothersome, Cataracts usually do not harm eye, The following may help people who have an early cataract:

Better eyeglasses Better lighting Magnifying lenses Sunglasses The only treatment for a cataract is surgery to remove it and applied

intra ocular lens . Surgery is done if you cannot perform normal activities, such as driving, reading, or looking at computer or video screens, even with glasses. Surgery is usually 'outpatient' and performed using local anesthesia. Approximately 90% of patients can achieve a corrected vision of 6/12 or better after surgery.

Treatment:

Phacoemulsification is the most widely used cataract surgery today. This procedure uses ultrasonic energy (U/S) to emulsify the cataract lens.

Extracapsular cataract extraction (ECCE), consists of removing the lens manually, but leaving the majority of the capsule intact. The lens is expressed through a 10–12 mm incision which is closed with sutures at the end of surgery.

Intracapsular cataract extraction (ICCE) is rarely performed. The lens and surrounding capsule are removed in one piece through a large incision while pressure is applied to the vitreous membrane

The best prevention involves controlling diseases that increase the risk of a cataract, and avoiding exposure to factors known to promote cataract formation.

Diabetes Eye inflammation Eye injury Family history of cataracts Long-term use of corticosteroids (taken by mouth) or certain other

medications Radiation exposure Smoking Surgery for another eye problem Too much exposure to ultraviolet light (sunlight)

Prevention :

wearing ultraviolet-protecting sunglasses may slow the development of cataract , avoiding fatty diet and there is studies that regular intake of antioxidants (such as vitamins A, C and E) would protect against the risk of cataracts.

pre op : B scan , stop anticoagulant medication explain the condition and how the surgery will done

( using of anesthesia ,and using of the artificial lens) how long the patient will be at the hospital consent form applying of dilating drops before the surgery

Nursing care :

post op : examine the eye for any bleeding and the cornea should

be free teach patient how to clean his eye no rubbing or over

bending or lifting weight more than 10 kg and avoid straining for about 1 month

using cartella shield at night for 2 weeks how to use eye drops ( antibiotic and steroid ) written instruction leaflet including contact number

Speculum MVR + calibri Anesthesia Viscoelastics Keratome + calibri Viscoelastics

Phacoemulsification

Capsulorhexis Hydrodesection

phaco probe + chopper Irrigation aspiration Viscoelastics

Lens injector + dialer irrigation aspiration Hydration