Comparisons between retinal vessel calibers and various optic disc morphologic parameters with different optic disc appearances: The Glaucoma Stereo Analysis Study.
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ABSTRACT:
SUBMITTER: Sugihara K
PROVIDER: S-EPMC8320981 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The Glaucoma Stereo Analysis Study (GSAS) is a multicenter collaborative study of the characteristics of glaucomatous optic disc morphology using a stereo fundus camera. Using GSAS dataset, the formulas for predicting different glaucomatous optic disc appearances were established. The GSAS dataset containing three-dimensionally-analyzed optic disc topographic parameters from 187 eyes with primary open-angle glaucoma was assessed with discrimination analyses to obtain formulas predictive of glaucomatous optic disc appearances: focal ischemic (FI); generalized enlargement (GE), myopic glaucomatous (MY), and senile sclerotic (SS). Using 38 optic disc parameters-substituted discrimination analyses with a stepwise forward-selection method, six parameters (temporal and nasal rim-disc ratios, mean cup depth, height variation contour, disc tilt angle, and rim decentering absolute) were selected into the formulas. The area under the receiver operating characteristic curves for predicting the four disc types with established formulas were 0.88, 0.91, 0.93, and 0.86 for FI, MY, SS, and GE, respectively. Age, visual acuity, refractive error, glaucoma (normal or high-tension glaucoma), and baseline intraocular pressure differed significantly among the four optic disc types, suggesting the appearances represent different clinical glaucoma phenotypes. Using six optic disc topographic parameters obtained by stereo fundus camera, the GSAS classification formulas predicted and quantified each component of different optic disc appearances in each eye and provided a novel parameter to describe glaucomatous optic disc characteristics.
| S-EPMC5298323 | biostudies-literature
Project description:PurposeTo assess the suitability of digital stereo images for optic disc evaluations in glaucoma.MethodsStereo color optic disc images in both digital and 35-mm slide film formats were acquired contemporaneously from 29 subjects with various cup-to-disc ratios (range, 0.26-0.76; median, 0.475). Using a grading scale designed to assess image quality, the ease of visualizing optic disc features important for glaucoma diagnosis, and the comparative diameters of the optic disc cup, experienced observers separately compared the primary digital stereo images to each subject's 35-mm slides, to scanned images of the same 35-mm slides, and to grayscale conversions of the digital images. Statistical analysis accounted for multiple gradings and comparisons and also assessed image formats under monoscopic viewing.ResultsOverall, the quality of primary digital color images was judged superior to that of 35-mm slides (P < 0.001), including improved stereo (P < 0.001), but the primary digital color images were mostly equivalent to the scanned digitized images of the same slides. Color seemingly added little to grayscale optic disc images, except that peripapillary atrophy was best seen in color (P < 0.0001); both the nerve fiber layer (P < 0.0001) and the paths of blood vessels on the optic disc (P < 0.0001) were best seen in grayscale. The preference for digital over film images was maintained under monoscopic viewing conditions.ConclusionsDigital stereo optic disc images are useful for evaluating the optic disc in glaucoma and allow the application of advanced image processing applications. Grayscale images, by providing luminance distinct from color, may be informative for assessing certain features.
| S-EPMC3061503 | biostudies-literature
Project description:PurposeThe Glaucoma Stereo Analysis Study (GSAS), a cross sectional multicenter collaborative study, used a stereo fundus camera to assess various morphological parameters of the optic nerve head (ONH) in glaucoma patients and investigated the relationships between these parameters and patient characteristics.Subjects and methodsThe study included 187 eyes of 187 subjects with primary open angle glaucoma or normal tension glaucoma (male: female = 100: 87, age = 61±9 years). Stereo pairs of ONH photographs were made with a stereo fundus camera (nonmyd WX). ONH morphological parameters were calculated with prototype analysis software. In addition to 35 standard parameters, we defined three novel parameters: disc tilt angle, rim decentering, and the absolute value of rim decentering. The correlation between each parameter and patient characteristics was analyzed with Spearman's rank correlation coefficient.ResultsPatient characteristics included refractive error of -3.38±3.75 diopters, intraocular pressure (IOP) of 13.6±2.6 mmHg, and visual field mean deviation (MD) of -4.71±3.26 dB. Representative ONH parameters included a horizontal disc width of 1.66±0.28 mm, vertical disc width of 1.86±0.23 mm, disc area of 2.42±0.63 mm2, cup area of 1.45±0.57 mm2, and cup volume of 0.31±0.22 mm3. Correlation analysis revealed significant negative associations between vertical cup-to-disc ratio (0.82±0.08) and MD (r = -0.40, P<0.01) and between disc tilt angle (10.5±12.5 degrees) and refractive error (r = -0.36, P<0.01). Seventy-five percent of the eyes had a positive value for rim decentering (0.30±0.42), indicating that rim thinning manifested more often as an inferior lesion than a superior lesion.ConclusionWe used stereoscopic analysis to establish a database of ONH parameters, which may facilitate future studies of glaucomatous changes in ONH morphology.
| S-EPMC4055679 | biostudies-literature
Project description:PURPOSE:To evaluate the relationship between pattern electroretinogram (PERG) and optic disc morphology in glaucoma suspect and glaucoma. METHODS:Eighty-six eyes of glaucoma suspect and 145 eyes of manifest glaucoma subjects were included in this study. Average peripapillary retinal nerve fiber layer (RNFL) thickness was obtained with spectral-domain optical coherence tomography, and optic disc imaging was performed using the Heidelberg Retinal Tomograph (HRT). Visual function was evaluated with perimetry (SITA and frequency doubling technology) and PERG. Scatter plots and correlation coefficients were evaluated between visual function and RNFL thickness or optic disc structure. RESULTS:Scatter plots of PERG and perimetry according to RNFL thickness change showed that PERG started to decrease earlier than did perimetry. The differences between linear and logarithmic R2 were largest for the scatter plot of SITA 24-2 (linear R2 = 0.415; logarithmic R2 = 0.443) and the smallest for P50 amplitude of PERG (linear R2 = 0.136, logarithmic R2 = 0.138). In glaucoma suspect, HRT parameters such as cup shape measure (CSM) and linear cup-disc ratio (CDR) had significant correlations with PERG amplitudes (P = 0.016 for P50 and 0.049 for N95 in CSM, P = 0.012 for P50 in CDR). However, in glaucoma patients, mean RNFL thickness was associated with PERG amplitude (P = 0.011 for P50 and 0.002 for N95). CONCLUSIONS:PERG deterioration occurred earlier than did perimetry according to RNFL thickness decrease. PERG amplitudes were significantly correlated with disc morphology in glaucoma suspect. These results suggest that PERG can detect ganglion cell dysfunction before the cells die.
| S-EPMC6837750 | biostudies-literature
Project description:PURPOSE:To quantify the variability of 5 glaucoma specialists' optic disc margin (DM), rim margin (RM), and rim width (RW) estimates. DESIGN:Inter-observer reliability analysis. METHODS:Clinicians viewed stereo-photographs from 214 subjects with glaucoma or ocular hypertension and digitally marked the DM and RM. For each photograph, the centroid of each clinician's DM was calculated, and an averaged DMcentroid was determined. The axis between the DMcentroid and the fovea was used to establish 12 30-degree sectors. Measurements from the DMcentroid to each clinician's DM (DMradius) and RM (RMradius) were used to generate a RW (DMradius-RMradius) and cup-to-disc ratio (CDR) (RMradius/DMradius) by sector. Parameter means, standard deviations, and coefficient of variations (COVs) were calculated across all clinicians for each eye. Parameter means for each clinician, and intraclass correlation coefficients (ICC), were calculated across all eyes by sector. RESULTS:Among all eyes, the median COV by sector ranged from 3% to 5% for DMradius, 20% to 25% for RMradius, and 26% to 30% for RW. Sectoral ICCs for CDR ranged from 0.566 to 0.668. Sectors suspicious for rim thinning by 1 clinician were frequently overlooked by others. Among 1724 sectors in which at least 1 clinician was suspicious for rim thinning (CDR ≥ 0.7), all 5 clinicians' CDRs were ≥ 0.7 in only 499 (29%), and 2 of the 5 clinicians failed to detect rim thinning (CDR < 0.7) in 442 (26%). CONCLUSION:In this study, glaucoma specialist RM, DM, and RW discordance was frequent and substantial, even in sectors that were suspicious for rim thinning.
| S-EPMC6064671 | biostudies-literature
Project description:PurposeTo present a digital image subtraction technique to alert clinicians to signs of glaucomatous optic disc progression.MethodsNinety-two glaucomatous eyes (65 patients) were included. Thirty-three eyes were identified as progressive and 59 as stable based on comparison of baseline and follow-up stereoscopic disc photographs by three masked glaucoma specialists. The disc images were aligned and converted to gray scale and underwent histogram matching to enhance contrast and account for illumination differences. The difference in image intensity between baseline and follow-up images was shown as a colormap superimposed on the grayscale follow-up image. A graded scale (1, no progression, to 5, definitive progression) was used by three masked glaucoma experts to score progression probability on the colormap images. Sensitivity, specificity, and accuracy of the classification were computed. Weighted κ statistics summarized agreement of categorical gradings.ResultsMedian time interval between two visits was 4.4 years (range: 1.0-16.8). Clinicians detected glaucoma deterioration in 25 to 27 of the progressive group and 8 to 10 of stable eyes based on subtraction maps. Sensitivities/specificities of the clinicians were 0.76 to 0.82 and 0.86 to 0.89, respectively. Classification accuracy ranged from 81.5% to 84.8%. Agreement among clinicians was good (weighted κ = 0.68; 95% confidence interval [CI]: 0.60-0.77) for progression grades (1-5 scales) and was substantial (weighted κ = 0.81; 95% CI: 0.74-0.85) for binary scores.ConclusionsThe proposed software provides a single static image that clinicians can use with other structural/functional tests to detect glaucoma progression.Translational relevanceProvision of a subtraction colormap in the setting of electronic medical records can improve monitoring of glaucoma by alerting clinicians to possible signs of progression.
| S-EPMC5661381 | biostudies-literature
Project description:ObjectivesTo evaluate the performance of a deep learning based Artificial Intelligence (AI) software for detection of glaucoma from stereoscopic optic disc photographs, and to compare this performance to the performance of a large cohort of ophthalmologists and optometrists.MethodsA retrospective study evaluating the diagnostic performance of an AI software (Pegasus v1.0, Visulytix Ltd., London UK) and comparing it with that of 243 European ophthalmologists and 208 British optometrists, as determined in previous studies, for the detection of glaucomatous optic neuropathy from 94 scanned stereoscopic photographic slides scanned into digital format.ResultsPegasus was able to detect glaucomatous optic neuropathy with an accuracy of 83.4% (95% CI: 77.5-89.2). This is comparable to an average ophthalmologist accuracy of 80.5% (95% CI: 67.2-93.8) and average optometrist accuracy of 80% (95% CI: 67-88) on the same images. In addition, the AI system had an intra-observer agreement (Cohen's Kappa, κ) of 0.74 (95% CI: 0.63-0.85), compared with 0.70 (range: -0.13-1.00; 95% CI: 0.67-0.73) and 0.71 (range: 0.08-1.00) for ophthalmologists and optometrists, respectively. There was no statistically significant difference between the performance of the deep learning system and ophthalmologists or optometrists.ConclusionThe AI system obtained a diagnostic performance and repeatability comparable to that of the ophthalmologists and optometrists. We conclude that deep learning based AI systems, such as Pegasus, demonstrate significant promise in the assisted detection of glaucomatous optic neuropathy.
| S-EPMC7002599 | biostudies-literature
Project description:This study characterizes differences in glaucomatous eyes with and without high axial myopia using custom automated analysis of OCT images. 452 eyes of 277 glaucoma patients were stratified into non (n = 145 eyes), mild (n = 214 eyes), and high axial myopia (axial length (AL) > 26 mm, n = 93 eyes). Optic disc ovality index, tilt and rotation angle of Bruch´s membrane opening (BMO) and peripapillary choroidal thickness (PCT) were calculated using automated and deep learning strategies. High myopic optic discs were more oval and had larger BMO tilt than mild and non-myopic discs (both p < 0.001). Mean PCT was thinnest in high myopic eyes followed by mild and non-myopic eyes (p < 0.001). BMO rotation angle, global retinal nerve fiber layer (RNFL) thickness and BMO-minimum rim width (MRW) were similar among groups. Temporal RNFL was thicker and supranasal BMO-MRW was thinner in high myopic eyes. BMO tilt and PCT showed moderate and temporal RNFL and nasal BMO-MRW showed weak but significant associations with AL in multivariable analyses (all p < 0.05). Large BMO tilt angle and thin PCT are characteristics of highly myopic discs and were not associated with severity of glaucoma. Caution should be exercised when using sectoral BMO-MRW and RNFL thickness for glaucoma management decisions in myopic eyes.
| S-EPMC8065167 | biostudies-literature
Project description:PurposeTo objectively classify the optic discs of open-angle glaucoma (OAG) patients into Nicolela's four disc types, i.e., focal ischemic (FI), myopic (MY), senile sclerotic (SS), and generalized enlargement (GE), with swept-source optical coherence tomography (SS-OCT).MethodsThis study enrolled 113 eyes of 113 OAG patients (mean age: 62.5 ± 12.6; Humphrey field analyzer-measured mean deviation: -9.4 ± 7.3 dB). Newly developed software was used to quantify a total of 20 optic disc parameters in SS-OCT (DRI OCT-1, TOPCON) images of the optic disc. The most suitable reference plane (RP) above the plane of Bruch's membrane opening was determined by comparing, at various RP heights, the SS-OCT-measured rim parameters and spectral-domain OCT-measured circumpapillary retinal nerve fiber layer thickness (cpRNFLT), with Pearson's correlation analysis. To obtain a discriminant formula for disc type classification, a training group of 72 eyes of 72 OAG patients and a validation group of 60 eyes of 60 OAG patients were set up.ResultsCorrelation with cpRNFLT differed with disc type and RP height, but overall, a height of 120 μm minimized the influence of disc type. Six parameters were most significant for disc type discrimination: disc angle (horizontal), average cup depth, cup/disc ratio, rim-decentering ratio, average rim/disc ratio (upper and lower nasal). Classifying the validation group with these parameters returned an identification rate of 80.0% and a Cohen's Kappa of 0.73.ConclusionOur new, objective SS-OCT-based method enabled us to classify glaucomatous optic discs with high reproducibility and accuracy.
| S-EPMC4996503 | biostudies-literature
Project description:PurposeTo explore the potential relationship between optic disc haemorrhage, venous pulsation pressure (VPP), ocular perfusion pressures and visual field change in glaucomatous and glaucoma suspect eyes.Materials and methodsThis prospective observational study examined 155 open angle glaucoma or glaucoma suspect eyes from 78 patients over 5 years. Patients were followed with 3 monthly non-mydriatic disc photographs, 6 monthly standard automated perimetry and annual ophthalmodynamometry. The number of disc haemorrhages in each hemidisc was counted across the study period. Visual field rate of change was calculated using linear regression on the sensitivity of each location over time, then averaged for the matching hemifield. VPP and central retinal artery diastolic pressure (CRADP) were calculated from the measured ophthalmodynanometric forces (ODF). The difference between brachial artery diastolic pressure (DiastBP) and CRADP was calculated as an index of possible flow pathology along the carotid and ophthalmic arteries.ResultsMean age of the cohort was 71.9 ± 7.3 Years. 76 out of 155 eyes (49%) followed for a mean period of 64.2 months had at least 1 disc haemorrhage. 62 (81.6%) of these 76 eyes had recurrent haemorrhages, with a mean of 5.94 recurrences over 64.2 months. Using univariate analysis, rate of visual field change (P<0.0001), VPP (P = 0.0069), alternative ocular perfusion pressure (CRADP-VPP, P = 0.0036), carotid resistance index (DiastBP-CRADP, P = 0.0108) and mean brachial blood pressure (P = 0.0203) were significantly associated with the number of disc haemorrhages. Using multivariate analysis, increased baseline visual field sensitivity (P = 0.0243, coefficient = 0.0275) was significantly associated with disc haemorrhage, in conjunction with higher VPP (P = 0.0029, coefficient = 0.0631), higher mean blood pressure (P = 0.0113, coefficient = 0.0190), higher carotid resistance index (P = 0.0172, coefficient = 0.0566), and rate of visual field loss (P<0.0001, coefficient = -2.0695).ConclusionsHigher VPP was associated with disc haemorrhage and implicates the involvement of venous pathology, but the effect size is small. Additionally, a greater carotid resistance index suggests that flow pathology in the ophthalmic or carotid arteries may be associated with disc haemorrhage.
| S-EPMC5536188 | biostudies-literature