Isopter contraction : it refers to mild generalised constriction of central as well as peripheral field
Baring of blind spot : Exclusion of blind spot from the central field due to inward curve of the outer boundary of 30 degree central field
Small wing shaped paracentral scotoma : It may appear either above or below the blind spot in the Bjerrum's area
Seidel's scotoma : With the passage of time, paracentral scotoma joins the blind spot to form Seidel's scotoma
Arcuate or Bjerrum's scotoma : Extension of the Seidel's scotoma in an area either above or below the fixation point to reach the horizontal line.
Ring or double arcuate scotoma : It develops when two arcuate scotomas join together.
Roenne's central nasal step :
It is created when two arcuate scotomas run in different arcs and meet to form a sharp right angled defect at the horizontal meridian
Peripheral field defects :
The peripheral nasal step of Roenne's results from unequal contraction of the peripheral isopter.
Advanced glaucomatous field defects : The visual field loss gradually spreads centrally as well as peripherally and eventually only a small island of central vision (tubular vision ) and an accompanying temporal island are left.
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