Predicting the Glaucomatous Central 10-Degree Visual Field From Optical Coherence Tomography Using Deep Learning and Tensor Regression

PURPOSE

To predict the visual field (VF) of glaucoma patients within the central 10° from optical coherence tomography (OCT) measurements using deep learning and tensor regression.

DESIGN

Cross-sectional study.

METHODS

Humphrey 10-2 VFs and OCT measurements were carried out in 505 eyes of 304 glaucoma patients and 86 eyes of 43 normal subjects. VF sensitivity at each test point was predicted from OCT-measured thicknesses of macular ganglion cell layer + inner plexiform layer, retinal nerve fiber layer, and outer segment + retinal pigment epithelium. Two convolutional neural network (CNN) models were generated: (1) CNN-PR, which simply connects the output of the CNN to each VF test point; and (2) CNN-TR, which connects the output of the CNN to each VF test point using tensor regression. Prediction performance was assessed using 5-fold cross-validation through the root mean squared error (RMSE). For comparison, RMSE values were also calculated using multiple linear regression (MLR) and support vector regression (SVR). In addition, the absolute prediction error for predicting mean sensitivity in the whole VF was analyzed.

RESULTS

RMSE with the CNN-TR model averaged 6.32 ± 3.76 (mean ± standard deviation) dB. Significantly (P < .05) larger RMSEs were obtained with other models: CNN-PR (6.76 ± 3.86 dB), SVR (7.18 ± 3.87 dB), and MLR (8.56 ± 3.69 dB). The absolute mean prediction error for the whole VF was 2.72 ± 2.60 dB with the CNN-TR model.

CONCLUSION

The Humphrey 10-2 VF can be predicted from OCT-measured retinal layer thicknesses using deep learning and tensor regression.

Dynamic Scheimpflug Ocular Biomechanical Parameters in Untreated Primary Open Angle Glaucoma Eyes

Purpose

To characterize the corneal biomechanical properties of glaucoma eyes by comparing the dynamic Scheimpflug biomechanical parameters between untreated glaucoma and control eyes.

Methods

Cross-sectional observational data of dynamic Scheimpflug analyzer (Corvis ST) examinations were retrospectively collected from 35 eyes of 35 consecutive patients with untreated normal tension glaucoma and 35 eyes of 35 healthy patients matched on age and IOP. Ten biomechanical parameters were compared between the two groups using multivariable models adjusting for IOP, central corneal thickness, age, and axial length. The Benjamini-Hochberg method was used to correct for multiple comparison.

Results

In multivariable models, glaucoma was associated with smaller applanation 1 time (P < 0.001, coefficient = −0.5865), applanation 2 time (P = 0.012, coefficient = −0.1702), radius (P = 0.006, coefficient = −0.5447), larger peak distance (P = 0.011, coefficient = 0.1023), deformation amplitude ratio at 1 mm (P < 0.001, coefficient = 0.072), and integrated radius (P < 0.001, coefficient = 1.094). These associations consistently indicate greater compliance of the cornea in glaucoma eyes.

Conclusions

Untreated normal tension glaucoma eyes were more compliant than healthy eyes. The greater compliance (smaller stiffness) of normal tension glaucoma eyes may increase the risk of optic nerve damage. These results suggest the relevance of measuring biomechanical properties of glaucoma eyes.

Deep learning model to predict visual field in central 10° from optical coherence tomography measurement in glaucoma

BACKGROUND/AIM

To train and validate the prediction performance of the deep learning (DL) model to predict visual field (VF) in central 10° from spectral domain optical coherence tomography (SD-OCT).

METHODS

This multicentre, cross-sectional study included paired Humphrey field analyser (HFA) 10-2 VF and SD-OCT measurements from 591 eyes of 347 patients with open-angle glaucoma (OAG) or normal subjects for the training data set. We trained a convolutional neural network (CNN) for predicting VF threshold (TH) sensitivity values from the thickness of the three macular layers: retinal nerve fibre layer, ganglion cell layer+inner plexiform layer and outer segment+retinal pigment epithelium. We implemented pattern-based regularisation on top of CNN to avoid overfitting. Using an external testing data set of 160 eyes of 131 patients with OAG, the prediction performance (absolute error (AE) and R² between predicted and actual TH values) was calculated for (1) mean TH in whole VF and (2) each TH of 68 points. For comparison, we trained support vector machine (SVM) and multiple linear regression (MLR).

RESULTS

AE of whole VF with CNN was 2.84±2.98 (mean±SD) dB, significantly smaller than those with SVM (5.65±5.12 dB) and MLR (6.96±5.38 dB) (all, p<0.001). Mean of point-wise mean AE with CNN was 5.47±3.05 dB, significantly smaller than those with SVM (7.96±4.63 dB) and MLR (11.71±4.15 dB) (all, p<0.001). R² with CNN was 0.74 for the mean TH of whole VF, and 0.44±0.24 for the overall 68 points.

CONCLUSION

DL model showed considerably accurate prediction of HFA 10-2 VF from SD-OCT.

The usefulness of the Deep Learning method of variational autoencoder to reduce measurement noise in glaucomatous visual fields

The aim of the study was to investigate the usefulness of processing visual field (VF) using a variational autoencoder (VAE). The training data consisted of 82,433 VFs from 16,836 eyes. Testing dataset 1 consisted of test-retest VFs from 104 eyes with open angle glaucoma. Testing dataset 2 was series of 10 VFs from 638 eyes with open angle glaucoma. A VAE model to reconstruct VF was developed using the training dataset. VFs in the testing dataset 1 were then reconstructed using the trained VAE and the mean total deviation (mTD) was calculated (mTDVAE). In testing dataset 2, the mTD value of the tenth VF was predicted using shorter series of VFs. A similar calculation was carried out using a weighted linear regression where the weights were equal to the absolute difference between mTD and mTDVAE. In testing dataset 1, there was a significant relationship between the difference between mTD and mTDVAE from the first VF and the difference between mTD in the first and second VFs. In testing dataset 2, mean squared prediction errors with the weighted mTD trend analysis were significantly smaller than those form the unweighted mTD trend analysis.

Usefulness of data augmentation for visual field trend analyses in patients with glaucoma

AIM

To investigate the usefulness of data augmentation in visual field (VF) trend analyses in patients with glaucoma.

METHOD

This study included 6380 VFs from 638 eyes of 417 patients with open-angle glaucoma. Various affine transformations were applied to augment the VF data: (1) rotation, (2) scaling, (3) vertical and horizontal shift and (4) a combination of these different transformations. Using pointwise linear regression (PLR), the total deviation (TD) values of a patient's 10th VF were predicted using TD values from shorter VF series (from first to third VFs (VF1-3) to first to ninth VFs (VF1-9)) with and without VF data augmentation, and the root mean squared error (RMSE) was calculated.

RESULTS

With PLR, mean RMSE without VF augmentation averaged from 3.95 (VF1-3) to 19.01 (VF1-9) dB. The RMSE was significantly improved by applying the different transformations: (1) rotation (from VF1-3 to VF1-7), (2) scaling (from VF1-3 to VF1-6), (3) vertical and horizontal shifts (from VF1-3 to VF1-4) and (iv) a combination of these (from VF1-3 to VF1-7). Progression rates in VF1-10 had better agreement with those in shorter VF series when a combination of affine transformation was applied. The differences in rates were between 1.9 (VF1-3) and 0.39 (VF1-9) dB if augmentation was used, which was significantly smaller than that observed when augmentation was not applied (from 2.6 with VF1-3 to 0.26 dB with VF1-9).

CONCLUSION

It is useful to apply VF data augmentation techniques when predicting future VF progression in glaucoma using PLR, especially with short VF series.

Detection of Subclinical Corneal Ectasia Using Corneal Tomographic and Biomechanical Assessments in a Japanese Population

PURPOSE

To test the detection of subclinical corneal ectasia using integrated Scheimpflug tomography and biomechanical assessment in a Japanese population.

METHODS

This prospective, case-control study included 23 patients with very asymmetric ectasia (VAE) and 70 normal controls. Patients with VAE had defined clinical ectasia in one eye and a fellow eye with normal topography (VAE-NT). Objective topography for confirming normal topography in VAE-NT cases included having 0% similarity and 0% severity derived from Placido-disk based topography. Scheimpflug-based corneal tomography and corneal biomechanical assessment were performed. The Belin/Ambrósio Enhanced Ectasia Deviation index (BAD-D), Corvis Biomechanical Index (CBI), and Tomographic Biomechanical Index (TBI) were compared and their discriminating ability for detecting ectasia was assessed.

RESULTS

For differentiating normal and VAE-NT eyes, the areas under the receiver operating curve for the BAD-D, CBI, and TBI were 0.668, 0.660, and 0.751, respectively. The TBI cut-off of 0.259 provided 52.17% sensitivity and 88.57% specificity. Fourteen VAE-NT cases (60.9%) were abnormal in at least one of the criteria of the BAD-D > 1.60 (39.1%), CBI > 0.5 (26.1%), or TBI > 0.29 (43.5%). Conversely, nine VAE-NT cases (39.1%) exhibited normal values for the BAD-D, CBI, and TBI.

CONCLUSIONS

In the current study, 40% of VAE-NT eyes were classified as normal by the BAD-D, CBI, and TBI. Although some of these cases may truly represent unilateral ectasia, further advances are needed to enhance ectasia detection and characterize the susceptibility for ectasia progression. [J Refract Surg. 2019;35(6):383-390.].

Deep learning based noise reduction method for automatic 3D segmentation of the anterior of lamina cribrosa in optical coherence tomography volumetric scans

A deep-learning (DL) based noise reduction algorithm, in combination with a vessel shadow compensation method and a three-dimensional (3D) segmentation technique, has been developed to achieve, to the authors best knowledge, the first automatic segmentation of the anterior surface of the lamina cribrosa (LC) in volumetric ophthalmic optical coherence tomography (OCT) scans. The present DL-based OCT noise reduction algorithm was trained without the need of noise-free ground truth images by utilizing the latest development in deep learning of de-noising from single noisy images, and was demonstrated to be able to cover more locations in the retina and disease cases of different types to achieve high robustness. Compared with the original single OCT images, a 6.6 dB improvement in peak signal-to-noise ratio and a 0.65 improvement in the structural similarity index were achieved. The vessel shadow compensation method analyzes the energy profile in each A-line and automatically compensates the pixel intensity of locations underneath the detected blood vessel. Combining the noise reduction algorithm and the shadow compensation and contrast enhancement technique, medical experts were able to identify the anterior surface of the LC in 98.3% of the OCT images. The 3D segmentation algorithm employs a two-round procedure based on gradients information and information from neighboring images. An accuracy of 90.6% was achieved in a validation study involving 180 individual B-scans from 36 subjects, compared to 64.4% in raw images. This imaging and analysis strategy enables the first automatic complete view of the anterior LC surface, to the authors best knowledge, which may have the potentials in new LC parameters development for glaucoma diagnosis and management.

Validating the efficacy of the binomial pointwise linear regression method to detect glaucoma progression with multicentral database

BACKGROUND/AIM

We previously reported the benefit of applying binomial pointwise linear regression (PLR: binomial PLR) to detect 10-2 glaucomatous visual field (VF) progression. The purpose of the current study was to validate the usefulness of the binomial PLR to detect glaucomatous VF progression in the central 24°.

METHODS

Series of 15 VFs (Humphrey Field Analyzer 24-2 SITA-standard) from 341 eyes of 233 patients, obtained over 7.9±2.1 years (mean±SD), were investigated. PLR was performed by regressing the total deviation of all test points. VF progression was determined from the VF test points analyses using the binomial test (one side, p<0.025). The time needed to detect VF progression was compared across the binomial PLR, permutation analysis of PLR (PoPLR) and mean total deviation (mTD) trend analysis.

RESULTS

The binomial PLR was comparable with PoPLR and mTD trend analyses in the positive predictive value (0.18-0.87), the negative predictive value (0.89-0.95) and the false positive rate (0.057-0.35) to evaluate glaucomatous VF progression. The time to classify progression with binomial PLR (5.8±2.8 years) was significantly shorter than those with mTD trend analysis (6.7±2.8 years) and PoPLR (6.6±2.7 years).

CONCLUSIONS

The binomial PLR method, which detected glaucomatous VF progression in the central 24° significantly earlier than PoPLR and mTD trend analyses, shows promise for improving our ability to detect visual field progression for clinical management of glaucoma and in clinical trials of new glaucoma therapies.

Cross-Sectional Imaging Analysis of Epiretinal Membrane Involvement in Unilateral Open-Angle Glaucoma Severity

Purpose

To determine the relevance of epiretinal membranes (ERMs) in primary open-angle glaucoma (POAG) and potential risk for glaucoma severity.

Methods

Sixty eyes of 30 patients with POAG who had a unilateral ERM were analyzed; 60 nonglaucomatous eyes of 30 patients with a unilateral ERM also were recruited in this institutional cross-sectional study. Patients underwent swept-source (SS) optical coherence tomography (OCT) imaging and visual field testing. Intraindividual differences in the SS-OCT retinal nerve fiber layer (RNFL) disc cupping area measurements and visual field outcomes were analyzed in the two groups.

Results

In patients with POAG, the mean circumpapillary RNFL thickness in the eyes with an ERM was 75.6 ± 16.5 μm superiorly and 71.8 ± 26.0 inferiorly compared with the fellow eyes without an ERM (87.2 ± 23.6 μm, P = 0.0061 and 81.3 ± 27.7 μm, P = 0.034, respectively). The areas of disc cupping and cup-to-disc ratio seen on OCT horizontal and vertical B-scans were larger in eyes with an ERM than in the fellow eyes without ERM (P = 0.0004 and P = 0.0011, respectively). The average mean deviations were -11.6 ± 7.5 dB in the ERM group and -8.19 ± 6.4 dB in the group with no ERM (P = 0.029). Eyes with an ERM received more antiglaucoma eye drops (P = 0.018). Those differences were not seen between eyes with an ERM or fellow eyes in patients without glaucoma.

Conclusions

The presence of an ERM can be a potential risk factor for unilateral severity in eyes with POAG.

Using Deep Learning and Transfer Learning to Accurately Diagnose Early-Onset Glaucoma From Macular Optical Coherence Tomography Images

PURPOSE

We sought to construct and evaluate a deep learning (DL) model to diagnose early glaucoma from spectral-domain optical coherence tomography (OCT) images.

DESIGN

Artificial intelligence diagnostic tool development, evaluation, and comparison.

METHODS

This multi-institution study included pretraining data of 4316 OCT images (RS3000) from 1371 eyes with open angle glaucoma (OAG) regardless of the stage of glaucoma and 193 normal eyes. Training data included OCT-1000/2000 images from 94 eyes of 94 patients with early OAG (mean deviation > -5.0 dB) and 84 eyes of 84 normal subjects. Testing data included OCT-1000/2000 from 114 eyes of 114 patients with early OAG (mean deviation > -5.0 dB) and 82 eyes of 82 normal subjects. A DL (convolutional neural network) classifier was trained using a pretraining dataset, followed by a second round of training using an independent training dataset. The DL model input features were the 8 × 8 grid macular retinal nerve fiber layer thickness and ganglion cell complex layer thickness from spectral-domain OCT. Diagnostic accuracy was investigated in the testing dataset. For comparison, diagnostic accuracy was also evaluated using the random forests and support vector machine models. The primary outcome measure was the area under the receiver operating characteristic curve (AROC).

RESULTS

The AROC with the DL model was 93.7%. The AROC significantly decreased to between 76.6% and 78.8% without the pretraining process. Significantly smaller AROCs were obtained with random forests and support vector machine models (82.0% and 67.4%, respectively).

CONCLUSION

A DL model for glaucoma using spectral-domain OCT offers a substantive increase in diagnostic performance.

Validating Variational Bayes Linear Regression Method With Multi-Central Datasets

Purpose

To validate the prediction accuracy of variational Bayes linear regression (VBLR) with two datasets external to the training dataset.

Method

The training dataset consisted of 7268 eyes of 4278 subjects from the University of Tokyo Hospital. The Japanese Archive of Multicentral Databases in Glaucoma (JAMDIG) dataset consisted of 271 eyes of 177 patients, and the Diagnostic Innovations in Glaucoma Study (DIGS) dataset includes 248 eyes of 173 patients, which were used for validation.

Prediction accuracy was compared between the VBLR and ordinary least squared linear regression (OLSLR). First, OLSLR and VBLR were carried out using total deviation (TD) values at each of the 52 test points from the second to fourth visual fields (VFs) (VF2–4) to 2nd to 10th VF (VF2–10) of each patient in JAMDIG and DIGS datasets, and the TD values of the 11th VF test were predicted every time. The predictive accuracy of each method was compared through the root mean squared error (RMSE) statistic.

Results

OLSLR RMSEs with the JAMDIG and DIGS datasets were between 31 and 4.3 dB, and between 19.5 and 3.9 dB. On the other hand, VBLR RMSEs with JAMDIG and DIGS datasets were between 5.0 and 3.7, and between 4.6 and 3.6 dB. There was statistically significant difference between VBLR and OLSLR for both datasets at every series (VF2–4 to VF2–10) (P < 0.01 for all tests). However, there was no statistically significant difference in VBLR RMSEs between JAMDIG and DIGS datasets at any series of VFs (VF2–2 to VF2–10) (P > 0.05).

Conclusions

VBLR outperformed OLSLR to predict future VF progression, and the VBLR has a potential to be a helpful tool at clinical settings.

En Face Optical Coherence Tomography Imaging of Beta and Gamma Parapapillary Atrophy in High Myopia

PURPOSE

Recent studies have suggested that OCT-based classification of parapapillary atrophy (PPA) may be helpful in distinguishing glaucomatous from myopic optic disc changes. However, the pathologic implications of PPA may be different in highly myopic eyes that exhibit optic disc deformations distinct from low-to-moderate myopia. Therefore, we conducted the current study to investigate factors associated with OCT-defined PPA zones measured in en face reconstructed swept-source OCT (SS OCT) images in highly myopic eyes.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Seventy-seven eyes of 55 subjects with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥26.5 mm) were included. Forty-nine eyes of 33 subjects had open-angle glaucoma (MG group), and 28 eyes of 22 did not (M group).

METHODS

The beta zone and the gamma zone PPA areas were measured in en face images reconstructed from 3-dimensional SS OCT volumetric scans. Relationships between the PPA areas and patient characteristics such as glaucoma, axial length, and age were evaluated using multivariate mixed-effects models. The diagnostic capability of each PPA zone area for detecting glaucoma was assessed with the receiver operating characteristic (ROC) curve analysis. Main outcome measures were areas of the beta zone and the gamma zone PPA measured in en face OCT images and factors associated with each PPA area.

RESULTS

Average ± standard deviation area of the beta and the gamma zone was 1.1±1.1 and 1.1±1.1 mm². The gamma zone was positively correlated with axial length (P = 0.006) and age (P = 0.04951) but not with glaucoma (P = 0.776). The beta zone was positively correlated with both axial length (P = 0.039) and glaucoma (P = 0.011). The areas under the ROC curve of the beta zone and the gamma zone areas were 0.686 and 0.560, respectively.

CONCLUSIONS

The OCT-defined beta zone was associated with glaucoma and axial length, whereas the gamma zone was correlated with axial length but not with glaucoma, in highly myopic eyes. The OCT-based classification showed poor diagnostic performance for glaucoma. Relationships between PPA areas and baseline clinical factors may be different between high myopia and non-high myopia.

Anterior segment Scheimpflug imaging for detecting primary angle closure disease

PURPOSE

To evaluate the capability of anterior segment Scheimpflug imaging for detecting primary angle closure disease (PACD): primary angle closure suspect, primary angle closure, and primary angle closure glaucoma, using cutoff points derived from reference databases of healthy subjects.

METHODS

Eighty-seven patients with PACD and 49 age-matched control subjects were included. We evaluated the sensitivity and specificity of anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) to differentiate patients with PACD from controls. Additionally, the study's raw data was analyzed via receiver operating characteristic curves for comparison.

RESULTS

One standard deviation from the normative data's mean values was used as the cutoff point and yielded a sensitivity and specificity of 96.2% and 92.6% for ACD, 97.1% and 75.9% for ACV, and 93.3% and 72.2% for ACA, respectively. Receiver operating characteristic analysis of the raw data showed the area under the curve to be 0.984, 0.975, and 0.931 for ACD, ACV, and ACA, respectively.

CONCLUSIONS

Our study demonstrated that the parameters of anterior segment Scheimpflug imaging, particularly ACD, accurately discriminate PACD. This was the first study to validate the device's normative data in a separate population. With its high reproducibility, ease of use, non-invasiveness, and speed, anterior segment Scheimpflug imaging is a potentially powerful screening tool for PACD.

Early results of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with two and four courses of cisplatin/S-1 and docetaxel/cisplatin/S-1 as neoadjuvant chemotherapy for locally advanced gastric cancer

Background

Neoadjuvant chemotherapy (NAC) is a promising method of improving the survival of resectable gastric cancer. Cisplatin/S-1 (CS) and docetaxel/cisplatin/S-1 (DCS) are both effective against metastatic gastric cancer. This report clarified the impact of these regimens on early endpoints, including the pathological responses, chemotherapy-related toxicities, and surgical results.

Methods

Patients with M0 and either T4 or T3 in case of junctional cancer or scirrhous type received two or four courses of cisplatin (60 mg/m2 at day 8)/S-1 (80 mg/m2 for 21 days with 1 week rest) or docetaxel (40 mg/m2 at day 1)/cisplatin (60 mg/m2 at day 1)/S-1 (80 mg/m2 for 14 days with 2 weeks rest) as NAC. Patients then underwent D2 gastrectomy and adjuvant S-1 chemotherapy for 1 year. The primary endpoint was the 3-year overall survival.

Results

Between October 2011 and September 2014, 132 patients were assigned to receive CS (n = 66; 33 in 2 courses and 33 in 4 courses) or DCS (n = 66; 33 in 2 courses and 33 in 4 courses). The respective major grade 3 or 4 hematological toxicities (CS/DCS) were leukocytopenia (14.1%/26.2%), neutropenia (29.7%/47.7%), anemia (14.1%/12.3%), and platelet reduction (3.1%/1.5%). The rate of pathological response, defined as a complete response or < 10% residual cancer remaining, was 19.4% in the CS group and 15.4% in the DCS group, and 15.6% in the two-course group and 19.0% in the 4-course group. The R0 resection rate was 72.7% in the CS group and 81.8% in the DCS group and 80.3% in the two-course group and the 74.2% in the four-course group. No treatment-related deaths were observed.

Conclusions

Our results do not support three-drug therapy with a taxane over two-drug therapy, or any further treatment beyond two cycles as an attractive candidate for the test arm of NAC.

Measurement repeatability of the dynamic Scheimpflug analyzer

PURPOSE

To evaluate the repeatability of corneal deformation parameters measured using a dynamic Scheimpflug analyzer and the impact of baseline clinical factors on the repeatability of each parameter.

STUDY DESIGN

Retrospective, cross-sectional study.

METHODS

Forty-eight eyes (48 healthy subjects; mean age, 49.0 ± 19.5 years) underwent repeated examinations with the Scheimpflug analyzer to evaluate the test-retest variability. The intraclass correlation coefficient (ICC) and repeatability coefficient as indicators of variability were computed for 35 parameters measured with the Scheimpflug analyzer. The associations between the magnitude of the test-retest variability and baseline factors, such as age, axial length (AL), intraocular pressure (IOP), and central corneal thickness (CCT), were analyzed.

RESULTS

The test-retest repeatability was excellent for 22 (62.9%) of 35 parameters (ICC ≥ 0.75), good for seven (20%), (ICC ≥ 0.6), fair for four (11.4%), (ICC ≥ 0.4), and poor for two (5.7%) parameters (ICC < 0.4). Age was associated positively with the magnitude of variability in 13 (37.1%) parameters; measurement variability was affected significantly by AL (5 parameters, 14.3%) and CCT (7 parameters, 20%) but, except for one parameter not by IOP.

CONCLUSION

Most parameters of the dynamic Scheimpflug analyzer showed favorable measurement reliability in healthy subjects. However, six parameters showed poor-to-fair repeatability. Age, AL, and CCT significantly affected the repeatability of several parameters. These results should be considered when clinicians use this device in clinical practice.

Factors Associated With Corneal Deformation Responses Measured With a Dynamic Scheimpflug Analyzer

Purpose

The purpose of this study was to clarify correlations between corneal deformation parameters measured with a dynamic Scheimpflug analyzer and baseline factors such as axial length, intraocular pressure (IOP), age, central corneal thickness (CCT), and corneal curvature.

Methods

Ninety-six eyes of 96 healthy subjects (mean 55.2 ± 16.1 years of age) were examined using a dynamic Scheimpflug analyzer. Eighteen of 35 deformation parameters were selected for analyses based on measurement reliability and clinical relevance. The associations between corneal deformation parameters and axial length, IOP, age, CCT, and average corneal power were evaluated using multivariate regression analyses.

Results

Deformation parameters were correlated significantly with axial length (n = 13), IOP (n = 13), age (n = 8), and CCT (n = 6) in the multivariate models. Longer axial length corresponded with greater corneal deformability, less viscous damping, and less movement of the entire eye. Higher IOP was associated with greater corneal resistance and less movement of the entire eye. Older age was associated with less corneal deformability and greater movement of the entire eye. Corneal curvature was correlated significantly with only three deformation parameters.

Conclusions

This study clarified the substantial impact of axial length, age, and IOP on the biomechanical responses of the cornea and the entire eye. In contrast, corneal curvature did not affect most of the deformation parameters. The current results confirmed the importance of corneal biomechanics, especially in eyes with longer axial length and in older subjects.

Investigating the usefulness of a cluster-based trend analysis to detect visual field progression in patients with open-angle glaucoma

BACKGROUND/AIMS

To investigate the usefulness of the Octopus (Haag-Streit) EyeSuite's cluster trend analysis in glaucoma.

METHODS

Ten visual fields (VFs) with the Humphrey Field Analyzer (Carl Zeiss Meditec), spanning 7.7 years on average were obtained from 728 eyes of 475 primary open angle glaucoma patients. Mean total deviation (mTD) trend analysis and EyeSuite's cluster trend analysis were performed on various series of VFs (from 1st to 10th: VF1-10 to 6th to 10th: VF6-10). The results of the cluster-based trend analysis, based on different lengths of VF series, were compared against mTD trend analysis.

RESULT

Cluster-based trend analysis and mTD trend analysis results were significantly associated in all clusters and with all lengths of VF series. Between 21.2% and 45.9% (depending on VF series length and location) of clusters were deemed to progress when the mTD trend analysis suggested no progression. On the other hand, 4.8% of eyes were observed to progress using the mTD trend analysis when cluster trend analysis suggested no progression in any two (or more) clusters.

CONCLUSION

Whole field trend analysis can miss local VF progression. Cluster trend analysis appears as robust as mTD trend analysis and useful to assess both sectorial and whole field progression. Cluster-based trend analyses, in particular the definition of two or more progressing cluster, may help clinicians to detect glaucomatous progression in a timelier manner than using a whole field trend analysis, without significantly compromising specificity.

Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

OBJECTIVE

To measure the parapapillary atrophy (PPA) area in en face images obtained with swept-source optical coherence tomography (SS-OCT), and to evaluate its relationship to glaucoma, myopia, and age in non-highly myopic subjects.

DESIGN

Retrospective, cross-sectional study.

PARTICIPANTS

Fifty eyes of 30 subjects with open-angle glaucoma (G group) and forty-three eyes of 26 healthy control subjects (C group). Eyes with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥ 26.5 mm) were excluded.

METHODS

Mean age ± standard deviation was 59.9 ± 12.4 years. The beta zone and the gamma zone PPA areas were measured in en face images reconstructed from three-dimensional SS-OCT images. Relationship between the PPA areas and patient characteristics such as glaucoma, axial length, and age was statistically evaluated using multivariate mixed-effects models.

MAIN OUTCOME MEASURES

Areas of the beta zone and the gamma zone PPA measured on en face OCT images.

RESULTS

Average ± standard deviation area of the beta and the gamma zone was 0.64 ± 0.79 and 0.16 ± 0.30 mm2, respectively. In multivariate models, the gamma zone significantly correlated with axial length (P = 0.001) but not with glaucoma (P = 0.944). In contrast, the beta zone significantly correlated with age (P = 0.0249) and glaucoma (P = 0.014).

CONCLUSIONS

En face images reconstructed from 3D SS-OCT data facilitated measurements of the beta and the gamma PPA zones even in eyes with optic disc distortion. The OCT-defined beta zone is associated with glaucoma and age, whereas the gamma zone correlated with myopia but not with glaucoma. This study confirmed the clinical usefulness of OCT-based classification of the PPA zones in distinguishing glaucomatous damage of the optic nerve from myopic damage in non-highly myopic eyes.

Clinical characteristics and outcomes of adenovirus infection of the urinary tract after renal transplantation

BACKGROUND

Urinary tract infection caused by human adenovirus (HAdV) after renal transplantation (RT) results in graft loss because of concomitant nephropathy and acute rejection and may result in death because of systemic dissemination.

METHODS

We assessed the time period between RT and disease onset, symptoms, treatment details, disease duration, renal graft function, outcomes, and complications.

RESULTS

HAdV infection of the urinary tract occurred in 8 of 170 renal transplant recipients. Symptoms were macrohematuria in all 8 patients, dysuria in 7, and fever in 5. The median period from RT to disease onset was 367 (range, 7-1763) days, and the median disease duration was 15 (range, 8-42) days. The mean serum creatinine (sCr) level prior to onset was 1.35 ± 0.48 mg/dL and the mean maximum sCr level during disease was 2.34 ± 1.95 mg/dL. These values were increased by ≥25% in 5 patients. The mean sCr levels when symptoms resolved was 1.54 ± 0.67 mg/dL, and no significant difference was seen before, during, or after disease onset (P = 0.069). Two patients were diagnosed with HAdV viremia and 1 with acute tubulointerstitial nephritis revealed on biopsy. In addition to a reduction in immunosuppressant dosage, 2 patients received gammaglobulins and 5 received ganciclovir.

CONCLUSION

Symptoms of all patients were alleviated, although some patients developed nephritis or viremia. Hence, the possibility of exacerbation should always be considered. Adequate follow-up observation should be conducted, and diligent and aggressive therapeutic intervention is required to prevent the condition from worsening.

Effects of ocular and systemic factors on the progression of glaucomatous visual field damage in various sectors

BACKGROUND/AIM

To investigate the effects of ocular and systemic risk factors for glaucomatous progression in different sectors of the visual field (VF).

METHOD

409 eyes from 268 patients with 10 reliable VFs from the Japanese Archive of Multicentral Databases in Glaucoma (JAMDIG) were investigated. VFs were divided into six sectors (mean total deviation (mTD)_s20+, mTD_s10-20 and mTD_s0-10, >20°, 10-20° and <10° in the superior hemifield, respectively; and mTD_i20+, mTD_i10-20 and mTD_i0-10, >20°, 10-20° and <10° in the inferior hemifield, respectively). The relationship between sectorial progression rate and eight variables (age, mTD at baseline VF, average intraocular pressure (IOP), SD of IOP, systemic hypertension, migraine, family history of glaucoma and smoking status) was investigated.

RESULT

The mTD progression rate was -0.21 dB/year. Older age was related to progression of mTD_s20+, mTD_s10-20, mTD_i20+ and mTD_i10-20. Mean IOP was not related to progression in any VF sector; however, a larger SD of IOP was related to progression of mTD_s20+, mTD_i0-10, mTD_i10-20 and mTD_i20+. Smoking status was related to progression in all inferior VF sectors (mTD_i0-10, mTD_i10-20 and mTD_i20+).

CONCLUSIONS

Smoking status is related to glaucomatous VF progression in all sectors of the inferior hemifield.

Evaluation of Glaucoma Progression in Large-Scale Clinical Data: The Japanese Archive of Multicentral Databases in Glaucoma (JAMDIG)

PURPOSE

To develop a large-scale real clinical database of glaucoma (Japanese Archive of Multicentral Databases in Glaucoma: JAMDIG) and to investigate the effect of treatment.

METHODS

The study included a total of 1348 eyes of 805 primary open-angle glaucoma patients with 10 visual fields (VFs) measured with 24-2 or 30-2 Humphrey Field Analyzer (HFA) and intraocular pressure (IOP) records in 10 institutes in Japan. Those with 10 reliable VFs were further identified (638 eyes of 417 patients). Mean total deviation (mTD) of the 52 test points in the 24-2 HFA VF was calculated, and the relationship between mTD progression rate and seven variables (age, mTD of baseline VF, average IOP, standard deviation (SD) of IOP, previous argon/selective laser trabeculoplasties (ALT/SLT), previous trabeculectomy, and previous trabeculotomy) was analyzed.

RESULTS

The mTD in the initial VF was -6.9 ± 6.2 dB and the mTD progression rate was -0.26 ± 0.46 dB/year. Mean IOP during the follow-up period was 13.5 ± 2.2 mm Hg. Age and SD of IOP were related to mTD progression rate. However, in eyes with average IOP below 15 and also 13 mm Hg, only age and baseline VF mTD were related to mTD progression rate.

CONCLUSIONS

Age and the degree of VF damage were related to future progression. Average IOP was not related to the progression rate; however, fluctuation of IOP was associated with faster progression, although this was not the case when average IOP was below 15 mm Hg.

Ethnic specific association of the CAV1/CAV2 locus with primary open-angle glaucoma

A single-nucleotide polymorphism (SNP) rs4236601 at the CAV1/CAV2 locus is associated with primary open-angle glaucoma (POAG). Rs4236601 is common in Caucasians but rare in East Asians. Here we conducted a haplotype-tagging SNP analysis followed by replication in a total of 848 POAG cases and 1574 controls drawn from 3 cities in China and 1 city in Japan. Two SNPs, rs4236601 (odds ratio [OR] = 6.25; P = 0.0086) and a tagging-SNP rs3801994 (OR = 1.32; P = 0.042), were associated with POAG in the Hong Kong Chinese cohort after age and gender adjustments. Rs4236601 was associated with POAG also in Shantou (OR = 6.09; P = 0.0037) and Beijing (OR = 3.92; P = 0.030) cohorts after age and gender adjustment, with a pooled-OR of 5.26 (P = 9.0 × 10(-6)) in Chinese; but it is non-polymorphic in the Osaka cohort. SNP rs3801994 showed a similar trend of effect in the Shantou and Beijing cohorts, with a pooled-OR of 1.23 (P = 0.022) and 1.20 (P = 0.063) in Chinese, prior to and after age and gender adjustment, respectively; but it showed a reverse effect in the Osaka cohort (OR = 0.58; P = 0.033) after the adjustments. We have thus confirmed the association of rs4236601 with POAG in different Chinese cohorts. Also, we found a common SNP rs3801994 of diverse associations with POAG between Chinese and Japanese.