From the Guidelines
Peripheral Scotoma Cause
The cause of peripheral scotoma is not directly addressed in the provided evidence, but based on the context of visual field defects discussed, it can be inferred that peripheral scotoma is likely caused by damage to the retina or optic nerve, affecting the peripheral visual field.
- The evidence primarily focuses on central visual field defects, such as central scotomas, and their impact on vision rehabilitation 1.
- However, the discussion on visual field defects and scotomas in general suggests that peripheral scotoma may result from similar underlying conditions, such as retinal disease, optic neuropathy, or brain injury 1.
- The use of microperimetry and other tests to assess central visual field defects may also be applicable to diagnosing peripheral scotoma, although this is not explicitly stated in the evidence 1.
- It is essential to note that the evidence provided is primarily focused on vision rehabilitation and central visual field defects, and more specific research on peripheral scotoma would be necessary to determine its exact causes.
From the Research
Causes of Peripheral Scotoma
The causes of peripheral scotoma, a type of visual field defect, can be attributed to various factors, including:
- Damage along the visual pathway, which results in a visual field defect that retinotopically corresponds to the damaged neural tissue 2
- Loss of neurons at the retinal ganglion cell level and higher, which can lead to scotomas that are usually invisible to patients 3
- Ocular abnormalities, such as glaucomatous optic neuropathy, which can cause characteristic visual field defects, including isolated scotomas, arcuate scotomas, nasal steps, and generalized depression 4
- Congenital conditions, such as tilted disc syndrome, which can present with visual field defects mimicking loss seen in neurological diseases 5
- Lesions behind the chiasm, which can cause homonymous hemianopia, where the same portion of the field is absent in both eyes 6
Types of Visual Field Defects
There are four classic types of visual field defects, including:
- Altitudinal field defects, which are usually associated with ocular abnormalities
- Central scotoma, which is characteristic of optic nerve disease or macular disease
- Bitemporal hemianopia, which signifies optic chiasm disease and is most frequently associated with pituitary tumors
- Homonymous hemianopia, which is found with lesions behind the chiasm 6
Detection and Diagnosis
Detection and diagnosis of peripheral scotoma can be achieved through various methods, including: