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Öğe Certain anatomical relations and the precise morphometry of the infraorbital foramen-canal and groove: An anatomical and cephalometric study(Lippincott Williams & Wilkins, 2001) Kazkayasi, M.; Ergin, A.; Ersoy, M.; Bengi, O.; Tekdemir, I.; Elhan, A.Objectives: To determine and to standardize the certain anatomical relations, and the precise size, course, and location of the infraorbital foramen, canal, and groove for facilitating surgical and invasive procedures. Study Design: This anatomical study consisted of two main steps, namely, the examination of skulls and the cephalometric analysis of the skulls. Measurements of the skulls and of the radiograms were performed. Methods: Thirty-five adult bony heads (70 sides) were studied regarding the localization and dimensions of the infraorbital groove (IOG), infraorbital canal (IOC), and infraorbital foramen (IOF) as well as their relationships with different anatomical landmarks. The cephalometric analysis of the skulls was measured for evaluating the relationships of certain anatomical points and the distances of the skulls in the cephalometric analysis. For this purpose, 13 different distances and two angles were measured on anteroposterior and lateral craniographies. Differences between data of skull and cephalogram measurements were analyzed by the Student t test. The Pearson correlation test was used in the statistical analysis of the 15 values in the cephalogram. Results: Examination of the 70 sides of the 35 bony heads revealed that the shape of the IOF was oval in 34.3%, round in 38.6%, and semilunar in 27.1% of all skulls. The IOF was single in 94.3% and double in 5.7% of the cases. The average distance from the IOF to the infraorbital margin and to the lateral process of the canine tooth in vertical direction and to the lateral nasal border in horizontal direction were 7.19 +/- 1.39 mm, 33.94 +/- 3.15, and 17.23 +/- 2.64 mm, respectively. In cephalometric analysis, when S-N (the distance between the center of the sella turcica and the nasion) and N-ANS (the distance between the nasion and the anterior nasal spine) distances were used as independent parameters for the linear analysis, the correlation of the three values for both independent parameters were statistically significant. Conclusion: While the IOF has no statistically significant changes with regard to the size of the skull, expressive changes take place in the course and the length of the IOG and IOC. Meticulous preoperative evaluation of the IOF and the route of the infraorbital nerve are necessary in patients who are candidates for maxillofacial surgery and regional block anesthesia If these measurements are taken into account, there will be little surgical risk, and this will be helpful in identifying the extent of the operative field.Öğe Change in retrobulbar circulation during menstrual cycle assessed by Doppler ultrasound(Elsevier Science Inc, 2002) Karadeniz, M.Y.; Yücel, A.; Kara, S.A.; Noyan, V.; Altinok, D.; Ergin, A.; Güney, S.Our purpose was to study the hemodynamic changes in the ophthalmic, central retinal and posterior ciliary arteries during the normal menstrual cycle and to relate the vascular changes to menstrual cycle. A total of 23 healthy women underwent serial color Doppler ultrasonography at least six times during a normal menstrual cycle, twice each in follicular, ovulatory and luteal phases. Pulsatility and resistance index and peak systolic velocity of the each arteries were assessed with color Doppler imaging. There was no statistical difference in any of the parameters during the menstrual cycle. This was supposed to be because generalized hormonal effects on heart rate, blood pressure, blood volume, cardiac output and on the diameter of the vessel cancel each other and this effect maintains the same ocular blood flow and perfusion during the menstrual cycle. (E-mail: mykaradeniz@hotmai.com) (C) 2002 World Federation for Ultrasound in Medicine Biology.Öğe Dynamic responses of two blocks under dynamic loading using experimental and numerical studies(Elsevier Sci Ltd, 2015) Cihan, H. K.; Ergin, A.; Cihan, K.; Guler, I.Block type quay walls are one of the most generally used type of gravity quay walls however seismic risks of this kind of structures have not already received the proper amount of attention. In this study, stability of block type quay wall which consists of two concrete blocks is investigated experimentally and numerically. 1 g shaking table tests are used for experimental study. Model scale is 1/10 and model is placed on rigid bed to ignore damage due to foundation deformation. Two different granular materials (Soil 1 and Soil 2) which have different nominal diameters are used as backfill materials to understand the effect of nominal diameters on structure's stability. During the experiments accelerations, pore pressures, soil pressures and displacements are measured for two blocks under different cycling loadings. Soil pressure test results are presented in non-fluctuating and fluctuating components to determine the distribution and application point of the fluctuating component on two blocks. By using experiment results, the friction coefficients between the rubble-block and block-block are determined and compared with recommended friction coefficients in standards. PLAXIS V8.2 software program is used for numerical study to determine the material properties. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Effect of bimatoprost on ocular circulation in patients with open-angle glaucoma or ocular hypertension(Springer, 2004) Akarsu, C.; Yilmaz, S.; Taner, P.; Ergin, A.Purpose: To study the effect of bimatoprost 0.03% (Lumigan) on ocular hemodynamics in patients with open-angle glaucoma or ocular hypertension. Methods: One randomly selected eye of each of 26 patients with open-angle glaucoma or ocular hypertension was enrolled. Each patient received a drop of bimatoprost 0.03% once daily for I month. The effect of bimatoprost on ocular circulation was assessed by color Doppler imaging (CDI), which measured peak systolic, end-diastolic blood flow velocities and resistance indices in the ophthalmic, posterior ciliary and central retinal arteries. Retrobulbar hemodynamics by CDI, intraocular pressure by Goldmann applanation tonometer, blood pressure by cuff, and heart rate by palpation were measured at baseline and at 1 month after bimatoprost treatment. Results: Blood flow velocities and resistance indices in all retrobulbar vessels showed no statistically significant differences between baseline and bimatoprost condition (P>0.05). Bimatoprost lowered intraocular pressure significantly (P<0.001), with a mean change of 6.5 mmHg (27%) after 1 month of treatment. The systolic (P=0.38) and diastolic (P=0.74) blood pressures and pulse rate (P=0.94) did not show statistically significant differences during the study period. Conclusions: The results of this study suggest that topical bimatoprost 0.03% significantly reduces intraocular pressure in patients with open-angle glaucoma or ocular hypertension. However, it does not have any effect on retrobulbar hemodynamics in open-angle glaucoma and ocular hypertension.Öğe Effects of moderate smoking on the central visual field(Wiley, 2004) Akarsu, C.; Yazici, B.; Taner, P.; Ergin, A.Purpose: To investigate whether moderate cigarette smoking has any effects on the central visual field. Methods: This study included 30 healthy, moderate cigarette smokers (10-20 cigarettes per day for at least the past 5 years) and 22 healthy non-smokers. After two training test sessions, all individuals underwent computerized visual field examinations (Humphrey 30-2 Full Threshold Test) with both white-on-white (W-W) perimetry and blue-on-yellow (B-Y) perimetry. One eye of each subject with reliable visual field test results was evaluated. The foveal threshold, mean deviation (MD), pattern standard deviation (PSD), short-term fluctuation (SF), corrected pattern standard deviation (CPSD), glaucoma hemifield test (GHT) and number of significantly depressed points deviating at p < 5%, p < 2%, p < 1% and p < 0.5% on the pattern deviation probability map of the smokers were compared with those of the non-smokers. Results: When the results of W-W perimetry were analysed, the smokers were found to have significantly lower foveal thresholds (p = 0.001) and mean retinal sensitivity (p = 0.02), and higher PSD (p = 0.002) and CPSD (p = 0.01) than the non-smokers. Short-term fluctuation was similar in both groups (p = 0.55). The number of significantly depressed points deviating at p < 5%, p < 2% and p < 1% on the pattern deviation probability map was similar for both groups (p > 0.55). The number of depressed points deviating at p < 0.5% on the pattern deviation probability map was higher for the smokers than for the non-smokers (p = 0.03). The results of B-Y perimetry showed the smokers to have a significantly lower foveal threshold than the non-smokers (p = 0.03). However, there were no significant differences in the global indices of the two groups (p > 0.05). The number of significantly depressed points deviating at p < 5%, p < 2%, p < 1% and p < 0.5% on the pattern deviation probability map was similar in both groups (p > 0.05). No significant difference in GHT was determined with either perimetry for the smokers compared with the non-smokers (p > 0.05). Conclusion: This study suggests that moderate cigarette smoking is associated with both diffuse and localized reductions in retinal sensitivity with W-W perimetry. Only reduction in the foveal threshold was observed with B-Y perimetry, with no hints of diffuse and localized reductions.Öğe Ocular Behcet's disease presenting with retinal tear and panuveitis(Nature Publishing Group, 2008) Örnek, K.; Onaran, Z.; Ergin, A.; Yalçındağ, N. F.…Öğe The reliability of grading the fixation preference test for the assessment of interocular visual acuity differences in patients with strabismus(Mosby-Elsevier, 2002) Şener, E.C.; Mocan, M.C.; Gedik, S.; Ergin, A.; Sanac, A.E.Purpose: The purpose of this study is to test the reliability of the grading system of standard fixation preference testing compared with the logarithmic scale of the minimum angle of resolution (logMAR) interocular visual acuity difference of patients with manifest strabismus and to test the strength of association between the interocular visual acuity difference and the grade of alternation. Methods: A total of 111 strabismic patients with large angle heterotropias (> 10 PD) were included in this study. The visual acuities of these patients were determined using the Snellen's, tumbling E, or Lea visual acuity charts as appropriate for the child's age and ability to cooperate. The results were converted to their logarithmic equivalents of minimum angle of resolution or recognition. Fixation preference was graded from 0 to 4 and was evaluated by observing the time-period through which fixation was maintained with the nonpreferred eye. Results: The median value of interocular visual acuity difference for grade 4 was determined as 0.0, grade 3 as 0.097, grade 2 as 0.17, grade 1 as 0.3, and grade 0 as 0.8. The grade of fixation preference was found to be inversely related to the logMAR interocular visual acuity difference (P < .0001). There was a significant difference between every fixation grade except grade 1 and grade 2 (P < .005). Conclusions. The grades used in fixation preference testing correlate with the logMAR visual acuity differences in strabismic amblyopic patients. However, the grading system does not imply a linear function in terms of visual acuity difference. The difference between the logMAR values of patients with grade 0 and 1 are more profound compared with other grades.Öğe Short-term effect of topical brinzolamide on human central corneal thickness(Sage Publications Ltd, 2008) Örnek, K.; Güllü, R.; Oğurel, T.; Ergin, A.PURPOSE. To investigate the effect of short-term brinzolamide application on human central corneal thickness (CCT). METHODS. Seventeen eyes of 16 patients who underwent neodymium: YAG laser posterior capsulotomy were included in the study group. Twenty-two subjects served as controls. Brinzolamide twice daily and fluorometholone four times daily were initiated after the procedure. Corneal thickness was evaluated with an ultrasound pachymetry from the central region. CCT measurements were performed before the procedure, at first day, and at the end of first week. RESULTS. The mean baseline CCT value was 535.1 +/- 37.8 mu m. In comparison to the control group (546.4 +/- 22.2 mu m), there was no statistically significant difference (p= 0.248). After brinzolamide instillation, the mean CCT values at first day and at first week was measured as 545.1 +/- 40.1 mu m and 538.8 +/- 39.4 mu m, respectively. The difference at first day was statistically significant when compared to the baseline values ( p= 0.00017). When compared to the control group, no statistically significant difference was observed for the mean CCT values of the first day and first week ( p= 0.906 and p= 0.484, respectively). In the fellow eyes, mean CCT values increased following the dorzolamide instillation (529.3 +/- 42.6 mu m, 534 +/- 41.7 mu m, and 533 +/- 41.9 mu m, respectively). No statistically significant difference was observed between the control group and fellow eye group when compared ( p= 0.162, p= 0.247, p= 0.270, respectively). CONCLUSIONS. Brinzolamide may cause a short-term increase in the human CCT, particularly on the first day.Öğe Sildenafil itself can not be a possible cause of non-arteritic ischemic optic neuropathy(Wiley-Blackwell Publishing, Inc, 2004) Taner, P.; Basar, M. M.; Bilgili, M. Y.; Ergin, A.; Batislam, E.…
