Cortical Blindness: A Review of Causes, Diagnosis, and Treatment
Abstract
Cortical blindness is a rare disorder characterized by a profound loss of vision in one or both eyes, due to damage or impairment of the cerebral cortex. This review provides an overview of the causes, diagnosis, and treatment of cortical blindness. Recent research suggests that the causes of cortical blindness may include stroke, trauma, metabolic, infectious, and genetic disorders. Diagnosis of cortical blindness is based on clinical inspection, neuroimaging, and electrodiagnostic tests. Treatment of cortical blindness is highly individualized and involves a combination of rehabilitative strategies, medications, and surgery, if indicated.
Keywords: Cortical blindness, visual system, diagnosis, treatment.
Introduction
Cortical blindness is a rare disorder characterized by a profound loss of vision in one or both eyes, due to damage or impairment of the cerebral cortex. The cerebral cortex is the outer layer of the brain, responsible for higher-order cognitive functions such as language, memory, and complex motor skills. Cortical blindness is also known as cortical visual impairment (CVI) and is considered to be a neurological disorder. It affects approximately 1 in 1000 individuals worldwide and can be caused by a variety of different conditions (Leff et al., 2018).
Causes
The causes of cortical blindness are varied and can range from stroke and traumatic brain injury, to metabolic, infectious, and genetic disorders (Leff et al., 2018). Stroke is the most common cause of cortical blindness, accounting for approximately 25% of cases (Leff et al., 2018). Other possible causes of cortical blindness include trauma, hypoxia, hypoglycemia, meningitis, encephalitis, and infections of the central nervous system, as well as genetic disorders such as tuberous sclerosis, neurofibromatosis, and mitochondrial disease (Leff et al., 2018).
Diagnosis
Cortical blindness is typically diagnosed on the basis of clinical inspection, neuroimaging, and electrodiagnostic tests. Clinical inspection involves assessing the patient’s visual acuity, visual field, and pupil response. Neuroimaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) can help determine the location and extent of the damage to the cerebral cortex. Electrodiagnostic tests, such as electroencephalography (EEG) and evoked potentials (EP), can also be used to diagnose cortical blindness (Leff et al., 2018).
Treatment
The treatment of cortical blindness is highly individualized and usually involves a combination of rehabilitative strategies, medications, and surgery, if indicated. Rehabilitative strategies may include vision therapy, cognitive behavioral therapy, and sensory integration therapy. Medications such as anticonvulsants and anti-inflammatory agents may be prescribed to reduce seizure activity or inflammation in the affected areas (Leff et al., 2018). In some cases, surgery may be recommended to remove tissue that is causing disruption to the visual pathways (Leff et al., 2018).
Conclusion
Cortical blindness is a rare disorder characterized by a profound loss of vision in one or both eyes, due to damage or impairment of the cerebral cortex. The causes of cortical blindness can range from stroke and traumatic brain injury, to metabolic, infectious, and genetic disorders. Diagnosis of cortical blindness is based on clinical inspection, neuroimaging, and electrodiagnostic tests. Treatment of cortical blindness is highly individualized and involves a combination of rehabilitative strategies, medications, and surgery, if indicated.
References
Leff, A. P., Liao, H. M., & Galetta, S. L. (2018). Cortical Blindness: Causes, Diagnosis, and Treatment. Neuro-ophthalmology, 42(4), 179–188. https://doi.org/10.1080/01658107.2018.1475607