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[IEEE 2018 Congreso Internacional de Innovacio?n y Tendencias en Ingenieri?a (CONIITI) [International Congress of Innovation and Trends in Engineering] - Bogota (2018.10.3-2018.10.5)] 2018 Congreso Internacional de Innovación y Tendencias en Ingeniería (CONIITI) - A Computer Vision Approach Based on the Retinal Nerve Fiber Thickness Analysis to Estimate the Risk of Suffering Glaucoma
摘要: According to estimations of the World Health Organization (WHO), approximately 4.5 million persons will become blind due to the primary Glaucoma. For these reasons, in this paper, we present a simple approach to estimate the risk of suffering from glaucoma that presents a patient. Our proposal relies on the automatic analysis of Optical Coherence Tomography (OCT) images through the calculus of nerve fiber and ganglionary vessels areas. To this aim, our system separates the two areas mentioned before through computer vision techniques and the Newton Interpolation Method. Once the two areas are separated, the system determines the size of each of them. This proposal was validated through an experiment carried out with OCT 30 images (per eye). The results are encouraging, and the suggestions provided by the system match with medical diagnosis.
关键词: Glaucoma,Optical Coherence Tomography,Computer vision,Retinal nerve fiber,Newton interpolation polynomial
更新于2025-09-19 17:15:36
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Eyes are Mirror of the Brain: Comparison of Multiple Sclerosis Patients and Healthy Controls Using OCT
摘要: Objective: To evaluate the thickness of choroid and retinal nerve fiber layer (RNFL) in Multiple Sclerosis (MS) patients with and without optic neuritis using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: In this cross-sectional study, both eyes of 52 MS patients [n=104 eyes; 62 eyes of MS patients without optic neuritis (MS-NON) and 42 eyes of MS patients with optic neuritis (MS-ON)] and only one eye of 36 healthy control subjects (n=36 eyes) were evaluated. Complete ophthalmologic examination and EDI-OCT scanning were completed for all participants. Choroidal thickness measurements were executed at three different points. Results: Choroidal thickness measurements were similar between MS patients and healthy control subjects. However, the mean subfoveal choroidal thickness was increased significantly in MS-ON group (399.13± 82.91 μm) compared to MS-NON group (342.71± 82.46 μm; p=0.004). Mean RNFL thickness was significantly reduced in MS patients (90.42± 13.31μm) compared to healthy controls (101.18± 10.75 μm; p < 0.001). Moreover, temporal RNFL thickness was significantly thinner in MS-ON group (54± 14.50 μm) than MS-NON group (62.15± 15.88 μm; p = 0.01). In MS patients, temporal RNFL thickness was correlated with both Expanded Disability Status Score (r = 0.383; p<0.001) and longer disease duration (r = –0.202; p = 0.04). Conclusion: The results of the present study suggest that RNFL thickness can be used as an important parameter while following up with MS patients. However, more studies using EDI-OCT are required with larger MS patient groups and automated method.
关键词: Retinal nerve fiber layer,Choroid,Multiple sclerosis,Expanded disability status scale,Optical coherence tomography
更新于2025-09-19 17:15:36
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Selective Laser Trabeculoplasty Protects Glaucoma Progression in the Initial Primary Open-Angle Glaucoma and Angle-Closure Glaucoma after Laser Peripheral Iridotomy in the Long Term
摘要: Purpose. To compare the ability of SLT in preventing glaucoma progression in the initial primary angle-closure glaucoma (PACG) after laser peripheral iridotomy and primary open-angle glaucoma (POAG) in the long term. Methods. 60 patients with the initial stage of PACG after laser peripheral iridotomy and 64 initial POAG patients were recruited in a prospective study. Complete success of selective laser trabeculoplasty (SLT) was de?ned as a 20% intraocular pressure (IOP) reduction with topical hypotensive medications without any hypotensive intervention. Pre-SLT rate of progression and post-SLT rate of progression (ROP) was detected in the both groups by means of the trend and the event analysis of perimetry, the Guided Progression Analysis, and the optical coherence tomography- (OCT-) based negative trend for either the thickness of the peripapillary retinal nerve ?ber layer (RNFL) or ganglion cell complex (GCC). Results. IOP decreased signi?cantly after SLT in both the groups. 30% in PACG and 19% in POAG had the progression according to perimetry and 49% in PACG and 40% in POAG had the progression, respectively, according to OCT. After SLT, ROP was reduced from ? 0.14 ± 0.39 dB/year to ? 0.08 ± 0.48 dB/year, p ? 0.034, in PACG and from ? 0.09 ± 0.36 dB/year to ? 0.04 ± 0.43 dB/year, p ? 0.021, in POAG. According to RNFL trend analysis, ROP was reduced from ? 1.86 ± 2.9 μm/year to ? 1.38 ± 2.2 μm/year, p ? 0.039, and from ? 1.24 ± 2.23 μm/year to ? 0.76 ± 1.73 μm/year, p ? 0.037, in PACG and POAG, and according to GCC, ROP was reduced from ? 1.88 ± 2.9 μm/year to ? 1.34 ± 2.0 μm/year, p ? 0.040, and from ? 1.35 ± 2.16 μm/year to ? 0.91 ± 1.86 μm/year, p ? 0.040, in PACG and POAG, respectively. ROP was signi?cantly faster in PACD than in POAG between 2 and 6 years after SLT: ? 0.15 ± 0.46 dB/year and 0.02 ± 0.38 dB/year (p ? 0.042). However, it did not di?er signi?cantly according to OCT. Conclusion. SLT is an e?ective treatment for initial PACG after LPI and POAG that can prevent functional and structural deterioration in the long term.
关键词: Ganglion Cell Complex,Laser Peripheral Iridotomy,Optical Coherence Tomography,Primary Angle-Closure Glaucoma,Selective Laser Trabeculoplasty,Intraocular Pressure,Retinal Nerve Fiber Layer,Primary Open-Angle Glaucoma,Glaucoma Progression
更新于2025-09-16 10:30:52
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Custom Optical Coherence Tomography Parameters for Distinguishing Papilledema from Pseudopapilledema
摘要: SIGNIFICANCE: Causes of papilledema can be life-threatening; however, distinguishing papilledema from pseudopapilledema is often challenging. The conventional optical coherence tomography (OCT) scan for assessing the optic nerve often fails to detect mild papilledema. Our study suggests that parameters derived from volumetric OCT scans can provide additional useful information for detecting papilledema. PURPOSE: Optical coherence tomography analysis of the optic nerve commonly measures retinal nerve fiber layer thickness (RNFLT) along a 1.73-mm-radius scan path. This conventional scan, however, often fails to detect mild papilledema. The purpose of this study was to evaluate additional OCT-derived measures of the optic nerve head (ONH) and peripapillary retina for differentiating papilledema (all grades and mild) from pseudopapilledema. METHODS: Cirrus OCT ONH volume scans were acquired from 21 papilledema (15 mild papilledema), 27 pseudopapilledema, and 42 control subjects. Raw scan data were exported, and total retinal thickness within Bruch’s membrane opening (BMO) plus RNFLT and total retinal thickness at the following eccentricities were calculated using custom algorithms: BMO to 250, 250 to 500, 500 to 1000, and 1000 to 1500 μm. Minimum rim width was calculated, and BMO height was measured from a 4-mm Bruch’s membrane reference plane centered on the BMO. RESULTS: Retinal nerve fiber layer thickness from BMO to 250 μm, minimum rim width, and BMO height had significantly greater areas under the receiver operating characteristic curve than did conventional RNFLT for differentiating mild papilledema from pseudopapilledema (P < .0001) and greater sensitivities at 95% specificity. Using cutoff values at 95% specificity, custom parameters detected 10 mild papilledema patients, and conventional RNFLT detected only 1. Bruch’s membrane opening heights above the reference plane were observed in papilledema only, although many papilledema cases had a neutral or negative BMO height. CONCLUSIONS: Using OCT volumetric data, additional parameters describing peripapillary tissue thickness, neuroretinal rim thickness, and ONH position can be calculated and provide valuable measures for differentiating mild papilledema from pseudopapilledema.
关键词: optical coherence tomography,papilledema,optic nerve head,pseudopapilledema,retinal nerve fiber layer thickness
更新于2025-09-12 10:27:22
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Effects of Cataract Extraction on the Outcomes of Automated Perimetry and Retinal Nerve Fiber Layer Thickness Measurements by Optical Coherence Tomography in Primary Angle Closure Glaucoma
摘要: Objective: To evaluate the effect of cataract extraction on both visual field and retinal nerve fiber layer thickness measurements in primary angle closure glaucoma (PACG) eyes. Methods: Retrospective cohort study on 30 PACG eyes underwent cataract extraction. Changes in RNFL thickness and visual field parameters including mean deviation (MD), visual field index (VFI) and pattern standard deviation (PSD) were analyzed within 6 months before and after cataract extraction. Results: Overall, MD (p=0.003) and VFI (p=0.004) improved significantly after cataract extraction, whereas PSD showed no significant change (p=0.6). In the 10 eyes with MD worse than -20 dB, mean MD improved by 3.4 ± 3.56 dB (from -24.36 ± 3.06 dB to -20.96 ± 5.06 dB, p=0.01) and mean VFI improved by 16.25 ± 15.66% (from 23.38 ± 9.65% to 39.63 ± 20.83%, p=0.02). PSD showed no significant change after cataract extraction (p=0.07). In the 20 eyes with MD better than -20 dB, MD and VFI also improved postoperatively, but the changes did not reach statistical significance: mean MD improved by 1.64 ± 3.65 dB (from -11.57 ± 5.57 dB to -9.92 ± 5.36 dB, p=0.05) whilst mean VFI improved by 4.57 ± 12.29% (from 74.95 ± 17.95% to 79.52 ± 17.26%, p=0.07). RNFL thickness did not show any significant changes after cataract extraction (p=0.13). Conclusions: Both MD and VFI improved after cataract extraction, especially in eyes with pre-operative MD worse than -20 dB. PSD and RNFL thickness showed no significant change after cataract extraction.
关键词: Perimetry,Visual field,Extraction,Retinal nerve fiber layer thickness,Optical coherence tomography,Primary angle closure glaucoma,Cataract
更新于2025-09-10 09:29:36
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Retinal Nerve Fiber Layer Volume Measurements in Normal Children Using Spectral Domain Optical Coherence Tomography
摘要: Purpose: To measure retinal nerve fiber layer (RNFL) volume in normal children using spectral domain optical coherence tomography (SD-OCT). Methods: This study included 79 eyes of 54 normal children between 4 and 15 years of age evaluated from February 2012 to November 2012. All participants underwent ocular examination and 3D-disc scanning using SD-OCT. RNFL volume was calculated between 2.5 and 5 mm diameter circles using the length, width, and height of each pixel derived from the RNFL thickness map with Matlab software. The relationship between RNFL volume and thickness was analyzed. Results: The RNFL volumes of the mean total, superior, nasal, inferior, and temporal areas were 1.48 ± 0.09 mm3, 0.45 ± 0.04 mm3, 0.29 ± 0.04 mm3, 0.46 ± 0.03 mm3, and 0.29 ± 0.04 mm3, respectively. Comparing RNFL volume and conventional circumpapillary RNFL thickness measured using built-in software, a strong correlation between mean total, superior, and inferior areas (R = 0.980, 0.953 and 0.932, respectively) and a moderate correlation between the nasal and temporal areas were observed (R = 0.545 and 0.514, respectively). The negative correlations between RNFL thickness and RNFL volumes of the mean total, superior, nasal, inferior, and temporal areas and age were not significant (p > 0.05). Conclusions: This study reports RNFL volume measured from RNFL thickness map analysis in normal children. These data regarding RNFL volume of normal children may provide useful information for diagnosis and monitoring of pediatric glaucoma.
关键词: Normal children,Retinal nerve fiber layer,Spectral domain optical coherence tomography,Volume
更新于2025-09-10 09:29:36
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Parameters of ocular fundus on spectral-domain optical coherence tomography for glaucoma diagnosis
摘要: In this review, we summarize the progression of several parameters assessed by spectral-domain optical coherence tomography (SD-OCT) in recent years for the detection of glaucoma. Monitoring the progression of defects in the retinal nerve fiber layer (RNFL) thickness is essential. Imaging and analysis of retinal ganglion cells (RGCs) and inner plexiform layer (IPL), respectively, have been of great importance. Optic nerve head (ONH) topography obtained from 3D SD-OCT images is another crucial step. Other important assessments involve locating the Bruch’s membrane opening (BMO), estimating the optic disc size and rim area, and measuring the lamina cribrosa displacement. Still other parameters found in the past three years for glaucoma diagnosis comprise central retinal artery resistive index, optic disc perfusion in optical coherence tomography angiography (OCTA) study, peripapillary choroidal thickness, and choroidal area in SD-OCT. Recently, several more ocular fundus parameters have been found, and compared with the earlier parameters to judge the accuracy of diagnosis. While a few of these parameters have been widely used in clinical practice, a fair number are still in the experimental stage.
关键词: optic nerve head,retinal nerve fiber layer,lamina cribrosa,optical coherence tomography,macular thickness,ganglion cells,glaucoma progression
更新于2025-09-09 09:28:46
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Color vision testing versus pattern visual evoked potentials and optical coherence tomography parameters in subclinical optic nerve involvement in multiple sclerosis
摘要: Acute idiopathic demyelinating optic neuritis is frequently the initial manifestation of multiple sclerosis (MS). We aimed to discuss the value of color vision testing to detect possible optic nerve involvement in patients with MS who had no history of optic neuritis. We evaluated color vision with Farnsworth-Munsell 100 (FM-100) hue test. Total error scores (TES), partial error scores for the red-green axis (RGS) and blue-yellow axis (BYS) were calculated. Topographic optic disc parameters (RNFL, RA, DA, CV, RV, and vertical C/D ratio), total macular volume (TMV), central macular thickness (CMT), and retinal ganglion cell layer (RGCL) were determined using spectral domain optical coherence tomography (SD-OCT). Choroidal thickness (CT) was measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Pattern visual evoked potentials (PVEP) were also performed. Twenty-eight patients with RRMS (56 eyes) and 25 healthy controls (50 eyes) were included. P100 latencies were significantly delayed and P100 amplitudes were significantly reduced in the patient group compared with the controls (p (cid:1) 0.05). Statistically significant thinning was found in temporal quadrant in the patient group compared with the controls (p = 0.002). TES RGS, and BYS were all increased in the patient group but this was not statistically significant. We found no correlation between TES, RGS, BYS, and P100 latencies or OCT parameters. In our investigation as to whether color vision testing could be a simple biomarker for showing neurodegeneration of the anterior visual pathway regardless of optic neuritis, PVEP and OCT-assessed RNFL thickness seemed to be a more valuable biomarker than color vision testing.
关键词: Visual evoked potentials,Optical coherence tomography,Color vision,Multiple sclerosis,Subclinical optic neuritis,Retinal nerve fiber layer
更新于2025-09-09 09:28:46
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Quantitative analysis of the retinal nerve fiber layer, ganglion cell layer and optic disc parameters by the swept source optical coherence tomography in patients with migraine and patients with tension-type headache
摘要: The aim of the study was to measure the thicknesses of the inner retinal segments and optic nerve head (ONH) parameters in migraineurs and patients with tension-type headache (TTH) in headache-free period using swept source optical coherence tomography (SS-OCT) and to compare the outcomes with each other and those of healthy subjects. The study population consisted of 23 migraineurs, 22 TTH patients, and 25 controls with a best-corrected visual acuity of 20/20 and without a history of systemic or ocular disease. Macular ganglion cell inner plexiform layer (mGCIPL), macular ganglion cell complex (mGCC), circumpapillary retinal nerve fiber layer (cpRNFL), and ONH parameters were evaluated using SS-OCT, and the areas under the receiver-operating characteristic (ROC) curves were calculated to determine the ability of these parameters to distinguish between the patient and normal eyes. There were not statistically significant differences between the measurements acquired from migraineurs, TTH patients, and the controls. The outcomes of the patients with TTH were very similar to those of the normal participants. The areas under the ROC curves (AUC) correlated highly with the measurements obtained from the same subfields for the mGCC, MGCIPL, cpRNFL, and ONH parameters. In conclusion, SS-OCT presented reproducible and reliable measurements of posterior segment layers of the eyes, especially in sectoral configuration, and the parameters did not show significant difference between the groups.
关键词: Migraine,Swept source optical coherence tomography,Retinal nerve fiber layer,Ganglion cell layer,Tension-type headache
更新于2025-09-09 09:28:46
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Diagnostic Accuracy of Glaucoma With Sector-Based and a New Total Profile–Based Analysis of Neuroretinal Rim and Retinal Nerve Fiber Layer Thickness
摘要: PURPOSE. To compare the diagnostic accuracy of conventional sector-based analysis with a method devised to detect the smallest localized neuroretinal rim and retinal nerve fiber layer thickness (RNFLT) damage. METHODS. One eye of 151 glaucoma patients and 83 healthy controls (median age and MD, 71.7 and 66.7 years, and (cid:2)3.6 and (cid:2)0.3 dB, respectively) was imaged with spectral-domain optical coherence tomography (OCT). Bruch’s membrane opening-minimum rim width (BMO-MRW) and RNFLT were determined at 18 intervals and also averaged for each sector. A classification of glaucoma was made with sectoral analysis when the sectoral value was below the 1%, 5%, or 10% normative limit (from an independent normative dataset); and with total analysis when a given number of measurements was below the 1%, 5%, or 10% normative limit. RESULTS. With the 1% normative limit, BMO-MRW sectoral analysis yielded sensitivity of 87% and specificity of 92%; while at the same specificity (92%), total analysis yielded sensitivity of 88%. With RNFLT, sectoral analysis yielded sensitivity of 85% and specificity of 95%; while at the same specificity (95%), total analysis yielded sensitivity of 83%. The results for the 5% and 10% normative limits yielded lower specificity but higher sensitivity. In the whole glaucoma population, none of the sensitivity values of the sectoral and total analysis at the same specificities were statistically different. CONCLUSIONS. The diagnostic accuracy of sectoral analysis was equivalent to total analysis. These results indicate that BMO-MRW and RNFLT defects were wide and deep enough for detection by conventional sectoral analysis.
关键词: diagnostic accuracy,neuroretinal rim,retinal nerve fiber layer
更新于2025-09-09 09:28:46