Anatomical diagram and educational infographic detailing the human visual pathway and associated visual field defects. The central illustration shows a superior (dorsal) view of the brain, highlighting the optic nerve, optic chiasm (decussation point), optic tract, lateral geniculate body, optic radiations, and the primary visual cortex in the occipital lobes. Pathways are color-coded (red and blue) to demonstrate the transition from nasal and temporal retinal fibers to the contralateral and ipsilateral hemispheres. Black lesion bars indicate specific sites of damage along this pathway. Flanking the central diagram are clinical representations of visual field loss patterns. The 'Right' panel displays bilateral defects including bitemporal hemianopia, incongruous homonymous hemianopia, and congruous homonymous hemianopia. The 'Left' panel displays unilateral or localized defects including central scotoma, centrocaecal scotoma, arcuate scotoma, and temporal wedge. This diagram serves as a neuro-ophthalmological guide for localizing lesions within the central nervous system based on perimetry findings.

This composite educational image presents two clinical cases correlating neuroimaging findings with visual field defects. Case 1 (A-E) depicts left homonymous hemianopia. T1-weighted contrast-enhanced MRI in axial (A) and coronal (B) planes shows a heterogeneously enhancing mass in the suprasellar region (yellow circles), involving the optic chiasm and third ventricle floor. Schematic (C) and anatomical diagram (D) illustrate the corresponding lesion in the right optic tract and the resulting left hemifield blindness. The Esterman binocular field test (E) confirms significant unseen points (black dots) in the left visual field. Case 2 (F-J) depicts bitemporal hemianopia. MRI scans (F, G) reveal a residual suprasellar mass (yellow circles) inseparable from the hypothalamus and optic chiasm. The schematic (H) and optic pathway diagram (I) show a midline chiasmal injury, leading to peripheral scotomas. The Esterman test (J) demonstrates peripheral blind spots consistent with bitemporal vision loss. This comparison illustrates how specific anatomical injuries along the optic pathway correlate with distinct patterns of binocular visual impairment.

A multi-modal neuro-ophthalmic assessment of a patient with chiasmal compression. The composite includes fundus photographs, Humphrey visual field (VF) tests, and Optical Coherence Tomography (OCT) of the Retinal Nerve Fiber Layer (RNFL) and Ganglion Cell Layer (GCL). The fundus photographs of the right and left optic nerves show a clinically normal appearance with healthy disc margins and vasculature. Automated perimetry (VF) reveals a classic bitemporal hemianopia, characterized by significant sensitivity loss in the temporal hemifields of both eyes. The OCT RNFL thickness maps and circular tomograms appear largely within normal limits (coded green in quadrant/clock-hour maps), indicating minimal retrograde axonal loss at the disc level. However, the Ganglion Cell Analysis (GCL+IPL) thickness and deviation maps demonstrate clear 'binasal' macular thinning that respects the vertical midline, corresponding to the temporal visual field defects. This clinical scenario illustrates that macular GCL thinning can precede detectable RNFL atrophy in chronic compressive chiasmopathy, such as that caused by a pituitary adenoma.