Is Meyers loop part of optic radiation?
Meyer’s loop constitutes the most anterior extension of the optic radiation in the temporal horn. Patients with intractable epilepsy may undergo temporal lobe surgery, and their optic tract is susceptible to potential injury. Consequently, neurosurgeons must appreciate the surgical implications of this pathway.
Does optic radiation carry information from both eyes?
Recall that the fibers of the optic chiasm carry information about objects in the temporal hemifields of both eyes (i.e., the right hemifield of the right eye and the left hemifield of the left eye).
What is the loop of Meyer?
The Meyer loop is part of the inferior optic radiation that sweeps back on itself into the temporal lobe, just lateral to the temporal horn of the lateral ventricle. It can be injured in temporal lobectomy, resulting in a superolateral field cut, the so called pie-in-the-sky field cut.
What is inferior radiation?
The term inferior optic radiation refers to the more ventral of two portions of the optic radiation; the other is the superior optic radiation. The inferior radiation conveys information from the inferior part of the retina, which ‘sees’ the upper part of the visual field ( Crosby-1962; Carpenter-1983 )..
What are optic radiations made of?
The optic radiation (also known as the geniculocalcarine tract, the geniculostriate pathway, and posterior thalamic radiation) are axons from the neurons in the lateral geniculate nucleus to the primary visual cortex.
What happens if you cut the optic chiasm?
The entire left optic nerve would be cut and there would be a total loss of vision from the left eye. Damage at site #2: partial damage to the left optic nerve. Here, information from the nasal visual field of the left eye (temporal part of the left retina) is lost. Damage at site #3: the optic chiasm would be damaged.
What is the Calcarine fissure?
The calcarine fissure, or calcarine sulcus, is located on the medial surface of the occipital lobe and divides the visual cortex (a.k.a. calcarine cortex) into two.
Why does macular sparing occur?
Macular sparing may be caused by collateral vascular supply to the macular region or by the very large macular representation in the occipital cortex; additionally, bilateral representation of macular vision has been suspected.
What is right homonymous hemianopia?
What is homonymous hemianopsia? Homonymous hemianopsia is a condition in which a person sees only one side ― right or left ― of the visual world of each eye. The person may not be aware that the vision loss is happening in both eyes, not just one.