Direct and transsynaptic retrograde degeneration and optic nerve head microvascular changes in patients with hemianopia

Abstract

Purpose: To investigate optic nerve head (ONH) microvascular changes secondary to transsynaptic retrograde degeneration (TRD), comperatively with direct retrograde degeneration and healthy controls. Methods: Patients with hemianopia due to intracranial lesion included in the study. Intracranial lesion was categorized by location: postgeniculate (causing TRD), chiasmal (causing direct retrograde degeneration). For the postgeniculate lesions, the eye on the same side of the lesion was defined as the ipsilateral eye and the eye on the opposite side as the contralateral eye. Optic disc microvasculature was evaluated with the help of optic coherence tomography angiography. Results: Sixteen eyes of 16 patients with chiasmal lesion, 28 eyes of 14 patients with postgeniculate lesion, and 30 eyes of 30 healthy subjects were included in the study. Ipsilateral eyes of the patients with postgeniculate lesion had decreased vessel density at the temporal sectors compatible with the affected nasal side of the visual field. Contralateral eyes showed no reduction of the vessel density at the affected nasal sectors. The eyes with chiasmal lesions had decreased vessel density at the peripapillary region and nasal half of the ONH compatible with temporal hemianopia. Vascular changes in the chiasmal lesion were more prominent than those of the postgeniculate lesion. Retinal nerve fiber layer and ganglion cell complex thickness were reduced. Conclusion: Vessel density of ONH was reduced in patients with homonymous hemianopia, providing evidence for TRD secondary to acquired postgeniculate lesion. Direct retrograde degeneration was more prominent in affected sectors when compared to TRD.

The different structure-function correlation as measured by OCT and Octopus perimetry cluster analysis in intracranial tumor and glaucoma patients

“…Previous research showed the chiasmal lesion caused more prominent optic nerve head vessel density decrease than postgeniculate lesion, which indicated the direct retrograde degeneration might be more prominent than TRD [22]. And our study shows the RNFL thinning is less prominent than glaucoma' RGCs' degeneration, both of the direct and trans-synaptic retrograde induced by the intracranial tumor.…”

“…Whereas, tumors arising post lateral geniculate body cause damage to the optic radiation after the tertiary neurons in the visual pathway and lead to the trans-synaptic retrograde retinal degeneration (TRD). It also causes the RNFL thinning and the optic nerve head vessel density decrease [18,21,22]. This is mechanically different from the damage of RGCs and axons in glaucoma.…”

Degeneration of the Sensorimotor Tract in Degenerative Cervical Myelopathy and Compensatory Structural Changes in the Brain

“…Chronic cord compression progression led to axonal destruction at the site of compression and cranial compression (Huber et al, 2018 ; Martin et al, 2018 ). Transsynaptic degeneration (TSD)may be related to the decreased excitability of α motoneurons in the spinal cord (Zheng et al, 2017 ), microangiopathy (Celik Buyuktepe et al, 2021 ), and pathological nerve remodeling (Lawlor et al, 2018 ). All of these factors may lead to apoptosis, inflammation, or ischemia, which ultimately mediate neuron damage and are responsible for remote degeneration in spinal cord tracts.…”

The different structure-function correlation as measured by OCT and octopus perimetry cluster analysis in intracranial tumor and glaucoma patients

“…Whereas, tumors arising in the post lateral geniculate body cause damage to the optic radiation after the tertiary neurons in the visual pathway and lead to trans-synaptic retrograde retinal degeneration (TRD). It also causes the RNFL thinning and the optic nerve head vessel density to decrease ( 16 , 19 , 20 ). This is mechanically different from the damage to RGCs and axons in glaucoma.…”