ADULT CATARACT

Age Related Cataract

The lens becomes thicker and heavier and the protein fibers begin to break down The proteins form clumps that distort light as it penetrates the lens and reaches the retina Nuclear sclerosis: Age-related change in the density of the crystalline lens nucleus that occurs in all elderly caused by compression of older lens fibers in the nucleus by new formation. It is a normal condensation process in the lens nucleus Earliest symptom of Age-related cataract: improved near vision without glasses ("second sight"). This occurs from an increase in the refractive index of the central lens, creating a myopic shift in refraction. Other symptoms may include poor hue discrimination or monocular diplopia. Most nuclear cataracts are bilateral but may be asymmetric

CLASSIFICATION ACCORDING TO MATURITY

Immature Cataract Mature Cataract Hypermature Cataract Morgagnian Cataract Indumescent

Lens is partially opaque Lens is completely opaque Shrunken and wrinkled anterior capsule; often milky

A hypermature cataract in which total liquefaction of cortex allows

the nucleus to sink inferiorly

If the lens takes up water

SYMPTOMS 1) Painless gradual diminution of vision: due to a) Lenticular opacity b) Refractive error induced : due to the changes in refractive index of lens

Cortical cataract index hypermetropia

Nuclear cataract index myopia. , a previously ,ie presbyopic patient may be able to read again without the aid of spectacles. This known as 'second sight'.

2) Seeing fixed black spots in the field of vision 3) Monocular diplopia or polyopia due to irregular refraction by the lens. Vision steadily diminishes until only light perception (LP) remains in the mature stage of cataract

SIGNS Cortical or soft cataract: hydration followed by coagulation of proteins appears primarily in the cortex of the lens.

Incipient stage: Wedge shaped spokes of opacity striae) extend from the periphery of the cortex, to the center. The areas between them are clear.

Immature stage: The process of opacification advanced further. The lens appears greyish. Clear lens are still present in the cortex and therefore iris shadow is present

Progressive sometimes rapid hydration of the cortical layers may cause swelling of the lens, thus making the AC shallow (intumescent cataract) leading to increase IOP.

Mature stage: Eventually the entire cortex becomes opaque and white. The cataract is said to ripe or mature no iris shadow is seen. The vision is now reduced to HM or PL

Slit lamp findings reveal that lens is completely opacified; ROR (red orange reflex) cannot be seen. This is visualized with pupils fully dilated In performing cataract surgery, it is important for the surgeon to prevent ENDOTHELIAL TOUCH. The corneal endothelium is a single layer for cells which do not regenerate. It touched, scratched or manipulated during surgery, it will decompensate and opacify. You might have removed the cataract but there is still opacification due to poor surgical technique.

Subscapular Nuclear

Cortical

Christmas Tree Cataract

- Lies directly under the lens capsule

- form after anterior lens epithelial cells become necrotic from a variety of causes including iritis, keratitis, inflammation associated with atopic dermatitis, irradiation, or electrical burns.

- The opacification of the lens is due to a migration of adjacent epithelial cells into the damaged area and subsequent transformation of these cells into a plaque of multiple layers of myofibroblasts.

- The most posterior layer of these cells remain epithelial cells and will produce a new lens capsule.

- Over time the myofibroblasts resolve leaving a wrinkled appearance to the lens capsule

- lies just in front of the posterior capsule

- more common than anterior

- more profound effect on vision than a comparable nuclear or cortical cataract.

- Patients troubled by headlights of incoming cars and bright light

- Near vision more impaired than distance vision.

- Common in aging where near vision is worse; more profound effect on vision associated with poorer outcomes

- Associated with myopia. Myopic Shift

Near vision is better. Patient may feel that their vision is restored. However, this is only temporary.

Overtime, the lens will grow and thicken and the cataract will mature.

Near vision may appear normal. However, if Snellen chart and other tests will be done, patient’s visual acuity is still low

- “second sight of the aged” - Yellowish early and brunescent in

later stages - Hard in consistency. Since the opacity is central vision is

good in dim light (when pupil dilates) and poor in bright light (when pupil constricts).

Gives rise to index myopia. (second sight)

Appears brown or even black due to deposition of melanin.

Progress is very slow and takes a long time to mature

May involve the anterior, posterior, or equatorial cortex

Start as clefts and vacuoles Typical cuneiform (wedge-shaped) or

radial spoke – like opacities Does not affect vision that much Since the opacity is peripheral vision is

good in bright light (when the pupil constricts) and poor in dim light when Pupil dilates.

Gives rise to index nypetmetropia Appear greyish in immature stage and

white in mature stage Progress is gradual

- Uncommon - Polychromatic (glows when you check on slit-

lamp exam), needle-like deposits in the deep cortex and nucleus.

- Shape is similar to Christmas tree.

Presenile Cataract Mean age of cataract development at 65 y.o. (according to the American Academy of Ophthalmology and the Philippine Board of Ophthalmology) Presence of systemic disorders may cause earlier onset of cataract formation

DIABETES MELLITUS

Aside from cataract, can affect refractive index of lens and its amplitude of accommodation,

Prevention: good sugar control

can affect refractive index and affect, can affect amplitude of accommodation

cataract starts 50+ y.o.

a) Classical Diabetic Cataract

sorbitol accumulates within the lens snowflake cortical opacities in the young diabetic

b) Age-related Cataract

Occurs earlier in DM patients

nuclear opacities are common and progress rapidly

c) Premature presbyopia

Due to reduced pliability of lens

Early loss of accommodation or ability of the eye to adjust to distance due to agin

MYOTONIC DYSTROPHY

Visually innocuous, fine cortical

Evolves into visually disabling stellate posterior subcapsular

Iridescent opacities in the 3rd decade.

Cataract by the 5th decade.

Develops slowly, takes about 2 decades for cataract to develop.

ATOPIC DERMATITIS

in 10% of patients with severe dermatitis, cataract develop. a) shield-likedense anterior subcapsular

plaque b) posteriorsubcapsular

NEUROFIBROOMATOSIS TYPE 2

Posterior subcapsular or posterior cortical opacities.

Traumatic Cataract Trauma is the most common cause of unilateral cataract in young individuals secondary to physical trauma due to their active lifestyle and risk taking behaviors.

Bilateral cataracts are not as common but are possible depending on the extent of injury

is most commonly due to a foreign body injury to the lens or blunt trauma to the eyeball. Air rifle pellets are a frequent cause; less frequent causes include arrows, rocks, contusions, overexposure to heat ("glassblower's cataract"), and ionizing radiation. Most traumatic cataracts are preventable. In industry, the best safety measure is a good pair of safety goggles

Traumatic "star-shaped" cataract in the posterior lens. This is usually due to ocular contusion and is only detectable through a well-dilated pupil Traumatic cataract with wrinkled anterior capsule Imprint of iris pigment on anterior surface of lens

DIRECT PENETRATING

Injury to lens; once capsule is torn and vitreous aqueous sips into the lens → lens will opacify

CONCUSSION

Can cause an “imprinting” of iris pigment on the anterior lens capsule (Vossius Ring) and rosette cataracts blunt trauma to anterior segment of eye

ELECTRIC SHOCK OR LIGHTNING

Can denature the lens

IONIZING RADIATION

Tumor Treatment

INFRARED RADIATION

If intense, may cause true exfoliation or lamellar delamination of anterior lens capsule

Drug-induced Cataract

Corticosteroids administered over a long period of time, either systemically or in drop form, can cause lens opacities. Other drugs associated with cataract include phenothiazines, amiodarone, and strong miotic drops such as phospholine iodide, used in the treatment of glaucoma.

STEROIDS

Systemic, topical, (even

inhaled form) are cataractogenic

opacities are initially posterior subcapsular then later affect anterior subcapsular region then later becomes mature cataract

Early opacities may regress if steroids discontinued but

May also progress even if steroids have been stopped

Given in uveitis

CHLORPROMAZINE

Innocuous fine, stellate, yellowish – brown granules on anterior lens capsule within the pupillary area

Dose-related and irreversible

central, anterior capsular granules

BUSULPHAN (MYERAN)

used in treatment of chronic myelocytic leukemia, may occasionally cause lens opacity

AMIODARONE

in treatment of cardiac arrhythmias, causes inconsequential anterior subcapsular opacities

GOLD

in treatment of rheumatoid arthritis, innocuous anterior capsular opacities in 50% of pts of >3yrs treatment

ALLOPURINOL

increases the risk of cataracts in the elderly if dose exceeds 400g or duration of >3yrs Treatment

Secondary Cataract

complicated cataract, develop as a result of some other primary ocular disease Cataract 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. Intraocular 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

CHRONIC ANTERIOR UVEITIS

is the most common cause of secondary cataract

uvea: iris, choroid, cilliary body

polychromatic lustre at posterior pole is earliest finding which may not progress if uveitis is arrested

posterior or anterior opacities progress to maturity

ACUTE CONGESTIVE ANGLE

Closure glaucoma

Lens-induced glaucoma can present in two forms: phacomorphic and phacolytic

Phacomorphic glaucoma – increased IOP d/t tumescent lens covering the pupil; aqueous can’t drain to the pupil

Phacolytic glaucoma – lens appear to be mature but there is problem with the lens proteins such that they escape onto the anterior chamber and clog up the trabecular meshwork

For both cases, treatment remains to be cataract removal

small, grey-white, anterior subcapsular or capsular opacities within the pupillary area (glaukomflecken)

HIGH (PATHOLOGIC) MYOPIA

posterior subcapsular opacities and

early – onset nuclear sclerosis

HEREDITARY FUNDUS DYSTROPHY

retinitis pigmentosa, Leber congenital amaurosis, gyrate atrophy, Stickler syndrome; posterior subcapsular cataracts

Retinitis pigmentosa – progressive degenerative dse that leads to complete blindness, no cure, hereditary