scholarly journals Involvement of Anoikis in Dissociated Optic Nerve Fiber Layer Appearance

2021 ◽  
Vol 22 (4) ◽  
pp. 1724
Author(s):  
Tsunehiko Ikeda ◽  
Kimitoshi Nakamura ◽  
Takaki Sato ◽  
Teruyo Kida ◽  
Hidehiro Oku
Keyword(s):  
Optic Nerve ◽  
Nerve Fiber ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Internal Limiting Membrane ◽  
Retinal Ganglion ◽  
Ilm Peeling ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Optic Nerve Fiber

Dissociated optic nerve fiber layer (DONFL) appearance is characterized by dimpling of the fundus when observed after vitrectomy with the internal limiting membrane (ILM) peeling in macular diseases. However, the cause of DONFL remains largely unknown. Optical coherence tomography (OCT) findings have indicated that the nerve fiber layer (NFL) and ganglion cells are likely to have been damaged in patients with DONFL appearance. Since DONFL appearance occurs at a certain postoperative period, it is unlikely to be retinal damage directly caused by ILM peeling because apoptosis occurs at a certain period after tissue damage and/or injury. However, it may be due to ILM peeling-induced apoptosis in the retinal tissue. Anoikis is a type of apoptosis that occurs in anchorage-dependent cells upon detachment of those cells from the surrounding extracellular matrix (i.e., the loss of cell anchorage). The anoikis-related proteins βA3/A1 crystallin and E-cadherin are reportedly expressed in retinal ganglion cells. Thus, we theorize that one possible cause of DONFL appearance is ILM peeling-induced anoikis in retinal ganglion cells.

scholarly journals β-alanine supplementation induces taurine depletion and causes alterations of the retinal nerve fiber layer and axonal transport by retinal ganglion cells

2019 ◽  
Vol 188 ◽  
pp. 107781 ◽  
Author(s):  
Diego García-Ayuso ◽  
Johnny Di Pierdomenico ◽  
Francisco J. Valiente-Soriano ◽  
Ana Martínez-Vacas ◽  
Marta Agudo-Barriuso ◽  
...  
Keyword(s):  
Nerve Fiber ◽  
Axonal Transport ◽  
Retinal Ganglion Cells ◽  
Retinal Nerve Fiber Layer ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Retinal Nerve Fiber

scholarly journals Minimizing activation of overlying axons with epiretinal stimulation: The role of fiber orientation and electrode configuration

2018 ◽  
Author(s):  
Timothy Esler ◽  
Robert R. Kerr ◽  
Bahman Tahayori ◽  
David B. Grayden ◽  
Hamish Meffin ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Nerve Fiber ◽  
Retinal Ganglion Cells ◽  
Ganglion Cell Layer ◽  
Ganglion Cells ◽  
Cell Layer ◽  
Retinal Ganglion ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Stimulation Of

ABSTRACTObjective. Currently, a challenge in electrical stimulation of the retina is to excite only the cells lying directly under the electrode in the ganglion cell layer, while avoiding excitation of the axons that pass over the surface of the retina in the nerve fiber layer. Since these passing fibers may originate from distant regions of the ganglion cell layer. Stimulation of both target retinal ganglion cells and overlying axons results in irregular visual percepts, significantly limiting perceptual efficacy. This research explores how differences in fiber orientation between the nerve fiber layer and ganglion cell layer leads to differences in the activation of the axon initial segment and axons of passage. Approach. Axons of passage of retinal ganglion cells in the nerve fiber layer are characterized by a narrow distribution of fiber orientations, causing highly anisotropic spread of applied current. In contrast, proximal axons in the ganglion cell layer have a wider distribution of orientations. A four-layer computational model of epiretinal extracellular stimulation that captures the effect of neurite orientation in anisotropic tissue has been developed using a modified version of the standard volume conductor model, known as the cellular composite model. Simulations are conducted to investigate the interaction of neural tissue orientation, stimulating electrode configuration, and stimulation pulse duration and amplitude. Main results. The dependence of fiber activation on the anisotropic nature of the nerve fiber layer is first established. Via a comprehensive search of key parameters, our model shows that the simultaneous stimulation with multiple electrodes aligned with the nerve fiber layer can be used to achieve selective activation of axon initial segments rather than passing fibers. This result can be achieved with only a slight increase in total stimulus current and modest increases in the spread of activation in the ganglion cell layer, and is shown to extend to the general case of arbitrary electrode array positioning and arbitrary target neural volume. Significance. These results elucidate a strategy for more targeted stimulation of retinal ganglion cells with experimentally-relevant multi-electrode geometries and readily achievable stimulation requirements.

Dissociated optic nerve fiber layer in a case of Terson syndrome

2019 ◽  
Vol 30 (5) ◽  
pp. NP11-NP14
Author(s):  
Koushik Tripathy
Keyword(s):  
Optic Nerve ◽  
Nerve Fiber ◽  
Pars Plana Vitrectomy ◽  
Vitreous Hemorrhage ◽  
Internal Limiting Membrane ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Terson Syndrome ◽  
Optic Nerve Fiber ◽  
Pars Plana

Purpose: To report a case of Terson syndrome who developed dissociated optic nerve fiber layer appearance after pars plana vitrectomy. Case report: The author reports a young male patient with Terson syndrome who developed bilateral vitreous hemorrhage and sub-internal limiting membrane hemorrhage after road traffic accident. He underwent pars plana vitrectomy and removal of the already detached internal limiting membrane and the sub-internal limiting membrane hemorrhage in both eyes. In both eyes, dissociated optic nerve fiber layer was appreciated and left eye had a peculiar resemblance to the appearance of cystoid macular edema. Conclusions: Dissociated optic nerve fiber layer appearance may be noted following vitrectomy and removal of detached internal limiting membrane in patients with vitreous hemorrhage and sub-internal limiting membrane bleed due to Terson syndrome.

DISSOCIATED OPTIC NERVE FIBER LAYER APPEARANCE AFTER INTERNAL LIMITING MEMBRANE PEELING FOR IDIOPATHIC MACULAR HOLE

Retina ◽  
2003 ◽  
Vol 23 (4) ◽  
pp. 561-563 ◽  
Author(s):  
MASAHIRO MIURA ◽  
ANN E. ELSNER ◽  
MASAHIRO OSAKO ◽  
TAKUYA IWASAKI ◽  
TADASHI OKANO ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Nerve Fiber ◽  
Macular Hole ◽  
Internal Limiting Membrane ◽  
Idiopathic Macular Hole ◽  
Fiber Layer ◽  
Internal Limiting Membrane Peeling ◽  
Nerve Fiber Layer ◽  
Membrane Peeling ◽  
Optic Nerve Fiber

Incidence and quantitative analysis of dissociated optic nerve fiber layer appearance: real loss of retinal nerve fiber layer?

2017 ◽  
Vol 28 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Yoon J. Kim ◽  
Kyoung S. Lee ◽  
Soo G. Joe ◽  
June-Gone Kim
Keyword(s):  
Optic Nerve ◽  
Nerve Fiber ◽  
Mechanical Damage ◽  
Ilm Peeling ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Optic Nerve Fiber ◽  
Group I ◽  
Significant Difference ◽  
Sd Oct

Purpose: To assess the association between appearance of dissociated optic nerve fiber layer (DONFL) after internal limiting membrane (ILM) peeling and changes in the macular nerve fiber layer (NFL) area by spectral-domain optical coherence tomography (SD-OCT). Methods: This study included 132 consecutive patients who had successfully undergone vitrectomy with ILM peeling for idiopathic epiretinal membrane or macular holes and had been followed up for ≥6 months. Two examiners evaluated macular 5-line raster horizontal SD-OCT images and categorized the patients on the basis of presence (group I) or absence (group II) of DONFL. The average macular NFL areas in both groups were measured using ImageJ at baseline and 1, 3, and 6 months after surgery. Results: Among the 132 eyes of 132 patients, DONFL was noted in 42 (31.8%), 104 (78.8%), 106 (80.3%), and 106 (80.3%) eyes at 1, 3, and 6 months and at the last visit (12.8 ± 6.5 months) after surgery. These layers appeared most commonly between 1 and 3 months after ILM peeling. There was no significant difference in average macular NFL area between groups I and II (3453.4 ± 125.3 and 3513.0 ± 100.2 pixels, respectively) at 6 months after surgery (p = 0.56). Conclusions: Appearance of DONFL increased between postoperative months 1 and 3. Moreover, there was no significant difference in average NFL in terms of DONFL. Thus, appearance of DONFL might represent macular NFL rearrangement and reorganization rather than true mechanical damage to the NFL after ILM peeling.

The human fetal retinal nerve fiber layer and optic nerve head: A DiI and DiA tracing study

1997 ◽  
Vol 14 (3) ◽  
pp. 433-447 ◽  
Author(s):  
T. Fitzgibbon
Keyword(s):  
Optic Nerve ◽  
Nerve Fiber ◽  
Retinal Nerve Fiber Layer ◽  
Optic Nerve Head ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Carbocyanine Dyes ◽  
Retinal Nerve Fiber

AbstractThe organization of the primate nerve fiber layer and optic nerve head with respect to the positioning of central and peripheral axons remains controversial. Data were obtained from 32 human fetal retinae aged between 15 and 21 weeks of gestation. Crystals of the carbocyanine dyes, DiI or DiA, and fluorescence microscopy were used to identify axonal populations from peripheral retinal ganglion cells. Peripheral ganglion cell axons were scattered throughout the vitreal-scleral depth of the nerve fiber layer. Such a scattered distribution was maintained as the fibers passed through the optic nerve head and along the optic nerve. There was a rough topographic representation within the optic nerve head according to retinal quadrant such that both peripheral and central fibers were mixed within a wedge extending from the periphery to the center of the nerve. There was no indication that the fibers were reorganized in any way as they passed through the optic disc and into the nerve. The present results suggest that any degree of order present within the fiber layer and optic nerve is not an active process but a passive consequence of combining the fascicles of the retinal nerve fiber layer. Optic axons are not instructed to establish a retinotopic order and the effect of guidance cues in reordering fibers, particularly evident prechiasmatically and postchiasmatically, does not appear to be present within the nerve fiber layer or optic nerve head in humans.

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