What are visual field defects?

From the Guidelines

Visual field defects are abnormalities in a person's peripheral or central vision that occur when there is damage to the visual pathway between the eye and the brain, and can manifest as blind spots, areas of diminished vision, or complete loss of vision in specific regions of the visual field, as described in the 2023 vision rehabilitation preferred practice pattern 1. These defects can be caused by various conditions including glaucoma, stroke, brain tumors, retinal disorders, optic nerve damage, or trauma. The specific pattern of the defect often helps identify where along the visual pathway the damage has occurred. For example, damage to the right optic tract typically causes left-sided visual field defects in both eyes, while damage to one optic nerve causes vision loss in that eye only. Visual field defects are diagnosed through visual field testing, where patients indicate when they can see lights or objects in different areas of their peripheral vision. Some common types of visual field defects include:

• Homonymous bilateral field defects, which are blind spots in the right or left halves of the visual fields of both eyes, also known as hemianopsia or quadrantanopia 1
• Central scotoma, which is a blind spot in the central area of the visual field, and can be diagnosed with codes such as H53.411, H53.412, or H53.413 1
• Altitudinal field defects, which are blind spots in the upper or lower halves of the visual field. Treatment depends on the underlying cause and may include medications, surgery, or management of contributing conditions. Early detection is crucial as some visual field defects, particularly those caused by progressive conditions like glaucoma, can lead to permanent vision loss if not addressed promptly, as noted in the 2021 primary open-angle glaucoma preferred practice pattern 1. Additionally, visual field defects can impact daily activities, such as reading and mobility, and can be addressed through rehabilitation and occupational therapy, as described in the 2023 vision rehabilitation preferred practice pattern 1. It is essential to assess the severity of glaucoma damage, which can be estimated according to categories such as mild, moderate, or severe, based on visual field abnormalities and optic disc or RNFL damage, as outlined in the 2021 primary open-angle glaucoma preferred practice pattern 1. Self-reported functional status or difficulty with vision can be assessed using specific questionnaires, such as the National Eye Institute - Visual Function Questionnaire-25 and Glau-QOL, as mentioned in the 2021 primary open-angle glaucoma preferred practice pattern 1.

From the FDA Drug Label

Elevated IOP represents a major risk factor for glaucomatous field loss The higher the level of IOP, the greater the likelihood of optic nerve damage and visual field loss. Elevated intraocular pressure is a major risk factor in the pathogenesis of glaucomatous visual field loss The higher the level of intraocular pressure, the greater the likelihood of glaucomatous visual field loss and optic nerve damage.

Visual field defects are explained simply as damage to the optic nerve caused by high intraocular pressure (IOP), which can lead to glaucomatous field loss. The higher the IOP, the greater the likelihood of optic nerve damage and visual field loss 2 3.

• Key points:
  • High IOP is a major risk factor for glaucomatous field loss
  • The higher the IOP, the greater the likelihood of optic nerve damage and visual field loss
  • Glaucomatous field loss is a type of visual field defect caused by damage to the optic nerve

From the Research

Types of Visual Field Defects

• Altitudinal field defects: present above or below the horizontal midline, usually associated with ocular abnormalities 4
• Central scotoma: characteristic of optic nerve disease or macular disease 4
• Bitemporal hemianopia: signifies optic chiasm disease, most frequently associated with pituitary tumors 4
• Homonymous hemianopia: the same portion of the field is absent in both eyes, found with lesions behind the chiasm 4

Causes and Impact of Visual Field Defects

• Visual field defects can be caused by brain injury, stroke, tumors, traumatic brain injury, brain surgery, or demyelination 5
• They can lead to impairment of daily activities such as reading, driving, and obstacle avoidance, compromising the patient's quality of life 5, 6
• Homonymous hemianopia can affect cognitive visual functions, including visual search, safe navigation, and reading 7

Rehabilitation and Treatment of Visual Field Defects

• Various rehabilitation therapies have been developed to improve visual field defects, including eye-movement training, reading training, and visual field restitution therapy 5
• Optical, compensatory, and restitution therapies are used in practice, but none have shown consistent and significant benefits 6
• Rehabilitative techniques such as optical therapies, eye movement-based therapies, and visual field restitution therapies have been tried with varying degrees of success 7