Näkökenttävauriot

Näkökenttävauriot, also known as visual field defects or scotomas, are blind spots or areas of reduced vision within the normal visual field. These defects can vary in size, shape, and location, and their presence indicates an issue somewhere along the visual pathway, from the eye to the brain. Common causes include damage to the retina, optic nerve, or visual processing centers in the brain.

Retinal conditions like glaucoma, diabetic retinopathy, macular degeneration, and retinal detachments can cause localized scotomas. Glaucoma, for example, often leads to peripheral vision loss that can progress to central vision impairment if left untreated. Diabetic retinopathy can cause fluctuating or fixed blind spots due to bleeding or swelling in the retina. Macular degeneration specifically affects central vision, leading to difficulty with detailed tasks like reading.

Optic nerve damage, caused by conditions such as optic neuritis (inflammation), ischemic optic neuropathy (lack of blood flow), or tumors, can result in more generalized visual field defects, often affecting central vision or specific patterns of loss. Traumatic injuries to the head can also damage the optic nerve.

Brain lesions, including strokes, tumors, or multiple sclerosis, can affect the visual cortex or pathways leading to it. The specific location of the brain damage will determine the pattern of the visual field defect. For instance, a stroke affecting one side of the brain might cause a homonymous hemianopia, where vision is lost in the same half of the visual field in both eyes.

Diagnosis of näkökenttävauriot typically involves visual field testing, also known as perimetry. This objective test maps out the areas of vision loss by presenting lights in different parts of the visual field and recording the patient's responses. Further investigations like optical coherence tomography (OCT) or magnetic resonance imaging (MRI) may be used to identify the underlying cause. The treatment depends on the underlying condition.