Roennes 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. Roennes 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. Screening
The United States Preventive Services Task Force stated, as of 2013, that there was insufficient evidence to recommend for or against screening for glaucoma. Therefore, there is no national screening program in the US. Screening, however, is recommended starting at age 40 by the American Academy of Ophthalmology.There is a glaucoma screening program in the UK. Those at risk are advised to have a dilated eye examination at least once a year.
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 Bjerrums 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 the blind spot. Siedels sickle-shaped scotoma: Paracentral scotoma joins with the blind spot to form the Seidel sign. Arcuate or Bjerrums scotoma:  It is formed at later stages of glaucoma by extension of Seidels 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 to form a Ring or Double arcuate scotoma. This defect is seen in advanced stages of glaucoma.