Purpose: To investigate differences in ocular blood flow between people of African (AD) and European descent (ED) with healthy eyes.Methods: Retrobulbar and retinal capillary blood flow was assessed in one eye of 58 participants (24 AD, 34 ED) with healthy eyes with systemic blood pressure lower than 140/90. Retrobulbar blood flow was measured in the ophthalmic artery (OA), central retinal artery (CRA), nasal (NPCA) and temporal posterior ciliary arteries (TPCA). Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) were assessed. Retinal capillary blood flow was assessed using mean retinal flow and avascular space defined as the percent of area measured with no blood flow. Groups were compared using t-tests and Pearson correlations were compared using Fisher r-toz transformation.Results: Compared to people of ED, people of AD had significantly lower EDV in the NPCA (p=0.01), and higher RI in the CRA (p=0.04) and TPCA (p=0.01). No significant differences were observed in mean retinal capillary flow or avascular area. In the CRA, a significant positive correlation was observed between pattern standard deviation (PSD) and PSV (p=0.02) and this correlation was significantly different from that observed in the ED group (p=0.01). A significant correlation was also observed between PSD and EDV (0.04) in the AD group. Conclusion:This study suggests that retrobulbar blood flow is lower in healthy eyes in persons of AD compared to ED. This may provide a mechanism through which people of AD are at increased risk for ophthalmic diseases such as glaucoma.
Background:Intravenous regional block, called the Bier's block, refers to an analgesic technique applied for soft tissue surgeries and closed bone manipulations of the limbs. There are a number of complications in traditional method of block, including pain in tourniquet site, immediate return of pain after tourniquet deflation, wound hemostasis and some others.Objectives:The aim of this study was to assess the outcomes and complications of our new method of blockage.Patients and Methods:In this experimental study, twenty-five patients undergoing hand surgery were prospectively studied. Induced anesthesia was a modification of the Bier's block with two concurrent changes including insertion of the intravenous cannula at the antecubital region rather than distal and the proximal anesthetic direction by an elastic band wrapped tightly around the proximal forearm distal to the cannulation site. The pain relief was measured by the verbal descriptive scale at intervals after block, during the operation, after deflation of the tourniquet and one hour after the operation.Results:This study showed the presence of analgesia at surgical and tourniquet sites during the operation in 96% of patients, as well as considerable pain relief at surgical site during one hour after deflation of the tourniquet.Conclusions:The study indicated advantages of this modified Bier's block compared to the traditional one including ability to perform surgery on upper limb bones and considerable pain relief at surgical and tourniquet sites during the operation until one hour thereafter.
There is an association between orbital vector measurement and involutional entropion and ectropion. Measuring the orbital vector may help predict the development of these lid malpositions.
PurposeTo assess if there are differences in the structure-function associations between healthy and glaucomatous eyes.MethodsStructure-function associations were assessed in healthy and glaucomatous eyes in three datasets, globally and in the six sectors of the optic nerve head. Structural parameters included rim area (RA) and retinal nerve fiber layer thickness (RNFLT). Functional parameters included unweighted mean of sensitivity thresholds (MS) and unweighted mean of total deviation values (MD), assessed with standard automated perimetry, short-wavelength automated perimetry, frequency-doubling technology perimetry, or contrast sensitivity perimetry. All structural and functional parameters were expressed as percent of mean normal. SF associations were assessed with correlation analyses (Pearson, Spearman and Kendall). We also assessed the SF associations with linear regression analyses: the generalized estimating equation (GEE) was used to adjust for inter-eye correlations and ordinary least squares (OLS) linear models were used when these adjustments were not necessary. We applied Bonferroni corrections to adjust for the impact of multiple comparisons.ResultsOverall, none of the Pearson correlations tested in healthy eyes were significant (correlations ranged from -0.17 to 0.37), whereas 77% of the correlations tested in glaucomatous eyes were significant (correlations ranged from 0.01 to 0.79). Similarly, none of the slopes obtained with GEE and OLS were significant in healthy eyes (slopes ranged from -0.30 to 0.87), whereas 82% of the slopes obtained in glaucomatous eyes were significant (slopes ranged from 0.02 to 1.38).ConclusionsSignificant associations between structure and function were consistently observed in glaucomatous eyes, but not in healthy eyes. These differences in association should be considered in the design of structure-function models for progression.
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