摘要：現代人的日常活動中，有百分之八十的資訊直接或間接來自視覺系統的傳遞，而視覺的知識傳遞仰賴自然或人工照明加以完成，人工照明光源中，發光二極體 (LightEmitting Diode, LED) 照明以環保節能的優勢深獲期許。然LED 是由半導體材料所製成的發光元件，而白光LED 光譜落於400 nm – 550 nm 區間，屬於視網膜藍光危害區，且其中尖銳的藍光波峰所呈現的單點強度，可能對視網膜產生傷害而未被使用者察覺，長期暴露也可能對黃斑部產生累積性的負面效應，因此LED 照明如何呈現最適合生理機轉的光學表現，有待醫學體系的專業研究並定義。本計畫預計針對白光 LED 做為室內照明之建議波長與頻譜分佈進行檢驗分析，透過動物實驗，以視網膜電波圖 (electroretinogram , ERG)檢查視網膜功能上所受的影響，也以組織切片觀察感光細胞形貌上的改變，研析白光LED 照明對使用者視網膜生理結構的影響。本團隊將延伸現有之初步研究結果，再透過執行本計畫之前期研究，觀察27 隻大鼠視網膜感光細胞生理變化。根據前期研究之結果設計動物實驗，以LED 全頻譜光源，色溫度3300 – 7000 K 、暴露時間24 h - 540 h 等暴露參數組合進行分組實驗，實驗組93 隻大鼠在不同參數組合條件下，而2 組控制組則以15 隻進行T5 螢光燈管照光，另15 隻進行白熾燈泡之照光，觀察視網膜感光細胞產生的光化學(photochemical)結構變化，藉以推論白光LED 光源對視網膜感光細胞的影響，以及高劑量短時間暴露之劑量效應關係。
Abstract: It is estimated that over 80% of the information processed in the human brain is directlyor indirectly interpreted by the visual system. To perform this function, the light source isneed and essential to ocular system. Among a wide variety of artificial lighting selection,Light Emitting Diode (LED) is surged by the energy conservation trend globally. However,LED is developed from an indicator rather than illuminator, as a result, there are healthconcerns and practical issues should be studied before further expansion. White light LEDwavelength is ranged from 400 nm to 550 nm which is the retinal hazard region.Moreover, the sharp blue peak in the spectrum signifies the strong intensity which causesblue light hazard, but hard to be recognized by human eyes. Macular degeneration is alsoprojected with long term exposure of this type of light source. Therefore, medical study anddescription is critical to clarify its mechanism and dose response relationship.A pilot study will be initiated based on our preliminary result to define the physicalcharacteristics and measurements for further animal study. As for this pilot study, 9 six toeight-weeks-old male Wistar rats are exposed to single wavelength 460 nm LED lightsource for a week (12h light / 12h dark) under the intensity of 2500 lux; while a group of9 rats are exposed to T5 fluorescent light (2500lux / 6500 K) and another group of 9 ratsare exposed to incandescent light (2500 lux / 4500 K) for the same condition to serve as thecontrol groups. The rats will be sacrificed and their retinal tissues will be taken forpathological analysis after a week of exposure. Some biomarkers will be investigated andidentified such as phyknosis, mitochondria swollen, increase of phagosomes and myeloidbody on retinal pigment epithelial (RPE) indicating the photochemical injure by the blue lightexposure. Furthermore, the rats will be scanned by electroretinogram (ERG) during theexposure process at 3-hours, 60-hours, and 168-hours period to compare the biopsy results.Developing from the pilot study, we will expand the animal study by a variety ofparameters to further confirm the blue light hazard. Full spectrum LED with Correlated ColorTemerature (CCT) 3300 - 7000K will be adapted; Intensity from 1750 -3000lux with totalexposure time range from 24 hours to 504 hours under the light cycle of 12h-dark /12h-light will be distributed into the parameter matrix. Accordingly, we will run the tests with93 rats with more pathological experiments to exam the apoptosis or necrosis condition onretinal photoreceptors. Two control groups (15 for fluorescent light and 15 for incandescentlight under the light cycle of 12h-dark / 12h-light) are also used to compare the tests. Weexpect to confirm the blue light photochemical injury to the retina with the signs of retinaldegeneration and Choroidal neovascularization on the photoreceptors. With this information,we hope to highlight the dose response relationship and exposure threshold for adaptingLED as an indoor light source.
indoor LED lighting
LED light source