The evaluation of visual quality about human eyes has always been an important issue in the field of eye science and visual optics,and it is mainly divided into subjective evaluation method and objective evaluation method,evaluation indicators including visual acuity,contrast sensitivity,wavefront aberration and retinal straylight,and so on.In addition,according to different principles and standards,visual system imaging quality evaluation methods can also be divided into visual refractive system and retinal nerve system evaluation,geometrical optics and physical optics evaluation,static and dynamic visual function evaluation.The selection of visual quality evaluation method should be considered from multiple dimensions on comprehensive consideration.in recent years,the improvement of quality of life promotes the development of visual quality assessment methods,and more attention is paid to the evaluation of continuous functional visual acuity.This article reviews the research progress of visual quality assessment methods.

With the improvement of cataract examination methods,intraocular lens (IOL) design and process,surgical equipments and techniques,cataract surgery was gradually developed from vision rehabilitation to refractive surgery.Therefore,the assessment of visual quality is getting more attention.Clinically,in addition to the extension of concept of visual acuity,contrast sensitivity function (CSF),modulation transfer function (MTF),point spread function (PSF),wavefront aberration and scattering index are also used,with a view to making a comprehensive assessment of visual quality of cataract patients preoperatively and postoperatively.Ophthalmologists should pay attention to the methods and results of evaluation on the visual quality,to provide support for the design of personalized surgery and the improvement of visual quality.

Recently,optical biometers based on swept-source optical coherence tomography (SS-OCT) technology have been applied to clinical ophthalmology.Compared with previous optical biometers,SS-OCT instruments have many advantages,such as faster processes,more accurate results,higher detection rate,and more built-in formulas for calculating the intraocular lens (IOL) power;moreover,SS-OCT images can be used to detect preliminary maculopathy and predict postoperative tilt of IOL.In this paper,we reviewed the application of SS-OCT biometer in cataract,mainly focus on the principle of work,the evaluation of repeatability and reproducibility,the consistency comparison with other biometers,and the application of SS-OCT in other aspects of cataract.

Objective: To evaluate the repeatability and reproducibility of swept-source optical coherence tomography biometrics (Tomey OA-2000) for measuring the biological parameters of the eyeballs in healthy people. Methods: A diagnostic test was carried out in this study.One hundred and three healthy volunteers who were recuited from July to September 2018 in Affiliated Hospital of North Sichuan Medical College were included, and the right eyes were examined.Two examiners used OA-2000 for 3 consecutive measurements, respectively.One week later, the first examiner used OA-2000 for 3 consecutive measurements.The ocular biological parameters including axial length (AL), anterior chamber depth (ACD), corneal curvature (K), lens thickness (LT), central corneal thickness (CCT), pupil diameter (PD), and white to white (WTW) were measured.The repeatability and reproducibility of each parameter based on within-subject standard deviation (S_W), repeatability limit of standard deviation (2.77S_W), coefficient of variation (CoV) and intra-class correlation coefficient (ICC) was evaluated.This study followed the Declaration of Helsinki.This study protocol was approved by Ethic Committee of the Affiliated Hospital of North Sichuan Medical College (No.2018ER[A]019). Results: Of the ocular biological parameters measured by OA-2000, CoV was less than 2% while ICC was greater than 0.950, except PD and WTW.The repeatability and reproducibility of K, AL and ACD were all good.For K₁(ø=2.5 mm and 3.0 mm), the S_W was less than 0.120 D, the 2.77S_W was less than 0.350 D, the CoV was less than 0.293%, and the ICC was greater than 0.990; For K₂ (ø = 2.5 mm and 3.0 mm) , the S_W were less than 0.175 D, the 2.77S_W were less than 0.485 D, the CoV was less than 0.396%, the ICC was greater than 0.980; for K_m (ø = 2.5 mm and 3.0 mm), the S_W were less than 0.099 D, 2.77S_W were less than 0.275 D, CoV was less than 0.227%, ICC was greater than 0.996; ACD S_W was less than 0.024 mm, 2.77S_W was less than 0.066 mm, CoV was less than 0.668%, ICC were greater than 0.993; the S_W of AL was less than 0.014 mm, the 2.77S_W was less than 0.038 mm, the CoV was less than 0.057%, and all of the ICCs were 1.000. Conclusions Except PD and WTW, the ocular biological parameters measured by OA-2000 have good repeatability and reproducibility, in which the accuracy of AL measurement is the highest.

Although binocular vision problems do not appear to be one of the common complications of refractive surgery, the available evidence suggests that these problems can occur after refractive surgery, and preoperative binocular vision status may predict the risk of postoperative binocular vision anomalies.Furthermore, because ophthalmologists usually do not clearly recognize binocular vision, or they do not pay enough attention to it, the existing literature may underestimate the actual prevalence of binocular vision problems after refractive surgery.This paper discusses the existing literature on refractive surgery-related binocular vision anomalies and recommends a screening protocol and risk stratification.It also discusses the expected results of binocular vision testing, the diagnostic criteria for common binocular vision problems, and strategies for treating these anomalies before and after refractive surgery.

The aim of this study was to construct the complete genome of Marek's disease virus serotype 814 strain as an infectious bacterial artificial chromosome (BAC). Using self-designed selection marker Eco-gpt (1.3 kb) and BAC vector pBeloBAC11 (7.5 kb), we constructed the transfer plasmid pUAB-gpt-BAC11. The plasmid pUAB-gpt-BAC11 and MDV total-DNA were cotransfected into secondary CEFs; we put the virus-containing cells in selection medium for eight rounds and obtained purified recombinant viruses. Recombinant viral genomes were extracted and electroporated into E. coli, BAC clones were identified by restriction enzyme digestion and PCR analysis. Finally, we obtained 38 BAC clones, DNA from various MDV-1 BACs was transfected into CEFs, and recombinant virus was reconstituted by transfection of MDV-BAC2 DNA. We successfully cloned the complete genome of MDV-1814 strain as an infectious bacterial artificial chromosome. With these cloned genomes, a revolutionary MDV-DNA engineering platform utilizing RED/ET recombination system was constructed successfully, which can help the understanding of MDV gene functions and promote the using of MDV as a vector for expressing foreign genes. In addition, it opens the possibility to generate novel MDV-1 vaccines based on the BACs.
Animals ; Chickens ; immunology ; virology ; Chromosomes, Artificial, Bacterial ; genetics ; Cloning, Molecular ; DNA, Recombinant ; genetics ; DNA, Viral ; genetics ; Fibroblasts ; metabolism ; Genetic Engineering ; methods ; Mardivirus ; classification ; genetics ; physiology ; Serotyping ; Transfection ; Viral Proteins ; genetics ; physiology ; Virus Replication

Objective:To evaluate the difference and agreement of cycloplegic refraction between adaptive optics visual simulator (VAO) and conventional refraction methods.Methods:A diagnostic test study was conducted.Thirty-one eyes of 31 healthy subjects including 15 males and 16 females were enrolled in November, 2019 in Affiliated Hospital of North Sichuan Medical College.Mean age of the subjects was (20.1±1.0) years, and the right eye was taken for data analysis.Cycloplegic refraction was measured by VAO and conventional refraction methods, respectively.Spherical power, cylindrical power, Jackson cross-cylinder power at axis 90° and 180° (J 0) and Jackson cross-cylinder power at axis 45° and 135° (J 45) vector powers were recorded.Paired t-test was used to compare the refractive parameters between different refraction methods, and the intraclass correlation coefficient (ICC) and Bland-Altman plots were used to evaluate the agreement between VAO and conventional refraction methods.This study adhered to the Declaration of Helsinki, and the research protocal was approved by an Ethics Committee of Affiliated Hospital of North Sichuan Medical College (No.2020ER[A]018). Written informed consent was obtained from each subject prior to any medical examination. Results:For subjective refraction, the ICC for spherical power, cylindrical power, J 0 and J 45 between VAO and phoropter were 0.97, 0.75, 0.84 and 0.09, respectively.For objective refraction, the ICC for spherical power, cylindrical power, J 0 and J 45 between VAO and autorefractor were 0.98, 0.70, 0.74 and 0.61, respectively.The mean differences in spherical power, cylindrical power, J 0 and J 45 between VAO and phoropter were (0.05±0.32), (-0.23±0.28), (-0.10±0.14) and (-0.04±0.16)D, respectively, and the differences in cylindrical power and J 0 were statistically significant (both at P<0.01), whereas no significant differences in spherical power and J 45 were found ( P=0.41, 0.18). The mean differences in spherical power, cylindrical power, J 0 and J 45 measured by VAO and autorefractor were (-0.70±0.26), (-0.07±0.46), (-0.03±0.27) and (0.01±0.12)D, respectively, and the spherical power measurement by VAO was significantly more negative than the autorefractor ( t=15.09, P<0.01), while no significant differences in cylindrical power, J 0 and J 45 were found ( P=0.39, 0.59, 0.63). No significant difference values in spherical power, cylindrical power, J 0 and J 45 were found between the two objective refraction methods and phoropter subjective refraction (all at P>0.05). Conclusions:With cycloplegia, spherical power obtained by VAO objective refraction is more negative compared with autorefractor.There is a good agreement of spherical power and astigmatism vector values measured by VAO and phoropter subjective refraction, and the measurement differences are clinically acceptable.

Adaptive optics (AO) can measure and correct wavefront aberrations in real time, which enables the optical system to adapt to external changes and maintain excellent optical performance, and has been gradually paid attention in the field of ophthalmology.AO technology can carry out optometry according to wavefront aberrations to improve the efficiency and accuracy of subjective and objective refraction, eliminate the influence of ocular aberrations on retinal imaging, provide more accurate data for the evaluation of optic nerve function, improve the effectiveness of visual perception training and provide vision care and treatment for special people, as well as simulate and predict postoperative visual outcome and give personalized schemes for refractive surgery and intraocular lens implantation.Moreover, AO combined with optical coherence tomography, optical scanning laser ophthalmoscope, and confocal scanning laser ophthalmoscope, can realize fundus imaging and retinal vascular imaging in real time, provide better sensitivity and resolution of retinal detection, distinguish fine details of retinal vessels and cone cells, and characterize retinal pigment epithelium topology and deformation, the application of which in posterior segment laser surgery, glaucoma diagnosis and follow-up, color blindness and retinal physiological activity research has been attracting attention.In this article, the principle and application of AO in ophthalmology were briefly reviewed.

Objective:To investigate the repeatability and correlation in tilt and decentration measurement of crystalline lens and intraocular lens (IOL) under non-mydriatic and mydriatic conditions using swept-source ocular coherence tomography CASIA2.Methods:A diagnostic test study was conducted.A total of 109 cataract patients (157 eyes) who received phacoemulsification with IOL implantation surgery in the Affiliated Hospital of North Sichuan Medical College from March to July 2020 were enrolled.The decentration and tilt of crystalline lens and IOL under non-mydriatic and mydriatic conditions were measured for three times by a single examiner using CASIA2 before and one week after surgery.The 0.5% compound tropicamide eye drops were used to dilate.Repeatability was evaluated by within-standard deviation, test-retest repeatability (TRT), coefficient of variation (CoV) and intraclass correlation coefficient (ICC). The correlation in decentration and tilt of crystalline lens and IOL between before and after mydriasis was assessed by Pearson correlation coefficient.This study adhered to the Declaration of Helsinki, and the study protocol was approved by an Ethics Committee of the Affiliated Hospital of North Sichuan Medical College (No.2020ER030-1). Written informed consent was obtained from all subjects before any medical examination.Results:The decentration of crystalline lens under non-mydriatic and mydriatic conditions was (0.217±0.112)mm and (0.220±0.110)mm, respectively, and the tilt was (5.017±1.422)° and (5.310±1.645)°, respectively.The decentration of IOL under non-mydriatic and mydriatic conditions was (0.245±0.136)mm and (0.250±0.145)mm, respectively, and the tilt was (5.144±1.345)° and (5.437±1.646)°, respectively.No significant difference was found between non-mydriatic and mydriatic conditions (all at P>0.05). Under both non-mydriatic and mydriatic conditions, the crystalline lenses of both eyes decentered and tilted toward the inferotemporal direction, and the IOL of right eyes decentered toward the inferior and tilted toward the inferotemporal direction, and the IOL of left eyes decentered and tilted toward the inferotemporal direction.Except the crystalline lens decentration, the measurement repeatability of crystalline lens tilt, IOL decentration and tilt in cataract patients before and after mydriasis was good, with ICC range in 0.815-0.984, TRT<50% and CoV≤14.840%.The measurement repeatability of crystalline lens decentration was poor, and the measurement repeatability of decentration axis, tilt and tilt axis of crystalline lens, and the repeatability of decentration and tilt of IOL were good in both eyes, with ICC range in 0.757-0.998, TRT<50% and CoV≤17.763%.There were good correlations in decentration, decentration axis, tilt and tilt axis of crystalline lens and IOL between non-mydriatic and mydriatic conditions (all r≥0.679, all at P<0.01). Conclusions:The measurement repeatability of decentration axis, tilt and tilt axis of crystalline lens and IOL, as well as the decentration of IOL by CASIA2 before and after mydriasis is good.The correlations of the measured parameters before and after mydriasis are good.

Objective:To systematically compare the accuracy of intraocular lens (IOL) power calculation formulas in cataract patients with shallow anterior chamber.Methods:A comprehensive literature search was conducted in MEDLINE, EMBASE, Cochrane Library, and the Chinese databases including CNKI, Wanfang, and VIP databases.The peer-reviewed literature on the accuracy of IOL power calculation formulas in cataract patients with shallow anterior chamber was searched from the establishment of the database until August 2020.Literature screening, data extraction and quality assessment were performed according to inclusion and exclusion criteria.The mean difference ( MD) of mean absolute error (MAE) among different formulas was analyzed.Meta-analysis was performed using Revman 5.3 software. Results:Seven studies involving 499 eyes were included.The accuracy of six formulas, Barrett Universal Ⅱ, Haigis, SRK/T, Hoffer Q, Holladay 1 and Holladay 2, was evaluated.The MAE of Barrett Universal Ⅱ was significantly lower than that of Hoffer Q ( MD=0.11 D; 95% CI: 0.05-0.17 D; P<0.001), Haigis ( MD=0.08 D; 95% CI: 0.03-0.13 D; P=0.002), and Holladay 2 ( MD=-0.06 D; 95% CI: -0.11--0.01 D; P=0.020). No significant difference was found in the remaining pairwise comparisons (all at P>0.05). Conclusions:The Barrett Universal Ⅱ formula is more accurate than Hoffer Q, Haigis, and Holladay 2 formulas in predicting IOL power in cataract patients with shallow anterior chamber.