From the Guidelines
Optic radiation lesions are associated with homonymous bilateral field defects, including homonymous hemianopsia, quadrantanopia, and central scotoma, as evidenced by the most recent study in 2023 1. The types of blindness associated with optic radiation lesions can be categorized into:
- Homonymous hemianopsia, which affects the same half of the visual field in both eyes, either right or left
- Quadrantanopia, which affects a quarter of the visual field, either superior or inferior
- Central scotoma, which affects the central area of the visual field, and can be unilateral or bilateral These visual field defects occur due to the topographic organization of optic radiations, which carry visual information from the lateral geniculate nucleus to the primary visual cortex. According to the 2023 study 1, the ICD-10 CM codes for these conditions include H53.411, H53.412, and H53.413 for central scotoma, and H53.461, H53.462, and H53.469 for homonymous bilateral field defects. It is essential to code any associated underlying cause of the blindness first, as specified in the ICD-10 CM guidelines 1. The specific types of blindness associated with optic radiation lesions are:
- Homonymous bilateral field defects, which can be further classified into:
- Homonymous hemianopsia
- Quadrantanopia
- Central scotoma, which can be unilateral or bilateral.
From the Research
Types of Blindness Associated with Optic Radiation Lesions
The types of blindness associated with optic radiation lesions can be categorized based on the location and extent of the lesion.
- Homonymous hemianopia: a visual field defect that affects the same side of the visual field in both eyes 2, 3
- Homonymous quadrantanopia: a visual field defect that affects one quadrant of the visual field in both eyes 2, 3
- Macular sparing: a condition where the central part of the visual field is spared despite damage to the optic radiation 2, 3
- Incongruous hemianopia: a visual field defect that affects different parts of the visual field in each eye 3
- Peripheral homonymous hemianopia: a visual field defect that affects the peripheral part of the visual field in both eyes 4
- Homonymous paracentral scotomas: a visual field defect that affects the central part of the visual field in both eyes 3
Factors Influencing the Type of Blindness
The type of blindness associated with optic radiation lesions can be influenced by several factors, including:
- Location of the lesion: lesions in different parts of the optic radiation can cause different types of visual field defects 2, 3, 4
- Extent of the lesion: the extent of the lesion can affect the severity and type of visual field defect 2, 3
- Depth of the lesion: deep lesions can affect the deeper strata of the optic radiation, causing different types of visual field defects 2