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1.
OCT Angiography of the Central Macular Capillary Network in Glaucoma Patients and Healthy Controls.
Müller, O, Todorova, MG, Schlote, T
Klinische Monatsblatter fur Augenheilkunde. 2018;(4):436-444
Abstract
PURPOSE We aimed to investigate central macular microvasculature by optical coherence tomography angiography (OCTA) and to analyse its relation to alterations in classical parameters of optical coherence tomography (OCT) in glaucoma patients. METHODS Using OCTA (Avanti incl. AngioVue; Optovue, Inc., Fremont, CA), the superficial flow (SF) and the superficial non-flow (SNF) area of the macula, as well as the S-ETDRS (based on Early Treatment Diabetic Retinopathy charts). and S-grid vessel density (zones 1 - 9) of the macula, were evaluated in 27 glaucoma patients (49 eyes) and compared to those of 27 age-matched healthy controls (50 eyes; p = 0.253). The interactions between OCTA parameters representing macular microvasculature and classical OCT measurements of the circumpapillary retinal nerve fibre layer (RNFL) and macular ganglion cells (mGCC) were analysed within groups (linear mixed-effects model). RESULTS SF, SNF, and S-ETDRS vessel density exhibited no significant difference between the glaucoma and control groups (all p ≥ 0.158). However, within the glaucoma group, decreased RNFL and mGCC thickness correlated significantly with decreased S-ETDRS density (zones 1; 2 - 9, p ≤ 0.033). The same held true for the interactions between the RNFL and mGCC thickness with S-grid density (zones 1 - 3; 6 - 9; p ≤ 0.033). For perimetric glaucoma patients, subgroup analyses demonstrated significantly reduced density maps of superficial foveal flow as well as significant interactions between OCT and OCTA parameters; this was not the case within the preperimetric group. CONCLUSIONS Even if the central macular microvasculature, as measured by SF and SNF, is found preserved in glaucoma, the strong positive relation between the central microvascular and structural changes in OCTA and OCT indicates that there are alterations in central macular microvasculature in subclinical glaucoma.
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2.
INFLUENCE OF VITRECTOMY SURGERY ON THE INTEGRITY OF OUTER RETINAL LAYERS IN DIABETIC MACULAR EDEMA.
Uji, A, Murakami, T, Suzuma, K, Yoshitake, S, Arichika, S, Ghashut, R, Fujimoto, M, Yoshimura, N
Retina (Philadelphia, Pa.). 2018;(1):163-172
Abstract
PURPOSE To investigate the influence of pars plana vitrectomy (PPV) on the integrity of photoreceptor layers in eyes with diabetic macular edema (DME) by using parallelism (a parameter that comprehensively reflects photoreceptor-retinal pigment epithelium [RPE] complex alterations) in spectral-domain optical coherence tomography (SD-OCT) imaging. METHODS A consecutive series of 64 eyes in 55 patients with diabetic macular edema who underwent pars plana vitrectomy were recruited into the study. Spectral-domain optical coherence tomography images were obtained preoperatively and 6 months after surgery. The morphologic features of the outer retinal layers were assessed quantitatively using parallelism and qualitatively by graders, including continuity of the external limiting membrane (ELM) line, continuity of the photoreceptor inner and outer segment (IS/OS) junction line, and the presence of hyperreflective foci in the outer retinal layers. The relationships between parallelism, visual acuity (VA), and photoreceptor layer status were evaluated. RESULTS After surgery, foveal thickness significantly decreased (P < 0.0001) and visual acuity improved (P < 0.0001) from baseline level. Postoperative parallelism (0.632 ± 0.137) was significantly higher than preoperative parallelism (0.531 ± 0.172) (P < 0.0001). A number of eyes with hyperreflective foci reduced after surgery, while separate evaluation of the inner and outer segment junction and external limiting membrane lines did not show significant changes. Moreover, preoperative and postoperative parallelism values showed significant correlations with postoperative visual acuity and serum lipid levels. Foveal thickness and logMAR visual acuity did not show significant correlations with any blood test data. CONCLUSION Pars plana vitrectomy might be effective for resolution of hyperreflective foci in outer retinal layers. Parallelism is a potential marker for localization of hyperreflective foci and useful as a predictive factor for postoperative visual acuity.
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3.
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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4.
New insights into diabetic retinopathy by OCT angiography.
Liu, G, Xu, D, Wang, F
Diabetes research and clinical practice. 2018;:243-253
Abstract
Diabetic retinopathy (DR) is one of the most common diabetic complications, which has become a leading cause for vision loss, mainly because of macular edema and vitreous hemorrhage. Optical coherence tomography (OCT) angiography is a novel technique to visualize vascular changes including microaneurysm, non-perfusion area, intraretinal microvascular abnormalities, and neovascularization. Recently, it is possible to quantify vascular density, foveal avascular zone area, non-perfusion area objectively using OCT angiography. In addition, OCT angiography also provides an alternative method to evaluate the effect of anti-vascular endothelial growth factor (VEGF) treatments by providing high resolution images of macular microcirculatory abnormalities. Thus OCT angiography is an effective method to investigate the vascular changes of the disease, and can also be potentially applied in the diagnosis, treatment, and follow up of DR.
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5.
Multimodal imaging of diabetic retinopathy.
Tran, K, Pakzad-Vaezi, K
Current opinion in ophthalmology. 2018;(6):566-575
Abstract
PURPOSE OF REVIEW Diabetic retinopathy is the most common microvascular complication of diabetes mellitus and a leading cause of blindness throughout the world. Ocular imaging continues to play a vital role in the diagnosis, management and monitoring of diabetic retinopathy. Major technological advancements in imaging over the past decade have improved our understanding and knowledge of diabetic retinopathy and therefore a multimodal approach to imaging has become the standard of care. RECENT FINDINGS Updates to traditional technologies such as digital fundus photography along with recent advancements in optical coherence tomography (OCT) and OCT angiography (OCTA) have provided clinicians with new information and improved efficiency. SUMMARY In this review, we describe the benefits and clinical applications of several imaging techniques in diabetic retinopathy including color photography, fluorescein angiography, OCT, OCTA and adaptive optics. Understanding the indications and limitations of each technology allows clinicians to gain the most information from each modality and thereby optimize patient care.
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6.
Raman, AFM and SNOM high resolution imaging of carotene crystals in a model carrot cell system.
Rygula, A, Oleszkiewicz, T, Grzebelus, E, Pacia, MZ, Baranska, M, Baranski, R
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. 2018;:47-55
Abstract
Three non-destructive and complementary techniques, Raman imaging, Atomic Force Microscopy and Scanning Near-field Optical Microscopy were used simultaneously to show for the first time chemical and structural differences of carotenoid crystals. Spectroscopic and microscopic scanning probe measurements were applied to the released crystals or to crystals accumulated in a unique, carotenoids rich callus tissue growing in vitro that is considered as a new model system for plant carotenoid research. Three distinct morphological crystal types of various carotenoid composition were identified, a needle-like, rhomboidal and helical. Raman imaging using 532 and 488 nm excitation lines provided evidence that the needle-like and rhomboidal crystals had similar carotenoid composition and that they were composed mainly of β-carotene accompanied by α-carotene. However, the presence of α-carotene was not identified in the helical crystals, which had the characteristic spatial structure. AFM measurements of crystals identified by Raman imaging revealed the crystal topography and showed the needle-like and rhomboidal crystals were planar but they differed in all three dimensions. Combining SNOM and Raman imaging enabled indication of carotenoid rich structures and visualised their distribution in the cell. The morphology of identified subcellular structures was characteristic for crystalline, membraneous and tubular chromoplasts that are plant organelles responsible for carotenoid accumulation in cells.
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7.
CASES IN REFINING MANAGEMENT OF DIABETIC MACULAR EDEMA.
Retina (Philadelphia, Pa.). 2018;:1-12
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8.
EFFICACY AND FREQUENCY OF INTRAVITREAL AFLIBERCEPT VERSUS BEVACIZUMAB FOR MACULAR EDEMA SECONDARY TO CENTRAL RETINAL VEIN OCCLUSION.
Lotfy, A, Solaiman, KAM, Abdelrahman, A, Samir, A
Retina (Philadelphia, Pa.). 2018;(9):1795-1800
Abstract
PURPOSE To compare the safety, efficacy, and frequency of intravitreal injection of aflibercept and bevacizumab for treatment of macular edema secondary to central retinal vein occlusion. DESIGN Prospective, comparative, randomized, interventional study. PATIENTS AND METHODS Eyes with macular edema secondary to central retinal vein occlusion were randomized between two groups according to the intravitreal injection used. Group A included eyes treated with intravitreal aflibercept, and Group B included eyes treated with intravitreal bevacizumab injections. The inclusion criteria were macular edema secondary to central retinal vein occlusion and follow-up duration of at least 12 months after the first injection. Exclusion criteria were macular ischemia, associated diabetes, hypertensive or renal retinopathy, other retinal disease, and previous anti-vascular endothelial growth factor injection. The main outcome measures are central foveal thickness, best-corrected visual acuity, time intervals between injections, improved retinal nonperfusion, and any reported complication. RESULTS Group A included 39 patients with a mean age of 57.4 ± 8.2 years. Group B included 40 eyes with a mean age of 56.5 ± 9.1 years. Twelve months after the first injection, central foveal thickness significantly improved from 475.45 ± 71.05 m to 259.11 ± 20.67 m in Group A and from 460.22 ± 89.38 m to 264.29 ± 32.05 m in Group B; best-corrected visual acuity significantly improved from 0.81 ± 0.16 logarithm of the minimum angle of resolution (20/125) to 0.34 ± 0.14 logarithm of the minimum angle of resolution (20/40) in Group A and from 0.73 ± 0.15 logarithm of the minimum angle of resolution (20/100) to 0.33 ± 0.17 logarithm of the minimum angle of resolution (20/40) in Group B; the mean number of injections was 3.72 ± 2.93 in Group A and was 5.44 ± 2.85 in Group B (P < 0.05); and the mean interval between injections was 54.23 ± 8.47 days in Group A and was 35.12 ± 7.76 days in Group B (P < 0.05). Retinal nonperfusion improved in 9/12 eyes in Group A and in 3/8 eyes in Group B (P < 0.05). CONCLUSION Both aflibercept and bevacizumab are comparably effective for treatment of macular edema secondary to central retinal vein occlusion without significant complications. However, the burden of frequent intravitreal injections could be significantly reduced when using aflibercept.
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9.
ASYMMETRIC DIABETIC RETINOPATHY PROGRESSION IN PATIENTS WITH AXIAL ANISOMETROPIA.
Kim, DY, Song, JH, Kim, YJ, Lee, JY, Kim, JG, Yoon, YH, Joe, SG
Retina (Philadelphia, Pa.). 2018;(9):1809-1815
Abstract
PURPOSE To investigate the differences in the progression of diabetic retinopathy (DR) in both eyes of patients with axial anisometropia. METHODS A retrospective review was conducted on diabetic patients who had different axial lengths (difference greater than 1 mm) in each eye. The primary objective of this study was to analyze the differences in the progression of DR in both eyes of patients with axial anisometropia. Fundus images (fluorescein angiography and photographs of the fundus covering the Early Treatment Diabetic Retinopathy Study seven fields) were graded using the Early Treatment Diabetic Retinopathy Study DR grading system. Also, the severity of diabetic retinopathy was analyzed based on the axial length and subfoveal choroidal thickness. RESULTS Thirty-four of 6,963 patients with DR were included after applying the exclusion and inclusion criteria. The mean age was 53.53 ± 12.20 years and duration of diabetes was 9.63 ± 7.73 years. The mean axial length of the longer and shorter eye was 26.21 ± 2.04 mm and 23.21 ± 1.73 mm, respectively (P < 0.001). In shorter eyes, 61.7% (21 of 34) of the eyes had proliferative diabetic retinopathy. In contrast to the shorter eye, only 8 of the longer eyes (8 of 34, 23.5%) had proliferative diabetic retinopathy (McNemar test, P < 0.001). In eyes with thin subfoveal choroidal thickness (<250 µm), the proliferative diabetic retinopathy ratio was significantly lower (P = 0.007). CONCLUSION In patients with axial anisometropia, the longer eye had a lower degree of DR progression than the shorter eye. This result showed that elongation of the axial length had a protective effect against the progression of DR without individual confounding factors.
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10.
Rapid response to dexamethasone intravitreal implant in diabetic macular edema.
Lo Giudice, G, Avarello, A, Campana, G, Galan, A
European journal of ophthalmology. 2018;(1):74-79
Abstract
PURPOSE To evaluate the early effects of dexamethasone (DEX) intravitreal implants in patients with diabetic macular edema (DME). METHODS This was a prospective, single-arm, interventional clinical series. Eighteen patients (18 eyes) with chronic/recalcitrant or naive DME were included. Patients underwent single DEX intravitreal implant. Clinical assessments, including ophthalmologic examination, central retinal thickness (CRT) measurement by spectral-domain optical coherence tomography (SD-OCT) scan, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were carried out at baseline, 1-3 hours, and then 3, 7, and 30 days after treatment. The main outcome was change in CRT on SD-OCT, while secondary outcome measures included visual acuity (VA) and changes in IOP following implant. RESULTS Mean CRT significantly decreased from 565 ± 171 µm at baseline to 310 ± 89 µm at end of follow-up (p<0.001), with reduction becoming evident 1-3 hours after injection. Mean BCVA also significantly improved 7 days and 30 days after treatment up to 0.14 logMAR (p<0.05). All patients had a controlled IOP after the injection with only 1/18 eyes having a transient increase in IOP during follow-up. CONCLUSIONS This is the first study showing very early effects of DEX implants on CRT reduction and VA improvement in DME.