Research on New Test Lenses for Dioptric Power of Intraocular lenses
Objective Intraocular lenses are intended to replace the cataractous human lens when it is surgically removed. ALL intraocular lenses are labelled with dioptric power in aqueous.Whether the labelled value is exact is very important for both patients and doctors. Therefore,verification of tlte accuracy and calibration of the instrument used to measure intraocular lens dioptric power are of the utmost importance.However,in China there hasn t any normative test or calibration methods suggested to check these instruments,and so do any standards or regulations. The objective of this research is to realize the calibration of these instruments and unify the quantity value of intraocular lens dioptric power by developing a new set of test lenses.Method—According to the definition of intraocular lens dioptric power,first spherical aberration for different design structures is analyzed in air and in aqueous respectively. Then the optimum design structure is chosen and test lenses are manufactured.Next paraxial approximation is used to relate the lens parameters-with dioptric power and uncertainty budget is calculated.Finally experiments are done on different kinds of instruments and discussions are made.Result: The newly developed test lenses are composed of 8 pieces of lenses with dioptric power from-10m-1 to 30m-1 in the step of 5m1. The uncertainty of the standard value is about 0.06m-1 with coverage factor 2.Results show that the test lenses can realize the calibration of different kinds of instruments used to measure intraocular lens dioptric power very well.Conclusion: A new set of test lenses for dioptric power is designed and manufactured for intraocular lens instruments.Its quantity values can be traced to the highest National standard in China.Moreover,by experiments it is proved to be feasible and effective to realize metrological calibration of IOL power instruments. The research is also helpful to the establishment of metrological standard for intraocular lens dioptric power in China.
Metrology Intraocular lens test lens dioptric power calibration uncertainty
Zhang Jiyan Li Fei Liu Wenli Hong Baoyu
National Institute of Metrology,Beijing 100013 China Beijing Institute of Technology,Beijing 100081 National Institute of Metrology,Beijing 100013 China
国际会议
2009 9th International Conference on Electronic Measurement & Instruments(第九届电子测量与仪器国际会议 ICEMI2009)
北京
英文
151-155
2009-08-16(万方平台首次上网日期,不代表论文的发表时间)