Download Congenital Cataract

CATARACT
DONE BY
Jony Mallik
CATARACT SEMINAR
OBJECTIVES
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ANATOMY OF THE LENS
DEFINITION AND EPIDIMIOLOGY
CAUSES
AGE RELATED CATARACT
SYMPTOMS AND SIGNS
DDx OF GRADUAL LOSS OF VISION
TREATMENT
PRE-OPERATIVE ASSESMENTS
COMPLICATIONS
POST-OP care
CONGENITAL CATARACT
The lens
It’s crystalline.
Histology:
1. Capsule
2. Subcapsular epithelium (simple cuboidal).
• Synthesize protein for lens fiber
• Transport AA
• Maintains a cation pump to keep the lens clear
3. Lens fibers
Cross section:
1. Capsule
2. Cortex
3. nucleus
Ciliary muscle
• Innervation: 3rd CN
• Function:
• Constricts ciliary body
• Relaxes tension on lens
• Lens become spherical,
which increase the
refractive power
Ciliary process
• Attaches to the lenses by
suspensory ligament
(zonular fibers)
• Secrete the Aqueous humor
into the post. chamber
Definition of cataract
• Opacity of the lens, which occurs when fluid gathers between
the lens fibers.
When eyes work properly:
• Light passes through the cornea and the pupil to the lens.
• The lens focuses light & producing clear, sharp images on the
retina.
• As a cataract develops, the lens becomes clouded, which
scatters the light and prevents a sharply defined image from
reaching retina. As a result, vision becomes blurred.
Epidemiology
1. Cataracts remain the
leading cause of blindness.
2. Age-related cataract is
responsible for 48% of
world blindness, which
represents about 18
million people
3. Cataracts are also an
important cause of low
vision in both developed
and developing countries.
Causes of cataract
• Old age (commonest)
• Ocular & systemic diseases
– DM
– Uveitis
– Previous ocular surgery
• Systemic medication
– Steroids
– Phenothiazines
• Trauma & intraocular
foreign bodies
• Ionizing radiation
– X-ray
– UV
• Congenital
– Dominant
– Sporadic
– Part of a syndrome
– Abnormal galactose
metabolism
– Hypoglycemia
• Inherited abnormality
– Myotonic dystrophy
– Marfan’s syndrom
– Rubella
– High myopia
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Cataract
Divided to :
• Acquired cataract
Age - related cataract
Presenile cataract
Traumatic cataract
Drug induced cataract
Secondary cataract
• Congenital Cataract
Systemic association
Non-systemic association
Age -related cataract
It is the Most commonly occurred.
Classified according to:
 Morphological Classification
• Nuclear
• Cortical
• Subcapsular
• Christmas tree – uncommon
 Maturity classification
• Immature Cataract
• Mature Cataract
• Hypermature Cataract
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Nuclear cataract
Most common type
Age-related
Occur in the center of the lens.
In its early stages, as the lens changes
the way it focuses light, patient may
become more nearsighted or even
experience a temporary improvement in
reading vision. Some people actually
stop needing their glasses.
• Unfortunately, this so-called 2nd sight
disappears as the lens gradually turns
more densely yellow & further clouds
vision.
• As the cataract progresses, the lens may
even turn brown. Advanced discoloration
can lead to difficulty distinguishing
between shades of blue & purple.
Cortical cataract
• Occur on the outer edge of the lens (cortex).
• Begins as whitish, wedge-shaped opacities or streaks.
• It’s slowly progresses, the streaks extend to the center and
interfere with light passing through the center of the lens.
• Problems with glare are common with this type of cataract.
Subcapsular cataract
• Occur just under the capsule of the lens.
• Starts as a small, opaque area
• It usually forms near the back of the lens, right in the path of
light on its way to the retina.
• It’s interferes with reading vision
• Reduces vision in bright light
• Causes glare or halos around lights at night.
Posterior Subcapsular Cataracts
• Begins at the back of the lens (posterior pole) & spreads to the
periphery or edges of the lens.
• It can be developed when:
– Part of the eye are chronically inflamed.
– Heavy use of some medications (steroids).
• Affects vision more than other types of cataracts because the light
converges at the back of the lens.
• Anything constrict the pupils (bright light) makes it very difficult
for people with this type of cataract to see.
• Dilating drops useful in this type by keeping the pupils large and
thus allow more light into the eye.
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Immature Cataract
Lens is partially opaque
Two morphological forms are seen:
1. Cuneiform Cataract:
– Wedge shaped opacities in the peripheral cortex and
progress towards the nucleus.
– Vision is worse in low ambient illumination when the
pupil is dilated.
2. Cupuliform Cataract:
– A disc or saucer shaped opacities beneath the posterior
capsule.
– Vision is worse in bright ambient illumination when the
pupil is constricted.
Lens appears grayish white in color.
Iris shadow can be seen on the opacity with oblique illumination.
Mature Cataract
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Lens is completely opaque.
Vision reduced to just perception of light
Iris shadow is not seen
Lens appears pearly white
Right eye mature cataract, with obvious
white opacity at the centre of pupil
Hypermature Cataract
• Shrunken and wrinkled anterior capsule due to leakage of water
out of the lense.
• This may take any of two forms:
1. Liquefactive/Morgagnian Type
2. Sclerotic Cataract
Liquefactive/Morgagnian Type
• Cortex undergoes auto-lytic liquefaction and turns uniformly
milky white.
• The nucleus loses support and settles to the bottom.
Sclerotic Cataract
• The fluid from the cortex gets absorbed
and the lens becomes shrunken.
• There may be deposition of calcific
material on the lens capsule.
• Iridodonesis: Anterior chamber
deepens and iris becomes tremulous.
• The zonules become weak, increasing
the risk of subluxation / dislocation of
lens.
Symptoms
• A cataract usually develops
slowly, so:
– Causes no pain.
– Cloudiness may affect only a
small part of the lens
– People may be unaware of any
vision loss.
• Over time, however, as the
cataract grows larger, it:
– Clouds more the lens
– Distorts the light passing
through the lens.
– Impairs vision
• Reduced visual acuity (near
and distant object)
• Glare in sunshine or with
street/car lights.
• Distortion of lines.
• Monocular diplopia.
• Altered colours ( white
objects appear yellowish)
• Not associated with pain,
discharge or redness of the
eye
Signs
• Reduced acuity.
• An abnormally dim red reflex is seen when the eye is viewed
with an ophthalmoscope.
• Reduced contrast sensitivity can be measured by the
ophthalmologist.
• Only sever dense cataracts causing severely impaired vision
cause a white pupil.
• After pupils have been dilated, slit lamp examination shows the
type of cataract.
Gradual loss of vision
DDX:
1. Cataract
2. Glaucoma
3. Diabetic retinopathy
4. Hypertensive retinopathy
5. Age related macular degeneration
6. Retinitis pigmentosa
7. Trachoma
8. Onchocerciasis (river blindness)
9. Vitamin A deficiency
Treatment
• Glasses: Cataract alters the refractive power of the natural lens
so glasses may allow good vision to be maintained.
• Surgical removal: when visual acuity can't be improved with
glasses.
• Surgical techniques
– Phacoemulsification method.
– Extracapsular method.
– Intracapsular method
Pre-op assesments
• General health evaluation including blood pressure check
• Assessment of patients’ ability to co-operate with the
procedure and lie reasonably flat during surgery
• Instruction on eye drop instillation
• The eyes should have a normal pressure, or any pre-existing
glaucoma should be adequately controlled on medications.
• An operating microscope is needed, in order to reach the lens,
a small corneal incision is made close to the limbus for the
phaco-probe.
• It is important to appreciate anterior chamber depth and to
keep all instruments away from the corneal endothelium in the
plane of the iris.
Phacoemulsification:
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Corneal incision 2.75-3.2 mm
Viscoelastic to anterior chamber.
Capsulorhexis
Hydrodissection.
Phacoemulsification of the nucleus.
Aspiration of the cortex.
More viscoelastic.
Folded intraocular lens (IOL) is inserted under a cushion of
viscoelastic fluid which protect the corneal endothelium, the
lens unfold spontaneously within the capsular bag.
9. Vescicoelastic removed and replaced with balanced salt
solution.
10. Self sealing wound.
11. Sub conjunctival injection of steroid and antibiotics
12. Eyepad and protection eye shield.
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Phacoemulsification in cataract surgery
involves insertion of a tiny, hollowed tip that
uses high frequency (ultrasonic) vibrations to
"break up" the eye's cloudy lens (cataract). The
same tip is used to suction out the lens
Extra-capsular Cataract Extraction
(ECCE)
• The nucleus and the cortex is removed out of the capsule
leaving behind:
• Intact posterior capsule
• Peripheral part of the anterior capsule
• Zonules.
• This method:
• Provides support of placement of IOL
• Prevents vitreous from bulging forwards
• Acts as a barrier between anterior and posterior segment.
• All this results in decreasing the incidence of complications.
Intra-capsular Cataract Extraction
• The lens is removed as one single piece i.e., the nucleus and the
cortex are removed within the capsule of the lens after breaking
the zonules.
• There is no support left for posterior chamber IOL, therefore,
only anterior chamber IOL (ACL) can be implanted which has
risk of adverse corneal complications.
• There is no barrier left between anterior and posterior segment,
which increases the incidence of other complications.
• The only advantage is that after-cataract does not develop as
the entire capsule is removed.
Postoperative care after cataract
surgery
• Steroid drops (inflammation)
• Antibiotic drops (infection)
• Avoid
• Very strenuous exertion (rise the pressure in the eyeball)
• Ocular trauma.
Complications of cataract surgery
• Infective endophthalmitis
– Rare but can cause permanent severe reduction of vision.
– Most cases within two weeks of surgery.
– Typically patients present with a short history of a
reduction in their vision and a red painful eye.
– This is an ophthalmic emergency.
– Low grade infection with pathogen such as
Propionibacterium species can lead patients to present
several weeks after initial surgery with a refractory uveitis
• Suprachoroidal haemorrhage.
– Severe intraoperative bleeding can lead to serious and
permanent reduction in vision.
• Uveitis
– Postoperative inflammation is more common in certain
types of eyes for example in patients with diabetes or
previous ocular inflammatory disease.
• Ocular perforation.
• Postoperative refractive error
– Most operations aim to leave the patient emmetropic or
slightly myopic, but in rare cases biometric errors can
occur or an intraocular lens of incorrect power is used.
• Posterior capsular rupture and vitreous loss
– If the very delicate capsular bag is damaged during surgery
or the fine ligaments (zonule) suspending the lens are weak
(for example, in pseudoexfoliation syndrome), then the
vitreous gel may prolapse into the anterior chamber. This
complication may mean that an intraocular lens cannot be
inserted at the time of surgery. Patients are also at
increased risk of postoperative retinal detachment.
• Retinal detachment.
– This serious postoperative complication is, fortunately rare,
but is more common in myopic patients after intraoperative
complications.
• Cystoid macular oedema
– Accumulation of fluid at the macula postoperatively can
reduce the vision in the first few weeks after successful
cataract surgery. In most cases this resolves with treatment
of the post-operative inflammation.
• Glaucoma
– Persistently elevated intraocular pressure may need
treatment postoperatively.
• Posterior capsular opacification
– Scarring of the posterior part of the capsular bag, behind
the intraocular lens, occurs in up to 20% of patients. Laser
capsulotomy may be needed.
Congenital Cataract
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Occur in about 3:10000 live birth.
2/3 of case are bilateral (half of the cause can be identified)
The most common cause is genetic mutation usually AD
It can cause ambylopia in infants.
It is divided to:
1. Systemic association
2. Non-systemic association
Systemic association
1. Metabolic:
• Galactosaemia, galactokinase deficiency, Lowe
syndrome, others (hypoparathyroidism,
pseudohypoparathyroidism, mannosidosis)
2. Prenatal infection:
• Congenital rubella (~15% of cases), other intrauterine
infection (toxoplasmosis, cytoegalovirus, herpes
simplex varicella)
3. Chromosomal Abnormalities:
• Down syndrome~5%
• Patau (trisomy 13)
• Edward (trisomy 18 ) syndrome.
Bilateral cataracts in an infant due to
Congenital rubella syndrome
Non-systemic association
1. Isolated hereditary cataract
 About 25% of cases.
 Most frequently AD, but maybe AR or X-linked
 Better visual prognosis than coexisting ocular and
systemic abnormalities
 Classified to:
Zonular cataract: opacity occupies a discrete zone in
the lens
Polar cataract: opacities occupy subcapsular cortex at
anterior or posterior pole of lens
Zonular cataract
The lens opacities (“riders”) are located in only one layer of lens
fibers, often only in the equatorial region as shown here.
Congenital anterior polar cataract and
persistent pupillary membrane
2. Coronary (supranuclear) cataract: round opacities in
deep cortex surrounding nucleus like crown.
3. Blue dot cataract (cataracta punctata caerula):
common and innocuous, may coexist with other type
of lens opacities
4. Total (mature) cataract: frequently bilateral and
often begin as lamellar or nuclear
5. Membranous cataract (rare)
Nuclear cataract
This variant of the lamellar cataract affects only the outer layer of
the embryonic nucleus, seen here as a sutural cataract.
Congenital nuclear cataract
Management in congenital cataract
• Bilateral congenital cataract require urgent surgery
(lensectomy and vitrectomy) and the fitting of the contact lens
to correct the aphakia.
• After the age of 2 years there is a general agreement to use
intraocular lenses (IOLs), but before is still controversial
• Uniocular congenital cataract treatment remains
controversial.
• Follow-up for children with congenital cataract should
continue because of the risk for developing
– Glaucoma
– Amblyopia
– Strabismus
Thank You