What is wedge defect in glaucoma?
In summary, we found that 48% of glaucoma patients with mild central visual loss have defects in the inferotemporal visual field. They are often in the form of temporal wedge or sector defects that correlate well with related damage to the superior nasal optic disc nerve fiber bundles.
What causes nasal step defect?
Nasal step defects are caused by optic nerve disorders that affect the long, arching axons that originate temporal to the macula, entering the disc superiorly or inferiorly. A nasal step may begin as a small depression above or below (and respecting) the horizontal meridian in the nasal visual field (see Figure 3–8A).
What is arcuate defect?
Arcuate scotoma. A small, bow-shaped (arcuate) visual field defect that follows the arcuate pattern of the retinal nerve fibers; does not cross the horizontal median. Damage to ganglion cells that feed into a particular part of the optic nerve head. More common: Glaucoma.
Why does glaucoma respect horizontal midline?
Superior and inferior retinal nerve fibres terminate at and form the horizontal raphé, and there- fore glaucomatous visual field loss typically respects the horizontal midline. The earliest defects in glaucoma are probably small focal paracentral scoto- mas or depressions in sensitivity close to fixation.
What does a nasal step mean?
In practice the nasal step is an early and characteristic glaucomatous field defect like the isolated scotomas in the Bjerrum area, and it is easily detected and can be used as a sensitive marker in the follow up of glaucomatous damage.
What causes Seidel scotoma?
Seidel’s sign (also called Seidel’s scotoma) is a sickle-shaped scotoma that is a superior or inferior extension of the blind spot. It occurs in some patients with glaucoma.
What is altitudinal scotoma?
Altitudinal visual field defect (VFD), which involves the loss of visual sensation in the horizontal half of the visual field, is caused mainly by anterior ischemic optic neuropathy (AION),1,2,3 or rarely by compressive neuropathy due to a tumor or aneurysm.
What is ring scotoma?
Ring scotoma is an annular field defect centered on fixation. Age-related macular degeneration in the elderly and hydroxychloroquine toxicity in younger patients are usual causes of central ring scotoma. We report bilateral ring scotoma as the presentation of adult onset Stargardt’s disease.
What is Bayoneting in the eye?
In severely advanced glaucoma with complete loss of retinal tissue, retinal vessels may disappear as they make a sharp turn into the cup, termed bayoneting or “bean-pot” cupping. Deeper vessels as they re-emerge may appear out of focus [3].