2d. OD Congenital Anomalies And Colour Blindness Flashcards
(19 cards)
What is the characteristic appearance of an optic disc coloboma?
A large, excavated disc with an inferior defect; can be unilateral or bilateral.
What is the most common optic disc anomaly?
Optic nerve head drusen.
Which condition presents with a central glial tuft over the disc?
Morning glory disc anomaly.
What systemic association is seen with morning glory disc anomaly?
Midline craniofacial defects and basal encephalocele.
What is the typical appearance of optic nerve head drusen on fundus exam?
Lumpy, irregular disc with autofluorescent calcified bodies.
Which test is diagnostic for optic nerve head drusen?
B-scan ultrasonography or fundus autofluorescence.
What is a double ring sign?
A feature seen in optic nerve hypoplasia — small disc surrounded by a ring of sclera and pigment.
What are the features of optic nerve hypoplasia?
Small disc, reduced visual acuity, associated midline CNS anomalies.
What type of inheritance is seen in red-green color blindness?
X-linked recessive.
Which test is used for screening color vision defects?
Ishihara chart.
Which test can quantify color vision defects?
Farnsworth-Munsell 100 hue test.
What is the most common type of congenital color blindness?
Red-green color deficiency (protanomaly and deuteranomaly).
__________ presents as a large excavated disc, often with an inferior defect.
Optic disc coloboma
The double ring sign is indicative of _________ .
Optic nerve hypoplasia
The morning glory disc anomaly is associated with _________ and basal encephalocele.
Midline cranial defects
Optic nerve head drusen appear as lumpy, autofluorescent material and are best visualized on _________ .
B-scan ultrasonography
Red-green color blindness is inherited in an _________ pattern.
X-linked recessive
The __________ is used to screen for color vision defects, while the ____________ is used to quantify them.
Ishihara chart, Farnsworth-Munsell 100 hue test
The most common congenital color vision defect is __________ .
red-green deficiency
