Predictive factors for photic phenomena after refractive,rotationally asymmetric,multifocal intraocular lens implantation

AIM： To investigate the independent factors associated with photic phenomena in patients implanted with refractive,rotationally asymmetric,multifocal intraocular lenses（MIOLs）.METHODS： Thirty-four eyes of 34 patients who underwent unilateral cataract surgery,followed by implantation of rotationally asymmetric MIOLs were included.Distance and near visual acuity outcomes,intraocular aberrations,preferred reading distances,preoperative and postoperative refractive errors,mesopic and photopic pupil diameters,and the mesopic and photopic kappa angles were assessed.Patients were also administered a satisfaction survey.Photic phenomena were graded by questionnaire.Independent-related factors were identified by correlation and bivariate logistic regression analyses.RESULTS： The distance from the photopic to the mesopic pupil center（pupil center shift） was significantly associated with glare/halo symptoms [odds ratio（OR）=2.065,95% confidence interval（CI）=0.916-4.679,P=0.006] and night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007）.The preoperative photopic angle kappa was significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041）.The photopic angle kappa was also significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041） and with night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007） in patients implanted with rotationally asymmetric MIOLs.CONCLUSION： A large pupil center shift and misalignment between the visual and pupillary axis（angle kappa）may play a role in the occurrence of photic phenomena after implantation of rotationally asymmetric MIOLs.

Comparative analysis of visual quality between unilateral implantation of a trifocal intraocular lens and a rotationally asymmetric refractive multifocal intraocular lens

·AIM:To compare visual quality after unilateral cataract surgery with implantation of trifocal intraocular lens(IOL)and asymmetric refractive multifocal IOL.·METHODS:The prospective nonrandom,comparative study consisted of 60 eyes of 60 patients suffering unilateral cataract surgery with implantation of two different IOLs:AT LISA tri 839 MP(30 eyes;Carl Zeiss Meditec,Germany)and LS-313 MF30(30 eyes;Oculentis GmbH,Germany).Visual acuity,refractive outcome,contrast sensitivity,defocus curves,quality of vision,and optical phenomena were evaluated at3 mo postoperatively.·RESULTS:There were no statistical differences between groups in uncorrected distance visual acuity(P=0.13)and uncorrected near visual acuity(P=0.54).In contrast,uncorrected intermediate visual acuity was better in trifocal group compared to the refractive multifocal group(P=0.02).No significant statistical between-group difference was detected in cylinder(P=0.43).Compared to trifocal group,spherical refraction and spherical equivalent in refractive multi focal group were more myopic(P<0.01).Under photopic conditions,no significant statistical differences were found between groups in contrast sensitivity at 3 and 6 cycles per degree(cpd).The refractive multifocal group performed better at 12 and 18 cpd than the trifocal group(P=0.01,P=0.034,respectively).The questionnaires of quality of vision and optical phenomena showed no differences between groups.·CONCLUSION:Trifocal IOL is superior to refractive multifocal IOL in intermediate visual acuity.Rotationally asymmetric refractive multifocal IOL is more myopic in automated refraction and significantly better for the photopic contrast sensitivity at high frequency.

Giant Asymmetric Transmission and Optical Rotation of a Three-Dimensional Metamaterial

We show that giant asymmetric transmission and optical rotation for linear polarizations can be achieved by a chiral three-dimensional metamaterial composed of L-shaped and C-shaped metallic particles. Numerical calcu- lations on the electric field distributions indicate that the coupling between the electric dipolar and quadrupolar resonances in the L- and C-shaped metallic particles contributes to these effects.

Secondary positioning of rotationally asymmetric refractive multifocal intraocular lens in a patient with glaucoma:A case report

BACKGROUND Asymmetric multifocal intraocular lenses(IOLs)are now widely used in the modern cataract surgery,providing a good level of visual performance over a range of distances and high postoperative patient satisfaction.We report a case of improved visual quality after shifting the near segment of an asymmetrical multifocal IOL to the superotemporal placement in the dominant eye of a glaucoma patient.CASE SUMMARY A 72-year-old woman with bilateral glaucoma underwent phacoemulsification in the dominant eye(left eye)with implantation of an asymmetrical multifocal IOL.Postoperative uncorrected distance visual acuity(UDVA)was 0.0 logMAR(20/20 Snellen)and uncorrected near visual acuity(UNVA)was 0.1 logMAR(20/25 Snellen).Two weeks later,the patient presented to our clinic with decreased vision due to migration of lens epithelial cells to IOL anterior surface and edema of corneal endothelial cells.Anterior capsule polishing and superotemporal placement of near segment[+3.00 diopter(D)addition(add)]of IOL were performed.As a result,UDVA at the first week and first year after reposition was 0.0 logMAR(20/20 Snellen),and compared with 0.3 logMAR(20/40 Snellen)in the first week,the UNVA was improved to 0.0 logMAR(20/20 Snellen)one year after surgery.CONCLUSION The postoperative inflammatory reaction and lens epithelial cells proliferation were obvious in this glaucoma patient.Capsule polishing and rotation of the lens were beneficial to the patient,which not only enhanced the patient's vision,but also improved the patient's satisfaction.Therefore,glaucoma patients need to be cautious of implanting multifocal IOLs.Placement of a near segment of an asymmetrical multifocal IOL in the dominant eye should be performed on an individual basis.

Prediction of mass transfer coefficients in an asymmetric rotating disk contactor using effective diffusivity

Mass transfer characteristics have been investigated in a 113 mm diameter asymmetric rotating disk contactor of the pilot plant scale for two different liquid–liquid systems. The effects of operating parameters including rotor speed and continuous and dispersed phase velocities on the volumetric overall mass transfer coefficients are investigated. The results show that the mass transfer performance is strongly dependent on agitation rate and interfacial tension, but only slightly dependent on phase flow rates. In this study, effective diffusivity is used instead of molecular diffusivity in the Grober equation for estimation of dispersed phase overall mass transfer coefficient.The enhancement factor is determined experimentally and there from an empirical expression is derived for prediction of the enhancement factor as a function of Reynolds number. The predicted results compared to the experimental data show that the proposed correlation can efficiently predict the overall mass transfer coefficients in asymmetric rotating disk contactors.

Field-free molecular orientation enhanced by tuning the intensity ratio of a three-color laser field

We theoretically study the field-free molecular orientation induced by a three-color laser field. The three-color laser field with a large asymmetric degree can effectively enhance the molecular orientation. In particular, when the intensity ratio of the three-color laser field is tuned to a proper value of I3： I2： I1= 0.09 ： 0.5 ： 1, the molecular orientation can be improved by - 20% compared with that of the two-color laser field at intensity ratio I2： I1= 1 ： 1 for the same total laser intensity of 2×10^13W/cm^2. Moreover, we investigate the effect of the carrier-envelope phase（CEP） on the molecular orientation and use the asymmetric degree of the laser field to explain the result. We also show the influences of the laser intensity, rotational temperature, and pulse duration on the molecular orientation. These results are meaningful for the theoretical and experimental studies on the molecular orientation.

Energy Absorption Characteristics of a Novel Asymmetric and Rotatable Re-entrant Honeycomb Structure

Based on the symmetric re-entrant honeycomb(S-RH)structure with negative Poisson’s ratios,a novel asymmetric and rotatable re-entrant honeycomb(AR-RH)structure was proposed.Both the S-RH structure and AR-RH structure were produced by the 3D printing technology.Through experimental test and finite element simulation,the deformation mechanism and energy absorption characteristics of the AR-RH structure and the S-RH structure with negative Poisson’s ratios at different impact velocities were compared.The experimental test and finite element simulation results show that the novel AR-RH structure with negative Poisson’s ratios has stronger energy absorption capacity than the S-RH structure,and it has been verified that the rotatability of AR-RH can indeed absorb energy.Furthermore,the degree of asymmetry of the AR-RH structure was discussed.

Matching by solenoids in space charge dominated LEBTs

The betatron matching of a rotationally asymmetric beam in space charge dominated low-energy beam transports （LEBTs） where solenoids are used for the transverse matching has been studied. For better understanding, the coupling elements of a beam matrix are interpreted in special forms that are products of a term defined by the Larmor rotation angle and another by the difference between the beam matrix elements in the two transverse planes. The coupling form originally derived from the rotationally symmetric field in solenoids still holds when taking into account the rotationally asymmetric space charge forces that are due to the unequal emittance in the two transverse planes. It is shown in this paper that when an LEBT mainly comprising solenoids transports a beam having unequal emittance in the two transverse planes and the linear space charge force is taken into account, the initial Twiss parameters can be modified to obtain the minimum and equal emittance at the LEBT exit. The TRACE3D calculations also prove the principle. However, when quadrupoles that are also rotationally asymmetric are involved in between solenoids, the coupling between the two transverse planes becomes more complicated and the emittance increase is usually unavoidable. A matching example using the CSNS （China Spallation Neutron Source） LEBT conditions is also presented.