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    CHAPTER I

    INTRODUCTION

    The crystalline lens is a remarkable structure that in its normal state functions to

    bring images into focus on the retina. Symptoms associated with lens disorders are

    primarily visual. The lens is best examined with the pupil dilated. A magnified view

    of the lens can be obtained with a slitlamp or by using the direct ophthalmoscope with

    a high plus (+1! setting.1

    The lens is a vital refractive element of the human eyes. "#resbyopic symptoms

    are due to decreased accommodative ability with age and result in diminished ability

    to perform near tasks. $oss of lens transparency results in blurred vision (without

    pain! for both near and distance. %f the lens is partially dislocated (subluxation! due to

    congenital& developmental& or ac'uired causes& visual blur can be due to a change in

    refractive error. %n ""& the orld )ealth *rganiation estimated that lens pathology

    (cataract! was the most common cause of blindness worldwide& affecting over 1,

    million people across the globe. Senile cataract is a vision-impairing disease

    characteried by gradual& progressive thickening of the lens. %t is one of the leading

    causes of blindness in the world today. 1&"

    %n %ndonesia cataract becomes the first rank that cause blindness. *f course

    blindness will reduce productivity and cause many impairment to the patient. ataract

    surgery is available in %ndonesia but low vision associated with cataracts may still be

    prevalent& as a result of long waits for operations and barriers to surgical uptake& such

    as cost& lack of information and transportation problems.

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    CHAPTER II

    LITERATURE REVIEW

    2.1 Anatomy of the Lens

    The lens is located behind the iris and pupil in the anterior compartment of the

    eye. The anterior surface is in contact with the a'ueous on the corneal side/ the

    posterior surface is in contact with the vitreous. The anterior pole of the lens and

    the front of the cornea are separated by approximately 0.mm."

    The lens is held in place by the onular fibers (suspensory ligaments!& which runbetween the lens and the ciliary body. These onular fibers& which originate from

    the region of the ciliary epithelium& are a series of fibrillin-rich fibers that

    converge in a circular one on the lens. 2oth an anterior and a posterior sheet

    meet the capsule 13"mm from the e'uator and are embedded into the outer part

    of the capsule (13"4m deep!. %t also is thought that a series of fibers meets the

    capsule at the e'uator. "

    Fi. 1 !"oss anatomy of the a#$%t h$man %ens

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    2.2 Cata"a&t

    A. Definition

    The crystalline lens is a remarkable structure that in its normal state functions to

    bring images into focus on the retina. 2ecause the lens is avascular and has no

    innervation& it must derive nutrients from the a'ueous humor. 1

    A cataract is present when the transparency of the lens is reduced to the point

    that the patient5s vision is impaired. The term cataract comes from the 6reek

    word katarraktes (downrushing/ waterfall!.0 A cataract is any opacity or

    discoloration of the lens& whether a small& local opacity or the complete loss of

    transparency. These ones of opacity may be subcapsular& cortical& or nuclear

    and may be anterior or posterior in location. %n addition to of the nucleus and

    cortex& there may be a yellow or amber color change to the lens. 7

    A senile cataract& occurring in the elderly& is characteried by an initial

    opacity in the lens& subse'uent swelling of the lens and final shrinkage with

    complete loss of transparency.

    8ig. " 9ormal lens and lens with cataract

    '. E(i#emio%oy

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    Age-related cataract is a common cause of visual impairment and responsible for

    7:; of world blindness& which represents about 1: million people& according

    to the orld )ealth *rganiation ()*!. %n ""& the orld )ealth

    *rganiation calculated that the number of visually impaired people worldwide

    was in excess of 1ye Study reported that

    0:.:; of men and 7.?; of women older than ,7 years had visually significant

    cataracts.

    =eveloping countries also face other challenges such as poor uptake of services

    because of a lack of patient information& misinformation from traditional healers&

    superstition& poor 'uality of services& monetary costs& distance to services& and

    the need for an escort. >ven where facilities are available& there is often a lack of

    surgeons& instruments& and other e'uipment (exacerbated by poor maintenance!&

    and a shortage of consumables and medications. =eveloping intraocular lens

    manufacturing facilities in these countries (such as the 8red )ollows 8oundation

    in >ritrea and 9epal!& will reduce costs and improve access to surgery. "

    C. Etio%oy

    The etiology of cataract that are @

    1 *ld age (commonest!

    " Associated with other ocular and systemic diseases (diabetes& uveitis& previous

    ocular surgery!

    0 Associated with systemic medication (steroids& phenothiaines!

    7 Trauma and intraocular foreign bodies

    %oniing radiation (-ray& BC!

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    < ongenital (dominant& sporadic or part of a syndrome& abnormal galactose

    metabolism& hypoglycaemia!

    , Associated with inherited abnormality (myotonic dystrophy& DarfanEs

    syndrome& $oweEs syndrome& rubella& high myopia!

    D. C%assifi&ation

    The following is a classification of the various types of cataracts.

    a! Time of occurrence

    lassification of cataract according to time of occurence

    1! Ac'uired cataract

    Senile cataract (F years old!

    ataract with systemic disease

    2ilateral cataracts may occur in association with the following systemic

    disorders@ diabetes mellitus& hypocalcemia (of any cause!& myotonic

    dystrophy& atopic dermatitis& galactosemia& and $oweEs& ernerEs& and =ownEs

    syndromes. 1

    Secondary and complicated cataracts

    ataract may develop as a direct effect of intraocular disease upon the

    physiology of the lens (eg& severe recurrent uveitis!. The cataract usually

    begins in the posterior subcapsular area and eventually involves the entire

    lens structure. %ntraocular diseases commonly associated with the

    development of cataracts are chronic or recurrent uveitis& glaucoma& retinitis

    pigmentosa& and retinal detachment. These cataracts are usually unilateral.

    The visual prognosis is not as good as in ordinary age-related cataract. 1

    #ostoperative cataract

    After-cataract denotes opacification of the posterior capsule following

    extracapsular cataract extraction. #ersistent subcapsular lens epithelium may

    favor regeneration of lens fibers& giving the posterior capsule a Gfish eggG

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    appearance (>lschnigEs pearls!. The proliferating epithelium may produce

    multiple layers& leading to frank opacification. These cells may also undergo

    myofibroblastic differentiation. Their contraction produces numerous tiny

    wrinkles in the posterior capsule& resulting in visual distortion. All of these

    factors may lead to reduced visual acuity following extracapsular cataract

    extraction. 1

    Traumatic ataract

    Traumatic cataract is most commonly due to a foreign body inHury to the lens

    or blunt trauma to the eyeball. Air rifle pellets and fireworks are a fre'uent

    cause/ less-fre'uent causes include arrows& rocks& contusions& overexposure

    to heat (GglassblowerEs cataractG!& and ioniing radiation. Dost traumatic

    cataracts are preventable. %n industry& the best safety measure is a good pair

    of safety goggles. 1

    Toxic cataract

    orticosteroids administered over a long period of time& either systemically

    or in drop form& can cause lens opacities. *ther drugs associated with

    cataract include phenothiaines& amiodarone& and strong miotic drops such asphospholine iodide. 1

    "! ongenital cataract