Histopathology of Corneal Lenticules Obtained from Small Incision Lenticule Extraction (SMILE) versus Microkeratome Excision

Purpose: To study the alterations on the lenticules extracted after femtosecond (Femto) small incision lenticule extraction (SMILE) versus the corneal free cap removed using a microkeratome. Methods: The visuMax (500 kHz; laser energy: 180 nJ) was used for small-incision lenticule extraction. Free caps from human cadaveric corneas were excised by microkeratome. The collected lenticules were examined with the light and transmission electron microscope (TEM) for histological analysis, DNA fragmentation was assessed by agarose gel electrophoresis, DNA damage was evaluated using comet assay, and corneal proteins secondary structure was assessed by Fourier transform infrared spectroscopy (FTIR). Results: Light microscopic examination showed the presence of more edematous stroma under Femto SMILE than under free cap with a percentage change of 101.6%. In the Femto SMILE group, TEM examination showed pyknotic keratocytes, disruption, and cavitation of the collagen arrays stromal area under Femto SMILE. The DNA fragmentation for the Femto SMILE group revealed one undefined band with a size of 1.1 Kbp. The comet assay analysis indicated the presence of 3% and 8.0% tailed cells for the free cap and Femto SMILE groups, respectively. The tail lengths were 1.33 ± 0.16 and 1.67 ± 0.13 μm (P < 0.01), the percentage of tail DNA was 1.41 ± 0.18% (P < 0.01) and 1.72 ± 0.15%, and the tail moments were 1.88 ± 0.12 AU and 2.87 ± 0.14 AU (P < 0.001) for the free cap and Femto SMILE groups, respectively. FTIR spectroscopy of the Femto smile group revealed disorders in the secondary and tertiary structure of the proteins. Conclusion: Femto SMILE technique induced more structural changes, DNA fragmentation, DNA damage, and corneal proteins secondary structure alteration than those induced by a microkeratome cutting. These changes may be attributed to the deep penetration of high energy levels to the corneal layer. These findings may highlight the potential impact of the Femto SMILE on the cornea and the necessity for managing the laser parameters used

Development and validation of a correction equation for Corvis tonometry.

Primary objectiveThis study uses numerical analysis and validation against clinical data to develop a method to correct intraocular pressure (IOP) measurements obtained using the Corvis Tonometer for the effects of central corneal thickness (CCT), and age.Materials and methodsFinite element analysis was conducted to simulate the effect of tonometric air pressure on the intact eye globe. The analyses considered eyes with wide variations in IOP (10-30 mm Hg), CCT (445-645 microns), R (7.2-8.4 mm), shape factor, P (0.6-1) and age (30-90 years). In each case, corneal deformation was predicted and used to estimate the IOP measurement by Corvis (CVS-IOP). Analysis of the results led to an algorithm relating estimates of true IOP as a function of CVS-IOP, CCT and age. All other parameters had negligible effect on CVS-IOP and have therefore been omitted from the algorithm. Predictions of corrected CVS-IOP, as obtained by applying the algorithm to a clinical data-set involving 634 eyes, were assessed for their association with the cornea stiffness parameters; CCT and age.ResultsAnalysis of CVS-IOP measurements within the 634-large clinical data-set showed strong correlation with CCT (3.06 mm Hg/100 microns, r(2) = 0.204) and weaker correlation with age (0.24 mm Hg/decade, r(2) = 0.009). Applying the algorithm to IOP measurements resulted in IOP estimations that became less correlated with both CCT (0.04 mm Hg/100 microns, r(2) = 0.005) and age (0.09 mm Hg/decade, r(2) = 0.002).ConclusionsThe IOP correction process developed in this study was successful in reducing reliance of IOP measurements on both corneal thickness and age in a healthy European population

Rotation and Magnetic Force Effects on Peristaltic Transport of Non -Newtonian Fluid in a Symmetric Channel

In this paper, the impact of magnetic force, rotation, and nonlinear heat radiation on the peristaltic flow of a hybrid bio -nanofluids through a symmetric channel are investigated. Under the assumption of a low Reynolds number and a long wavelength, the exact solution of the expression for stream function, velocity, heat transfer coefficient, induced magnetic field, magnetic force, and temperature are obtained by using the Adomian decomposition method. The findings show that the magnetic force contours improve when the magnitude of the Hartmann number M is high and decreases when rotation increases. Lastly, the effects of essential parameters that appear in the problem are analyzed through a graph. Plotting all figures is done using the MATHEMATICA  software

Assessing students in community settings: the role of peer evaluation

The assessment of students in community settings faces unique difficulties. Since students are usually posted in small groups in different community settings and since the learning (largely) takes place outside the classroom, assessing student performance becomes an intrinsically complex endeavor. In this article, the proposition is made and tested that peers may be used to accurately assess particular aspects of performance, in particular those which need extensive and close observation. Examples are: Effort displayed while working in a community, quality of the interaction with that community, display of leadership, and subject-matter contributions

Covid-19 vaccine acceptance and hesitancy among medical students of Faisalabad

Objectives: The study was conducted to determine the Covid-19 vaccine acceptance and hesitancy among the medical students who are more susceptible to be infected being the frontline workers. Methodology: This analytical cross sectional study was conducted in medical students of 1st to final year MBBS of various medical institutions of Faisalabad. Study duration was 3 months (August 2021 to October 2021). The sample size was 391 and divided in 2 age groups i.e. above and below 21 years and 245 (62.7%) comprised of females. The inclusion criteria were those students who gave consent and filled out the questionnaire and the exclusion criteria was who didn't concede. The data was analysed on SPSS 25. Confidence interval was set to be 95% with 5% margin of error. Results: More than half of the participants i.e. 214 (54.7) have got Sinopharm vaccine. Vaccine hesitancy was found in 28 (7.2%) students and major reason was concern about vaccine safety. Significant relationship (p = < 0.05) was found in all factors related to ‘concerns regarding Covid-19 vaccines and trust of official information’; in all except one in factors related to ‘awareness and overall attitude regarding vaccine acceptance’ and in all except one in factors related to ‘perception of vulnerability to COVID-19 and attitude regarding usefulness of vaccine for community’. Conclusion: Covid-19 vaccine hesitancy was found in one out of every 14 medical students. They were concerned about the efficacy of Covid-19 vaccines. Most of the participants also showed concerns regarding severe adverse effects of these vaccine and on vaccine trials also before making it available for general public. At the same time, participants showed trust on information about Covid-19 vaccine from government and public health experts. Although vaccine hesitancy was present in only 7.2% of participants, health education programmes should be arranged to improve awareness and trust on Covid-19 vaccine. Concerns of medical students should be addressed on priority as future health care providers. Keywords: Covid-19, medical students, vaccine acceptance, hesitanc

Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems

Study DesignThe efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected.PurposeThis study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems.Overview of LiteraturePercutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available.MethodsWe conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared.ResultsPercutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident.ConclusionsFluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients

ASSESSMENT OF CARDIAC FUNCTION IN PATIENTS WITH CHRONIC MYELOID LEUKEMIA TREATED WITH IMATINIB AT THE NATIONAL CENTER OF HEMATOLOGY

Objective: The objective was to study the assessment of the possible cardiotoxic effect of imatinib using echocardiography.Methods: Prospective study included 50 patients that treated at the National Hematology Center of Al-Mustansiriya University from May 2008 to December 2009, echocardiography was used to measure the cardiac ejection fraction accurately, indices of ventricular ejection and relaxation and measurement of left ventricular internal diameter in diastole and (LVIDd) at baseline and after 12 months.Results: 24 (41%) were men and 26 (59%) were women. Their ages ranged from 18 to 74 years, with a median age of 36.8 years. At baseline, mean EF was 0.63±0.057 and after 12 months; mean EF was 0.64±0.068 (p>0.05). Mean peak emptying rate at baseline was 3.23±0.5 ED/s, and after 1 year was 3.21±0.5 ED/s (p>0.05). Time to peak filling rate at baseline was 144±26 ms, and after 1 year was 143±25 ms (p>0.05). There is a significant inverse trend for both LVIDd and LVID in systole (LVIDs) reduced as age increase; the female had significantly lower LVIDd and LVIDs compared to male.Conclusion: We find no evidence of significant impairment in cardiac function over 12 months of imatinib treatment. Advancing age associated with reduced cardiac performance for patients receiving imatinib