Local Weighted Learning Algorithm Based Opacified Lens Nucleus' Spectral Transmittance Measurement

Objective: To analyze the spectral transmittance characteristics of the human opacified lens nucleus and two different types of intraocular lenses as reference standards.Method: Firstly,29 opacified lens nucleuses were obtained through surgery of modern extra capsular cataract extraction.A UV filter type artificial crystal and a blue light filter artificial crystal were collected.Secondly,using the WGD-8A modular multi-function grating spectrometer measured the spectral transmittance of 29 opacified lens nucleuses and the two intraocular lenses.Then the locally weighted learning(Local Weighted Learning,LWL)algorithm was proposed and used to process the measured curves.Finally,these transmittance curves were analyzed and illustrated.Result: The feasibility and reliability of the experiment was testified by comparing the two artificial crystalline lens data with the experimentally measured data.In the studied wavelength,the spectral transmittance of Rayner intraocular lens and HOYA PY-60 AD intraocular lens is mostly similar to its own official data.Then the experimentally measured curves for the 29 three different grades of opacified lens nucleus transmission were illustrated and described.Conclusion: In this paper,the LWL algorithm is proposed fo r the transmittance measurement.It is verified that the LWL algorithms not only can filter the data interference effectively,but also can fit the data characteristics accurately.The spectral transmittance of the opacified lens nucleus is processed by using the LWL algorithm.The spectral transmittance of different grades of the opacified lens nucleus is significantly different.Deepening with the color of the nucleus,the penetrating light's wavelength gets longer and more light of short wavelength is filtered.The opacified lens nucleus of grade standard ? only decreases the light intensity and does not filter out visible light,which means visible light can pass through the nucleus among the measurement spectral range but the transmission is decreasing.However,for the grade standard IV and V,with nucleus color deepening gradually,the lens nucleus can filter out more of short wavelength of visible light and the spectral transmittance decreases obviously.For patients who has yellowish nucleus after implanted intraocular lens can notreach a natural state when looking at things.The research of the opacified lens nucleus' spectral transmission has great value for developing new artificial lens.