Cataract Flashcards
Cause of caratogenesis
- Hydration : reversible
- Denaturation of lens proteins : irreversible (Oxidative
damage to membrane and proteins) - Slow sclerosis : hard cataract (aggragation and
compaction of lens proteins causing scattering of
light)
Classification of senile cataract
2 forms:
• Cortical (soft) (75%) – due to marked
hydration of lens -> coagulation of proteins
• Nuclear (hard) (25%) - dehydration and
compaction of the nucleus - May be assoc
with pigment deposition
(urochrome/melanin) derived from amino
acids.
Main feature of immature senile cataract
Periphral
Grayish white
Wedge shaped
Iris shadow
Mature cataract
characters
- Complete opacification
- Whole of cortex involved
- Pearly white in colour
- No iris shadow
Hypermature cataract
When it occurs
Types
• Morgaganian hypermature cataract:
- Liquefaction of entire cortex, nucleus sinks down
• Sclerotic hypermature cataract:
- Shrinkage of lens due to leakage of water
- Ant. capsule thickens and wrinkles
- Due to shrinkage of lens, AC deepens and
there may be iridodonesis
Second sight phenomenon
Distant vision diminishes due to progressive
index myopia but near vision in these patients
may improve due to same reason so that they
may be able to read without their presbyopic
glasses, Nuclear cataract:
Complications of Cataract
I. Lens Induced Glaucoma
Phacomorphic Glaucoma
Phacolytic Glaucoma
II. Lens Induced Uveitis
III. Subluxation or Dislocation of Lens
Complicated cataract
Etiology
Chronic Uveitis
glaucoma
retinitis pigmentosa
retinal detachment
The cataract usually begins in the Posterior Subcapsular Area and
eventually involves the entire lens.
Slit lamp examination of Complicated cataract
- Bread crumb appearance
- Polychromatic luster
Toxic/ Drug Induced cataract
• Corticosteroids: Posterior subcapsular cataract
• Strong Miotics: Phospholone Iodide
IOLs are made of
(Polymethyl Methacrylate), Silicone or
Acrylic (foldable).
Feature and treatment of Posterior capsule opacity
“Elschnig’s pearls”
YAG Laser capsulotomy
