• Title/Summary/Keyword: 수정체수술

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Optical Models of the Finite Schematic Eyes for Presbyopia (노안을 위한 정밀 모형안 설계)

  • Baarg, Saang-Bai
    • Korean Journal of Optics and Photonics
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    • v.19 no.6
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    • pp.439-447
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    • 2008
  • There is a need for a finite schematic presbyopic eye that models vision and image quality under various conditions such as cataract or refractive surgery, as well as near vision corrections with an ophthalmic lens or contact lens. Using recently measured biometric data of presbyopic eyes, new model eyes were designed that are optically and anatomically close to real eyes. The parameters changing significantly with age were incorporated into models for four different age groups. The new model eyes have alpha angle, decentered pupil, aspheric GRIN lens and aspheric retinal surface. It is likely that the new finite presbyopic model eyes will be useful for designing visual instruments such as low vision aids, PALs, IOL and contact lenses, and for the clinical prediction of the retinal image quality of a presbyopic patient.

The Effect of Extracapsular Cataract Extraction and Posterior Chamber Lens Implantation on Intraocular Pressure (백내장적출술 및 인공수정체삽입술이 안압에 미치는 영향)

  • Cha, Soon-Cheol;Lee, Kyoo-Won
    • Journal of Yeungnam Medical Science
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    • v.11 no.2
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    • pp.277-283
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    • 1994
  • We studied the change in intraocular pressure (IOP) in 15 consecutive cataract patients who underwent extracapsular cataract extraction and posterior chamber lens implantation between Feb. 1993 and Apr. 1993 to evaluate the effect of this surgery on postoperative IOP. To evaluate the clinical usefulness of non-contact tonometer, the intraocular pressures were measured with Kowa non-contact tonometer (TM-2000, Japan) as well as Goldmann applanation tonometer. There was a decrease in IOP of $3.4{\pm}2.9$mmHg (p<0.00l) 3 months after this surgery and the intraocular pressure differences between pseudophakic eyes and contralateral phakic eyes at 3 months postoperatively were $2.4{\pm}3.8$mmHg (p<0.05). The correlation coefficient between non-contact tonometer and Goldmann tonometer was 0.8876 (p=0.001) in the postoperative 76 eyes. Therefore, our results suggest that extracapsular cataract extracion and posterior chamber lens implantation alone can be a useful surgical method in cataract patient with ocular hypertension, and non-contact tonometer was relatively accurate in measuring the postoperative intraocular pressure.

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Development of Ideal Model Based Optimization Procedure with Heuristic Knowledge (정위적 방사선 수술에서의 이상표적모델과 경험적 지식을 활용한 수술계획 최적화 방법 개발)

  • 오승종;송주영;최경식;김문찬;이태규;서태석
    • Progress in Medical Physics
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    • v.15 no.2
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    • pp.84-93
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    • 2004
  • Stereotactic radiosurgery (SRS) is a technique that delivers a high dose to a target legion and a low dose to a critical organ through only one or a few irradiations. For this purpose, many mathematical methods for optimization have been proposed. There are some limitations to using these methods: the long calculation time and difficulty in finding a unique solution due to different tumor shapes. In this study, many clinical target shapes were examined to find a typical pattern of tumor shapes from which some possible ideal geometrical shapes, such as spheres, cylinders, cones or a combination, are assumed to approximate real tumor shapes. Using the arrangement of multiple isocenters, optimum variables, such as isocenter positions or collimator size, were determined. A database was formed from these results. The optimization procedure consisted of the following steps: Any shape of tumor was first assumed to an ideal model through a geometry comparison algorithm, then optimum variables for ideal geometry chosen from the predetermined database, followed by a final adjustment of the optimum parameters using the real tumor shape. Although the result of applying the database to other patients was not superior to the result of optimization in each case, it can be acceptable as a plan starling point.

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A Clinical Study of Ocular Dimention and Visual Acuity Before and After Cataract Surgery Over Ninety Years Old (90세 이상 초고령 환자들의 백내장 수술전.후 안수치와 시력에 관한 임상연구)

  • Lee, Jung-Mi;Kim, In-Suk;Shin, Jin-Ah
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.3
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    • pp.275-280
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    • 2010
  • Propose: Due to the rapid growth of medical technologies and the increasing population of older people, we investigated clinical status of ocular dimensions and visual acuity for pre and post cataract surgeries of people over age 90. Methods: From March 2007 to February 2009, we investigated eighty-two eyes of forty-eight patients who had undergone cataract surgeries at an ophthalmic clinic (Ansung, Kyungi-do), investigated maximum corrected vision, axial length, anterior chamber depth and accompanied ocular diseases before and after the surgeries based on the collected data. Results: As patients aged, axial length unchanged but anterior chamber depth decreased over all due to the increase of intraocular lens thickness, and men tended to have a higher degree than women. Seventy-one (86.6%) of eighty-two eyes showed improved corrected vision than before surgeries and forty-three (52.4%) eyes could see more than visual acuity of 0.5. Conclusions: Patients with the systemic disease and accompanied ocular disease showed low vision less than 0.5 after cataract surgery compared to same healthy age peoples. But the others improved correction visual acuity more than 0.5, so the cataract surgery was surely necessary for people over 90 years old and also the presence of ocular disease could have a great influence on correction visual acuity.

Right coronary artery atresia in Marfan's syndrome: A case report (Marfan 증후군에 동반된 우관상동맥 폐쇄증 - 1 례 보고 -)

  • 이재원
    • Journal of Chest Surgery
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    • v.34 no.9
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    • pp.720-723
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    • 2001
  • A case of Marfan’s syndrome with atresia of right coronary artery is reported. A 45-year-old woman, who was diagnosed as Marfan’s syndrome 1 year ago, came to the hospital complaining of acute chest pain. The patient showed arachynodactyly, pectus carinatum, and long and slender extremities. In echocardiography there were severe aortic regurgitation measured grade IV and aortic dilatation of ascending aorta maximally 5.9 cm in diameter. Mitral regurgitation was mild, but there were also moderate left ventricular dilation and moderately decreased ejection fraction of left ventricle. At operation, atresia of right coronary artery was found. We performed Bentall type operation with SJM 27mm valved conduit for left coronary artery, and Piehler’s modification for right coronary artery bypass using 6mm PTFE graft. The atretic portion of right coronary artery from the suspected right coronary ostium to distal coronary flow was about 4 cm in length. The combination of right coronary artery atresia and Marfan’s syndrome is very rare. The author describes the rare case, which is treated with combined technique of Bentall and Piehler modification for reconstruction of coronary circulation.

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Accuracy of Astigmatic Correction Using Toric Intraocular Lens by Position and Size of Corneal Incision (각막절개 위치와 크기에 따른 난시교정인공수정체의 난시교정의 정확성)

  • Park, Wookyung;Kim, Man Soo;Kim, Eun Chul
    • Journal of The Korean Ophthalmological Society
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    • v.60 no.2
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    • pp.126-134
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    • 2019
  • Purpose: To assess the accuracy of toric intraocular lens (IOL) implantation by the location and size of the corneal incision. Methods: We retrospectively reviewed the medical records of 98 patients (98 eyes) who underwent phacoemulsification with toric IOL implantation from January 2014 to March 2017. The patients were divided into two groups: group 1 got an incision of the superior side of the cornea (n = 54) and group 2 received an incision on the temporal side of the eye (n = 44). For both groups, incisions were made at their steep corneal astigmatism axises. Each group was further divided into subgroups for whom different sized blades were employed (2.75 vs. 2.2 mm widths). We measured the refractive index and autokeratometric parameters. We postoperatively assessed residual astigmatism and any reduction thereof. Results: In both groups, uncorrected and best-corrected visual acuity, refraction cylinder astigmatism, and autokeratometric astigmatism improved statistically. Between two groups, corneal astigmatism decrease was not significant. Residual astigmatism also showed no significant differences between the two. Patients in both groups treated using 2.75 mm wide blades exhibited greater increases in corneal astigmatism. Conclusions: During cataract surgery, precise correction of astigmatism via toric IOL implantation is possible when surgically induced astigmatism is minimized by careful choice of the location and size of the corneal incision.

Prognostic Factors Affecting Postoperative Morbidity and Mortality in Destroyed Lung (파괴폐의 술후 합병증과 사망에 영향을 미치는 예후 인자)

  • 홍기표;정경영;이진구;강경훈;강면식
    • Journal of Chest Surgery
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    • v.35 no.5
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    • pp.387-391
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    • 2002
  • Background: Postoperative morbidity and mortality in destroyed lung are relatively high. We tried to identify the prognostic factors affecting postoperative morbidity and mortality in destroyed lung through a retrospective study. Material and method: The retrospective study was undertaken in 112 patients who had undergone pneumonectomy or pleuropneumonectomy for destroyed lung at Severance Hospital from 1970 to 2000. We analyzed the correlation between postoperative morbidity and mortality and etiology, duration of disease, preoperative FEV1, presence or absence of peroperative empyema, operation timing, the side of operation, duration of operation, and operation type. Result: There were 55 men and 57 women, aged 20 to 81 years (mean 44 years). Etiologic diseases were tuberculosis in 86 patients(76.8%) including tuberculos empyema in 20 and tuberculous bronchiectasis in 4, pyogenic empyema in 12(10,7%), bronchiectasis in 12(10.7%), and lung abscess in 2(1.8%). Postoperative morbidity were 25%(n=28) and postoperative mortality was 6%(n=7). The presence of preoperative empyema(p=0.016), pleuropneumonectomy(p=0.037) and preoperative FEV1 of less than 1.75 L(P=0.048) significantly increased the postoperative morbidity, If operation time was less than 300min, postoperative morbidity(p=0.002) and mortality(p=0.03) were significantly low. Conclusion: Postoperative morbidity and mortality in destroyed lung were acceptable. Postoperative morbidity and mortality were significantly low when operation time was less than 300 min. Preoperative existence of empyema, pleuropneumonectomy and preoperative FEV1 of less than 1.75 L significantly increased postoperative morbidity.

Mutation Induction and Selection of Salt-tolerant Plants by Heavy-ion Beam Irradiation in Tobacco Proembryo (중이온 빔 조사에 의한 담배의 돌연변이 유도와 내염성 식물의 선발)

  • ;Abe Tomoko
    • Korean Journal of Plant Tissue Culture
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    • v.25 no.2
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    • pp.103-107
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    • 1998
  • Tobacco proembryos were irradiated with 100 Gy of heavy-ion beams($^{14}\textrm{N}$, $^{20}\textrm{Ne}$: 135 Mev/u) after 24 to 96 hours of pollination as a mutagen and screened $\textrm{M}_{1}$ generation for morphological mutants and salt-tolerant plants. Morphological and physiological characteristics of the salt-tolerant plants derived from the irradiated proembryo are discussed in this report. Mutants irradiated proembryos with the beams after pollination produced various kinds of morphological variation. A total of 17 salt-tolerant plants were selected from tobacco cultivar (BY-4) by treatment with $^{14}\textrm{N}$ beam. Shapes of filament and pollen grain of most salt-tolerant plants were abnormal compared with non-irradiated wild type, and seeds weight and fertility obviously decreased. The germination rates of the several $\textrm{M}_{2}$ lines on the saline and the mannitol condition were higher than that of wild type.

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A Case of Isolated Traumatic Aniridia in a Pseudophakic Eye (위수정체안에서 발생한 외상무홍채증 1예)

  • Kwon, Mi Young;Hong, Hye Jin;Park, Dae Jin
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.12
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    • pp.1185-1189
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    • 2018
  • Purpose: We report a rare case of isolated traumatic aniridia in a pseudophakic eye. Case summary: A 69-year-old female came to our emergency department complaining of right eye pain and visual disturbance after trauma due to fall on the stairs. Five years earlier she had undergone an uncomplicated right sutureless phacoemulsification cataract extraction through a 2.2 mm temporal clear corneal incision, followed by insertion of a folding intracapsular intraocular lens. Total iris expulsion occurred through the cataract incision without extension of the wound or disruption of the posterior capsule or intraocular lens. Conclusions: We report a rare case of isolated traumatic aniridia in a pseudophakic eye, which has not been reported in the Republic of Korea.

An Integrative Review on Alterations of Sleep after Cataract Surgery (백내장 수술 후 수면 변화에 관한 통합적 고찰)

  • An, Gyeong-Ju
    • Journal of Korean Biological Nursing Science
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    • v.21 no.1
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    • pp.12-21
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    • 2019
  • Purpose: The purpose of this study was to review previous literature with an aim to explore the sleep disturbance level after a patient undergoes cataract surgery using an integrative review. Methods: We used the key words, 'cataract surgery', 'sleep', and 'intraocular lens' to find peer-reviewed publications in seven databases. Among 450 searched articles, eight articles were selected after exclusion of articles that did not meet the criteria. Results: Five of the articles submitted that subjective sleep quality of the patients with blue-filtering intraocular lens (BF-IOL) implant improved as compared to that before surgery. The change of saliva melatonin concentration after BF-IOL implant did not coincide in two of the articles. Two of the articles reported an increased level of intrinsically photosensitive retinal ganglion cells response after BF-IOL implantation. Conclusion: The published studies stated that BF-IOL implant did not have any negative impact on quality of sleep among cataract patients suffering with poor sleep. Rregardless of intraocular lens type, cataract surgery may increase photoreception of intrinsically photosensitive retinal ganglion cells one year after surgery although the mechanism was not clear. It is necessary to identify various factors influencing the quality of sleep such as gender and activities among cataract patients with BF-IOL implant in the future.