SENILE CATARACTRitika Kishore (56)

Definition of CataractThe term “Cataract” refers to the

development of any opacity in the lens or its capsule.

This leads to decrease vision.

ClassificationA. ETIOLOGICAL CLASSIFICATION 1.Congenital and Developmental

Cataract , due to formation of opaque lens fibers.

2.Acquired Cataract, due to degenerative processes leading to opacification of normally formed lens fibers.

SENILE CATARACT or AGE RELATED CATARACT

Traumatic CataractComplicated CataractMetabolic CataractElectric CataractRadiation CataractToxic CataractCataract associated with skin diseasesCataract associated with osseous diseasesCataract with miscellaneous syndromes

B. MORPHOLOGICAL CLASSIFICATION

SENILE CATARACT It is the most common form of cataract

affecting people of either gender above 50 years of age.

Usually one eye is affected earlier followed by the other eye.

Morphologically it is of two types: 1.Cortical (soft) Cataract.2.Nuclear (hard) Cataract

The cortical type starts as cuneiform or cupuliform cataract.

Both type may co-exist in the same lens.

Cuneiform is predominantly seen, 70%. ETIOLOGY : Etiopathogenesis is unclear, but

cataract is essentially an ageing process.

Risk Factors1. Age. Usually seen above 50 years , if

it occurs before 45, the term ‘pre-senile’ cataract is used.

2. Sex. Affects females more, some studies report.

3. Heredity. Age of onset and maturation is seen as a genetic trait.

4. UV radiations. 5. Dietary factors.6. Dehydrational crisis. Like in

diarrhea, cholera, etc.7. Smoking. Causes accumulation of

pigmented molecules and cyanates leading to protein denaturation.

Cataractogenic FactorsThere is a concept that says Cataract

results from multiple sub-threshold cataractogenic factors.

Age and other toxix stresses such as UV rays and smoking accelerate the cataract formation.

Decreased exposure to these factors have proven to delay cataract formation.

CORTICAL SENILE CATARACT.It is the result of decreased levels of

total proteins, amino acids and potassium of the lens.

There is increased concentration of sodium and hydration of the lens.

this ultimately leads to denaturation of lens proteins.

Stages of maturation of cortical type.1. Stage of lamellar separation. This

can be seen under slit lamp examination only, there is demarcation of cortical fibers, where they start to separate by fluid

2. Stage of incipient cataract. In this stage two different forms can be seen. a. Cuneiform senile cataract .

Seen as wedge shaped opacity with clear areas in between.

These extend from equator towards center and can be seen when pupils are dilated.

First seen in the nasal quadrant. these opacities are present both in

anterior and posterior cortex and their apices slowly progres towards the pupil.

On oblique illumination, these present as radical spokes.

On distant direct ophthalmoscopy, these opacities appear as dark lines agaisnt red fungal glow.

Visual disturbances are seen in later stages.

b. Cupuliform senile cataract. it has a saucer shaped opacity

(postero- subcapsular) which gradually extend outwards.

there is usually definitive demarcation between cataract and surrounding clear cortex.

This cataract lies in the visual axis, causes early loss of vision.

3. Immature Senile cataract . Opacification further progresses in this stage.

both forms can be recognized till the advanced stage of ISC.

the lens appears greyish white but clear cortex is present so iris shadow is visible.

in some patients, lens swell up due to hydration, this is called intumescent cataract, which may persist in next stage.

The anterior chamber becomes shallow due to swollen lens.

4. Mature senile cataract. In this stage opacification becomes complete.

Whole of the cortex is opaque.Lens become pearly white in colourIs Also labelled as ‘ripe cataract’

5. Hypermature senile cataract. It develops when mature cataract is untreated. It is of two types :

Morganian hypermature cataract. The cortex liquifies and lens becomes a bag of milky fluid. Small brownish nucleus settles at the bottom, altering its position with head posture.

Sclerotic type. The cortex becomes disintegrated and the lens shrinks due to leakage of water. The anterior capsule is wrinkled and thickened due to proliferation of anterior cells and dense white capsular cataract may be formed in the pupillary area. The anterior chamber becomes deep due to shrinkage of lens.

Nuclear Senile CataractIn this type, the usual degenerative

changes are aggravated due to dehydration and compaction of nucleus , leading to hard cataract.

There is increase in water insoluble proteins, but total proteins remain the same.

It may be associated with deposition of pigments like urochrome and melanin.

Maturation of Nuclear typeThe lens becomes inelastic and hard

with decreased ability to accommodate and obstructs the light rays.

The changes progress towards the periphery.

Thin layer of clear cortex is seen when it matures up to the capsule.

The nucleus becomes cloudy or tinted due to deposition of pigments.

Early nuclear senile cataract

Cataracta brunescens (amber/brown)

Cataracta nigra (black)

Cataracta rubra (red)

Clinical SymptomsGLARE or intolerance of bright lightUNIOCULAR POLYOPIA i.e. doubling or

trebling or visions due to irregular refraction by the lens.

COLOURED HALOS owing to the splitting of light by water droplets in lens.

BLACK SPOTS in front of eyes.DISTORTION OF IMAGES and blurring.LOSS OF VISION is painless and

gradually progressive.

In cupuliform, there is early loss of vision and vision is improved when pupils are dilated.

In cuneiform, there is delayed loss and vision is improved when pupils are contracted.

Vision diminishes with increased opacification until only perception of light and projection of rays remains in the stage of mature cataract.

Depiction of iris shadow