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45 Cards in this Set
- Front
- Back
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Posterior capsule of lens divides eye into ?
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Anterior and posterior segment
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Pupil divides anterior segment into ?
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Anterior (0.25 ml) and posterior chamber (0.06ml)
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Volume of
1) vitreous cavity 2) Eyeball 3) Orbit |
4 ml
6.5-7 ml 30 ml |
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Parts of eye developing from neural epithelium |
ROME 23 - retina, optic nerve, muscles of iris, epithelium of ciliary body - secondary and tertiary vitreous |
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Parts of eye developing from surface epithelium |
Lens, epithelium of cornea and conjunctiva (SLE) |
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Parts of eye developing from neural crest cells
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endothelium of cornea, descemet's membrane, stroma, trabecular meshwork
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Mesoderm |
Extraocular muscles, blood vessels, vitreous Vitreous, vascular endothelium, iris, choroid, corneal stroma, extraocular muscles, sclera (temporal) |
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Thinnest region of lens
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posterior pole
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Thickest region of lens
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Pre-equatorial
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location of nodal point of human eye, importance of the location
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Posterior to posterior pole
Imp : any opacity in this region is more significant |
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Where are lens generating cells present
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Equator
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MC congenital cataract
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Lamellar
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MC congenital cataract at birth
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Lamellar
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Mode of inheritance of lamellar
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AD
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True/False - Affection in lamellar is unilateral
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FALSE. ALWAYS B/L
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Associations of lamellar cataract
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Rickets
CRS |
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Rider's cataract is a variant of ?
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Lamellar cataract
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Anterior capsular cataract is s/o?
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Previous perforating injury
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Blue dot cataract involves which nucleus?
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Adult
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How is coronary cataract different from blue dot?
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presents only in 1 lamella
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Morphology in white nuclear cataract
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Cortex liquefies. Lens becomes fluid filled space. Nucleus shifts to bottom.
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Congenital morgagnian cataract is a feature of?
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CRS
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3 main features of CRS
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Ocular lesions
Heart disease Deafness |
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What are the ocular lesions in CRS?
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Cataracts
Glaucomas Mirophthalmia Salt and pepper retinopathy |
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Causes of salt and pepper retinopathy (mnemonic Carribean premier league - CPL)
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Congenital syphilis & CRS
Phenothiazine toxicity Lowe's syndrome |
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Features of lowe's syndrome
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-Oculocerebrorenal syndrome
-XLR -Amino acid abnormalities -Eye lesion : Posterior lenticonus |
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Conditions where lenticonus is seen
Anterior? Posterior? |
Anterior - Alport's (A-A)
Posterior - Lowe's syndrome |
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Rx of congenital cataract
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Surgery as early as possible. If not done, amblyopia develops.
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What happens when surgery is delayed in congenital cataracts? Why?
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Amblyopia results. This is due to impaired sensory reception from affected eye to brain. It develops before 6 years
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Amblyopia therapy
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-Spectacles
-Patching of normal eye (upto 10yrs) -Pleotropic exercises |
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Precipitating factors in senile cataracts (6)
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Malnutrition-age-obesity
Diarrhoea-dehydration UV rays |
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Antioxidants in lens preventing cataract formation (5)
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Vitamins C and E
Catalase, superoxide dismutase and glutathione |
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Enzyme channels in lens
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Myoinositol - Vit C transport
MIP 26 - water transport -dysregulation of these causes cataract |
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True/False
- Cortical cataract has increased water in lens - Nuclear cataract has decreased water in lens |
Both true
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Pigment in nuclear cataract
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urochrome
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What happens to
1) refractive index 2) elasticity in a nuclear cataract |
refractive index increases
elasticity decreases |
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Cuneiform and cupuliform are seen in what stage of maturation?
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Incipient stage
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Morphology of cuneiform
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Wedge opacities, periphery to centre
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Morphology of cupuliform
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Saucer opacity, centre to periphery, posterior subcapsular
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Features of incipient stage
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Polyopia
Coloured halos* *Other causes -Mucopurulent conjunctivits -Acute congestive glaucoma |
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Intumescence of cataract seen in which stage of maturation
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Immature*
*other features - partial cortex opacification - phacomorphic glaucoma (closure type) |
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Feature of mature stage
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Whole cortex opaque
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Types of hypermature
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-Morgagnian
-Nuclear sclerosis |
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Features of nuclear sclerosis
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-Fluid and protein seep through micropores
-Calcification and fibrosis of capsule -Degeneration of zonules (Spontaneous dislocation of lens possible) |
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Some symptoms of cataracts
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Painless gradual loss of vision
Glare Polyopia Coloured halos Day blindness Second sight Day blindness |
