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Figure 1 - Humphrey field analyser. Humphrey field analyser (HFA) is a tool for measuring the human visual field that is commonly used by optometrists, orthoptists and ophthalmologists, particularly for detecting monocular visual field. [1] The results of the analyser identify the type of vision defect.
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Visual field testing can be performed clinically by keeping the subject's gaze fixed while presenting objects at various places within their visual field. Simple manual equipment can be used such as in the tangent screen test or the Amsler grid. When dedicated machinery is used it is called a perimeter.
Confrontation visual field testing is an important part of a routine ophthalmological or neurological examination. It can be used for rapid and gross assessment of large-scale visual field problems due to ophthalmological or neurological diseases, such as homonymous and heteronymous hemianopias, quadranopsia, altitudinal visual loss, central/centrocecal scotoma etc. [1] [2] Test using a red ...
Visual field-bitemporal hemianopia Visual field-binasal hemianopia. A lesion involving complete optic chiasm, which disrupts the axons from the nasal field of both eyes, causes loss of vision of the right half of the right visual field and the left half of the left visual field. [3] This visual field defect is called as bitemporal hemianopia.
The visual field is "that portion of space in which objects are visible at the same moment during steady fixation of the gaze in one direction"; [1] in ophthalmology and neurology the emphasis is mostly on the structure inside the visual field and it is then considered “the field of functional capacity obtained and recorded by means of perimetry”.
A Humphrey Visual Field (HVF) can detect where areas of impaired vision have occurred, which usually shows up as central, centrocaecal, or paracentral scotomas for DOA patients. [4] Another visual test— optical coherence tomography (OCT) analyzes the optic nerve head—shows other structural consequences of the disease as retinal nerve fiber ...
Microperimetry, sometimes called fundus-controlled perimetry, [1] is a type of visual field test [2] which uses one of several technologies to create a "retinal sensitivity map" of the quantity of light perceived in specific parts of the retina [3] in people who have lost the ability to fixate on an object or light source. The main difference ...