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Computer Methods and Programs in... Jun 2022The optic nerve head (ONH) represents the intraocular section of the optic nerve, which is prone to damage by intraocular pressure (IOP). The advent of optical... (Review)
Review
The optic nerve head (ONH) represents the intraocular section of the optic nerve, which is prone to damage by intraocular pressure (IOP). The advent of optical coherence tomography (OCT) has enabled the evaluation of novel ONH parameters, namely the depth and curvature of the lamina cribrosa (LC). Together with the Bruch's membrane minimum-rim-width (BMO-MRW), these seem to be promising ONH parameters for diagnosis and monitoring of retinal diseases such as glaucoma. Nonetheless, these OCT derived biomarkers are mostly extracted through manual segmentation, which is time-consuming and prone to bias, thus limiting their usability in clinical practice. The automatic segmentation of ONH in OCT scans could further improve the current clinical management of glaucoma and other diseases. This review summarizes the current state-of-the-art in automatic segmentation of the ONH in OCT. PubMed and Scopus were used to perform a systematic review. Additional works from other databases (IEEE, Google Scholar and ARVO IOVS) were also included, resulting in a total of 29 reviewed studies. For each algorithm, the methods, the size and type of dataset used for validation, and the respective results were carefully analysed. The results show a lack of consensus regarding the definition of segmented regions, extracted parameters and validation approaches, highlighting the importance and need of standardized methodologies for ONH segmentation. Only with a concrete set of guidelines, these automatic segmentation algorithms will build trust in data-driven segmentation models and be able to enter clinical practice.
Topics: Bruch Membrane; Glaucoma; Humans; Intraocular Pressure; Optic Disk; Tomography, Optical Coherence
PubMed: 35429812
DOI: 10.1016/j.cmpb.2022.106801 -
Indian Journal of Ophthalmology May 2023Optic disc anomalies with abnormal tissue on the disc surface includes, myelinated nerve fiber, optic disc drusen, and Bergmeister papillae. Imaging the radial...
BACKGROUND
Optic disc anomalies with abnormal tissue on the disc surface includes, myelinated nerve fiber, optic disc drusen, and Bergmeister papillae. Imaging the radial peripapillary capillary (RPC) network in optic disc anomalies with optical coherence tomography-angiography (OCTA) can give information on the RPC network in these conditions.
PURPOSE
This video describes the OCTA of optic nerve head and RPC network using the angio disc mode in cases of optic disc anomalies with abnormal tissue on the disc surface.
SYNOPSIS
This video presents characteristic features of RPC network in one eye each of myelinated nerve fiber, optic disc drusen, and Bergmeister papillae.
HIGHLIGHTS
OCTA in optic disc anomalies with abnormal tissue on the disc surface show a dense RPC microvascular network. OCTA is an effective imaging modality to study vascular plexus/RPC and their alteration in these disc anomalies.
VIDEO LINK
https://youtu.be/zlflgijy56c.
Topics: Humans; Eye Abnormalities; Fluorescein Angiography; Microvessels; Optic Disk; Optic Disk Drusen; Persistent Hyperplastic Primary Vitreous; Retinal Vessels; Tomography, Optical Coherence
PubMed: 37203011
DOI: 10.4103/IJO.IJO_3137_22 -
Ophthalmic Research 2023This study aims to investigate the changes of retinal vascular system in primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) by optical... (Observational Study)
Observational Study
INTRODUCTION
This study aims to investigate the changes of retinal vascular system in primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) by optical coherence tomography (OCT) angiograph (OCTA) and to evaluate the diagnostic ability of changes of vessel density (VD) in different sectors and layers of optic disc and macular area in APAC and PACG.
METHODS
In this cross-sectional, observational study, 21 APAC patients (22 eyes) and 21 PACG patients (27 eyes) along with 17 healthy people were enrolled from August 2018 to March 2019. Optic disc region and macular region were imaged using swept-source OCTA system. VD of the macular region was quantified by Image J (1.52a, USA) and Matlab 2018a. The circumpapillary retinal nerve fiber layer (cpRNFL) thickness and ganglion cell complex thickness were obtained by spectral-domain OCT.
RESULTS
Compared with the healthy group, the cpRNFL thickness in superior sector was thicker in the APAC group, and this area had the most diffuse microvascular dropout as well. The difference in the macular superficial capillary plexus (SCP) VD between APAC and the control group was not statistically significant. The area under the ROC curves (AUC) of the total optic disc VD in the radial peripapillary capillary (RPC) layer was higher than the AUC of the papillary VD in the optic nerve head (ONH) layer. Compared to the control group, the total optic disc VD, peripapillary VD, and each quadrant of peripapillary VD were decreased in PACG (p < 0.01). In PACG macular region, SCP VD, and deep capillary plexus (DCP) VD, parafovea VD (except temporal sectors) decreased (p < 0.01). The PACG eyes had a greater decrease percentage of VD in total ONH than total macula. The diagnostic value of the VD in the ONH layer and the RPC layer was similar. The diagnostic value of the SCP VD in the macula was greater than the DCP VD in the macula. The AUC was no significant difference between cpRNFL thickness and the total optic disc VD AUC.
CONCLUSION
Elevated intraocular pressure preferentially affects vascular perfusion in the optic disc region more than the macular region in APAC and PACG. In the APAC eyes, there was a perfusion defect in the optic disc region and an increase in RNFL thickness. In this study, the OCTA vascular parameters have similar performance to the OCT structural parameters for glaucoma diagnosis in PACG.
Topics: Humans; Optic Disk; Tomography, Optical Coherence; Glaucoma, Angle-Closure; Glaucoma, Open-Angle; Cross-Sectional Studies; Retinal Vessels; Intraocular Pressure; Glaucoma; Perfusion; Fluorescein Angiography
PubMed: 37647877
DOI: 10.1159/000533874 -
Die Ophthalmologie Dec 2023
Topics: Reading; Visual Perception; Optic Disk
PubMed: 37071183
DOI: 10.1007/s00347-023-01850-4 -
Investigative Ophthalmology & Visual... Nov 2020Ocular rigidity (OR) is an important biomechanical property, thought to be relevant in the pathophysiology of open-angle glaucoma (OAG). This study aims to evaluate the...
PURPOSE
Ocular rigidity (OR) is an important biomechanical property, thought to be relevant in the pathophysiology of open-angle glaucoma (OAG). This study aims to evaluate the relationship between OR and neuroretinal damage caused by glaucoma.
METHODS
One hundred eight subjects (22 with healthy eyes, 23 with suspect discs, and 63 with OAG) were included in this study. OR was measured using a noninvasive optical coherence tomography (OCT)-based method developed by our group. We also measured central corneal thickness (CCT), corneal hysteresis (CH), and corneal resistance factor (CRF). Pearson and partial correlations were performed to evaluate the relationship between OR and glaucomatous damage represented by ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thicknesses, and neuroretinal rim area.
RESULTS
Significant positive correlations were found between OR and minimum GCC thickness (r = 0.325, P = 0.001), average GCC thickness (r = 0.320, P = 0.002), rim area (r = 0.344, P < 0.001), and RNFL thickness in the superior (r = 0.225, P = 0.023), and inferior (r = 0.281, P = 0.004) quadrants. These correlations were generally greater than those found for CCT, CH, and CRF. Furthermore, no correlation was found between OR and corneal biomechanical parameters. After adjusting for age, sex, and ethnicity, significant correlations were found between OR and minimum and average GCC thickness (r = 0.357, P = 0.001 and r = 0.344, P = 0.001, respectively), rim area (r = 0.327, P = 0.001), average RNFL thickness (r = 0.331, P = 0.001), and RNFL thickness in the superior (r = 0.296, P = 0.003) and inferior (r = 0.317, P = 0.001) quadrants.
CONCLUSIONS
In this study, we found a positive correlation between structural OCT-based parameters and OR, indicating more neuroretinal damage in eyes with lower OR. These findings could provide insight into the pathophysiology of OAG.
Topics: Aged; Biomechanical Phenomena; Cornea; Female; Glaucoma, Open-Angle; Humans; Intraocular Pressure; Male; Middle Aged; Nerve Fibers; Optic Disk; Optic Nerve Diseases; Retinal Ganglion Cells; Tomography, Optical Coherence; Visual Fields
PubMed: 33151280
DOI: 10.1167/iovs.61.13.11 -
Physica Medica : PM : An International... Sep 2022The aim of this study was to relate common toxicity endpoints with dose to the macula, optic disc, and lens for uveal melanoma patients treated with Iodine-125...
PURPOSE
The aim of this study was to relate common toxicity endpoints with dose to the macula, optic disc, and lens for uveal melanoma patients treated with Iodine-125 Collaborative Ocular Melanoma Study (COMS) eye plaque brachytherapy.
METHODS
A cohort of 52 patients treated at a single institution between 2005 and 2019 were retrospectively reviewed. Demographics, dosimetry, and clinical outcomes were recorded. Univariate, relative risk, and Kaplan-Meier analyses were performed to relate dose to toxicity endpoints including retinopathy, vision decline, and cataracts.
RESULTS
By the end of follow up (Median = 3.6 years, Range = 0.4 - 13.5 years), 65 % of eyes sustained radiation retinopathy, 40 % demonstrated moderate vision decline (>5 Snellen lines lost), and 56 % developed cataracts. Significant (p < 0.05) risk estimates exist for retinopathy and VA decline for doses >52 Gy to the macula and >42 Gy to the optic disc. Moreover, dose to the lens > 16 Gy showed a significant risk for cataract formation. Kaplan-Meier analysis demonstrated significantly different incidence of radiation retinopathy for > 52 Gy to the macula and > 42 Gy to the optic disc. In addition, the Kaplan-Meier analysis showed significantly different incidence of cataract formation for patients with lens dose > 16 Gy.
CONCLUSIONS
Dose-effect relationships exist for the macula and optic disc with respect to the loss of visual acuity and the development of retinopathy. To better preserve vision after treatment, further research is needed to reduce macula, optic disc, and lens doses while maintaining tumor control.
Topics: Brachytherapy; Cataract; Eye Injuries; Eye Neoplasms; Humans; Iodine Radioisotopes; Melanoma; Optic Disk; Radiation Injuries; Radiotherapy Dosage; Retinal Diseases; Retrospective Studies
PubMed: 35981450
DOI: 10.1016/j.ejmp.2022.08.001 -
Experimental Eye Research Aug 2020The lamina cribrosa is the initial site of glaucomatous injury. Pathological changes to the lamina cribrosa include posterior displacement of the lamina cribrosa, loss...
The lamina cribrosa is the initial site of glaucomatous injury. Pathological changes to the lamina cribrosa include posterior displacement of the lamina cribrosa, loss of trophic support, and remodeling of the extracellular matrix. Optic nerve head (ONH) astrocytes and lamina cribrosa cells synthesize extracellular matrix proteins to support and maintain the lamina cribrosa under physiological conditions. During glaucoma, these cells respond to mechanical strain and other stimuli, which leads to pathological remodeling of the ONH. Although ONH astrocytes and lamina cribrosa cells have been previously cultured, there is no well-accepted, straightforward technique to isolate both cell types from a single dissected human ONH. To better understand the pathophysiology of glaucoma, we obtained and cultured lamina cribrosa explants from human donor eyes. Initially, cells that grew out from the explant were ONH astrocytes and lamina cribrosa cells. Using a specialized medium, we isolated pure populations of lamina cribrosa cells and ONH astrocytes. ONH astrocytes expressed glial fibrillary acidic protein (GFAP). Lamina cribrosa cells expressed alpha-smooth muscle actin (α-SMA), but were negative for GFAP. This method of ONH cell isolation and cell-culture will provide a technique to better understand the molecular and cell-specific changes in glaucomatous damage to the ONH.
Topics: Astrocytes; Blotting, Western; Cells, Cultured; Extracellular Matrix Proteins; Glial Fibrillary Acidic Protein; Humans; Optic Disk
PubMed: 32522476
DOI: 10.1016/j.exer.2020.108103 -
Acta Ophthalmologica Sep 2022To map the morphology of the retina and optic disc in adolescents with surgically treated hydrocephalus (HC) in infancy and to compare the results with healthy controls.
PURPOSE
To map the morphology of the retina and optic disc in adolescents with surgically treated hydrocephalus (HC) in infancy and to compare the results with healthy controls.
METHODS
The study comprised 26 adolescents (16 male, mean age 15 years) with HC and 31 sex- and aged-matched controls. The following optical coherence tomography (OCT) parameters were obtained: macular retinal thickness (MRT) and volume (MRV), thickness of the macular and peripapillary retinal nerve fibre layer (ppRNFL), and area of the optic disc, cup and rim.
RESULTS
The MRT was thinner amongst those with HC compared with controls (right eye (RE) 262.2 ± 15.3 and 275.8 ± 15.1 μm; p = 0.0051), and the MRV was smaller (RE 7.37 ± 0.36 and 7.83 ± 0.35 mm ; p = 0.0002). The HC group showed a thinner ppRNFL (RE 88.3 ± 14.9 and 103.5 ± 8.1 μm; p = 0.0002) but a thicker central macular RNFL (RE 11.6 ± 10.4 and 2.07 ± 3.00 μm; p = <0.0001) and foveal minimum (RE 211.1 ± 32.0 and 186.3 ± 15.9 μm; p = 0.0013). Optic disc variables showed no difference between groups. Correlations were found in the HC group between best corrected visual acuity (expressed in logMAR) and ppRNFL (RE r = -0.56, p = 0.018), and disc area (RE r = -0.52, p = 0.033).
CONCLUSION
Thinner ppRNFL and MRT and smaller MRV were found in adolescents with surgically treated HC in infancy compared with controls. In contrast, the central macular RNFL and foveal minimum were thicker. Further studies are required to evaluate the diagnostic value of OCT to indicate increased intracranial pressure timely and follow-up in individuals with surgically treated HC.
Topics: Adolescent; Aged; Humans; Hydrocephalus; Male; Nerve Fibers; Optic Disk; Retina; Retinal Ganglion Cells; Tomography, Optical Coherence
PubMed: 35507694
DOI: 10.1111/aos.15162 -
Translational Vision Science &... Oct 2023To evaluate the interocular differences of the peripapillary structural and vascular parameters and that of association with axial length (AL) in participants with...
PURPOSE
To evaluate the interocular differences of the peripapillary structural and vascular parameters and that of association with axial length (AL) in participants with myopic anisometropia using swept-source optical coherence tomography.
METHODS
This prospective cross-sectional study included 90 eyes of 45 participants. Each participant's eyes were divided into the more and less myopic eye respectively according to spherical equivalent. The β- and γ-parapapillary atrophy (PPA) areas, Bruch's membrane opening distance, border length, and border tissue angle were measured manually. Peripapillary choroidal vascularity index and choroidal thickness (CT) values in superior, nasal, inferior, and temporal were calculated using a custom-built algorithm based on MATLAB.
RESULTS
The interocular difference in AL and spherical equivalent was 0.62 ± 0.26 mm and -1.50 (-2.13, -1.25) diopters (D), respectively. The interocular difference in spherical equivalent was highly correlated with that of the AL. The β- and γ-PPA areas were significantly greater in more myopic eyes. The mean and inferior peripapillary choroidal vascularity index and all regions of peripapillary CT were significantly lower in the more myopic eyes. The interocular difference in AL was significantly positively correlated with the interocular differences in γ-PPA area and border length and negatively correlated with the interocular differences in temporal choroidal vascularity index and mean, inferior, and temporal peripapillary CT. There was an independent correlation between the interocular differences in AL and the interocular differences in γ-PPA area, inferior, and temporal peripapillary CT.
CONCLUSIONS
Significant differences between both groups were detected in most peripapillary parameters, especially in peripapillary CT. The γ-PPA area, border length, and peripapillary CT were significantly correlated with the elongation of AL.
TRANSLATIONAL RELEVANCE
The current study characterized and analyzed the peripapillary parameters in myopic anisometropia, which helped to monitor myopic progression.
Topics: Humans; Anisometropia; Optic Disk; Prospective Studies; Cross-Sectional Studies; Myopia
PubMed: 37850949
DOI: 10.1167/tvst.12.10.16 -
Indian Journal of Ophthalmology Dec 2023To analyze the clinical profile, presentation, possible pathophysiology, and outcomes of central retinal artery occlusion (CRAO) following blunt trauma in pediatric...
BACKGROUND
To analyze the clinical profile, presentation, possible pathophysiology, and outcomes of central retinal artery occlusion (CRAO) following blunt trauma in pediatric subjects.
METHODOLOGY
The medical charts of subjects aged 18 years or less with a diagnosis of CRAO following blunt ocular trauma were analyzed retrospectively for demography, details of the trauma, ocular findings, additional imaging reports if any, and final outcome. A Medline search was done (key words like central retinal artery occlusion, blunt trauma, children, pediatric subjects, and adolescents) to gather information available in the literature on the subject.
RESULTS
A total of 11 patients (11 eyes), mean age of 14.3 ± 3.4 years, and 100% male preponderance, with an average time duration from trauma to presentation to the hospital of 8.1 days were included. Visual acuity ranged from no light perception (four eyes) to finger count at a 1 m distance. Intraocular pressure was raised in three patients, of which two were suffering from sickle cell disease. In two eyes, the CRAO coexisted with optic nerve avulsion and the cilioretinal artery was spared. Disk pallor was seen in six eyes as early as 12 days from the trauma. None of the cases revealed any bony fracture in the CT scan.
CONCLUSION
CRAO was observed to be an important primary or contributory cause of visual loss in children following blunt trauma, reflex vasospasm being the most common etiology. Early onset disk pallor could suggest an underlying vascular compromise of both retinal and optic disk circulation in addition to direct disk damage.
Topics: Adolescent; Humans; Male; Child; Female; Retrospective Studies; Pallor; Retinal Artery Occlusion; Optic Disk; Eye Injuries; Wounds, Nonpenetrating
PubMed: 37991294
DOI: 10.4103/IJO.IJO_3337_22