Effect of High-Order Aberrations and Satisfaction on Cataract Patients Implanted with Four Types of AcrySof Blue Light Filtering Intraocular Lens

Objective: The objective is to evaluate the visual acuity, high-order aberrations and satisfaction in the cataract patients with the implantation of different types of AcrySof blue light filtering intraocular lens, which would provide the clinical guidance for the selection of individualized intraocular lens. Methods: From January 2019 to December 2020, the patients with age-related cataract in Guangzhou Red Cross Hospital were equally randomized to be divided into four groups. 20 patients (20 eyes) were implanted with AcrySof (SN60WF), which was the blue light filtering single focus group;20 patients (20 eyes) were implanted with blue light filtering aspheric multifocal intraocular lens (AcrySof ReSTOR IOL +3.0D, SN6AD1), which was the multifocal intraocular lens group;20 patients (20 eyes) were implanted with aspheric astigmatism correction intraocular lens (Toric SN6AT), which was the astigmatism group;20 patients (20 eyes) were implanted with blue filtering aspheric multifocal astigmatism correction intraocular lens (AcrySof ReSTOR IOL +2.5D IQ, SV25T0), which was the ART group. Three months after the operation, the patients were followed up with slit lamp to check the visual acuity, including uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity (UCNVA), best corrected distance visual acuity, (BCDVA);the questionnaire surveys on the satisfaction of different intraocular lens implantation (far and near vision, glare, halo and abnormal visual symptoms);the iTrace visual function analyzer was used to check the total high-order aberrations (spherical aberration, wisdom aberration and Clover aberration) in the 3 mm pupil diameter. Results: Three months after cataract surgery, American Simplified version of questionnaire survey showed that the scores of near removing glasses in the multifocal group and the ART group were significantly better than those in the single focus group and the astigmatism group (P < 0.05);there was no significant difference in the satisfaction of far removing glasses, glare and halo in each group (P > 0.05). Three months after cataract surgery, there were statistically significant differences about UCDVA, BCDVA and UCNVA among the four groups (F = 18.189, P < 0.001), the UCNVA in the multifocal group and ART group was significantly better than that in the single focus group and the astigmatism group (P < 0.01). The difference of higher-order aberrations (total higher-order aberrations, wisdom aberrations, spherical aberrations, clover aberrations) was no statistically significant among the four groups (P > 0.05). Conclusion: Different types of AcrySof blue light filtering intraocular lens implantation could improve the far vision and satisfaction of cataract patients, without different higher-order aberrations. Multifocal intraocular lens and ART intraocular lens could significantly improve the far vision of patients and reduce the dependence on near glasses.

Study on high-order frequency selective surface with interdigital capacitance loading

The application of frequency selection surfaces(FSSs)is limited by large area,narrow bandwidth,low stopband inhibition and large ripple in the passband.A method for designing high-order wide band miniaturized-element frequency selective surface(MEFSS)with capacitance loading is introduced.The proposed structure is composed of multiply sub-wavelength interdigital capacitance layer,sub-wavelength inductive wire grids separated by dielectric substrates.A simple equivalent circuit model,composed of short transmission lines coupled together with shunt inductors and capacitors,is presented for this structure.Using the equivalent circuit model and electromagnetic(EM)model,an analytical synthesis procedure is developed that can be used to synthesize the MEFSS from its desired system-level performance indicators such as the center frequency of operation,bandwidth and stopband inhibition.Using this synthesis procedure,a prototype of the proposed MEFSS with a third-order bandpass response,center frequency of 2.75 GHz,fractional bandwidth of 8%is designed,fabricated,and measured.The measurement results confirm the theoretical predictions and the design procedure of the structure and demonstrate that the proposed MEFSS has a stable frequency response with respect to the angle of incidence of the EM wave in the±30°range incidence,and the in-band return loss is greater than 18 dB,and the rejection in the stopband is greater than 25 dB at the frequency of 3.2 GHz.

Amplification characteristics in active tapered segmented cladding fiber with large mode area

A kind of tapered segmented cladding fiber(T-SCF)with large mode area(LMA)is proposed,and the mode and amplification characteristics of T-SCFs with concave,linear,and convex tapered structures are investigated based on finite-element method(FEM)and few-mode steady-state rate equation.Simulation results indicate that the concave tapered structure can introduce high loss for high-order modes(HOMs)that is advantageous to achieve single-mode operation,whereas the convex tapered structure provides large effective mode area that can help to mitigate nonlinear effects.Meanwhile,the small-to-large amplification scheme shows further advantages on stripping off HOMs,and the large-to-small amplification scheme decreases the heat load density induced by the high-power pump.Moreover,singlemode propagation performance,effective mode area,and heat load density of the T-SCF are superior to those of tapered step index fiber(T-SIF).These theoretical model and numerical results can provide instructive suggestions for designing high-power fiber lasers and amplifiers.