This document discusses different types of cataracts including age-related cataract (senile cataract), drug-induced cataract, and traumatic cataract. It provides detailed information on the pathogenesis, clinical presentation, and histopathology of various cataract subtypes such as nuclear cataract, cortical cataract, and posterior subcapsular cataract. Specific drug-induced and traumatic cataracts are also examined, along with the effects of radiation and chemical injuries on lens opacity formation. The document is an extensive reference source on cataract pathology authored by Prof. Naimatullah Khan Kundi of the Department of Ophthalmology at Khyber Teaching Hospital in P
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Age related cataract
1. Age Related Cataract (Senile Cataract)
Drug Induced Cataract
Traumatic Cataract
By
Prof. Naimatullah Khan Kundi
Head, Department of Ophthalmology
Khyber Teaching Hospital
Peshawar
3. Lens & Cataract (Pathology)
Aging Chances
Age related cataract (Senile Cataract)
Very common cause of visual impairment in
older adults
50-70% between ages 60-75yrs
Pathogenesis:
Multifactorial and not completely understood.
As lens ages its wt. ↑
Thickness ↑
Accommodative power ↓
Lens Nucleus compressed and hardened (Nuclear
Sclerosis) as new layers of cortical fibers as formed
concentrically
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4. Lens & Cataract (Pathology)
Lens proteins (Crystallines) – chemically modified and
aggregate into high molecular wt. proteins
The resulting proteins aggregates cause:
Abrupt fluctuations in refractive index
Scatter light rays
Reduce transparency
Chemical modification of nuclear lens proteins also produce
pigmentation (yellow/brownish hue with advancing ages)
↓ concentration of glutathione and K+, ↑conc. of Na+
and Ca++, ↑ Hydration
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6. Lens & Cataract (Pathology)
Nuclear
In adults past middles ages some degree of nuclear sclerosis
and yellowing is considered physiologically normal. This
condition interferes minimally with visual function
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7. Lens & Cataract (Pathology)
Nuclear
2. Excessive sclerosis and
yellowing (nuclear
sclerosis) cause central
opacity. Degree of
scleroses, yellowing and
opacifications evaluated
with SL bio-microscope
and examination of red
reflex (Pupil dilated)
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8. Lens & Cataract (Pathology)
Nuclear (cont’d)
3.
Progression slow
4.
BL, (± asymmetric)
5.
Visual impairment greater of distance vision than
of near vision
6.
↑ refractive index and thus myopic shift in
refraction (Lenticular myopia). This myopic shift
transiently enables presbyopic individulas to
read without spectacles
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(second sight)
8
9. Lens & Cataract (Pathology)
Nuclear (cont’d)
7.
Monocular diplopia:
Abrupt change in the refractive index between the sclerotic
nucleus and the cortex
7.
Progressive yellowing of the lens causes poor hue
discrimination esp. at the blue end of the visible spectrum
8.
Photopic retinal function may ↓ with advanced nuclear
cataract
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10. Lens & Cataract (Pathology)
10.
In very advanced cases the nucleus becomes opaque and brown
(brunescent)
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11. Lens & Cataract (Pathology)
11.
Histopathology:
Nucleus homogenous with loss of celluler
laminations.
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12. Lens & Cataract (Pathology)
Cortical Cataract
1.
Early changes:
2.
3.
4.
Changes in ionic composition + hydration + cortical
opacification
BL, often Asymmetrical
First visible signs of cortical cataract formation
(SL bio-microscope) are vacuoles & water clefts
in ant. And post. cortex
Cuneiform opacities (cortical spokes): wedge
shaped, form near the periphery the lens, with
pointed ends oriented toward the center
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13. Lens & Cataract (Pathology)
5.
Cortical Cataract
The cortical spokes appear white when viewed with SL
bio-microscope and dark shadows when viewed by
retroillumination.
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14. Lens & Cataract (Pathology)
Cortical Cataract (cont’d)
6.
Their effect on VA varies greatly, depending
upon the location of the opacity relative to the
visual axis
7.
Common symptom:
Glare from intense focal light sources (e.g. Car head
light)
8.
Monocular diplopia may also result
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15. Lens & Cataract (Pathology)
Cortical Cataract (cont’d)
9.
Progression:
10.
11.
vary, some times unchanged for prolonged
periods, while others progress rapidly
The wedge shaped opacities may enlarge
and coalesce to form large cortical opacities.
Intumscent Cataract:
As lens continues to take up water it may swell
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16. Lens & Cataract (Pathology)
12.
Mature Cataract:
When the entire lens from the capsule to the
nucleus becomes white and pacified
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17. Lens & Cataract (Pathology)
13.
Hypermature Cataract:
when degenerated and
liquefied cortical
material leaks through
the lens capsule,
leaving capsule
wrinkled and shrunken
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18. Lens & Cataract (Pathology)
14.
Morgagnian Cataract:
with further liquefaction
of the cortex allows free
movements of the
nucleus within the
capsular bag.
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20. Lens & Cataract (Pathology)
Cortical Cataract (cont’d)
15.
Histopathology:
Hydropic swelling of the lens fibers
Globules (morgagnian) of eosinophilic
material observed in slit-like spaces
between lens fibers
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21. Lens & Cataract (Pathology)
Posterior Subcapsular (cupuliform)
cataract (PSC)
1.
PSCs often seen in patients younger than
those presenting with nuclear/cortical
cataracts
2.
PSC located in the posterior cortical layer
and is axial in location
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22. Lens & Cataract (Pathology)
Posterior Subcapsular (cupuliform)
cataract (PSC)
3.
First indication: subtle iridescent sheen in the
posterior cortical layers (SLB exam)
Later stages:
Granular opacities and
A plaque like opacities of posterior subcapsular
Tuesday, December cortex appear
24, 2013
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23. Lens & Cataract (Pathology)
Posterior Subcapsular (cupuliform)
cataract (PSC)
Patient complains of
glare and
↓ vision
PSC obscures more of the pupillary area when
In bright light
miosis is induced by:
Bright light
Accommodation
Miotics
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24. Lens & Cataract (Pathology)
Posterior Subcapsular (cupuliform) cataract
(PSC)
5.
6.
7.
Near VA tends to be decreased more than
distance VA
Some patients experience monocular diplopia
Other causes of PSC:
1.
2.
3.
4.
5.
Age related – main type
Trauma
Corticosteroids
Inflammations
Ionizing radiations
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25. Lens & Cataract (Pathology)
Posterior Subcapsular (cupuliform) cataract
(PSC)
8.
Histopathology
1.
Posterior migration of lens epithelial
cells in the posterior sub-capsular area,
with aberrant enlargement
2.
These swollen epithelial cells are called
Wedl (Bladder) cells
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28. Drug induced cataracts
Corticosteroids
Long term use of steroids cause PSCs
Occurrence related to:
1.
Dose
2.
Duration of treatment
3.
Susceptibility to steroids (vary)
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29. Drug induced cataracts
Corticosteroids (cont’d)
Cataract Formation:
Nasal spray
Systemic / Topical / Sub-conjunctival
Eye lid dermatitis (steroids treatment)
Histopathology:
Similar to senescent PSC changes
Some steroid-induced PSCs in children may
be reversible with cessation of the drug
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30. Drug induced cataracts
Phenothiazines
Chloropromazine, Thioridazine
Phenotiazines, a major group of Psycho-tropic medications, can cause
pigmented deposits in the anterior lens epithelium in an axial configuration
Deposits appear to be affected by dose and duration
Visual changes associated with phenothiazine are usually insignificant
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31. Drug induced cataracts
Miotics
Anticholinesterases (Ecothiophate, demacrium)
pilocarpine, phospholine lodide
These can cause cataracts
Cataract dose and duration related
Cataract may progress to posterior cortical and
nuclear
First appears as small vacuoles within and
posterior to the anterior lens capsule and
epithelium (Best appreciated by retroillumiunation)
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32. Drug induced cataracts
Miotics
Visually significant cataracts common in
elderly patients (Topical
anticholinesterase)
Progressive cataract not reported in
children (Echothiophate for
accommodative esotropia)
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35. Traumatic Cataract
Traumatic lens damage may be caused by:
1.
Mechanical injury
2.
Physical forces
Electrical current
3.
Radiation
Chemicals
Osmotic influences (diabetes mellitus)
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36. Traumatic Cataract
Contusion (Blunt injury)
Vossius ring
Blunt trauma to eye can sometimes cause
pigment from pupillary ruff to be imprinted on
anterior lens surface in a ring shape
It is visually insignificant
It indicates previous trauma
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38. Traumatic Cataract
Contusion (Blunt injury)
Blunt, non perforating injury
may cause lens opacification
(acute event / late sequela)
Cataract may involve a
portion or entire lens
Often the initial manifestation
is a stellate / rosette-shaped
opacification, axial in location
(PSC)
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39. Traumatic Cataract
Contusion (Blunt injury)
Rosette cataract may progress to
opacification of entire lens
In some cases lens capsule may be
ruptured by the force of blunt trauma,
with subsequent hydration and rapid
opacification of the lens
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40. Traumatic Cataract
Contusion (Blunt injury)
Perforating and penetrating injuries
Penetrating injury of lens often results in
opacification of cortex at site of rupture,
progressing rapidly to complete opacification
A small perforating injury of the lens capsule
may heal, resulting in a small focal cortical
cataract
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41. Radiation-induced cataracts
Ionizing radiations
Lens is extremely sensitive to ionizing
radiations
Cataract clinically apparent after period
of up to 20 yrs
Latency related to:
Dose and
Age of patient
A young patient with more actively growing lens
cells is more susceptible
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42. Radiation-induced cataracts
Ionizing radiations (cont’d)
Clinically:
Punctate opacities within posterior
capsule and feathery anterior subcapsular opacities that radiate towards
the equator of the lens
These may progress to complete
opacification
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43. Radiation-induced cataracts
Infra-red radiations (Glasses blower’s
cataract)
Intense heat and infra-red radiations
cause outer layer of the anterior capsule
to peel off as a single layer (true
exfoliation)
May be associated with cortical cataract
Rarely seen today
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44. Radiation-induced cataracts
Ultra-voilet radiations (UV)
Prolong exposure to UV radiations in the
UVB range (Sun exposure) is associated
with ↑ risk of:
Cortical
PSCs
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(Epidemiologic Evidence)
44
45. Radiation-induced cataracts
Micro-wave Radiations
Non-ionizing radiations with wavelength
between IR and short waves on the
electromagnetic spectrum
No evidence of cataract by microwaves
Biological effect – thermal
Microwaves could theoretically cause
cataract:
Dose levels would be so high as to induce
hyperthermic brain damage
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46. Chemical injuries
Alkalis and Acids
Alkalis injuries to ocular surface result in cataract
Alkalis compounds penetrate eye readly causing:
1.
↑ Aqueous pH
2.
↓ Aqueous Glucose
3.
↓ Aqueous Ascorbate
Cortical cataract:
Acutely or delayed effect
Associated injuries:
Damage to cornea,
conjunctiva, iris etc.
Acids: Tends penetrate eye less easily than alkali
Acid injuries are less likely to result in cataract formation
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