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Arquivos Brasileiros de Oftalmologia 2023The purpose of this study was to assess the optic nerve head microvascular changes in pseudoexfoliative and primary open-angle glaucoma and define the relationship... (Observational Study)
Observational Study
PURPOSE
The purpose of this study was to assess the optic nerve head microvascular changes in pseudoexfoliative and primary open-angle glaucoma and define the relationship between vessel density and retinal nerve fiber layer thickness.
METHODS
This observational cross-sectional study assessed 72 eyes with primary open-angle glaucoma, 41 eyes with pseudoexfoliative glaucoma, and 60 healthy eyes. On the basis of optic nerve head-centered, 4.5 mm × 4.5 mm scan size images, we evaluated the vessel density, as well as the peripapillary sector, inside disk, and all sectoral quadrants.
RESULTS
Both glaucoma Groups had lower vessel density in all regions compared with the healthy Group (p<0.05 for all variables). Vessel densities of the nasal inferior, inferior nasal, and inferior temporal sectors in both glaucoma Groups showed similar results (p=0.157, p=0.128, p=0.143, respectively). Eyes with pseudoexfoliative glaucoma had significantly lower vessel densities than eyes with primary open-angle glaucoma in all other regions (p<0.05 for all variables). For both glaucoma Groups, the average retinal nerve fiber layer thickness positively correlated with vessel density in all peripapillary sectors (p<0.05 for all variables).
CONCLUSIONS
Reduction in vessel density correlated with the thinning of retinal nerve fiber layer in both glaucoma Groups. Decreased vessel density in the optic nerve head can be used to demonstrate the microvascular pathologies and possible ischemic changes that lead to faster progression and worse prognosis in pseudoexfoliative glaucoma.
Topics: Humans; Optic Disk; Glaucoma, Open-Angle; Visual Fields; Tomography, Optical Coherence; Retinal Ganglion Cells; Nerve Fibers; Glaucoma; Retinal Vessels; Intraocular Pressure
PubMed: 37878951
DOI: 10.5935/0004-2749.2021-0420 -
Molecular Medicine Reports May 2024Glaucoma is a group of progressive optic nerve disorders characterized by the loss of retinal ganglion cells, a thinner retinal nerve fibre layer and cupping of the... (Review)
Review
Glaucoma is a group of progressive optic nerve disorders characterized by the loss of retinal ganglion cells, a thinner retinal nerve fibre layer and cupping of the optic disk. Apoptosis is a physiological cell death process regulated by genes and plays a crucial role in maintaining tissue homeostasis, ensuring the natural development and immune defence of organisms. Apoptosis has been associated with glaucoma and inhibiting apoptosis by activating phosphatidylinositol 3-kinase‑protein kinase B or other medicines can rescue pathological changes in glaucoma. Due to the complex crosstalk of apoptosis pathways, the pathophysiological mechanism of apoptosis in glaucoma needs to be fully elucidated. The present review aimed to discuss the mechanism of cell apoptosis in glaucoma, improve the understanding of the pathophysiology of glaucoma, summarize new directions for the treatment of glaucoma and lay the foundation for new treatment strategies for glaucoma.
Topics: Humans; Glaucoma; Optic Disk; Optic Nerve Diseases; Apoptosis; Cell Death
PubMed: 38516770
DOI: 10.3892/mmr.2024.13207 -
Acta Biomaterialia Apr 2022In-vivo optic nerve head (ONH) biomechanics characterization is emerging as a promising way to study eye physiology and pathology. We propose a high-accuracy and...
In-vivo optic nerve head (ONH) biomechanics characterization is emerging as a promising way to study eye physiology and pathology. We propose a high-accuracy and high-efficiency digital volume correlation (DVC) method to characterize the in-vivo ONH deformation from optical coherence tomography (OCT) volumes. Using a combination of synthetic tests and analysis of OCTs from monkey ONHs subjected to acutely elevated intraocular pressure, we demonstrate that our proposed methodology overcame several challenges for conventional DVC methods: First, a pre-registration technique was used to remove large ONH rigid body motion in OCT volumes which could lead to analysis failure; second, a modified 3D inverse-compositional Gaussian Newton method was used to ensure sub-voxel accuracy of displacement calculations despite high noise and low image contrast of some OCT volumes; third, a tricubic B-spline interpolation method was applied to improve computational efficiency; fourth, a confidence parameter was introduced to guide the searching path in the displacement calculation; fifth, a confidence-weighted strain calculation method was applied to further improve the accuracy. The proposed DVC method had displacement errors smaller than 0.037 and 0.028 voxels with Gaussian and speckle noises, respectively. The strain errors in the three directions were less than 0.0045 and 0.0018 with Gaussian and speckle noises, respectively. Compared with the conventional DVC method, the proposed method reduced the errors of displacement and strain calculations by up to 70% under large body motions, with 75% lower computation time, while saving about 30% memory. Our study demonstrates the potential of the proposed technique to investigate ONH biomechanics. STATEMENT OF SIGNIFICANCE: The biomechanics of the optic nerve head (ONH) in the posterior pole of the globe play a central role in eye physiology and pathology. The application of digital volume correlation (DVC) to the analysis of optical coherence tomography (OCT) images of the ONH has emerged as a promising way to quantify ONH biomechanics. Conventional DVC methods, however, face several important challenges when analyzing OCT images of the ONH. We introduce a high-accuracy and high-efficiency DVC method to characterize in vivo ONH deformations from OCT volumes. We demonstrate the new method using synthetic tests and actual OCT data from monkey ONHs. The new method also has the potential to be used to study other tissues, as OCT applications continue to expand.
Topics: Biomechanical Phenomena; Biophysics; Intraocular Pressure; Optic Disk; Tomography, Optical Coherence
PubMed: 35196556
DOI: 10.1016/j.actbio.2022.02.021 -
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 -
Eye (London, England) May 2014To determine whether the ratio of optic disk diameter to disk-to-macula distance (DD/DM) in children with optic nerve hypoplasia (ONH) changes over time.
PURPOSE
To determine whether the ratio of optic disk diameter to disk-to-macula distance (DD/DM) in children with optic nerve hypoplasia (ONH) changes over time.
PATIENTS AND METHODS
Fifteen subjects (29 eyes) enrolled in a prospective registry study on ONH had fundus photography performed under the age of 24 months and again at 60 months. Using the ratio of the DD/DM method, the relative size of the optic disk was assessed twice for each photo by one masked expert examiner to determine whether any change in relative disk size occurred over time.
RESULTS
There was no change in relative optic disk size between initial and final fundus photographs. The average (± SD) age at the time of initial and final fundus photography was, respectively, 11.6 ± 5.2 months and 60.6 ± 1.3 months. Strong concordance was noted between the average DD/DM of the initial and the final photographs (ρ=0.939; 95% CI: 0.893, 0.981). There was negligible difference between the individual time point measurements (-0.011 ± 0.03) (95% LOA: -0.07, 0.04).
CONCLUSION
There were no clinically significant changes in relative optic disk size over time in children with ONH; thus, DD/DM measurements need not be adjusted by age beyond 1 year in children with this disorder.
Topics: Age Factors; Child, Preschool; Disease Progression; Female; Humans; Infant; Macula Lutea; Optic Atrophy; Optic Disk; Reproducibility of Results
PubMed: 24556885
DOI: 10.1038/eye.2014.12 -
Investigative Ophthalmology & Visual... Apr 2020To measure the ex vivo pressure-induced strain response of the human optic nerve head and analyze for variations with glaucoma diagnosis and optic nerve axon damage.
PURPOSE
To measure the ex vivo pressure-induced strain response of the human optic nerve head and analyze for variations with glaucoma diagnosis and optic nerve axon damage.
METHODS
The posterior sclera of 16 eyes from 8 diagnosed glaucoma donors and 10 eyes from 6 donors with no history of glaucoma were inflation tested between 5 and 45 mm Hg. The optic nerve from each donor was examined for degree of axon loss. The posterior volume of the lamina cribrosa (LC) was imaged with second harmonic generation and analyzed using volume correlation to calculate LC strains between 5 and 10 and 5 and 45 mm Hg.
RESULTS
Eye length and LC area were larger in eyes diagnosed with glaucoma (P ≤ 0.03). Nasal-temporal EXX and circumferential Eθθ strains were lower in the LC of diagnosed glaucoma eyes at 10 mm Hg (P ≤ 0.05) and 45 mm Hg (P ≤ 0.07). EXX was smaller in the LC of glaucoma eyes with <25% axon loss compared with undamaged normal eyes (P = 0.01, 45 mm Hg). In general, the strains were larger in the peripheral than central LC. The ratio of the maximum principal strain Emax in the peripheral to central LC was larger in glaucoma eyes with >25% axon loss than in glaucoma eyes with milder damage (P = 0.004, 10 mm Hg).
CONCLUSIONS
The stiffness of the LC pressure-strain response was greater in diagnosed glaucoma eyes and varied with glaucomatous axon damage. Lower LC strains in glaucoma eyes with milder damage may represent baseline biomechanical behavior that contributes to axon loss, whereas greater LC strain and altered radial LC strain variation in glaucoma eyes with more severe damage may be caused by glaucoma-related remodeling.
Topics: Aged; Aged, 80 and over; Biomechanical Phenomena; Case-Control Studies; Female; Glaucoma; Humans; Imaging, Three-Dimensional; In Vitro Techniques; Male; Optic Disk; Reference Values; Sclera; Specimen Handling; Stress, Mechanical
PubMed: 32343781
DOI: 10.1167/iovs.61.4.41 -
PloS One 2020This study aims to investigate correlation between metabolic risk factors and optic disc cupping and the development of glaucoma.
PURPOSE
This study aims to investigate correlation between metabolic risk factors and optic disc cupping and the development of glaucoma.
METHODS
This study is a retrospective, cross-sectional study with over 20-year-old patients that underwent health screening examinations. Intraocular pressure (IOP), fundus photographs, Body Mass Index (BMI), waist circumference (WC), serum triglycerides, serum HDL cholesterol (HDL-C), serum LDL cholesterol (LDL-C), systolic blood pressure (BP), diastolic BP, and serum HbA1c were obtained to analyse correlation between metabolic risk factors and glaucoma. Eye with glaucomatous optic neuropathy(GON) was defined as having an optic disc with either vertical cup-to-disc ratio(VCDR) ≥ 0.7 or a VCDR difference ≥ 0.2 between the right and left eyes by measuring VCDR with deep learning approach.
RESULTS
The study comprised 15,585 subjects and 877 subjects were diagnosed as GON. In univariate analyses, age, BMI, systolic BP, diastolic BP, WC, triglyceride, LDL-C, HbA1c, and IOP were significantly and positively correlated with VCDR in the optic nerve head. In linear regression analysis as independent variables, stepwise multiple regression analyses revealed that age, BMI, systolic BP, HbA1c, and IOP showed positive correlation with VCDR. In multivariate logistic analyses of risk factors and GON, higher age (odds ratio [OR], 1.054; 95% confidence interval [CI], 1.046-1.063), male gender (OR, 0.730; 95% CI, 0.609-0.876), more obese (OR, 1.267; 95% CI, 1.065-1.507), and diabetes (OR, 1.575; 95% CI, 1.214-2.043) remained statistically significant correlation with GON.
CONCLUSIONS
Among the metabolic risk factors, obesity and diabetes as well as older age and male gender are risk factors of developing GON. The glaucoma screening examinations should be considered in the populations with these indicated risk factors.
Topics: Adult; Aged; Cross-Sectional Studies; Deep Learning; Female; Glaucoma; Humans; Lipids; Male; Middle Aged; Optic Disk; Retrospective Studies; Risk Factors
PubMed: 32941514
DOI: 10.1371/journal.pone.0239071 -
The British Journal of Ophthalmology Nov 2003
Topics: Cerebral Hemorrhage; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Leukomalacia, Periventricular; Optic Disk
PubMed: 14609819
DOI: 10.1136/bjo.87.11.1309 -
Scientific Reports Jan 2024We aimed to determine the effect of optic disc tilt on deep learning-based optic disc classification. A total of 2507 fundus photographs were acquired from 2236 eyes of...
We aimed to determine the effect of optic disc tilt on deep learning-based optic disc classification. A total of 2507 fundus photographs were acquired from 2236 eyes of 1809 subjects (mean age of 46 years; 53% men). Among all photographs, 1010 (40.3%) had tilted optic discs. Image annotation was performed to label pathologic changes of the optic disc (normal, glaucomatous optic disc changes, disc swelling, and disc pallor). Deep learning-based classification modeling was implemented to develop optic-disc appearance classification models with the photographs of all subjects and those with and without tilted optic discs. Regardless of deep learning algorithms, the classification models showed better overall performance when developed based on data from subjects with non-tilted discs (AUC, 0.988 ± 0.002, 0.991 ± 0.003, and 0.986 ± 0.003 for VGG16, VGG19, and DenseNet121, respectively) than when developed based on data with tilted discs (AUC, 0.924 ± 0.046, 0.928 ± 0.017, and 0.935 ± 0.008). In classification of each pathologic change, non-tilted disc models had better sensitivity and specificity than the tilted disc models. The optic disc appearance classification models developed based all-subject data demonstrated lower accuracy in patients with the appearance of tilted discs than in those with non-tilted discs. Our findings suggested the need to identify and adjust for the effect of optic disc tilt on the optic disc classification algorithm in future development.
Topics: Male; Humans; Middle Aged; Female; Optic Disk; Deep Learning; Tomography, Optical Coherence; Eye Abnormalities; Glaucoma
PubMed: 38177229
DOI: 10.1038/s41598-023-50256-4