Trans 004 Acute Non Traumatic Visual Loss Flashcards
❛ Metabolic disorders are generally inherited in ❜
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What fashion
Autosomal recessive
❛ Clinically, enzyme deficiencies produce systemic and opthalmic signs and symptoms by several mechanisms: ❜
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4 mechanisms
❛ 1) Accumulation of undegraded products, 2) Lack of production of an essential substrate, 3) Blockage of the normal conversion of one product to the other, 4) Activation of alternate metabolic pathways unfavorable to cellular integrity. ❜
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lens dislocation is metabolic disease ❛
Homocysteinuria
❛ o
o
o
o
Loss of transparency of the perifoveal retina due to edema or deposition of abnormal material in the ganglion cells
In Tay-Sachs disease, Sandhoff disease, NiemannPick disease Disapperas over time as ganglion cells die and optic atrophy develops ❜
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Cherry red spot
What MPS
❛ o Lacks alpha-L-iduronidase o Severe corneal clouding, +RPE
degeneration, optic nerve head
swelling, optic atrophy, and
o
glaucoma
Claw hand, deafness, joint disease, intellectual disability, low nasal bridge ❜
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❛ Hurler (MPS I) ❜
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What MPs ❛ o Signs and symptoms usually appear after the age of 5 years o Claw-hand deformities, joint stiffness, aortic valve insufficiency, hernias, and deafness o Ocular features: Corneal clouding, Pigmentary retinal degeneration
Glaucoma, ❜
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❛ Scheie (MPS I-s; formerly ops v) ❜
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What MPs ❛ Most patients have severe bone involvement, with little or
no intellectual impairment ❜
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❛ Longer life expectancey than those with Hurler syndrome Arachnoid cysts with spinal rhinorrhea are characteristic feature Cervical corn may be compressed as a result of MPS accumulation ❜
— Page 2 ❛ Ocular manifestations: Progressive corneal clouding, Chronic disc edema, Retinal degeneration, Diminished elecroretinogram
❜
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❛ Hunter-Scheie (MPS IH-s) ❜
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❛ o Lacks iduronate-2-sulfatase o No corneal clouding, optic atrophy, +RPE degeneration o Frontal bossing, coarse facial features, worse over time ❜
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What MPs
❛ Hunter (MPS II) ❜
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What-mps ❛ o Lacks N-acetyl-galactosamine-6sulfatase or B-galactosidase o With corneal clouding, no corneal
o
degeneration
Abnormal spine, bell-shaped chest, knock-knees, short stature ❜
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❛ Morquio (MPS IV) ❜
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❛ o Multiple enzyme deficiency o Hazy cornea, no RPE degeneration o Coarse facial features, short stature, carpal tunnel o Autosomal recessive transmission ❜
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What mucolipidoses
❛ PSEUDO-HURLER POLYDYSTROPHY ❜
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What
Sphingolipidoses ❛ o Lack sphingomyelinase o Cherry-red spot (macular
halo),
Corneal opacification,
Difficulty with up- and down-
gaze,
Nystagmus
o
Loss of motor skills, loss of muscle tone, tremors, enlarged abdomen ❜
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❛ NIEMANN-PICK DISEASE ❜
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Symptoms of what? ❛ a) Enlarged liver and spleen or swellin gin abdomen by around 3 months, which may progress with aage
b) Feeding issues, failure to thrive
c) Frequent respiratory infections
d) Red spot in the eye
e) Irritability ❜
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Niemann-pick disease
What sphingolipidoses ❛ o Lack alpha-galactosidase A – essential in glycosphingolipid catabolism o Corneal verticillata (whorled streaks) and spokelike cataract, Lid edema, Myelinated nerve fiber, Mild
optic atrophy,
opthalmoplegia
Papillidema,
Nystagmus,
Internuclear
o
Bilateral inferior sub capsular lens opacities. ❜
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❛ FABRY DISEASE (ANGIOKERATOMA CORPORIS DIFFUSUM UNIVERSALE) ❜
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What sphingolipidoses ❛ o Acid B-glucosidase o Paralytic strabismus, Looped saccades, Abnormal eye
movement
o
Hepatomegaly, splenomegaly, neuropathies (olfaction, cognition, convulsions) ❜
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❛ GAUCHER DISEASE ❜
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❛ o Lacks hexosaminidase A ❜
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❛ Cherry-red spot, Nystagmus, ❜
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optic atrophy ❛ Mental deterioration, blind, deaf, paralytic ❜
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What sphingolipidoses
Tay-sachs disease
In summary, what are the ocular features in MPs vs mucolipidoses vs sphingolipidoses
MPs ❛ Ocular features
- Corneal clouding
- Retinal pigmentary degeneration
• Optic atrophy ❜
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sphingolipidoss
Mucolipidoses
❛ Ocular features
• Corneal clouding
• Macular cherryred spot ❜
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❛ Characterized by primarily by cirrhosis of the liver, progressive degeneration of CNS and Keyser-Fleischer ring of the cornea
- Hepatolenticular disease
- Accumulation of copper
• Keyser-Fleischer ring ❜
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Wilson’s disease
❛ Occurs in only 15-20% affected Fine deposition between the anterior and posterior lens capsule, forming a disc-like opacity axially, with tapering spokes or metal-like extensions
• Portal hypertension, increased bleeding, neuropsychiatric symptoms (often parkinsonism) ❜
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Sunflower cataract
❛ An inability to metabolize galactose due to deficit in the activity of an enzyme, galactose-I-phosphate uridyl transferase ❜
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❛ Cataract – described as an “oil droplet” cataract, due to accumulation of galactitol in the lens Followed by development of z onular or nuclear cataract ❜
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Galactosemia
❛ Most common form of the glycogen storage disease
- Deficiency of the enzyme glucose-6-phosphatase in the liver, kidney and small intestine
- Characterized by short stature, massive hepatomegaly, hypoglycemia, lactic acidosis and hyperlipiidemia
- Multiple bilaterally symmetrical, yellowish, non-elevated
discrete paramacular lesions ❜
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Von gierke’S disease
❛ • Non-progressive enlargement of the cornea (diameter ≥ 13 mm) (normal diameter: 11mm)
- Rare, usually bilateral, congenital condition
- Usually X-linked but may be autosomal recessive or dominant
• 90% of affected patients are male ❜
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Megalocornea
❛ • A clear cornea with normal thickness
- Diameter < 9 mm in the newborn and < 10 mm after 2 years of age
- Isolated microcornea is very rare
- May be autosomal dominant or recessive
• Others: cataracts, colobomas, high hyperopia, cornea plana, and persistent fetal vasculature ❜
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Micro cornea
❛ Thickening & anterior displacement of the Schwalbe line
• Looks like an irregular white line just concentric with and anterior to the limbus ❜
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❛ On gonioscopy, it is a continuous or broken ridge protruding into the anterior chamber
• Pigmented spots may be seen on the internal surface of the ridge
• Often associated with Axenfeld-Rieger syndrome and Arteriohepatic Dysplasia (Alagille’s syndrome) ❜
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❛ POSTERIOR EMBRYOTOXON ❜
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