415 research outputs found
Preoperative factors predictive of postoperative decimal visual acuity ≥ 1.0 following surgical treatment for idiopathic epiretinal membrane
Hiroshi Kunikata1, Toshiaki Abe2, Jiro Kinukawa1, Kohji Nishida1,31Department of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, Japan; 2Division of Clinical Cell Therapy, Tohoku University Graduate School of Medicine, Sendai, Japan; 3Department of Ophthalmology, Osaka University Medical School, Suita, JapanPurpose: To report the preoperative best-corrected visual acuity (BCVA) and foveal thickness (FT) values that lead to a postoperative decimal BCVA of ≥ 1.0 after surgical removal of an idiopathic epiretinal membrane (ERM).Methods: This is a retrospective case series of 73 eyes that underwent surgery for removal of an idiopathic ERM. All eyes had been treated by a single surgeon using a 25-gauge transconjunctival sutureless vitrectomy and indocyanine green-assisted internal limiting membrane peel. The BCVA and FT were measured at baseline and 6 months postoperatively.Results: A postoperative decimal BCVA ≥ 1.0 was obtained in eyes with a preoperative decimal BCVA ≥ 0.3 but not in those with a preoperative decimal BCVA ≤ 0.2. The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly (P = 0.002) higher in eyes with a preoperative decimal BCVA ≥ 0.5 (50%) than in eyes with a preoperative decimal BCVA < 0.5 (11%). Additionally, a postoperative decimal BCVA of ≥ 1.0 was obtained in 51% of the eyes that had a preoperative FT < 400 µm, compared with only 21% of eyes with a preoperative FT ≥ 400 µm (P = 0.01). The incidence of obtaining a postoperative decimal BCVA ≥ 1.0 was significantly higher in eyes with preoperative decimal BCVA ≥ 0.5 and FT < 400 µm (60%) than in eyes with preoperative decimal BCVA ≥ 0.5 and FT ≥ 400 µm (20%; P = 0.03 ) or preoperative BCVA < 0.5 and FT ≥ 400 µm (7%; P < 0.001).Conclusions: These findings indicate that eyes with both preoperative BCVA ≥ 0.5 and FT < 400 µm have a significantly better chance of obtaining a postoperative decimal BCVA ≥ 1.0 following idiopathic ERM removal.Keywords: 25-gauge vitrectomy, optical coherence tomography, epimacular membrane, epiretinal membrane, visual acuity, foveal thicknes
Successful Removal of Large Intraocular Foreign Body by 25-Gauge Microincision Vitrectomy Surgery
We describe a new technique for removing a large intraocular foreign body by 25-gauge microincision vitrectomy surgery (25G-MIVS). Noncomparative interventional case series were performed at a single centre. Two patients with a long smooth intraocular vitreal foreign body underwent phacoemulsification and aspiration, intraocular lens implantation, 25G-MIVS, and extraction of the foreign body. The foreign body was removed through a posterior capsulorhexis, anterior continuous curvilinear capsulorhexis, and a corneal incision. In both cases, the foreign body was safely removed through the corneal incision, and IOL was implanted and well positioned. The surgical incision did not require suturing. No postoperative complications associated with this technique were found. The corneal endothelial cell density was maintained over 2000 cells/mm2 in both cases during recent follow-up examinations. Our findings indicate that 25G-MIVS with this technique can be used to extract a long slender smooth foreign body. It is safe, without complications, and can be performed without enlarging the 25-gauge sclerotomy
Central retinal artery occlusion following severe blow-out fracture in young adult
A 20-year-old woman was involved in a traffic accident while riding a motorcycle. The vision in her right eye was severely reduced. At the first examination, the eyelids of her right eye were severely swollen, and the eye could barely be seen. The fundus was not visible. She had no light perception in her vision. Computed tomography revealed a severe blow-out fracture in her right eye. Surgery was immediately performed to correct the fracture and the eye globe was replaced in the orbit. On the fourth postoperative day, the right fundus was visible and a cherry-red spot and milky-white edema were seen. Fluorescein angiography showed an arterial filling defect. Four months later, her visual acuity was light perception. Our case shows that a central retinal artery occlusion can be a complication of a blow-out fracture of the lower orbital wall and can lead to severe visual loss even with early surgical repair
Neurosteroids as stress modulators and neurotherapeutics: Lessons from the retina
Neurosteroids are rapidly emerging as important new therapies in neuropsychiatry, with one such agent, brexanolone, already approved for treatment of postpartum depression, and others on the horizon. These steroids have unique properties, including neuroprotective effects that could benefit a wide range of brain illnesses including depression, anxiety, epilepsy, and neurodegeneration. Over the past 25 years, our group has developed ex vivo rodent models to examine factors contributing to several forms of neurodegeneration in the retina. In the course of this work, we have developed a model of acute closed angle glaucoma that involves incubation of ex vivo retinas under hyperbaric conditions and results in neuronal and axonal changes that mimic glaucoma. We have used this model to determine neuroprotective mechanisms that could have therapeutic implications. In particular, we have focused on the role of both endogenous and exogenous neurosteroids in modulating the effects of acute high pressure. Endogenous allopregnanolone, a major stress-activated neurosteroid in the brain and retina, helps to prevent severe pressure-induced retinal excitotoxicity but is unable to protect against degenerative changes in ganglion cells and their axons under hyperbaric conditions. However, exogenous allopregnanolone, at a pharmacological concentration, completely preserves retinal structure and does so by combined effects on gamma-aminobutyric acid type A receptors and stimulation of the cellular process of macroautophagy. Surprisingly, the enantiomer of allopregnanolone, which is inactive at gamma-aminobutyric acid type A receptors, is equally retinoprotective and acts primarily via autophagy. Both enantiomers are also equally effective in preserving retinal structure and function in an in vivo glaucoma model. These studies in the retina have important implications for the ongoing development of allopregnanolone and other neurosteroids as therapeutics for neuropsychiatric illnesses
The effects measurement of hand massage by the autonomic activity and psychological indicators
This study examined the effects of hand massage on autonomic activity, anxiety, relaxation and sense of affinity by performing it to healthy people before applying the technic in actual clinical practice. Findings were showed below : 1) the significant increase in the pNN50 and the significant decrease in the heart rate meant the intervention of massage increased the autonomic nervous activity, improved the parasympathetic nerve activity and reduced the sympathetic nerve activity. This means the subjects were considered to be in a state of relaxation. 2) Salivary α amylase has been reported as a possible indicator for sympathetic nerve activity. In this study, there was no significant difference in the salivary α amylase despite a decrease after massage. 3) State anxiety score is temporal situational reactions while being in the state of anxiety and this score decreased significantly after massage. 4) The level of willingness to communicate with other person and the sense of affinity toward the massage-performer had a positive change of 70 percent. From this, it can be considered that a comfortable physical contact between a patient and a nursing profession, who are in a supported-supportive relationship, leads to an effect of shortening the gap in their psychological distance
Correlation of Papillomacular Nerve Fiber Bundle Thickness with Central Visual Function in Open-Angle Glaucoma
Purpose. To determine the correlation of reduced retinal thickness in the central papillomacular bundle (CPB) to central visual function, including central retinal sensitivity and visual acuity, in glaucoma patients. Methods. This study enrolled 50 eyes of 50 patients with open-angle glaucoma who were carefully screened for comorbid conditions that can cause decreased central visual function, such as cataracts or macular diseases. We used a novel CPB analysis comprising a program for optical coherence tomography that measured RNFL thickness and GCC thickness in the CPB and divided lengthwise into three parts (upper, middle, and lower CPB). The relationship of these parameters, including conventional macular thickness, to visual field sensitivity in four central standard automated perimetry points (the central four thresholds) and BCVA was analyzed. Results. The two parameters most highly correlated with central four thresholds were macular GCCT and macular RNFLT. The two parameters most highly correlated with BCVA were middle CPB (mid-CPB) GCCT and mid-CPB RNFLT. A multiple regression analysis revealed that mid-CPB GCCT was an independent factor impacting central retinal thresholds and BCVA. Conclusions. Our results suggest that mid-CPB RNFLT and GCCT, parameters of a novel papillomacular bundle analysis, are candidate biomarkers of decreased central visual function in glaucomatous eyes
Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches
Purpose: Fractographic analysis has been used to investigate the fracture behavior of Computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns by subjecting them to compression tests. However, it is difficult to investigate details of the fracture, including its initiation and propagation, using in vitro tests. The aim of this study was to determine the fracture origins and the order of crack initiation of CAD/CAM composite crowns using in silico nonlinear dynamic finite element analysis (FEA). Material and methods: The following materials were used: Cerasmart (CS), Katana Avencia Block (KA), and Shofu Block HC (HC) as CAD/CAM crowns, Panavia SA Cement Plus (SA) as a luting material, and Clearfil DC Core Plus (DC) as an abutment. The elastic moduli and fracture strain of each material were obtained from the stress–strain curve of in vitro three-point bending tests. The fracture origins and order of crack initiation of the materials were determined by in silico nonlinear dynamic compression analysis. Load-displacement curves were statistically compared with the results of the in vitro compression tests (Pearson's correlation test, α = 0.05). Results: The nonlinear dynamic FEA demonstrated that crack initiation was primarily observed near the lingual side of the CAD/CAM crowns and immediately propagated to the central fossa. The models were fractured following the in vitro fracture strains, showing the same order for the products tested (CS/KA/HC, SA, and DC). Load-displacement curves with the use of CS, KA, and HC were significantly correlated to the corresponding in vitro compression tests results (CS: r = 0.985, p < 0.05, KA: r = 0.987, p < 0.05, and HC: r = 0.997, p < 0.05). Conclusions: The in silico model established in this study clarified the crack initiation of the CAD/CAM composite crowns and the order of crack initiation among the investigated products, suggesting that the present approach is useful for analyzing the fracture behavior of CAD/CAM composite crowns in detail.Yamaguchi S., Katsumoto Y., Hayashi K., et al. Fracture origin and crack propagation of CAD/CAM composite crowns by combining of in vitro and in silico approaches. Journal of the Mechanical Behavior of Biomedical Materials 112, 104083 (2020); https://doi.org/10.1016/j.jmbbm.2020.104083
The enantiomer of allopregnanolone prevents pressure-mediated retinal degeneration via autophagy
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MicroRNA profiling reveals marker of motor neuron disease in ALS models
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder marked by the loss of motor neurons (MNs) in the brain and spinal cord, leading to fatally debilitating weakness. Because this disease predominantly affects MNs, we aimed to characterize the distinct expression profile of that cell type to elucidate underlying disease mechanisms and to identify novel targets that inform on MN health during ALS disease time course. microRNAs (miRNAs) are short, noncoding RNAs that can shape the expression profile of a cell and thus often exhibit cell-type-enriched expression. To determine MN-enriched miRNA expression, we used Cre recombinase-dependent miRNA tagging and affinity purification in mice. By defining thein vivomiRNA expression of MNs, all neurons, astrocytes, and microglia, we then focused on MN-enriched miRNAs via a comparative analysis and found that they may functionally distinguish MNs postnatally from other spinal neurons. Characterizing the levels of the MN-enriched miRNAs in CSF harvested from ALS models of MN disease demonstrated that one miRNA (miR-218) tracked with MN loss and was responsive to an ALS therapy in rodent models. Therefore, we have used cellular expression profiling tools to define the distinct miRNA expression of MNs, which is likely to enrich future studies of MN disease. This approach enabled the development of a novel, drug-responsive marker of MN disease in ALS rodents.SIGNIFICANCE STATEMENTAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons (MNs) in the brain and spinal cord are selectively lost. To develop tools to aid in our understanding of the distinct expression profiles of MNs and, ultimately, to monitor MN disease progression, we identified small regulatory microRNAs (miRNAs) that were highly enriched or exclusive in MNs. The signal for one of these MN-enriched miRNAs is detectable in spinal tap biofluid from an ALS rat model, where its levels change as disease progresses, suggesting that it may be a clinically useful marker of disease status. Furthermore, rats treated with ALS therapy have restored expression of this MN RNA marker, making it an MN-specific and drug-responsive marker for ALS rodents.</jats:p
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