37 research outputs found

    Time resolved speckle contrast optical spectroscopy at quasi-null source-detector separation for non-invasive measurement of microvascular blood flow

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    Time (or path length) resolved speckle contrast optical spectroscopy (TD-SCOS) at quasi-null (2.85 mm) source-detector separation was developed and demonstrated. The method was illustrated by in vivo studies on the forearm muscle of an adult subject. The results have shown that selecting longer photon path lengths results in higher hyperemic blood flow change and a faster return to baseline by a factor of two after arterial cuff occlusion when compared to SCOS without time resolution. This indicates higher sensitivity to the deeper muscle tissue. In the long run, this approach may allow the use of simpler and cheaper detector arrays compared to time resolved diffuse correlation spectroscopy that are based on readily available technologies. Hence, TD-SCOS may increase the performance and decrease cost of devices for continuous non-invasive, deep tissue blood flow monitoring

    Recanalization Therapies for Large Vessel Occlusion Due to Cervical Artery Dissection: A Cohort Study of the EVA-TRISP Collaboration

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    Background and Purpose: This study aimed to investigate the effect of endovascular treatment (EVT, with or without intravenous thrombolysis [IVT]) versus IVT alone on outcomes in patients with acute ischemic stroke (AIS) and intracranial large vessel occlusion (LVO) attributable to cervical artery dissection (CeAD). Methods: This multinational cohort study was conducted based on prospectively collected data from the EVA-TRISP (EndoVAscular treatment and ThRombolysis for Ischemic Stroke Patients) collaboration. Consecutive patients (2015–2019) with AIS-LVO attributable to CeAD treated with EVT and/or IVT were included. Primary outcome measures were (1) favorable 3-month outcome (modified Rankin Scale score 0–2) and (2) complete recanalization (thrombolysis in cerebral infarction scale 2b/3). Odds ratios with 95% confidence intervals (OR [95% CI]) from logistic regression models were calculated (unadjusted, adjusted). Secondary analyses were performed in the patients with LVO in the anterior circulation (LVOant) including propensity score matching. Results: Among 290 patients, 222 (76.6%) had EVT and 68 (23.4%) IVT alone. EVT-treated patients had more severe strokes (National Institutes of Health Stroke Scale score, median [interquartile range]: 14 [10–19] vs. 4 [2–7], Padjusted 0.56 [0.24–1.32]). EVT was associated with higher rates of recanalization (80.5% vs. 40.7%; ORadjusted 8.85 [4.28–18.29]) compared to IVT. All secondary analyses showed higher recanalization rates in the EVT-group, which however never translated into better functional outcome rates compared to the IVT-group. Conclusion: We observed no signal of superiority of EVT over IVT regarding functional outcome in CeAD-patients with AIS and LVO despite higher rates of complete recanalization with EVT. Whether pathophysiological CeAD-characteristics or their younger age might explain this observation deserves further research

    Multi-laboratory performance assessment of diffuse optics instruments: the BitMap exercise

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    SIGNIFICANCE: Multi-laboratory initiatives are essential in performance assessment and standardization-crucial for bringing biophotonics to mature clinical use-to establish protocols and develop reference tissue phantoms that all will allow universal instrument comparison. AIM: The largest multi-laboratory comparison of performance assessment in near-infrared diffuse optics is presented, involving 28 instruments and 12 institutions on a total of eight experiments based on three consolidated protocols (BIP, MEDPHOT, and NEUROPT) as implemented on three kits of tissue phantoms. A total of 20 synthetic indicators were extracted from the dataset, some of them defined here anew. APPROACH: The exercise stems from the Innovative Training Network BitMap funded by the European Commission and expanded to include other European laboratories. A large variety of diffuse optics instruments were considered, based on different approaches (time domain/frequency domain/continuous wave), at various stages of maturity and designed for different applications (e.g., oximetry, spectroscopy, and imaging). RESULTS: This study highlights a substantial difference in hardware performances (e.g., nine decades in responsivity, four decades in dark count rate, and one decade in temporal resolution). Agreement in the estimates of homogeneous optical properties was within 12% of the median value for half of the systems, with a temporal stability of <5  %   over 1 h, and day-to-day reproducibility of <3  %  . Other tests encompassed linearity, crosstalk, uncertainty, and detection of optical inhomogeneities. CONCLUSIONS: This extensive multi-laboratory exercise provides a detailed assessment of near-infrared Diffuse optical instruments and can be used for reference grading. The dataset-available soon in an open data repository-can be evaluated in multiple ways, for instance, to compare different analysis tools or study the impact of hardware implementations

    Prevalence of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma in Upper Egypt

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    <p>Abstract</p> <p>Background</p> <p>Pseudoexfoliation (PXF) is a recognized risk factor for developing cataract, glaucoma and lens dislocation. PXF is also associated with increased risk of complications during cataract surgery due to poor mydriasis and zonular weakness. The aim of this study is to report the prevalence of pseudoexfoliation among Upper Egyptians attending the ophthalmology clinic of Assiut University Hospital.</p> <p>Methodology</p> <p>A retrospective, chart review study conducted in the period from February 2002 to August 2009. A total of 7738 patients aged 40 years or older attending the general ophthalmic clinics were included in this study. A detailed evaluation including ophthalmic and general history, slit lamp biomicroscopy, intraocular pressure measurement, gonioscopy and dilated eye examination were performed. Patients with pseudoexfoliative material on the anterior lens surface and ⁄ or the pupillary margin in either or both eyes were labeled as having PXF.</p> <p>Results</p> <p>Out of the 7738 patients included, three hundred twenty (4.14%) subjects had PXF. Mean age of PXF group was 68.15 years (SD 8.16, range 40-92 years). PXF was bilateral in 82.2% of cases. It was significantly associated with cataract, glaucoma and hearing loss. Of the PXF patients, 65% had cataract, 30.3% had glaucoma and 8.1% had hearing loss.</p> <p>Conclusion</p> <p>Pseudoexfoliation appears to be a common disorder in older individuals in Upper Egypt.</p

    A case of a retained intralenticular foreign body for two years

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    Mete G&amp;uuml;ler1, Turgut Yilmaz2, Mehmet Yigit2, G&amp;uuml;lsen &amp;Uuml;lk&amp;uuml;2, Sermal Arslan21Department of Ophthalmology, Elazig Harput State Hospital, Turkey; 2Departmant of Ophthalmology, Elazig Education and Research HospitalAbstract: We report a case of a missed metallic intraocular foreign body retained in the lens over a two-year period without causing inflammatory reaction, which presented with cataract later. A 24-year-old man presented with a progressive blurring of vision in the left eye for two years. He had had a history of metal-on-metal activity two years before. He had pain for one day in left eye and it was healed by the following day. Biomicroscopic examination revealed cataract, an intralenticular foreign body, and a corneal scar at seven o&amp;rsquo;clock meridian of the cornea in the left eye. Best-corrected visual acuity was 20/200 in the left eye. Intralenticular foreign body removal, phacoemulsification, and an intraocular lens implantation was performed under local anesthesia. The intralenticular foreign body was metallic and its size was about 2 &amp;times; 2 mm. Two weeks after the operation best corrected visual acuity was 20/20 in left eye. A retained foreign body should be considered in each patient with a history of penetrating ocular trauma and all efforts must be made to exclude presumptive diagnosis of intraocular foreign body.Keywords: cataract, intralenticular foreign body, penetrating intraocular injur

    Spontaneous corneal perforation in a patient with lamellar ichthyosis and dry eye

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    Burak Turgut1, Orhan Aydemir1, Murat Kaya1, Peykan T&amp;uuml;rk&amp;ccedil;&amp;uuml;og? lu2, Tamer Demir1, &amp;Uuml;lk&amp;uuml; &amp;Ccedil;eliker11Firat University School of Medicine, Department of Ophthalmology, Elazig, Turkey; 2Inonu University School of Medicine, Department of Ophthalmology, Malatya, TurkeyAbstract: We report spontaneous corneal perforation in a patient with lamellar ichthyosis. The patient presented with complaints of pain, redness, diminished vision, and discharge in her right eye for 15 days. Visual acuities were light perception in the right and 20/400 in the left eye. Cicatricial ectropion in both lower eyelids and 2 mm perforation site in the center of the right cornea were observed. Lamellar ichthyosis was suspected because of scaling and excessive dryness of entire body skin and was confirmed by skin biopsy. Amniotic membrane transplantation and transient tarsorraphy was performed and systemic anti-ichthyosis therapy was started. The follow-up visits were not possible because of patient inconsistency. In patients with cicatricial ectropion secondary to ichthyosis, corneal health should be closely monitored because of the perforation risk.Keywords: lamellar ichthyosis, cornea, spontaneous perforatio

    Levels of circulating homocysteine, vitamin B6, vitamin B12, and folate in different types of open-angle glaucoma

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    Burak Turgut, Murat Kaya, Sermal Arslan, Tamer Demir, Mete G&uuml;ler, Mehmet Kaan KayaFırat University School of Medicine, Department of Ophthalmology, Elazıg, TurkeyObjective: To compare the levels of plasma homocysteine (Hcy), vitamin B6 (vit-B6), serum vitamin B12 (vit-B12), and folate in healthy individuals and in patients with normal tension glaucoma (NTG), pseudoexfoliative glaucoma (PXG), or primary open-angle glaucoma (POAG).Study design: A prospective controlled trial.Participants and methods: Forty healthy subjects, 48 patients with NTG, 38 patients with PXG, and 34 patients with POAG were included in the study. Those who used vitamin supplements or medications affecting Hcy and vitamin levels were excluded from the study. The levels of Hcy and vit-B6 were measured by High Performance Liquid Chromatography (HPLC). The levels of serum vit-B12 and folic acid were measured by competitive chemiluminescent enzyme immunoassay (CEI). One-way analysis if variance (ANOVA), analysis of covariance (ANCOVA), and the Tukey honestly significant difference test were used for statistical analysis.Results: The mean Hcy level of the PXG group was 15.46 &plusmn; 9.27 &mu;mol/L which was significantly higher (P = 0.03) than that of the control group. There were no statistical differences in serum vit-B12 and folate levels among control subjects and NTG, PXG and POAG groups (P &gt; 0.05). It was found that the mean plasma vit-B6 level was significantly higher in subjects with NTG (P = 0.03) and POAG (P = 0.025) versus controls. Mean vit-B6 levels in NTG and POAG were 30.50 &plusmn; 11.29 &mu;g/L and 30 &plusmn; 12.15 &mu;g/L, respectively.Conclusions: The plasma level of Hcy was found to be increased only in PXG patients and the plasma levels of vit-B6 were found to increase in the NTG and POAG sample groups. Using homocysteine and vit-B6 levels as the determinants of hyperhomocysteinemia still needs further research.Keywords: normal tension glaucoma, pseudoexfoliative glaucoma, primary open-angle glaucoma, homocysteine, vitamin B

    Cesarean Scar Pregnancy: A Tertiary Center Case Series And Literature Review

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    Aim: To examine the characteristics, management and outcomes of cesarean scar pregnancies at a single tertiary obstetric centre over a three-year period. Method: A retrospective study was performed on 8 cases of cesarean scar pregnancy identified between January 2009 and June 2012 from the medical files. Results: The mean gestational age was 58.2 days (35-120). The average time for β-hCG levels to return to normal values after treatment for cesarean scar pregnancy was 3.4 weeks (2-6). The mean number of previous cesarean sections was 1.9 (1-4) and the mean interval time after the last cesarean section was 20 months (10-48). Laparotomy with excision of the sac and primary repair (n=5) and methotrexate (n=3) were the modalities of management. Conclusion: Cesarean scar pregnancy is a potentially life-threatening complication of pregnancy that constitutes a diagnostic and therapeutic challenge. Decision on treatment modality should be determined on individualized basis depending on factors such as gestational age, β-hCG levels, fetal cardiac activity, desire of future fertility and the experience and facilities available

    High-density speckle contrast optical tomography of brain activity

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    A new method for the tomographic monitoring of cerebral blood flow changes is presented. The method is based on speckle contrast optical tomography (SCOT) to recover 3D brain activation changes due to forepaw stimulation.</p
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