55 research outputs found
Novel Technique to Overcome the Nonavailability of a Long Needle 9-0 Polypropylene Suture for Sutured Scleral Fixation of the Posterior Chamber Intraocular Lens Using a Single Fishermanās Knot
Purpose. To describe a method to overcome the nonavailability of a long needle 9-0 polypropylene suture for sutured scleral fixation of the posterior chamber intraocular lens (PC-IOL) using a single fishermanās knot (SFK). Methods. First, a 10-0 polypropylene suture was passed from the sclera to the ciliary sulcus using a long needle. A 9-0 suture was tied to the unpassed portion of the 10-0 suture with an SFK. We pulled the 10-0 suture to pass the SFK through the sclera, and then we cut the knot and removed the 10-0 suture. IOL fixation with 9-0 sutures used the conventional techniques used for sutured scleral-fixated IOL. Preoperative and postoperative visual acuity, corneal astigmatism, and endothelial cell count and intraoperative/postoperative complications were evaluated. Results. An SFK joining the two sutures was passed through the sclera without breakage or slippage. A total of 35 eyes from 35 patients who underwent sutured scleral fixation of the IOL. An intraoperative complication (minor intraocular hemorrhage) was recorded in four cases. Knot exposure, IOL dislocation, subluxation, and retinal detachment were not observed. Conclusions. The SFK offers the opportunity to use 9-0 sutures for the long-term safety and may not require the surgeon to learn any new technique
Analysis of Peripapillary Retinal Vessel Diameter in Unilateral Normal-Tension Glaucoma
Purpose. This study sought to analyze peripapillary retinal vessel diameter and evaluate its correlation with retinal nerve fiber layer (RNFL) thickness in patients with unilateral normal-tension glaucoma (NTG). Methods. This retrospective study included 37 patients with unilateral NTG and 40 healthy controls. The unilateral NTG patients were selected based on RNFL photography and unilateral visual field (VF) defects from the Humphrey central 30-2 threshold test. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured and calculated using retinal photographs and a computer-assisted calculation program. The RNFL thickness was measured using spectral domain optical coherence tomography. Results. The mean CRAE and CRVE were significantly narrower in the glaucomatous and fellow eyes of the unilateral NTG patients than they were in the normal subjects (p<0.001). There was no significant correlation between CRAE/CRVE and RNFL thickness. There was only a significant correlation between VF severity and RNFL thickness in unilateral NTG eyes. Conclusions. Both NTG-affected eyes and NTG-fellow eyes in the unilateral NTG patients had narrower central retinal vessel diameters than did the eyes of normal subjects. Our results show that vascular factors may play a role in the NTG pathogenesis
The Analysis of Emotion Authenticity Based on Facial Micromovements
People tend to display fake expressions to conceal their true feelings. False expressions are observable by facial micromovements that occur for less than a second. Systems designed to recognize facial expressions (e.g., social robots, recognition systems for the blind, monitoring systems for drivers) may better understand the userās intent by identifying the authenticity of the expression. The present study investigated the characteristics of real and fake facial expressions of representative emotions (happiness, contentment, anger, and sadness) in a two-dimensional emotion model. Participants viewed a series of visual stimuli designed to induce real or fake emotions and were signaled to produce a facial expression at a set time. From the participantās expression data, feature variables (i.e., the degree and variance of movement, and vibration level) involving the facial micromovements at the onset of the expression were analyzed. The results indicated significant differences in the feature variables between the real and fake expression conditions. The differences varied according to facial regions as a function of emotions. This study provides appraisal criteria for identifying the authenticity of facial expressions that are applicable to future research and the design of emotion recognition systems
Revisiting the Diagnostic Performance of the Modified Nine-Step Test for Obstructive and Patulous Eustachian Tube Dysfunction
The nine-step test is a classical method for evaluating Eustachian tube function. It directly assesses the patient’s capacity to equilibrate middle ear pressure by swallowing. However, there are insufficient studies to appraise its diagnostic performance. The purpose of this study is to evaluate the sensitivity, specificity, and cut-off value of the nine-step test in patients with obstructive Eustachian tube dysfunction (oETD) and patulous Eustachian tube (PET). Enrolled subjects were divided into three groups. Control (50 ears of healthy volunteers), oETD (19 ears with oETD), and PET (29 ears with PET). Receiver operating characteristics curve analysis was conducted to evaluate the diagnostic performance of maximal peak pressure difference (ETTmd) in the nine-step test. Both the oETD group and the PET group showed decreased ETTmd. The nine-step test showed moderate accuracy when used to diagnose oETD (area under the curve = 0.875) and PET (area under the curve = 0.769). The highest diagnostic performance was observed when the cut-off value was 13 daPa for both the oETD group (sensitivity = 73.7%, specificity = 90.0%) and the PET group (sensitivity = 58.6%, specificity = 90.0%). The nine-step test has moderate diagnostic performance for oETD and PET
Diffuse Retinal Nerve Fiber Layer Defects Identification and Quantification in Thickness Maps
Citation: Shin JW, Uhm KB, Seong M, Kim YJ. Diffuse retinal nerve fiber layer defects identification and quantification in thickness maps. Invest Ophthalmol Vis Sci. 2014;55:3208-3218. DOI:10.1167/iovs.13-13181 PURPOSE. To report retinal nerve fiber layer (RNFL) defect identification and quantification in RNFL thickness maps according to the structural RNFL loss, and to evaluate diffuse RNFL defects. METHODS. A total of 170 patients with glaucoma and 186 normal subjects were consecutively enrolled. We defined RNFL defects in an RNFL thickness map by the degree of RNFL loss. The reference level for RNFL defect determination was set as a 20% to 70% degree of RNFL loss with a 1% interval. To identify RNFL defects, each individual RNFL thickness map was compared to the normative database map by using MATLAB software, and the region below the reference level was detected. The area, volume, location, and angular width of each RNFL defect were measured. Diffuse RNFL defects were defined as having an angular width > 308. RESULTS. The optimal reference level for glaucomatous RNFL defects identification was 42% loss of RNFL. Retinal nerve fiber layer defects were identified in all (100%) of the 170 glaucoma patients and false-positive RNFL defects were detected in 16 (8.16%) cases among the 186 normal subjects. In all, 64.1% of glaucoma patients had diffuse RNFL defects, and 47.7% of diffuse RNFL defects were associated with mild glaucoma patients. The volume of diffuse RNFL defects was significantly associated with the severity of glaucomatous damage (P Ā¼ 0.009). Diffuse RNFL defects were located closer to the center of the optic disc than localized RNFL defects (P < 0.001). CONCLUSIONS. Retinal nerve fiber layer thickness map analysis is an effective method for analyzing RNFL defects. Quantitative measurements (area, volume, location, and width) were useful to understanding diffuse RNFL defects
Retinal Nerve Fiber Layer Defect Volume Deviation Analysis Using Spectral-Domain Optical Coherence Tomography
Citation: Shin JW, Uhm KB, Seong M. Retinal nerve fiber layer defect volume deviation analysis using spectral-domain optical coherence tomography. Invest Ophthalmol Vis Sci. 2015;56:21-28. DOI:10.1167/iovs. 14-15558 PURPOSE. To report the retinal nerve fiber layer (RNFL) defect volume deviation according to structural RNFL loss in RNFL thickness maps. METHODS. Retinal nerve fiber layer defect is defined in RNFL thickness maps by the degree of RNFL loss. A 20% to 70% degree of RNFL loss was set with a 1% interval as the reference level for determining the boundary of RNFL defects. Each individual RNFL thickness map was compared with a normative database map and the region below the reference level was identified as an RNFL defect. The RNFL defect volume was calculated by summing the volumes of each pixel inside RNFL defect. The RNFL defect volume deviation was calculated by summing the differences between the normative database and the subject's RNFL measurements. To evaluate the glaucoma diagnostic ability, the areas under the receiver operating characteristics curves (AUCs) were calculated. RESULTS. Retinal nerve fiber layer defect volume and RNFL defect volume deviation (0.984 and 0.986, respectively) had significantly greater AUCs than all circumpapillary RNFL thickness parameters (all P < 0.001). In the early stage of RNFL loss (under 31% loss of RNFL), RNFL defect volume deviation showed better diagnostic performance than the RNFL defect volume. In multivariate analysis, RNFL defect volume and RNFL defect volume deviation were significantly associated with the mean deviation in visual field tests. CONCLUSIONS. Retinal nerve fiber layer defect volume deviation is a useful tool for diagnosing glaucoma and monitoring RNFL change. In early stage of RNFL loss, RNFL defect volume deviation is more sensitive for detecting glaucoma than the RNFL defect volume measurements. Keywords: retinal nerve fiber defect, lost and remaining volume, glaucoma, spectral-domain optical coherence tomography G laucoma is a progressive optic neuropathy that damages retinal ganglion cells and their axons. The progressive loss of retinal ganglion cell axons results in retinal nerve fiber layer (RNFL) loss. Retinal nerve fiber layer defect identification and assessment of progression are important for diagnosing and managing glaucoma. Optical coherence tomography (OCT) allows objective and quantitative in vivo RNFL thickness measurements. 1 RNFL thickness represents the remaining portion of retinal ganglion cell axons, retinal blood vessels, and glial cells after glaucomatous damage. 2-4 Most studies have focused on remaining RNFL thickness to diagnose and monitor glaucoma. 5-8 In a recent study, the volumetric analysis showed better diagnostic ability than RNFL thickness 9 ; however, the remaining volumes of RNFL defects are not necessarily proportional to the amount of glaucomatous damage. To the best of our knowledge, there have been no reports that simultaneously evaluated the remaining and lost parts of the RNFL. This study measured RNFL defect volume (remaining part of RNFL) and RNFL defect volume deviation (estimated lost part of RNFL) using an RNFL thickness map of spectral-domain OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA). These results were compared with conventional circumpapillary RNFL thickness. The advantages and limitations of RNFL defect volume and RNFL defect volume deviation were considered. METHODS Participants A total of 160 glaucoma patients and 160 healthy control subjects were enrolled. They had visited either the general health care clinic or the glaucoma clinic at Hanyang University Medical Center from September 2012 to January 2013. The institutional review board of Hanyang University Medical Center approved the study protocol and the tenets of the Declaration of Helsinki were followed. Informed consent was obtained from all participants before beginning the study. All subjects underwent a comprehensive ophthalmic examination, including a visual acuity test, applanation tonometry
Swept-Source OCT Angiography Features in Patients after Macular Hole Surgery
This study aimed to compare findings of optical coherence tomography (OCT) angiography (OCTA) between eyes with nearly recovered and partially recovered outer retina after full-thickness macular hole (FTMH) surgery and to identify OCTA findings associated with visual acuity. We retrospectively reviewed 30 patients who underwent surgery for idiopathic FTMH. Swept-source OCT (SS-OCT) and OCTA were performed preoperatively and at three and six months postoperatively. Subgroups were divided according to the integrity of the external limiting membranes and ellipsoid zones postoperatively. Correlations of best-corrected visual acuity six months postoperatively with SS-OCT and OCTA measurements were analyzed. There was no difference in preoperative retinal or choroidal vascular index on OCTA between the nearly and partially recovered groups. Six months postoperatively, the choriocapillaris flow-void area was significantly higher in the partially recovered group than in the fellow eye. The nearly recovered group showed better choroidal vascular flow, and vision at six months postoperatively correlated with the ratio of the operated eye’s choriocapillaris flow-void area to the fellow eye. Sufficient choriocapillaris flow on OCTA is associated with better outer retinal recovery and visual outcomes after macular hole surgery
Phylogeny Trumps Chemotaxonomy: A Case Study Involving Turicella otitidis
The genus Turicella was proposed to harbor clinical strains isolated from middle-ear fluids of patients with otitis media. 16S rRNA phylogeny showed that it belonged to the mycolic acid-containing actinobacteria, currently classified in the order Corynebacteriales, and was closely related to the genus Corynebacterium. A new genus was proposed for the organisms as unlike corynebacteria they lacked mycolic acids and had different menaquinones. Here, we carried out large-scale comparative genomics on representative strains of the genera Corynebacterium and Turicella to check if this chemotaxonomic classification is justified. Three genes that are known to play an essential role in mycolic acid biosynthesis were absent in Turicella and two other mycolate-less Corynebacterium spp., explaining the lack of mycolic acids resulted from the deletion of genes and does not confer any phylogenetic context. Polyphasic phylogenetic analyses using 16S rRNA, bacterial core genes and genes responsible for synthesizing menaquinones unequivocally indicate that Turicella is a true member of the genus Corynebacterium. Here, we demonstrate that menaquinone and mycolic acid that have been used as critical taxonomic markers should be interpreted carefully, particularly when genome-based taxonomy is readily available. Based on the phylogenetic analysis, we propose to reclassify Turicella otitidis as Corynebacterium otitidis comb. nov.
The Association between Female Reproductive Factors and Open-Angle Glaucoma in Korean Women: The Korean National Health and Nutrition Examination Survey V
Purpose. We investigated associations between female reproductive factors and open-angle glaucoma (OAG) in Korean females using the Korea National Health and Nutrition Examination Survey (KNHANES). Methods. A nationwide, population-based, cross-sectional study was conducted. We enrolled 23,376 participants from the KNHANES who had undergone ophthalmologic exams from 2010 through 2012. Associations between undiagnosed OAG and female reproductive factors such as age at menarche and menopause, parity, history of lactation, and administration of oral contraceptives (OC) or hormone replacement therapy (HRT) were determined using stepwise logistic regression analyses. Results. Of the enrolled participants, 6,860 participants (397 with OAG and 6,463 without OAG) met our study criteria and were included in the analyses. In the multivariate logistic regression analysis after adjusting for all potential confounding factors, only early menopause (younger than 45 years) was significantly associated with OAG in participants with natural menopause (OR 2.28, 95% CI 1.17ā4.46). Age at menarche, parity, history of lactation, and administration of OC or HRT were not significantly associated with OAG. Conclusions. Only early menopause was associated with an increased risk of OAG in our study, in contrast to previous Western studies reporting both early menopause and late menarche as associated factors
Wide scan imaging with swept-source optical coherent tomography for glaucoma diagnosis.
To determine glaucoma-discriminating abilities of macular and circumpapillary retinal nerve fiber layer (cpRNFL) thickness measurements of wide scan (12X9mm) using swept-source optical coherence tomography (SS-OCT) compared to measurements of standard macula and disc scans (6 X 6 mm).This retrospective chart review study included 60 glaucomatous and 62 healthy eyes of total 122 subjects who visited a glaucoma clinic and were examined with wide, standard macula, and standard disc scans of SS-OCT (DRI-OCT-1 Atlantis; Topcon Inc., Tokyo, Japan) on the same day. Thickness measurements of the ganglion cell layer plus inner plexiform layer (mGCIPL), mGCIPL plus nerve fiber layer (mGCC), and total retinal layer (TRL) were assessed in wide and standard macula scans. Thickness measurements of cpRNFL were assessed in wide and standard disc scans. The repeatability and agreement of measurements taken in each scan were evaluated using intraclass correlation coefficients (ICCs). The abilities of parameters to discriminate between glaucoma and normal groups were assessed using areas under receiver operating characteristic curves (AUCs).The repeatability and agreement of all parameters showed high ICC values (all ā„ 0.800). AUCs for mGCIPL thickness were 0.710-0.847 and 0.701-0.836 in standard macula and wide scans, respectively. AUCs for cpRNFL thickness were 0.749-0.902 and 0.726-0.897 in standard disc and wide scans, respectively. There were no significant differences in AUCs between wide and standard scans.The agreement between SS-OCT wide and standard scans for mGCIPL, mGCC and cpRNFL measurements were excellent. As the glaucoma-discriminating ability of wide scans was comparable to that of standard macula/disc scans, a single wide scan can replace separate standard macula/disc scans for evaluating glaucoma
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