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COMPARISON OF THE INTERNAL LIMITING MEMBRANE INSERTION TECHNIQUE AND THE INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE WITH VITRECTOMY TO TREAT MACULAR HOLE-ASSOCIATED RETINAL DETACHMENT.
Zhu, K, Lei, B, Wong, W, Zhang, J, Guo, Y, Chen, H, Song, F, Chang, Q, Xu, G, Zhang, Y
Retina (Philadelphia, Pa.). 2021;(1):37-44
Abstract
PURPOSE To compare the anatomical and functional outcomes of macular hole (MH)-associated retinal detachment after vitrectomy with the internal limiting membrane (ILM) insertion technique or the inverted ILM flap technique. METHODS In this retrospective observational study, we reviewed the medical records of 49 eyes with MH-associated retinal detachment that underwent vitrectomy with the ILM insertion (26 eyes) or ILM flap (23 eyes) technique. RESULTS The MH closure rate at 12 months was greater in the ILM flap group versus the ILM insertion group (95% vs. 73%, respectively, P = 0.059). The postoperative best-corrected visual acuity (BCVA) at 12 months was significantly better in the ILM flap group (P = 0.014). All eyes (100%) showed an improvement in the BCVA of ≥0.3 logarithm of the minimum angle of resolution (15 Early Treatment Diabetic Retinopathy Study letters) in the ILM flap group versus 20 eyes (77%) in the ILM insertion group (P = 0.026). The preoperative BCVA and the ILM flap technique were significantly correlated with the postoperative BCVA (P = 0.028 and 0.027, respectively) and BCVA improvement (≥0.3 logarithm of the minimum angle of resolution [15 Early Treatment Diabetic Retinopathy Study letters]; P = 0.003 and 0.026, respectively). CONCLUSION The inverted ILM flap technique was more effective in improving the postoperative BCVA in patients with MH-associated retinal detachment when compared with the ILM insertion technique. The preoperative BCVA and the ILM flap technique were independent prognostic factors for visual outcomes in patients with MH-associated retinal detachment.
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Automated Deformation-Based Analysis of 3D Optical Coherence Tomography in Diabetic Retinopathy.
Khansari, MM, Zhang, J, Qiao, Y, Gahm, JK, Sarabi, MS, Kashani, AH, Shi, Y
IEEE transactions on medical imaging. 2020;(1):236-245
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Abstract
Diabetic retinopathy (DR) is a significant microvascular complication of diabetes mellitus and a leading cause of vision impairment in working age adults. Optical coherence tomography (OCT) is a routinely used clinical tool to observe retinal structural and thickness alterations in DR. Pathological changes that alter the normal anatomy of the retina, such as intraretinal edema, pose great challenges for conventional layer-based analysis of OCT images. We present an alternative approach for the automated analysis of OCT volumes in DR research based on nonlinear registration. In this paper, we first obtain an anatomically consistent volume of interest (VOI) in different OCT images via carefully designed masking and affine registration. After that, efficient B-spline transformations are computed using stochastic gradient descent optimization. Using the OCT volumes of normal controls, for which layer-based segmentation works well, we demonstrate the accuracy of our registration-based analysis in aligning layer boundaries. By nonlinearly registering the OCT volumes of DR subjects to an atlas constructed from normal controls and measuring the Jacobian determinant of the deformation, we can simultaneously visualize tissue contraction and expansion due to DR pathology. Tensor-based morphometry (TBM) can also be performed for quantitative analysis of local structural changes. In our experimental results, we apply our method to a dataset of 105 subjects and demonstrate that volumetric OCT registration and TBM analysis can successfully detect local retinal structural alterations due to DR.
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3D Retinal Vessel Density Mapping With OCT-Angiography.
Sarabi, MS, Khansari, MM, Zhang, J, Kushner-Lenhoff, S, Gahm, JK, Qiao, Y, Kashani, AH, Shi, Y
IEEE journal of biomedical and health informatics. 2020;(12):3466-3479
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Abstract
Optical Coherence Tomography Angiography (OCTA) is a novel, non-invasive imaging modality of retinal capillaries at micron resolution. Recent studies have correlated macular OCTA vascular measures with retinal disease severity and supported their use as a diagnostic tool. However, these measurements mostly rely on a few summary statistics in retinal layers or regions of interest in the two-dimensional (2D) en face projection images. To enable 3D and localized comparisons of retinal vasculature between longitudinal scans and across populations, we develop a novel approach for mapping retinal vessel density from OCTA images. We first obtain a high-quality 3D representation of OCTA-based vessel networks via curvelet-based denoising and optimally oriented flux (OOF). Then, an effective 3D retinal vessel density mapping method is proposed. In this framework, a vessel density image (VDI) is constructed by diffusing the vessel mask derived from OOF-based analysis to the entire image volume. Subsequently, we utilize a non-linear, 3D OCT image registration method to provide localized comparisons of retinal vasculature across subjects. In our experimental results, we demonstrate an application of our method for longitudinal qualitative analysis of two pathological subjects with edema during the course of clinical care. Additionally, we quantitatively validate our method on synthetic data with simulated capillary dropout, a dataset obtained from a normal control (NC) population divided into two age groups and a dataset obtained from patients with diabetic retinopathy (DR). Our results show that we can successfully detect localized vascular changes caused by simulated capillary loss, normal aging, and DR pathology even in presence of edema. These results demonstrate the potential of the proposed framework in localized detection of microvascular changes and monitoring retinal disease progression.
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Region-specific ischemia, neovascularization and macular oedema in treatment-naïve proliferative diabetic retinopathy.
Lange, J, Hadziahmetovic, M, Zhang, J, Li, W
Clinical & experimental ophthalmology. 2018;(7):757-766
Abstract
IMPORTANCE Region-specific pathology in proliferative diabetic retinopathy enhances our understanding and management of this disease. BACKGROUND To investigate non-perfusion, neovascularization and macular oedema. DESIGN A cross-sectional, observational, non-randomized study. PARTICIPANTS Consecutive 43 eyes of 27 treatment-naïve patients. METHODS Ultra-widefield fluorescein angiography for studying specific zones, that is, far-peripheral zone, mid-peripheral zone and central retina (cr), and spectral-domain optical coherence tomography for analysing thickness of macular layers. MAIN OUTCOME MEASURES Non-perfusion index (NPI) and neovascularization index (NVI) in different zones, thickness of cr, retinal nerve fibre layer, ganglion cell layer (GCL), inner nuclear layer (INL) and outer plexiform layer in parafoveal regions. RESULTS The NPI of far-periphery and NVI of mid-periphery were the highest by one-way analysis of variance testing. Ischemic retina defined as high NPI in far-periphery was significantly related to macular oedema via a binary classification approach (P < 0.05). The ischemic retina was correlated with a decreased thickness of both retinal nerve fibre and GCL (P < 0.05); macular oedema was correlated with increased INL thickness (P < 0.0001). CONCLUSIONS AND RELEVANCE The region-specific correlation of NPI of far-periphery and NVI of mid-periphery, but not with central retinal thickness, suggests different pathogeneses of neovascularization and macular oedema. Retinal nerve fibre layer and GCL, both biomarkers of diabetic retinal neuronopathy, are associated with retinal ischemia, but not with macular oedema, suggesting that diabetic microangiopathy and neuronopathy possess distinct pathogenic pathways. The strong correlation between macular oedema and INL indicates that intracellular oedema is a determining factor of diabetic macular oedema.
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The Clinical Importance of Changes in Diabetic Retinopathy Severity Score.
Ip, MS, Zhang, J, Ehrlich, JS
Ophthalmology. 2017;(5):596-603
Abstract
PURPOSE To investigate the clinical importance of changes in diabetic retinopathy severity score (DRSS) in patients with diabetic macular edema (DME) treated with intravitreal ranibizumab. DESIGN Post hoc analysis of the phase III RIDE and RISE studies of ranibizumab for treatment of DME. PARTICIPANTS Four hundred sixty-eight eyes treated with ranibizumab from randomization with gradable DRSS on baseline fundus photographs. METHODS Visual and anatomic outcomes were examined in eyes grouped according to DRSS change from baseline to month 24. MAIN OUTCOME MEASURES Mean best-corrected visual acuity (BCVA) letter score change, proportion of patients with 15 or more Early Treatment Diabetic Retinopathy Study (ETDRS) letter score change, mean contrast sensitivity change, proportion of patients with resolved macular edema, and leakage on fluorescein angiography. RESULTS Most (56.8%) patients treated with ranibizumab experienced 1-step or more improvement in DRSS from baseline to month 24; 40.0% had no change, and 3.2% experienced DRSS worsening. Patients with DRSS stability or improvement had greater mean BCVA letter score changes (+15.1, +14.2, +11.3, and +11.2 letters for ≥3-step improvement, ≥2-step improvement, 1-step improvement, and no DRSS change, respectively) compared with +5.0 letters in patients who had any DRSS worsening. Best-corrected visual acuity letter score gain of 15 letters or more was more common in patients with 2-step or 3-step or more DRSS improvement (51.9% and 44.6%, respectively) compared with those with a 1-step DRSS improvement, no change, or worsening (37.9%, 39.6%, and 26.7%, respectively). A loss of 15 letters or more in BCVA was more common in patients with any DRSS worsening (13.3%) compared with patients who had stable or improved DRSS (0%-2.8%). Resolution of macular edema was more common in patients with DRSS improvement: 84.2%, 87.7%, and 92.3% of patients with 1-step, 2-step or more, and 3-step or more improvement in DRSS achieved central foveal thickness of 250 μm or less, compared with 65.2% and 53.3% of patients who had no DRSS change or any DRSS worsening. CONCLUSIONS These findings provide further support that improvement in DRSS is a clinically important outcome that should be evaluated as a measure of treatment effectiveness in future studies of diabetic eye disease.