Research Higher-order Aberrations Of Different MoIOL Using OPD-Scan ? Aberrometer

ObjectiveTo apply OPD-Scan III(Nidek,Gamagori,Japan)aberrometer in the measurement of higher order aberrations following cataract surgery when different aspheric,Mo IOL(monofocal intraocular lens)are implanted and at the same time compare the results with intraocular aberrations of the normal crystalline lens of younger patients.The aim is to find the reason for the decline in the quality of vision,glare and blurred vision that have been reported by patients after implantation of IOL(intraocular lens)following cataract surgery and also this information can help in providing reference for the selection and design of customized IOL in cataract patients.Methods65 senile cataract patients in the period of June 2016 to December 2016 from our hospital were taken into the study.A total of inpatient cases involving 65 eyes,comprising of 36 eyes from 36 female patients and29 cases(29 eyes)involving male patients.The age range was between 58 to 80 years old with a mean age of 71± 2.25 years old.Aprospective randomized controlled study was done and the patients were randomly divided into two groups.Each group had no significant difference involving nuclear hardness and age.In group A,a single piece of aspherical IOL(RAYNER 920H)was implanted.In group B,HOYA PY-60 AD IOL having an aspherical surface was implanted.The power of IOL implanted in both groups were within the range of 19.0D to 24.0D.Group C involved young patients selected from the same hospital involving patients' families and university students who volunteered in this study,comprising a total of 30 cases(30 eyes).Random selection of the laterality of the eye was done.A total of 15 cases(15 eyes)from male patients and 15 cases(15 eyes)were examined from female patients.The age range was between 12 to 30 years old with a mean age of 19±1.83 years old.Group A and B both underwent phacoemulsification combined with IOL implantation.IOL power was calculated by using the SRK-?formula.In order to obtain a good post-operative vision and meet the demand of myopia,the target refraction was set to-0.50 D.Postoperatively OPD-Scan III wavefront aberrometer was used to measure the intraocular aberrationsof the three groups under a pupillary diameter of 3 and 5 mm.The examination include the total higher order aberration(HOA)?total coma(TC)?total trefoil(TT)root mean square(RMS)and Zernike coefficient for spherical aberration(Z40).SPSS 17.0(American IBM company)statistical software package was used for analysis.The three groups of quantitative data were compared by using One-Way Analysis of Variance for independent samples.A value of p< 0.05 was taken as statistically significant.Subjective visual symptoms were collected by questionnaire from all three groups.Results1? With a 3 mm diameter pupil,the total intraocular higher-order aberrations(HOA),total coma(TC),total trefoil(TT)RMS of both group A and B showed no statistically significant difference(p> 0.05).However intraocular spherical aberration(Z40)are different and have statistical significance(p< 0.05).Comparison of the intraocular total higher order aberrations(HOA),total coma(TC),total trefoil(TT)RMS of group A and B were larger than those of group C,and the difference was statistically significant(p< 0.05).The intraocular spherical aberration(Z40)of group Cwith group A and B showed no statistically significant difference(p> 0.05).2? With a 5 mm diameter pupil,the intraocular total higher order aberrations(HOA),total coma(TC)and spherical aberration(Z40)of group A and B were different and was statistically significant(p<0.05).The totaltrefoil(TT)RMS showed no statistically significant difference(p>0.05).When group A and B were compared with group C,group A and B revealed intraocular higher-order aberrations(HOA),total coma(TC),totaltrefoil(TT)RMS higher than that of group C with an obvious difference which was statistically significant(p< 0.05).The intraocular spherical aberration(Z40)value difference between group A and group C were statistically significant(p< 0.05)whereas between group B and group C showed no significant difference(p> 0.05).Conclusion1?The best corrected visual acuity(BCVA)of the patients implanted with RAYNER 920 H aspheric intraocular lens(IOL)and HOYA PY-60 AD intraocular lens(IOL)improved postoperatively and there was no significant statistical difference.2?In clinical practice,patientswith large corneal coma having normal or small pupil can be considered for RAYNER 920 H IOL implantation.3?Group B(HOYA)IOL with the intraocular total spherical aberration(TSA)close to that of the crystalline lens of younger patients may be considered for those with a large pupil prior to cataract surgery for example night workers and glaucoma patients.They are more encouraged to choose negative spherical aberration IOL,because this type of IOL balances the corneal positive spherical aberration in the large pupil and is more advantageous than spherical IOL.4? At the same level of visual acuity(more than 0.8),IOL higher order aberration RMS is higher than that of the crystalline lens of young patients,but vision is better in a larger pupil.This may be one of the reasons pertaining to the unsatisfactory quality of vision following cataract surgery showing that IOL need further improvement in design.