Dissertation > Medicine, health > Ophthalmology > Eye surgery and surgery > Cataract surgery

Ray Tracing Method to Tetraflex Accommodative Intraocular Lens Apparent Regulation Research

Author ShiPengFei
Tutor ShangQingLi;ZhangBin
School Hebei Medical University
Course Ophthalmology
Keywords Forward Apparent accommodative depth of focus Intraocular lens Model eye ZEMAX
CLC R779.66
Type Master's thesis
Year 2014
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Objective:The cataract extraction combined intraocular lens implanta-tion has entered the refractive surgery category,with the patients graduallyincrease to the requirement of vision,so how to choose reasonable intraocularlens become the important factors influencing the operation effect,directlydecides the postoperative visual quality,Accommodative intraocular lens(accommodative intraocular lens,AIOL) in clinical has gained more and moreapplications,so how can make patients get more apparent adjustment researchbecome a hot spot,the majority of the studies at home and abroad is byobserving the patients after the operation of the indicators,to evaluate itsregulating function,then can be estimated before the surgery effect,achieveexpected apparent adjustment increase in theory,sparticularly important.Thisexperiment aims to Tetraflex accommodative intraocular lens apparentadjustment increase in the influence factors of preliminary discussion forclinical doctors before the operation comprehensive and provides the theorybasis for reasonable selection of intraocular lens,a better service to patients.Methods:Using the ZEMAX optical design software,according to theray tracing (ray-tracing) principle,construct Liou-Brennan artificial eyemodel, simulate the light through the optical system is built by thetransmission of the optical components.1Liou-Brennan artificial eyes simulation model in the550-nmmonochromatic light under the condition of10D,20D,30D three kind ofTetraflex accommodative intraocular lens under different pupil diameter (3mm,4mm,5mm) forward (0.2mm,0.4mm and0.6mm,0.8mm and1mm)cross-eyed apparent adjustment increase impact.2Simulated550nmunder monochromatic light,Tetraflex accommodativeintraocular lens in the eyes of the various types of model from focal modulation transfer function,the modulation transfer function curvedata,analyze its negative focal characteristics.3According to the first two part of the experimental data,the analysisTetraflex accommodative apparent adjustment increase after intraocular lensforward,then combined depth of focus,in the comprehensive comparison ofpseudophakic accommodation.Results:By calculating ZEMAX optical design and analysis software, draw thefollowing data:1Tetraflex accommodative diopter intraocular lens10D1.1Under the pupil diameter of3mm: Forward0.2mm, apparent adjustmentincreases0.1202D; forward0.4mm, apparent adjustment increases0.2414D;forward0.6mm, apparent adjustment increases0.3633D; forward0.8mm,apparent adjustment increases0.4859D; forward1mm, apparent adjustmentincreases0.6092D; defocus MTF provided negative defocus of-0.6D.1.2Under4mm pupil diameter:forward0.2mm, apparent adjustment increase0.1218D; forward0.4mm, apparent adjustment increase0.2448D; forward0.6mm, apparent adjustment increase0.3686D; forward0.8mm, apparentadjustment increase0.4932D; forward1mm, apparent adjustment increase0.6185D; defocus MTF provided negative defocus is-0.54D.1.3Under5mm pupil diameter:forward0.2mm, apparent adjustment increases0.1234D; Forward0.4mm, apparent adjustment increases0.249D; Forward0.6mm, apparent adjustment increases0.3753D; forward0.8mm, apparentadjustment increases0.5024D; forward1mm, apparent adjustment increase0.6302D; defocus MTF provided negative defocus is-0.54D.2Tetraflex accommodative diopter intraocular lens20D2.1Under pupil diameter3mm:forward0.2mm, apparent adjustment increase0.2617D; Forward0.4mm, apparent adjustment increases0.525D; Forward0.6mm, apparent adjustment increases0.7895D; Forward0.8mm, apparentadjustment increases1.055D; forward1mm, apparent adjustment increase1.322D; defocus MTF provided negative defocus is-0.54D. 2.2Under4mm pupil diameter:forward0.2mm, apparent adjustment increases0.266D; Forward0.4mm, apparent adjustment increases0.535D; Forward0.6mm, apparent adjustment increases0.805D; Forward0.8mm, apparentadjustment increases1.076D; forward1mm, apparent adjustment increase1.347D; defocus MTF provided negative defocus is-0.54D.2.3Under5mm pupil diameter:forward0.2mm, apparent adjustment increases0.272D; Forward0.4mm, apparent adjustment increases0.548D; Forward0.6mm, apparent adjustment increases0.825D; Forward0.8mm, apparentadjustment increases1.104D; forward1mm, apparent adjustment increase1.384D; defocus MTF provided negative defocus is-0.48D.3Tetraflex accommodative diopter intraocular lens30D3.1Under pupil diameter3mm:Forward0.2mm, apparent adjustment increases0.429D; Forward0.4mm, apparent adjustment increases0.86D; Forward0.6mm, apparent adjustment increases1.293D; Forward0.8mm, apparentadjustment increases1.728D; forward1mm, apparent adjustment increase2.163D; defocus MTF provided negative defocus is-0.63D.3.2Under4mm pupil diameter:forward0.2mm, apparent adjustment increases0.441D; Forward0.4mm, apparent adjustment increases0.885D; Forward0.6mm, apparent adjustment increases1.331D; Forward0.8mm, apparentadjustment increases1.7791D; forward1mm, apparent adjustment increase2.228D; defocus MTF provided negative defocus-0.63D.3.3Under5mm pupil diameter,forward0.2mm, apparent adjustment increases0.514D; Forward0.4mm:apparent adjustment increases0.976D; Forward0.6mm, apparent adjustment increases1.44D; Forward0.8mm, apparentadjustment increases1.905D; forward1mm, apparent adjustment increase2.372D; defocus MTF provided negative defocus-0.39D.Conclusion:In the eyes of the model, with the intraocular lens forward, the regulatingforce is also generated by the apparent increase in the apparent increase inforce generated when adjusting the diameter of the pupil also increases, andthe intraocular lens power greater impact on the overall change in the pseudo-accommodation power, the pupil diameter changes less impact on thepseudo-regulating force; highly hyperopia (30D) relative to patients with highmyopia patients (10D) can theoretically get a more clear regulatory force toguide the selection of the type of clinical crystals

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