We investigated birefringence-derived scleral artifacts in optical coherence tomography (OCT) images of eyes with pathologic myopia. This study included 76 eyes of 42 patients with pathologic myopia. ...Five sets of OCT B-scan images of the macula were obtained using commercial swept-source OCT. A dataset of prototype swept-source polarization-diversity OCT images was used to identify polarization-dependent OCT images (i.e., complex averaging of OCT signals from two polarization channels) and polarization-independent OCT images (i.e., intensity averaging of two OCT signals). Polarization-dependent OCT images and commercial OCT images were assessed for the presence of birefringence-derived artifacts by comparison with polarization-independent OCT images. Both polarization-dependent OCT images and commercial OCT images contained scleral vessel artifacts. Scleral vessel artifacts were present in 46 of 76 eyes (60.5%) imaged by polarization-dependent OCT and 17 of 76 eyes (22.4%) imaged by commercial OCT. The proportion of images that showed scleral vessel artifacts was significantly greater among polarization-dependent OCT images than among commercial OCT images (P < 0.001). Additionally, polarization-dependent OCT images showed low-intensity band artifacts. This study demonstrated the existence of birefringence-derived scleral artifacts in commercial OCT images and indicated that polarization-diversity OCT is an effective tool to evaluate the presence of these artifacts.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To evaluate the biologic efficacy of intravitreal bevacizumab (IVB) for iris neovascularization (INV) or neovascular glaucoma (NVG) in patients with ischemic retinal disorders.
Retrospective, ...consecutive, interventional case series.
Thirty patients (41 eyes) with INV or NVG secondary to ischemic retinal disorders.
Patients received IVB (1 mg) as the initial treatment for INV or NVG and were followed up for at least 6 months. Ophthalmic evaluations included measurement of visual acuity and intraocular pressure (IOP), a complete ophthalmic examination, and fluorescein angiography. Patients were divided into 3 subgroups: INV without elevated IOP (INV group), NVG with an open angle (O-NVG group), and NVG with angle closure (C-NVG group) for outcomes analysis.
The controllability of IOP by IVB, incidence of recurrence, and requirement for surgery to treat NVG.
No significant ocular or systemic adverse events developed during follow-up (range, 6-22 months; mean, 13.3 months). The mean IOP levels were 14.7, 31.2, and 44.9 mmHg at baseline in the INV, O-NVG, and C-NVG groups, respectively. In the INV group (9 eyes), the INV regressed or resolved after 1 injection. Iris neovascularization recurred in 4 eyes by 6 months and stabilized after repeated injections without IOP elevation. In the O-NVG group (17 eyes), rapid neovascular regression with successful IOP normalization (<or=21 mmHg) occurred in 12 eyes (71%) within 1 week after 1 injection. Five (29%) of the 17 eyes required surgery by 6 months despite repeated IVB injections, and a total of 7 eyes (41%) underwent surgery during follow-up. In the C-NVG group (15 eyes), IVB caused INV resolution but failed to lower the IOP. Fourteen (93%) of 15 eyes required surgery by 2 months after initial IVB and achieved IOP stabilization. The mean interval between IVB and surgery was significantly shorter in the C-NVG group than in the O-NVG group (P<0.001).
Intravitreal bevacizumab is well tolerated, effectively stabilized INV activity, and controlled IOP in patients with INV alone and early-stage NVG without angle closure. In advanced NVG, IVB cannot control IOP but may be used adjunctively to improve subsequent surgical results. Further evaluation in controlled randomized studies is warranted.
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 (mTD
). 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 mTD
. In testing dataset 1, there was a significant relationship between the difference between mTD and mTD
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.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To evaluate the usefulness of the application of the clustering method to the trend analysis (sectorwise regression) in comparison with the pointwise linear regression (PLR).
This study included 153 ...eyes of 101 patients with open-angle glaucoma. With PLR, the total deviation (TD) values of the 10th visual field (VF) were predicted using the shorter VF sequences (from first 3 to 9) by extrapolating TD values against time in a pointwise manner. Then, 68 test points were stratified into 29 sectors. In each sector, the mean of TD values was calculated and allocated to all test points belonging to the sector. Subsequently, the TD values of the 10th VF were predicted by extrapolating the allocated TD value against time in a pointwise manner. Similar analyses were conducted to predict the 11th-16th VFs using the first 10 VFs.
When predicting the 10th VF using the shorter sequences, the mean absolute error (MAE) values were significantly smaller in the sectorwise regression than in PLR. When predicting from the 11th and 16th VFs using the first 10 VFs, the MAE values were significantly larger in the sectorwise regression than in PLR when predicting the 11th VF; however, no significant difference was observed with other VF predictions.
Accurate prediction was achieved using the sectorwise regression, in particular when a small number of VFs were used in the prediction. The accuracy of the sectorwise regression was not hampered in longer follow-up compared with PLR.
Purpose
To evaluate the corneal biomechanical features of eyes with granular corneal dystrophy type 2 (GCD2) by analyzing corneal biomechanical indices obtained using a Corvis ST (CST) dynamic ...ultra-high-speed Scheimpflug imaging device.
Methods
In this retrospective case–control study, 35 CST parameters were compared in normal eyes (control) and eyes of patients with GCD2 treated at Osaka University Hospital, Osaka, Japan. The parameters included the Corvis Biomechanical Index (CBI), which is important in differentiating eyes with keratoconus from normal eyes. We measured the deposition rates of lesions in the central 7-mm region of the eye and assessed the correlation between the deposition rate and the CBI.
Results
Twenty-one eyes with GCD2 and 23 control eyes were analyzed. Eyes with GCD2 showed significantly less corneal stiffness in 15 CST parameters than did control eyes. In particular, the CBI was remarkably higher in eyes with GCD2 than in control eyes (
P
= 0.000006). Additionally, the deposition rate and the CBI were positively correlated.
Conclusions
GCD2 eyes had softer corneas than did control eyes in most biomechanical CST parameters, and one of the parameters (the CBI) was linked to the rate of deposited lesions. Since IOP may be underestimated in GCD2 eyes, management should be especially careful in GCD2 cases complicated by glaucoma.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
To determine whether focal abnormalities of the lamina cribrosa (LC) are present in glaucomatous eyes with localized retinal nerve fiber layer (RNFL) defects.
Cross-sectional, observational study.
We ...analyzed 20 eyes of 14 subjects with localized RNFL defects detected by masked grading of stereophotographs and 40 eyes of 25 age-matched healthy subjects recruited from the Diagnostic Innovations in Glaucoma Study at the University of California, San Diego.
All eyes had stereoscopic optic disc photography and in vivo LC imaging using enhanced depth imaging optical coherence tomography (EDI-OCT). Two masked graders identified focal LC defects defined by a standardized protocol using 48 radial scan EDI-OCT images. The kappa coefficient was calculated as a measure of the reliability of interobserver agreement.
The number of focal LC defects and the relationship between the location of LC defects and the location of localized RNFL defects.
Of 20 eyes with a localized RNFL defect, 15 (75%) had ≥1 LC defect compared with only 1 of 40 healthy eyes (3%). There were 13 eyes with localized RNFL defects that had 1 LC defect, 1 eye with 2 LC defects, and 1eye with 3 LC defects. The largest area LC defect was present in a radial line EDI-OCT scan corresponding with a localized RNFL defect in 13 of 15 eyes (87%). There was good agreement between graders as to whether an eye had an LC defect (kappa = 0.87; 95% confidence interval CI, 0.73-1.00; P<0.001) and the location of the largest defect (kappa = 0.72; 95% CI, 0.44-1.00; P<0.001).
Focal defects of the LC were frequently visible in glaucomatous eyes with localized RNFL defects. Focal abnormalities of the LC may be associated with focal retinal nerve fiber damage.
PURPOSE:To evaluate the efficacy of selective laser trabeculoplasty (SLT) for patients with open-angle glaucoma receiving maximal-tolerable medical therapy.
PATIENTS AND METHODS:Consecutive patients ...with open-angle glaucoma who were followed up for at least 1 year after SLT were retrospectively evaluated. The effectiveness was assessed using Kaplan-Meier survival analysis with 2 criteria for failure(1) intraocular pressure (IOP) equal to or more than baseline; and (2) <20% reduction from baseline, on 2 consecutive visits. Those 2 failure criteria also included loss of light perception, reoperation of SLT, and glaucoma surgery. Influence of baseline factors on success were assessed using mixed-effects Cox proportional hazard models.
RESULTS:Seventy-five eyes 39 primary open-angle glaucoma, 23 exfoliation glaucoma, and 13 secondary open-angle glaucoma (SOAG) of 59 patients (21 females) aged 65.5±15.9 (mean±SD) were included. Preoperative mean IOP was 23.3±6.5 mm Hg with 3.4±1.3 IOP lowering medications. The overall success ratio at the end of study period was 45.3% by criterion 1 and 14.2% by criterion 2. The success ratio by criterion 1 and 2 was 61.1% and 21.7% in primary open-angle glaucoma, 29.3% and 14.5% in exfoliation glaucoma, and 15.4% and 7.7% in SOAG, respectively. Higher preoperative IOP and diagnosis of SOAG were significantly associated with treatment failure (P<0.01 and 0.04, respectively).
CONCLUSIONS:One-year efficacy of SLT in controlling IOP was very limited in patients with maximal-tolerable medical therapy. Types of glaucoma and preoperative IOP were significant prognostic factors for treatment success.
Purpose
To evaluate changes in refractive error and corneal tomographic measurements after 24-h monitoring of intraocular pressure patterns with a contact lens sensor (CLS).
Study design
Prospective, ...longitudinal, observational study.
Patients and methods
Fourteen eyes of 14 consecutive patients who underwent 24-h CLS monitoring were enrolled. The objective spherical equivalent (SE) refractive error was measured using automated refraction and keratometry. The axial power, instantaneous power, and corneal thickness at the central, paracentral, midperipheral, and peripheral cornea were measured with swept-source anterior-segment optical coherence tomography. Measurements were performed at baseline, immediately after monitoring, and at follow-up visits 2–4 days after monitoring.
Results
The myopic SE increased significantly (
P
< 0.001) from − 5.1 ± 4.2 to − 6.0 ± 4.0, D after 24-h monitoring with a CLS and returned to the premonitoring level at the second visit (− 5.3 ± 4.4 D,
P
= 0.315). Decreases in the midperipheral and peripheral axial powers and the paracentral instantaneous power and increases in the central instantaneous power and peripheral corneal thickness occurred after CLS monitoring.
Conclusion
Twenty-four-hour monitoring with a CLS resulted in significant increases in the myopic refractive error and corneal central steepening and midperipheral flattening. Although these changes are transient and do not negate the clinical merits of the CLS, clinicians should be aware of these potential adverse events. Three-dimensional evaluation of corneal deformation with anterior segment optical coherence tomography is a powerful tool for assessing and improving the safety, tolerability, and accuracy of CLS devices.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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.
Trend analysis of visual field (VF) global indices may underestimate the rate of progression in severe glaucoma because of the influence of test points without detectable sensitivity. To test this ...hypothesis, we compared the rates of change of VF global indices with and without exclusion of undetectable points at various disease stages.
Six hundred and forty-eight eyes of 366 glaucoma patients with 8 or more reliable 30-2 standard automated perimetry over more than 2 years were enrolled. We calculated targeted mean total deviation (TMTD) by averaging total deviation except points which were consistently undetectable in 3 baseline tests. Eyes were classified as early (≥-6 dB), moderate (-6 dB to -12 dB), advanced (-12 dB to -20 dB), and severe (<-20 dB) based on baseline mean deviation (MD). The rates of change of MD and TMTD in each stage were statistically compared.
Mean age±SD at baseline was 56.9±11.9 years. The MD slope (-0.34 dB/y) in severe glaucoma was significantly slower than TMTD slope (-0.42 dB/y, P=0.028) and was slower than MD slopes in the other stages. Difference between MD slopes and TMTD slopes was most prominent in eyes with MD values less than -25 dB (P=0.002).
Undetectable locations in eyes with severe glaucoma may underestimate the rates of VF progression. Trend analysis of TMTD rather than global indices offers a practical and simple approach for alleviating underestimation of VF progression in severe glaucoma.
PDF
