| Project/Area Number |
07671939
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Kanazawa Medical University |
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Principal Investigator |
SASAKI Kazuyuki Kanazawa Medical University Medical Professor, 医学部, 教授 (60004850)
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| Co-Investigator(Kenkyū-buntansha) |
ASANO Kouichi Kanazawa Medical University Medical Assistant, 医学部, 助手 (20267743)
KOJIMA Masami Kanazawa Medical University Medical Lecturer, 医学部, 講師 (40183339)
NAKAIZUMI Hiroko Kanazawa Medical University Medical Assistant Professor, 医学部, 助教授 (70131026)
水野 敏博 金沢医科大学, 医学部, 助手 (20239247)
藤沢 来人 金沢医科大学, 医学部, 講師 (40199310)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | cataract / image analysis / spectro transmittance / lens opacity / simulation / lens model / projection retinal image / light transmittance / 散乱光強度 / 白内障、 / 画像解析、 / 分光透過率、 / 水晶体透明度、 / シミュレーション、 / 模型水晶体、 / 網膜投影像、 / 散乱光強度、 |
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| Research Abstract |
In order to simulate on image which is reflected on the retina through opacified lenses, the relationship between the quality of images through model catarctous and the grading of their opacification or opacification types was investigated. In the first year the following studies were performed : 1) Correlation between spectral transmisson factor (T%) and light scattering intensity (SI) in vivo was clarified by (or through) materials of extracted human nuclear cataract lenses and rat lenses. 2) The optical glass model of a lens with nuclear cataract was produced by a suspension of latex particles injected into the central cavity. The opacification grade of the model lenses was quantified by their T% and SI.The resolution of the lenses was evaluated by their modulation transfer function (MTF). 3) Using a steel camera with 35mm film, the quality and detail of photographed images through the model lenses were evaluated. The images obtained through the nuclear catarctous lens corresponded
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with over grade II of the Japanese Cataract Cooperative Epidemiology Study Group system, showing a decrease of contrast and brightness. In the second year of the study : 1) A new type of nuclear and subcapsular cataract model lens was developed. 1-1. To closely simulate human lens conditions, the nuclear cataract model was made of poly-methyl-methacrylate (PMMA) with a cutting wavelength below 390nm (UV). The shape of the nuclear cataract model was the biconvex IOL type and the opacification was made by the polymerization of both hydrophile and lyophobic monomers. 1-ii. Images through this mode were obtained through a steel camera. The decrease in contrast was diminished by cutting UV,making human figures recognizable as subjects through as much as 60% of the transmission lens. 1-iii. The model lens of subcapsular opacification composed of UV-cut IOL and hard contact lens (HCL) was attached behind IOL and whitish corpuscles were inserted in the gap between the lenses. 2) A new type of camera for image simulation was developed. The characteristics of the new camera are ; a model lens which is held in water and a CCD camera that is used as a photographic medium. Real time observation of the reflected images and image input into the computer were easily possible. The model lens with subcapsular opacity was examined by the new camera. To evaluate images through the model lenses, a visual acuity chart, point light source, resolution chart and human figure were used. 3) Images obtained through the model with subcapsular opacity did not show any decrease in image contrast or brightness under 130 cct of SI at the center of the opacity even when the opaque area was enlarged. 4) The simulation of an image was performed through a posterior subcapsular cataract for a particular case. The study was able to successfully obtain the characteristics of image quality through two types of lens opacification. Less
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