Temperature Distribution Simulation of the Human Eye Exposed to Laser Radiation

Introduction: Human eye is a sensitive part of human body with no direct protection and due to its lack of protection against the external heat waves, studying the temperature distribution of heat waves on the human eye is of utmost importance. Various lasers are widely used in medical applications such as eye surgeries. The most significant issue in the eye surgeries with laser is estimation of temperature distribution and its increase in eye tissues due to the laser radiation intensity. Experimental and invasive methods to measure the eye temperature usually have high risks.Methods: In this paper, human eye has been modeled through studying the temperature distribution of three different laser radiations, using the finite element method. We simulated human eye under 1064 nm Neodymium-Doped Yttrium Aluminium Garnet (Nd: YAG) laser, 193 nm argon fluoride (ArF) excimer laser, and 1340 nm Neodymium doped Yttrium Aluminum Perovskite (Nd: YAP) laser radiation.Results: The results show that these radiations cause temperature rise in retina, lens and cornea region, which will in turn causes serious damages to the eye tissues.Conclusion: This simulation can be a useful tool to study and predict the temperature distribution in laser radiation on the human eye and evaluate the risk involved in using laser to perform surgery

Clinical Features and Outcomes of Treatment for Fourth Nerve Palsy

Purpose: To evaluate the clinical features, etiology and outcomes of treatment for superior oblique (SO) palsy over a 10-year period at Labbafinejad Medical Center. Methods: A complete ophthalmologic examination with particular attention to forced duction test (FDT) and tendon laxity was performed in all patients preoperatively. The palsy was divided into congenital and acquired types. Results: Overall, 73 patients including 45 male (61.6%) and 28 female (38.4%) subjects with mean age of 19.7΁11.7 (range, 1.5-62) years, were operated from 1997 to 2007. SO palsy was congenital in 56 (76%) and acquired in 17 (24%) cases. The most common chief complaint was ocular deviation (52.1%). FDT was positive in only 7 (9.7%) cases. Other clinical findings included amblyopia (19.2%), head tilt (13.7%), chin down position (4.1%), facial asymmetry (6.8%) and tendon laxity (2.7%). Mean preoperative vertical deviation was 16.1 prism diopters (PD) which was decreased to 1.9 PD postoperatively. Mean exotropia and esotropia were 15 and 13.9 PD respectively before the operation and both decreased to 1.5 PD of horizontal deviation postoperatively. The most common type of SO palsy based on Knapp′s classification was type 3 (42.5%). The most common operated muscle was the inferior oblique (83.6%) and the most common type of operation was inferior oblique myectomy (83.6%). The success rate for initial surgery was 84% and was increased to 96% with a second intervention. Conclusion: The most common form of SO palsy requiring surgical intervention was congenital which occurred most frequently in young males. Most cases of SO palsy can be successfully treated with a single surgical procedure

Association of periodontal diseases to anxiety and stress

The effect of periodontal diseases is not equal for the people of a same community. There are risk factors in some people making them more sensitive to the disease spread. Getting infected to certain pathogens, cigarette, and uncontrolled diabetes increases the risk of periodontitis. Other factors such as stress, depression, and anxiety are not considered as absolute risk factors, yet. The biological justification for this relationship is that the psychological status and facing with stressors could change the immune response and made the individual more sensitive to the disease spread. The aim of the present article was to review the periodontal relationship with psychological factors of anxiety and stress. The research is conducted using review article method and by searching through keywords such as anxiety, periodontal disease, and stress in PubMed. Most of the published studies are backing up of a positive relationship between periodontitis and socio psychological factors. Diff erent lifestyles, stressful situation, hormonal changes, dental negligence, bad habits like smoking are considered as predisposing factors of periodontal diseases

Comparison of Ondansetron versus Clonidine efficacy for prevention of postoperative pain, nausea and vomiting after orthognathic surgeries : a triple blind randomized controlled trial

The aim of this randomized controlled triple blind trial was to compare the efficacy of clonidine with dexamethasone versus ondansetron with dexamethasone for postoperative pain, nausea and vomiting prevention in orthognathic surgery patients. In this clinical trial study, 30 consecutive patients with skeletal class III deformities were candidates for orthognathic surgery in Qaem hospital, Mashhad University of medical sciences, Mashhad, Iran from March to November 2017. These subjects were randomly assigned to two equal number groups, ondansetron or clonidine. Patients received either oral ondansetron 8mg or oral clonidine 150?g as premedication, 1 hour before the surgery (both dissolved in 20 cc of water). Also both groups received intravenous dexamethasone 8mg (1 hour preoperatively and every 4 hours intraoperatively). In this study, a total of 30 patients (14 males and 16 females) with a mean age of 23.9 ± 3.9 were investigated. The incidence of postoperative nausea in women was more than men (p=0.003), also the correlation between the incidence of PON and the surgery duration ? 3 hours was statistically significant (p = 0.050). The frequency of postoperative nausea (PON) in the ondansetron group was less than clonidine (53.3% vs 73.3% respectively). There was no postoperative vomiting (POV) in the ondansetron group, but 6.7% of cases in clonidine group suffered POV. Post-operative nausea in ondansetron group occurred significantly later than clonidine (525.0±233.2 vs 100.0±34.0 min; p<0.001). On the other hand, the incidence time of post-operative severe pain or in other word the analgesia time in clonidine group was significantly more than ondansetron one (875/0±68/5 vs 614.3±159.1 min; p<0.001). Ondansetron with dexamethasone premedication was more effective in controlling PONV after orthognathic surgery compared to clonidine with dexamethasone group

Investigating the Cost Efficiency in the Banking System: The Case of Bank Mellat

Banks have important roles in economy, such as mobilization of funds, intermediation, and utilization of fund and financial management. Even in developed economies, banks are on the center of financial and economic movements and they are the basis of monetary policies. In this research, we have investigated the cost-efficiency of banking systems (the case study of the Bank Mellat in the period 1991-2003). We have also estimated the cost-efficiency by using the parametric technique (econometrics) and Translog Stochastic Frontier Cost Function. The advantage of this method is that it divides inefficiency into two independent residuals including cost-inefficiency and stochastic factors. After estimating of the cost function and finding the inefficiency factor, we realize that 10 percent of variance of model's errors is attributed to inefficiency factors. On the other hand, our research show that the total cost to minimum cost ration of the Bank Mellat is 1.07. It means that during this period, the Bank Mellat had only 7 percent inefficiency and the trend of inefficiency was stable during the whole period

Effect of Horizontal Rectus Surgery on Clinical and Paraclinical Indices in Congenital Nystagmus

&lt;!--[if gte mso 9]&gt;&lt;xml&gt; Normal 0 false false false MicrosoftInternetExplorer4 &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;/xml&gt;&lt;![endif]--&gt; &lt;!--[if gte mso 10]&gt; &lt;style&gt;&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Table Normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; &lt;/style&gt; &lt;![endif]--&gt; &lt;p&gt;PURPOSE: To determine the effect of horizontal rectus muscle surgery on visual acuity, head posture and electronystagmographic indices in patients with congenital nystagmus. METHODS: This prospective comparative case series was conducted on 58 patients with congenital nystagmus over a period of three years. Patients were divided into three groups: the first group (29 cases) had head posture less than 20D, binocular visual acuity (BOVA) less than 20/30 and tropia less than 30D and underwent large recession of all four horizontal rectus muscles; the second group (23 cases) had head posture less than 20D, BOVA &lt; 20/30 and tropia more than 30D who underwent large recession of two horizontal rectus muscles; and the third group (6 cases) had head posture more than 20D with any BOVA or tropia who underwent Kestenbaum-Anderson surgery. RESULTS: Mean age of the patients was 18.7±9.1 years and mean follow-up period was 17.5±7.4 months. Visual acuity improved in all three study groups and was statistically significant in the 2-rectus group (P &lt; 0.001). The speed and amplitude of nystagmus waves decreased in all groups which was statistically significant in the 4-rectus group (P values, 0.02 and 0.04, respectively). A small myopic shift was seen in the 2-rectus and 4-rectus groups and a small hyperopic shift was found in the Kestenbaum-Anderson group. Statistically significant improvement was achieved in eye deviation in the 2-rectus group and in head posture in the Kestenbaum-Anderson group (P &lt; 0.001). CONCLUSION: Horizontal recti surgery in congenital nystagmus can improve visual acuity, ocular deviation and abnormal head posture, which is particularly marked with 2-rectus recession. Electronystagmographic indices improve especially with 4-rectus recession.&lt;/p&gt; &lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;o:OfficeDocumentSettings&gt; &lt;o:RelyOnVML /&gt; &lt;o:AllowPNG /&gt; &lt;/o:OfficeDocumentSettings&gt; &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;w:WordDocument&gt; &lt;w:View&gt;Normal&lt;/w:View&gt; &lt;w:Zoom&gt;0&lt;/w:Zoom&gt; &lt;w:PunctuationKerning /&gt; &lt;w:ValidateAgainstSchemas /&gt; &lt;w:SaveIfXMLInvalid&gt;false&lt;/w:SaveIfXMLInvalid&gt; &lt;w:IgnoreMixedContent&gt;false&lt;/w:IgnoreMixedContent&gt; &lt;w:AlwaysShowPlaceholderText&gt;false&lt;/w:AlwaysShowPlaceholderText&gt; &lt;w:Compatibility&gt; &lt;w:BreakWrappedTables /&gt; &lt;w:SnapToGridInCell /&gt; &lt;w:WrapTextWithPunct /&gt; &lt;w:UseAsianBreakRules /&gt; &lt;w:DontGrowAutofit /&gt; &lt;/w:Compatibility&gt; &lt;/w:WordDocument&gt; &lt;/xml&gt;&lt;![endif]--&gt;&lt;!--[if gte mso 9]&gt;&lt;xml&gt; &lt;w:LatentStyles DefLockedState="false" LatentStyleCount="156"&gt; &lt;/w:LatentStyles&gt; &lt;/xml&gt;&lt;![endif]--&gt; &lt;!-- /* Font Definitions */ @font-face {font-family:Palatino; mso-font-alt:"Book Antiqua"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:7 0 0 0 147 0;} @font-face {font-family:Nazanin; mso-font-alt:"Courier New"; mso-font-charset:178; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:8192 0 0 0 64 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:right; mso-pagination:widow-orphan; direction:rtl; unicode-bidi:embed; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&gt; &lt;!--[if gte mso 10]&gt; &lt;style&gt;&#13; /* Style Definitions */&#13; table.MsoNormalTable&#13; {mso-style-name:"Table Normal";&#13; mso-tstyle-rowband-size:0;&#13; mso-tstyle-colband-size:0;&#13; mso-style-noshow:yes;&#13; mso-style-parent:"";&#13; mso-padding-alt:0cm 5.4pt 0cm 5.4pt;&#13; mso-para-margin:0cm;&#13; mso-para-margin-bottom:.0001pt;&#13; mso-pagination:widow-orphan;&#13; font-size:10.0pt;&#13; font-family:"Times New Roman";&#13; mso-ansi-language:#0400;&#13; mso-fareast-language:#0400;&#13; mso-bidi-language:#0400;}&#13; &lt;/style&gt; &lt;![endif]--&gt