page_title: Glaucoma
section_title: Visual field defects in glaucoma
hierarchical_section_title: Glaucoma / Visual field defects in glaucoma
caption_attribution_description: A scene as it might be viewed by a person with retinitis pigmentosa.
context_page_description: Glaucoma is a group of eye diseases which result in damage to the optic nerve and cause vision loss. The most common type is open-angle glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous.
  Risk factors for glaucoma include increased pressure in the eye, a family history of the condition, and high blood pressure. For eye pressures, a value of greater than 21 mmHg or 2.8 kPa is often used, with higher pressures leading to a greater risk. However, some may have high eye pressure for years and never develop damage.
context_section_description: In glaucoma visual field defects result from damage to the retinal nerve fiber layer. Field defects are seen mainly in primary open angle glaucoma. Because of the unique anatomy of the RNFL, many noticeable patterns are seen in the visual field. Most of the early glaucomatous changes are seen within the central visual field,mainly in Bjerrum's area, 10-20° from fixation. 
  Following are the common glaucomatous field defects:
  Generalized depression: Generalized depression is seen in early stages of glaucoma and many other conditions. Mild constriction of central and peripheral visual field due to isopter contraction comes under generalized depression.  If all the isopters show similar depression to the same point, it is then called a contraction of visual field. Relative paracentral scotomas are the areas where smaller and dimmer targets are not visualized by the patient. Larger and brighter targets can be seen.  Small paracentral depressions, mainly superonasal are seen in normal tension glaucoma (NTG).  The generalized depression of the entire field may be seen in cataract also. 
  Baring of blind spot: Baring of blind spot means Exclusion of blind spot from the central field due to inward curve of the outer boundary of 30° central field . It is only an early non-specific visual field change, without much diagnostic value in glaucoma. 
  Small wing-shaped Paracentral scotoma: Small wing-shaped Paracentral scotoma within Bjerrum’s area is the earliest clinically significant  field defect seen in glaucoma. It may also be associated with nasal steps. Scotoma may be seen above or below blind spot.
  Siedel’s sickle-shaped scotoma: Paracentral scotoma joins with the blind spot to form the Seidel sign.
  Arcuate or Bjerrum’s scotoma:  It is formed at later stages of glaucoma by extension of Seidel’s scotoma in an area either above or below the fixation point to reach the horizontal line. Peripheral breakthrough may occur due to damage of nerve fibers. 
  Ring or Double arcuate scotoma: Two arcuate scotomas join together to form a Ring or Double arcuate scotoma. This defect is seen in advanced stages of glaucoma.
  Roenne’s central nasal step: It is created when two arcuate scotomas run in different arcs to form a right angled defect. This is also seen in advanced stages of glaucoma.
  Peripheral field defects: Peripheral field defects may occur in early or late stages of glaucoma. Roenne’s peripheral nasal steps occur due to contraction of peripheral isopter. 
  Tubular vision:  Since macular fibers are the most resistant to glaucomatous damage, the central vision remains unaffected until end stages of glaucoma. Tubular vision or Tunnel vision is the loss of peripheral vision with retention of central vision, resulting in a constricted circular tunnel-like field of vision. It is seen in the end stages of glaucoma. Retinitis pigmentosa, is another disease that causes tubular vision.
  Temporal island of vision: It is also seen in end stages of glaucoma. The temporal islands lie outside of the central 24 to 30° visual field , so it may not be visible with standard central field measurements done in glaucoma.
caption: Tubular vision
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