Image Based Question-66023

ldentify the visual defect shown in the photograph below ?

A. Right homonymous hemianopia.

B. Right homonymous hemianopia.

C. Right inferior homonymous quadrantanopia.

D. Right incongruous hemianopia.

Correct Answer » C Explanation

Ans:C. Right inferior homonymous quadrantanopia.

Types of visual field loss

Scotoma

• This is a defect surrounded by normal visual field. It may begin as a gradual enlargement of the blind spot.
• Relative scotoma – an area where objects of low luminance cannot be seen but larger or brighter ones can.
• Absolute scotoma – nothing can be seen at all within that area.

Hemianopia

• This is a binocular visual defect in each eye’s hemifield.

• Bitemporal hemianopia – the two halves lost are on the outside of each eye’s peripheral vision, effectively creating a central visual tunnel.

• Homonymous hemianopia – the two halves lost are on the corresponding area of the visual field in both eyes, i.e either the left or the right half of the visual field.

• Quadrantanopia – this is an incomplete hemianopia referring to a quarter of the schematic ‘pie’ of visual field loss.

• Right homonymous inferior quadrantanopia : Both lower right quadrants of the visual field experience loss of visual function; the cause of this visual defect is commonly located in the left hemisphere.

• Left homonymous inferior quadrantanopia involves visual defects in the lower left quadrant of each eye, with the cause usually being located in the right hemisphere of the brain.