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LENS AND CATARACT
ABIYE MULUGETA, MD
Addis Ababa University
Department of Ophthalmology
April, 2011
Objective
- Know the normal anatomy and function of the lens.
- Know the risk factors for the development of
cataract.
- K...
Normal crystalline lens
is transparent, biconvex
structure.
It is derived from the surface ectoderm.
It is composed of –ca...
• Lies posterior to iris and anterior to vitreous.
• Suspended in position by the zonular fiber.
• It depends on aqueous h...
• Functions
-to maintain its own clarity.
-provides accommodation.
-to refract light, the lens contributes
about 15-20 dio...
CATARACT
• Any congenital or acquired opacity in the lens
or lens capsule is called as cataract
Epidemiology
1. Cataracts remain the
leading cause of blindness.
2. Age-related cataract is
responsible for 48% of
world b...
Cataracts
• Cataract surgery is the most frequently
performed surgical procedure
• 50% of those over 65 develop vision imp...
Cataract
Causes
• Age
• Congenital
(genetic, metabolic)
• Trauma
• Uveitis
• Metabolic
• Surgery
• Drugs (eg steroids)
SENILE CATARACT
CATARACT IN DOWN'S SYNDROME
Bilateral cataracts in an infant due to
Congenital rubella syndrome
SENILE CATARACT
• Also called as age related cataract
• Usually above the age of 50 yrs
• Usually bilateral, but almost al...
CLASSIFICATION
Classified according to:
Morphological Classification
• Nuclear
• Cortical
• Subcapsular
Maturity classif...
Nuclear cataract
• Most common type
• Age-related
• Occur in the center of the lens
NUCLEAR SENILE CATARACT
Congenital nuclear cataract
Cortical cataract
• Occur on the outer edge of the lens (cortex).
• Begins as whitish, wedge-shaped opacities or streaks.
...
CORTICAL SENILE CATARACT
Mature Cataract
• Lens is completely opaque.
• Vision reduced to just perception of light
Right eye mature cataract, with ...
Hypermature Cataract
• 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 los...
Sclerotic Cataract
• The fluid from the cortex gets absorbed
and the lens becomes shrunken.
• There may be deposition of c...
Symptoms
• A cataract usually develops
slowly, so:
–Causes no pain.
–Cloudiness may affect only a
small part of the lens
–...
Symptoms of Cataracts
•Bright Colors Become Dull
•Halos Around Lights
Signs
• Reduced vision, minimum LP
• Only severe dense cataracts causing severely impaired vision
cause a white pupil.
• G...
Treatment
• Surgical removal.
• Surgical techniques
– Phacoemulsification method.
– Extracapsular method.
– Intracapsular ...
• Surgical management
Indications:- 1. visual improvement
2.Medical indications
3. Cosmetic indications
Before IOL implantation was
developed
• Aphakic spectacles
• Contact lenses
Pseudophakic eye
Phacoemulsification in cataract surgery
involves insertion of a tiny, hollowed tip that
uses high frequency (ultrasonic) v...
Postoperative care after cataract
surgery
• Steroid drops (inflammation)
• Antibiotic drops (infection)
• Avoid
• Very str...
Complications of cataract surgery
• Infective endophthalmitis( infection)
• Bleeding or haemorrhage
• Uveatis( Inflammatio...
Congenital Cataract
• Occur in about 3:10000 live birth.
• 2/3 of case are bilateral
• It can cause ambylopia in infants.
Management in congenital cataract
• Bilateral congenital cataract require urgent surgery
(lensectomy and vitrectomy) and t...
Complications of untreated cataract
- Blindness
- Glaucoma
- Uveitis
- Subluxation and dislocation.
References
• Duanes clinical ophthalmology
• BSCS
• Albert and Jakcbeic
• E-medicine
THANK YOU
4.lens and cataract
4.lens and cataract
4.lens and cataract
4.lens and cataract
4.lens and cataract
4.lens and cataract
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  • A cataract can be the reason sharp images become blurred, bright colors become dull, or seeing at night is more difficult. It may also be why the reading glasses or bifocals that used to help you read, or do other simple tasks, no longer seem to help.
  • Transcript of "4.lens and cataract"

    1. 1. LENS AND CATARACT ABIYE MULUGETA, MD Addis Ababa University Department of Ophthalmology April, 2011
    2. 2. Objective - Know the normal anatomy and function of the lens. - Know the risk factors for the development of cataract. - Know the sign and symptom of cataract. - Identify patients with cataract and be able to refer patients to a centre where they can undergo definitive treatment i.e. surgery. - Know the complications of untreated cataract.
    3. 3. Normal crystalline lens is transparent, biconvex structure. It is derived from the surface ectoderm. It is composed of –capsule lens epithelium cortex and nucleus It has no blood supply or nerve supply after fetal development.
    4. 4. • Lies posterior to iris and anterior to vitreous. • Suspended in position by the zonular fiber. • It depends on aqueous humor to meet its metabolic requirement and carry off its wastes. • It grows continuously throughout life. • Measures at birth adulthood • Equatorially 6.4mm 9mm. • Ap 3.5mm 5mm. • Weighs 90mg 255mg
    5. 5. • Functions -to maintain its own clarity. -provides accommodation. -to refract light, the lens contributes about 15-20 diopters of the refractive power of the eye.
    6. 6. CATARACT • Any congenital or acquired opacity in the lens or lens capsule is called as cataract
    7. 7. 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.
    8. 8. Cataracts • Cataract surgery is the most frequently performed surgical procedure • 50% of those over 65 develop vision impairing cataracts.
    9. 9. Cataract Causes • Age • Congenital (genetic, metabolic) • Trauma • Uveitis • Metabolic • Surgery • Drugs (eg steroids)
    10. 10. SENILE CATARACT
    11. 11. CATARACT IN DOWN'S SYNDROME
    12. 12. Bilateral cataracts in an infant due to Congenital rubella syndrome
    13. 13. SENILE CATARACT • Also called as age related cataract • Usually above the age of 50 yrs • Usually bilateral, but almost always one eye is affected earlier than the other
    14. 14. CLASSIFICATION Classified according to: Morphological Classification • Nuclear • Cortical • Subcapsular Maturity classification • Immature Cataract • Mature Cataract • Hypermature Cataract
    15. 15. Nuclear cataract • Most common type • Age-related • Occur in the center of the lens
    16. 16. NUCLEAR SENILE CATARACT
    17. 17. Congenital nuclear cataract
    18. 18. 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.
    19. 19. CORTICAL SENILE CATARACT
    20. 20. Mature Cataract • Lens is completely opaque. • Vision reduced to just perception of light Right eye mature cataract, with obvious white opacity at the centre of pupil
    21. 21. Hypermature Cataract • This may take any of two forms: 1.Liquefactive/Morgagnian Type 2.Sclerotic Cataract
    22. 22. Liquefactive/Morgagnian Type • Cortex undergoes auto-lytic liquefaction and turns uniformly milky white. • The nucleus loses support and settles to the bottom.
    23. 23. 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. • The zonules become weak, increasing the risk of subluxation / dislocation of lens.
    24. 24. 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
    25. 25. Symptoms of Cataracts •Bright Colors Become Dull •Halos Around Lights
    26. 26. Signs • Reduced vision, minimum LP • Only severe dense cataracts causing severely impaired vision cause a white pupil. • Good pupillary reaction • Normal IOP TARACT
    27. 27. Treatment • Surgical removal. • Surgical techniques – Phacoemulsification method. – Extracapsular method. – Intracapsular method
    28. 28. • Surgical management Indications:- 1. visual improvement 2.Medical indications 3. Cosmetic indications
    29. 29. Before IOL implantation was developed • Aphakic spectacles • Contact lenses
    30. 30. Pseudophakic eye
    31. 31. 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 .
    32. 32. Postoperative care after cataract surgery • Steroid drops (inflammation) • Antibiotic drops (infection) • Avoid • Very strenuous exertion (rise the pressure in the eyeball) • Ocular trauma.
    33. 33. Complications of cataract surgery • Infective endophthalmitis( infection) • Bleeding or haemorrhage • Uveatis( Inflammation) • Glaucoma • Vitreous loss • Cystoid macula • Retinal detachment . . .
    34. 34. Congenital Cataract • Occur in about 3:10000 live birth. • 2/3 of case are bilateral • It can cause ambylopia in infants.
    35. 35. Management in congenital cataract • Bilateral congenital cataract require urgent surgery (lensectomy and vitrectomy) and the fitting of the contact lens to correct the aphakia • Uniocular congenital cataract treatment remains controversial. • Follow-up for children with congenital cataract should continue because of the risk for developing – Glaucoma – Amblyopia – Strabismus
    36. 36. Complications of untreated cataract - Blindness - Glaucoma - Uveitis - Subluxation and dislocation.
    37. 37. References • Duanes clinical ophthalmology • BSCS • Albert and Jakcbeic • E-medicine
    38. 38. THANK YOU
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