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Anatomical Record (Hoboken, N.J. : 2007) Dec 2022Unlike the usual peripheral nerve, the optic nerve accompanies a thick "dural sheath," a thin "sheath of pia mater" (SPM), and multiple "septa," which divides the nerve...
Unlike the usual peripheral nerve, the optic nerve accompanies a thick "dural sheath," a thin "sheath of pia mater" (SPM), and multiple "septa," which divides the nerve fibers into fascicles. We collected specimens from 25 adult cadavers and 15 fetuses and revisited the histological architecture of the optic and oculomotor nerves. In the optic chiasma, the meningeal layer of the dura joins the pia to form a thick SPM, and the periosteum of the sphenoid is continuous with the dural sheath at the orbital exit of the bony optic canal. The septa appeared as a cluster of irregularly arrayed fibrous plates in the intracranial course near the chiasma. Thus, the septa were not derived from either the SPM or the dural sheath. In the orbit, the central artery of the retina accompanies collagenous fibers from the dural sheath and the SPM to provide the vascular sheath in the optic nerve. These connective tissue configurations were the same between adult and fetal specimens. At the optic disk, the dural sheath and SPM merged with the sclera, whereas the septa appeared to end at the lamina cribrosa. However, in fetuses without lamina cribrosa, the septa extend into the nerve fiber layer of the retina. The SPM and septa showed strong elastin immunoreactivity, in contrast to the absence of reactivity in the sheaths of the oculomotor nerve. Each S100 protein-positive Schwann sheath of the oculomotor nerve was surrounded by collagenous endoneurium. Glial fibrillary acidic protein-positive astrocytes showed a linear arrangement along the septa.
Topics: Adult; Humans; Optic Nerve; Optic Disk; Connective Tissue; Cadaver; Fetus
PubMed: 35358354
DOI: 10.1002/ar.24925 -
Optometry and Vision Science : Official... Sep 2020Scleral lenses (SLs) are increasing in scope, and understanding their ocular health impact is imperative. The unique fit of an SL raises concern that the landing zone...
SIGNIFICANCE
Scleral lenses (SLs) are increasing in scope, and understanding their ocular health impact is imperative. The unique fit of an SL raises concern that the landing zone causes compression of conjunctival tissue that can lead to resistance of aqueous humor outflow and increased intraocular pressure (IOP).
PURPOSE
This study aimed to assess changes in optic nerve head morphology as an indirect assessment of IOP and evaluate other IOP assessment methods during SL wear.
METHODS
Twenty-six healthy adults wore SL on one randomly selected eye for 6 hours, whereas the fellow eye served as a control. Global minimum rim width (optical coherence tomography) and IOP (Icare, Diaton) were measured at baseline, 2 and 6 hours after SL application, and again after SL removal. Central corneal thickness, anterior chamber depth, and fluid reservoir depth were monitored.
RESULTS
Minimum rim width thinning was observed in the test (-8 μm; 95% confidence interval [CI], -11 to -6 μm) and control (-6 μm; 95% CI, -9 to -3 μm) eyes after 6 hours of SL wear (P < .01), although the magnitude of thinning was not significantly greater in the lens-wearing eyes (P = .09). Mean IOP (Icare) significantly increased +2 mmHg (95% CI, +1 to +3 mmHg) in the test eyes (P = .002), with no change in the control eyes. Mean IOP changes with Diaton were +0.3 mmHg (95% CI, -0.9 to +3.2 mmHg) in the test eyes and +0.4 mmHg (95% CI, -0.8 to +1.7 mmHg) in the control eyes. However, Diaton tonometry showed poor within-subject variation and poor correlation with Icare. No clinically significant changes were observed in central corneal thickness or anterior chamber depth.
CONCLUSIONS
This study suggests that SLs have a minimal effect on IOP homeostasis in the normal eye during SL wear and an insignificant impact on the optic nerve head morphology in healthy adult eyes.
Topics: Adult; Anterior Chamber; Contact Lenses; Cornea; Female; Humans; Intraocular Pressure; Male; Optic Disk; Sclera; Time Factors; Tomography, Optical Coherence; Tonometry, Ocular; Young Adult
PubMed: 32932395
DOI: 10.1097/OPX.0000000000001567 -
The British Journal of Ophthalmology Feb 2022To evaluate the superficial vascular density of the optic nerve head in different stages of pseudoexfoliation disease using optical coherence tomography angiography...
PURPOSE
To evaluate the superficial vascular density of the optic nerve head in different stages of pseudoexfoliation disease using optical coherence tomography angiography (OCTA).
METHODS
In this cross-sectional study, 57 normal eyes, 41 eyes with pseudoexfoliation syndrome (PXS), 82 eyes with pseudoexfoliation glaucoma (PXG) and 27 non-glaucomatous fellow eyes of PXG (NL-PXG) that had OCTA were included. Circumpapillary RNFL (cpRNFL) thickness and circumpapillary capillary density (cpCD) were compared among the groups after adjusting for confounders using linear-mixed model.
RESULTS
PXG eyes had thinner global RNFL and lower cpCD (74.2±14.3 µm and 36.7±10.0%) than control (103.3±8.6 µm and 52.5±2.3%), PXS (96.8±8.8 µm and 51.5±2.3%), and NL-PXG eyes (96.3±11.1 µm and 50.1±3.9%) (p<0.001). After adjustment for age, gender and signal strength index, global cpRNFL thickness was comparable among control, PXS and NL-PXG. NL-PXG had the lowest cpCD (p=0.045) and sectoral cpCD compared to PXS and control eyes. Although cpCD was comparable between control and PXS (p=0.425) eyes, sectoral differences (p=0.009 and 0.004, for inferonasal and temporal-inferior cpCD, respectively) were detectable between the two groups. AUROC for differentiating NL-PXG eyes from normal were better for cpCD (0.78) compared to cpRNLF (0.69).
CONCLUSIONS
OCTA can detect reduced capillary density before significant changes in cpRNFL in fellow eyes of PXG patients. This can enable earlier detection of glaucomatous loss in pseudoexfoliation disease and enhance management of the disease.
Topics: Cross-Sectional Studies; Exfoliation Syndrome; Glaucoma, Open-Angle; Humans; Intraocular Pressure; Optic Disk; Tomography, Optical Coherence
PubMed: 33246938
DOI: 10.1136/bjophthalmol-2020-317605 -
Investigative Ophthalmology & Visual... Feb 2022Sigma 1 receptor (S1R) is expressed in retinal ganglion cells (RGCs) and astrocytes, and its activation is neuroprotective. We evaluated the contribution of S1R within...
PURPOSE
Sigma 1 receptor (S1R) is expressed in retinal ganglion cells (RGCs) and astrocytes, and its activation is neuroprotective. We evaluated the contribution of S1R within optic nerve head astrocytes (ONHAs) to growth and survival of RGCs in vitro.
METHODS
Wild-type (WT) RGCs and WT or S1R knockout (S1R KO) ONHAs were cocultured for 2, 4, or 7 days. Total and maximal neurite length, neurite root, and extremity counts were measured. Cell death was measured using a TUNEL assay. Signal transducer and activator of transcription 3 phosphorylation levels were evaluated in ONHA-derived lysates by immunoblotting.
RESULTS
The coculture of WT RGCs with WT or S1R KO ONHAs increased the total and maximal neurite length. Neurite root and extremity counts increased at 4 and 7 days when WT RGCs were cocultured with WT or S1R KO ONHAs. At all timepoints, the total and maximal neurite length decreased for WT RGCs in coculture with S1R KO ONHAs compared with WT ONHAs. Root and extremity counts decreased for WT RGCs in coculture with S1R KO ONHAs compared with WT ONHAs at 2 and 7, but not 4 days. RGC apoptosis increased in S1R KO ONHA coculture and S1R KO-conditioned medium, compared with WT ONHA coculture or WT-conditioned medium. S1R KO ONHA-derived lysates showed decreased phosphorylated signal transducer and activator of transcription 3 levels compared with WT ONHA-derived lysates.
CONCLUSIONS
The absence of S1R within ONHAs has a deleterious effect on RGC neurite growth and RGC survival, reflected in analysis of WT RGC + S1R KO ONHA indirect cocultures. The data suggest that S1R may enhance ganglion cell survival via glia-mediated mechanisms.
Topics: Animals; Apoptosis; Astrocytes; Blotting, Western; Cell Death; Cell Survival; Cells, Cultured; Disease Models, Animal; In Situ Nick-End Labeling; Mice; Mice, Inbred C57BL; Mice, Knockout; Neuroprotection; Optic Disk; Oxidative Stress; Receptors, sigma; Retinal Diseases; Retinal Ganglion Cells; Sigma-1 Receptor
PubMed: 35103752
DOI: 10.1167/iovs.63.2.1 -
Frontiers in Immunology 2022The axons of retinal ganglion cells (RGCs) pass through the optic nerve head (ONH) and form the optic nerve (ON). The ONH serves as an anatomical interface between the...
The axons of retinal ganglion cells (RGCs) pass through the optic nerve head (ONH) and form the optic nerve (ON). The ONH serves as an anatomical interface between the vitreous cavity and subarachnoid space. After inducing acute neuroinflammation by intravitreal injection of lipopolysaccharides (LPS), we observed inflammatory activation in the retina, but detect no signs of inflammation in the posterior ON or infiltration of inflammatory cells in the ONH. Therefore, we hypothesized that the ONH functions as a barrier to vitreous inflammation. Using transmission electron microscopy, we identified significant increase in G-ratio in the posterior ON on day 7 post intravitreal injection (PII) of LPS compared with the phosphate buffered saline (PBS) group. Moreover, using confocal imaging of tissue extracted from 1-eGFP reporter mice, we observed that the ONH astrocytes altered their spatial orientation by elongating their morphology along the axonal axis of RGCs in LPS- versus PBS-treated eyes; this was quantified by the ratio of longitudinal (D) and transverse (D) diameter of astrocytes and the proportion of longitudinally locating astrocytes. Supportive evidences were further provided by transmission electron microscopic imaging in rat ONH. We further conducted RNA sequencing of ONH on day 1 PII and found LPS induced clear upregulation of immune and inflammatory pathways. Furthermore, gene set enrichment analysis revealed that astrocyte and microglia contributed prominently to the transcriptomic alterations in ONH. Here, we report that the vitreous infectious insults induce morphological changes of ONH astrocytes and transcriptomic alterations in the ONH. Glial responses in the ONH may defend against vitreous infectious insults and serve as a barrier to inflammation for the central nervous system.
Topics: Animals; Inflammation; Lipopolysaccharides; Mice; Optic Disk; Phosphates; Rats; Retinal Ganglion Cells
PubMed: 36203577
DOI: 10.3389/fimmu.2022.987771 -
Sensors (Basel, Switzerland) Nov 2022Currently, glaucoma has become an important cause of blindness. At present, although glaucoma cannot be cured, early treatment can prevent it from getting worse. A...
Currently, glaucoma has become an important cause of blindness. At present, although glaucoma cannot be cured, early treatment can prevent it from getting worse. A reliable way to detect glaucoma is to segment the optic disc and cup and then measure the cup-to-disc ratio (CDR). Many deep neural network models have been developed to autonomously segment the optic disc and the optic cup to help in diagnosis. However, their performance degrades when subjected to domain shift. While many domain-adaptation methods have been exploited to address this problem, they are apt to produce malformed segmentation results. In this study, it is suggested that the segmentation network be adjusted using a constrained formulation that embeds prior knowledge about the shape of the segmentation areas that is domain-invariant. Based on IOSUDA (i.e., Input and Output Space Unsupervised Domain Adaptation), a novel unsupervised joint optic cup-to-disc segmentation framework with shape constraints is proposed, called SCUDA (short for Shape-Constrained Unsupervised Domain Adaptation). A shape constrained loss function is novelly proposed in this paper which utilizes domain-invariant prior knowledge concerning the segmentation region of the joint optic cup-optical disc of fundus images to constrain the segmentation result during network training. In addition, a convolutional triple attention module is designed to improve the segmentation network, which captures cross-dimensional interactions and provides a rich feature representation to improve the segmentation accuracy. Experiments on the RIM-ONE_r3 and Drishti-GS datasets demonstrate that the algorithm outperforms existing approaches for segmenting optic discs and cups.
Topics: Humans; Optic Disk; Image Interpretation, Computer-Assisted; Glaucoma; Fundus Oculi; Attention
PubMed: 36433345
DOI: 10.3390/s22228748 -
Acta Ophthalmologica Nov 2021To evaluate the basic characteristics of optic disc pit maculopathy (ODPM) and the efficacies of pars plana vitrectomy (PPV) treatment with different adjunctive... (Meta-Analysis)
Meta-Analysis
PURPOSE
To evaluate the basic characteristics of optic disc pit maculopathy (ODPM) and the efficacies of pars plana vitrectomy (PPV) treatment with different adjunctive strategies.
METHODS
The databases PubMed, EMBASE and Ovid up to April 2020 were searched to identify relevant studies. Statistical analyses were conducted with R software version 3.6.3.
RESULTS
Fifty-nine studies were eventually included for different aspects of statistical analyses. The pooling results suggest the general incidence of maculopathy in optic disc pit (ODP) is 51%, and the rate of serous macular detachment and retinoschisis is 49% and 58%, respectively. The incidence of sub-retinal fluid (SRF) only is 10%, intra-retinal retinal (IRF) fluid only is 14%, and SRF plus IRF is 69%. A lamellar macular hole (LMH) is present in 53% of cases, and 58% have communication between the macula with the pit. The incidence of posterior vitreous detachment (PVD), vitreo-papillary traction and vitreomacular traction (VMT) is 7%, 28% and 13%, respectively. Besides, the rate of complete anatomic success and visual improvement after PPV are both around 85%. Subgroup analysis reveals the anatomic, and visual success rates of PPV alone are 89% and 100%, respectively. Gas tamponade, laser or internal limiting membrane peeling (ILMP) during vitrectomy are less promising, while PPV with ILM flap stuffing could achieve better outcomes than cases without it.
CONCLUSION
Optic disc pit-associated maculopathy has different fundus characteristics. Based on the current evidence, PPV is effective for ODPM, and the combined application of gas tamponade, laser and ILMP should be used with caution.
Topics: Eye Abnormalities; Humans; Macular Degeneration; Optic Disk; Tomography, Optical Coherence; Vitrectomy
PubMed: 33421324
DOI: 10.1111/aos.14730 -
BMC Ophthalmology May 2023To investigate morphological and microcirculation changes of optic nerve head (ONH) in simple high myopia (SHM) and pathologic myopia(PM) to evaluate and identify ONH...
PURPOSE
To investigate morphological and microcirculation changes of optic nerve head (ONH) in simple high myopia (SHM) and pathologic myopia(PM) to evaluate and identify ONH changes in the development of PM.
METHODS
A cross-sectional clinical study was used. Medical records from 193 right eyes of 193 patients with high myopia (HM) were included. Using the Topocon swept source optical coherence tomograph (SS-OCT) and fundus camera to detect the parameters, we have assessed the relative position and size of ONH, tilt and rotation of ONH, angle α (Defined as between retinal temporal arterial vascular arcades was measured from the centre of ONH with 250 pixels' radius), size and type of peripapillary atrophy (PPA), the thickness of peripapillary retinal nerve fiber layer (PRNFL), peripapillary choriodal thickness (PCT) and peripapillary scleral thickness (PST), and peripapillary vessel density (PVD). In addition, subjects were grouped as SHM and PM according to retinopathy, and the above parameters were compared between the two groups.
RESULTS
Patients were divided into the SHM group (138 eyes) and the PM group (55 eyes). Paramters like older age, higher diopter and longer axial length (AL) of the PM were compared to SHM (t=-3.585, -8.808, -11.409, all P<0.05). There were no differences in the smallest diameter and area of ONH, rotation angle and ratio, or PST (all P>0.05). The angle α in PM was smaller than that in SHM (t = 2.728, P<0.01). The disc-fovea distance (DFD), the largest diameter, tilt index and ratio, PPA area and radian in PM were larger than in SHM (t=-3.962, Z=-2.525, t=-2.229, Z=-4.303, Z=-2.834, all P<0.05). The superior and inferior PRNFLs in PM were smaller than in SHM (t = 4.172, 4.263, all P<0.01). The temporoinferior PRNFL was the opposite (t=-2.421, P<0.01). The average PCT in PM (93.82 ± 29.96 μm) was smaller than in SHM (108.75 ± 30.70 μm) (P<0.05). The PVD in each direction of PM was smaller than that in SHM (t = 6.398, 4.196, 4.971, 3.267, 5.029, 5.653, 4.202, 5.146, 2.090, all P<0.05).
CONCLUSION
Compared with SHM, the PM patients were older, with higher diopter. Their AL and DFD were longer, the angle α was smaller, the tilt index was more extensive, the PPA area and radian were larger, PCT was generally thinner, and PVD was lower. When the PPA area was bigger than the ONH area, this already indicated the presence of PM. Based on these results, we suggest ophthalmologists and myopia patients pay more attention to ONH's morphology and microcirculation changes as there is a possibility that microcirculatory changes precede morphologic changes.
Topics: Humans; Optic Disk; Microcirculation; Cross-Sectional Studies; Myopia; Tomography, Optical Coherence
PubMed: 37165324
DOI: 10.1186/s12886-023-02949-7 -
Romanian Journal of Ophthalmology 2021Often misdiagnosed as melanoma, melanocytoma of the optic disc is a rare benign ocular lesion that requires minimal active intervention, but demands a life time...
Often misdiagnosed as melanoma, melanocytoma of the optic disc is a rare benign ocular lesion that requires minimal active intervention, but demands a life time follow-up. We present a case of a 32-year-old man who was referred to our institute for the management of choroidal melanoma of the optic disc, which was detected by chance when the patient presented to a general ophthalmologist with chief complaint of itching in both eyes. The patient had normal visual acuity and fundoscopy revealed classical optic disc melanocytoma. The ancillary tests confirmed the diagnosis. The patient was kept under follow-up for four years, which showed no increase in size of the lesion. The purpose of this presentation was to highlight the identifying features of ocular melanocytoma and differentiate it from other conditions requiring urgent intervention.
Topics: Adult; Biopsy; Fluorescein Angiography; Fundus Oculi; Humans; Male; Melanoma; Optic Disk; Optic Nerve Neoplasms
PubMed: 33817442
DOI: 10.22336/rjo.2021.18 -
PloS One 2021The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera....
The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. This study evaluated the retinal vessel calibers and correlations using GSAS fundus photographs between retinal vessels and 38 optic nerve head (ONH) morphologic parameters comprehensively. In all 240 eyes, the mean central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were 138.4 and 216.5 μm, respectively; the CRAE correlated with age, visual field scores and 19 ONH parameters and CRVE correlated with age, intraocular pressure, visual field scores and 11 ONH parameters. Among the different optic disc appearances including focal ischemia (FI) (n = 53, 22%), generalized enlargement (GE) (n = 53, 22%), myopic glaucoma (MY) (n = 112, 47%), and senile sclerosis (SS) (n = 22, 9%), the CRAE did not differ significantly; CRVE was significantly narrower in SS than in FI and MY. In FI, GE, MY, and SS disc types, CRAE correlated with 3, 14, 9, and 2 ONH parameters, respectively, and CRVE corelated with 9, 0, 12, and 6 ONH parameters, respectively. We confirmed previous observations on the effect of retinal vessel narrowing on glaucomatous changes in the ONH and visual field. The associations between retinal vessel caliber and ONH morphologic parameters vary among different optic disc appearances, suggesting different effects of vascular changes in each disc type.
Topics: Glaucoma; Humans; Intraocular Pressure; Male; Middle Aged; Optic Disk; Retinal Vessels
PubMed: 34324508
DOI: 10.1371/journal.pone.0250245