BACKGROUND Cataracts pose a significant clinical burden due to their complex pathogenesis.In recent years,an increase in cataracts coexisting with myopia has heightened the incidence of retinopathy and posterior vitre...BACKGROUND Cataracts pose a significant clinical burden due to their complex pathogenesis.In recent years,an increase in cataracts coexisting with myopia has heightened the incidence of retinopathy and posterior vitreous detachment.Additionally,symptoms of ocular axis elongation,lens nucleus hardening,and vitreous liquefaction have become more prevalent.While conventional extracapsular cataract extraction is commonly employed,it often yields suboptimal visual outcomes.Subsequent advancements in cataract phacoemulsification and lens implantation surgeries have gained widespread acceptance for their ability to improve refraction and significantly improve uncorrected visual acuity.AIM To investigate the effect of capsular treatment after phacoemulsification lens implantation in myopic patients with cataract.METHODS We selected 110 patients(with 134 eyes)with myopia and cataracts treated.These patients were categorized into two groups:an observation group(57 patients with 70 eyes)and a control group(53 patients with 64 eyes).The control group underwent cataract phacoemulsification and lens implantation,while the observation group received a refined capsular treatment based on the control group’s procedure.We assessed the differences in visual acuity and quality between the two groups before and after surgery.RESULTS At six months post-operation,the observation group exhibited significantly improved far vision,intermediate vision,near vision,lower objective scattering index,higher Modulation transfer function cut-off frequency,and overall vision metrics at different contrast levels(100%,20%and 9%)compared to the control group(P<0.05).The total score of the National Eye Institute Visual Function Questionnaire in the observation group at 6 months after operation was significantly higher than that in the control group(P<0.05).No significant difference in the incidence of adverse reactions was observed between the observation group and control group(P>0.05).CONCLUSION Capsular treatment demonstrates efficacy in improving visual acuity and quality after phacoemulsification lens implantation in myopic patients with cataracts,warranting its clinical application.展开更多
AIM:To observe the retinal and choroidal circulations in patients with non-arteritic permanent central retinal artery occlusion(NA-CRAO)via optical coherence tomography angiography(OCTA)and analyze their correlation w...AIM:To observe the retinal and choroidal circulations in patients with non-arteritic permanent central retinal artery occlusion(NA-CRAO)via optical coherence tomography angiography(OCTA)and analyze their correlation with visual acuity.METHODS:Sixty-two eyes with clinically confirmed acute NA-CRAO were included in the study and divided into:A type(mild n=29),B type(moderate n=27)and C type(severe n=6)based on the degree of visual loss,retinal edema,and arterial blood flow delay in fundus fluorescence angiography(FFA).Contralateral healthy eyes were used as the control group.Best-corrected visual acuity(BCVA),slit lamp microscopy,indirect ophthalmoscopy,fundus color photography,OCTA,and FFA were performed.Spearman’s correlation analysis was used to determine the correlations between retinal and choroidal vessels and visual acuity.RESULTS:There were no statistically significant differences in age,gender,and intraocular pressure among the three types and the control group(P>0.05).Vessel density in deep capillary plexus(VD-DCP)significantly decreased(P<0.05)in all three types of NA-CRAO patients compared to the control group.Vessel density in superficial vascular plexus(VD-SVP)significantly decreased(P<0.05)in type A patients and choriocapillaris flow area significantly decreased(P<0.05)in type B and type C patients compared to the control group;while outer retinal flow areas significantly increased in the type A(P<0.05)and decreased in type C patients(P<0.05).The retinal thickness significantly increased in type C group(P<0.05).The VD-SVP at fovea in the type A was significantly lower than both of type B and C.The VD-SVP at nasal parafovea in type A and B was significantly lower than type C(P<0.05).The logMAR BCVA of type A was significantly better than that of type B and C groups(P<0.05).Spearman’s correlation analysis showed that the logMAR BCVA was positively correlated with VD-SVP at fovea(r=0.679,P=0.031)and nasal parafovea(r=0.826,P=0.013).CONCLUSION:OCTA is valuable for assessing retinal ischemia,and evaluating visual impairment.Deep retinal vasculature is commonly affected in all NA-CRAO types.VDSVPs at fovea and nasal parafovea can serve as reliable markers of visual impairment in NA-CRAO.展开更多
AIM:To predict best-corrected visual acuity(BCVA)by machine learning in patients with ocular trauma who were treated for at least 6mo.METHODS:The internal dataset consisted of 850 patients with 1589 eyes and an averag...AIM:To predict best-corrected visual acuity(BCVA)by machine learning in patients with ocular trauma who were treated for at least 6mo.METHODS:The internal dataset consisted of 850 patients with 1589 eyes and an average age of 44.29y.The initial visual acuity was 0.99 log MAR.The test dataset consisted of 60 patients with 100 eyes collected while the model was optimized.Four different machine-learning algorithms(Extreme Gradient Boosting,support vector regression,Bayesian ridge,and random forest regressor)were used to predict BCVA,and four algorithms(Extreme Gradient Boosting,support vector machine,logistic regression,and random forest classifier)were used to classify BCVA in patients with ocular trauma after treatment for 6mo or longer.Clinical features were obtained from outpatient records,and ocular parameters were extracted from optical coherence tomography images and fundus photographs.These features were put into different machine-learning models,and the obtained predicted values were compared with the actual BCVA values.The best-performing model and the best variable selected were further evaluated in the test dataset.RESULTS:There was a significant correlation between the predicted and actual values[all Pearson correlation coefficient(PCC)>0.6].Considering only the data from the traumatic group(group A)into account,the lowest mean absolute error(MAE)and root mean square error(RMSE)were 0.30 and 0.40 log MAR,respectively.In the traumatic and healthy groups(group B),the lowest MAE and RMSE were 0.20 and 0.33 log MAR,respectively.The sensitivity was always higher than the specificity in group A,in contrast to the results in group B.The classification accuracy and precision were above 0.80 in both groups.The MAE,RMSE,and PCC of the test dataset were 0.20,0.29,and 0.96,respectively.The sensitivity,precision,specificity,and accuracy of the test dataset were 0.83,0.92,0.95,and 0.90,respectively.CONCLUSION:Predicting BCVA using machine-learning models in patients with treated ocular trauma is accurate and helpful in the identification of visual dysfunction.展开更多
Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiologi...Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiological evidence for the objective evaluation of VA.Methods We recruited 32 participants with myopia-related ametropia.They reported no other ocular diseases and had an uncorrected VA of 4.0 in both eyes.We used the block letter“E”at different visual angles and orientations as the graphic stimuli.The oddball paradigm,consisting of 4 modules,was used for ERP analysis.The standard stimuli of each module were identical,with a visual angle of 1°15′.The visual angles of the target stimuli were 1°15′,55′,24′,and 15′.The VA test was performed on each eye separately for all participants,and all characteristics of the P3 component were analyzed.Results There was no significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 55′group,or between the target stimulation angle 24′group and the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 24′group as well as the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 55′group and the 24′group as well as the 15′group.No significant differences were observed in the P3 amplitude between modules.Conclusion In the oddball paradigm,P3 elicitation indicated a cognitive response to the target stimuli.These data showed that the characteristics of P3 can be used as an objective evaluation of VA.展开更多
AIM: To compare the postoperative visual acuity among eyes with proliferative diabetic retinopathy(PDR) of different stages after pars plana vitrectomy(PPV) in type 2 diabetic patients. METHODS: A retrospective study ...AIM: To compare the postoperative visual acuity among eyes with proliferative diabetic retinopathy(PDR) of different stages after pars plana vitrectomy(PPV) in type 2 diabetic patients. METHODS: A retrospective study was conducted for PDR eyes undergoing PPV in type 2 diabetic patients. All patients were divided into three groups based on Chinese Ocular Fundus Diseases Society(COFDS) classification for PDR: Group A(primary vitreous hemorrhage), Group B(primary fibrovascular proliferation) and Group C(primary vitreous hemorrhage and/or fibrovascular proliferative combined with retinal detachment). The postoperative visual acuity and the change between postoperative and preoperative visual acuity were compared among three groups. The associated risk factors for postoperative visual acuity were analyzed in the univariate and multiple linear aggression. RESULTS: In total, 195 eyes of 195 patients were collected in this study, including 71 eyes of 71 patients in Group A, 75 eyes of 75 patients in Group B and 49 eyes of 49 patients in Group C. The eyes in Group A got better postoperative best-corrected visual acuity(BCVA) compared to the eyes in Group B and C(0.48±0.48 vs 0.89±0.63, P<0.001;0.48±0.48 vs 1.04±0.67, P<0.001;respectively). The eyes in Group A got more improvement of BCVA compared to the eyes in Group B and C(1.07±0.70 vs 0.73±0.68, P=0.004;1.07±0.70 vs 0.77±0.78, P=0.024;respectively). In the multiple linear regression analysis, primary fibro-proliferative type(β=0.194, 95%CI=0.060-0.447, P=0.01), retinal detachment type(β=0.244, 95%CI=0.132-0.579, P=0.02), baseline log MAR BCVA(β=0.192, 95%CI=0.068-0.345, P=0.004), silicone oil tamponade(β=0.272, 95%CI=0.173-0.528, P<0.001) was positively correlated with postoperative log MAR BCVA. Eyes undergoing phacovitrectomy had better postoperative BCVA(β=-0.144, 95%CI=-0.389 to-0.027, P=0.025). CONCLUSION: PDR eyes of primary vitreous hemorrhage type usually have better visual acuity prognosis compared to primary fibrovascular proliferation type and retinal detachment type. COFDS classification for PDR may have a high prognostic value for postoperative visual outcome and surgical management indications.展开更多
AIM:To compare the results of visual acuity(VA)measured by Early Treatment Diabetic Retinopathy Study(ETDRS)chart,5 m Standard Logarithm Visual Acuity(5 SL)chart,and 2.5 m Standard Logarithm Visual Acuity(2.5 SL)chart...AIM:To compare the results of visual acuity(VA)measured by Early Treatment Diabetic Retinopathy Study(ETDRS)chart,5 m Standard Logarithm Visual Acuity(5 SL)chart,and 2.5 m Standard Logarithm Visual Acuity(2.5 SL)chart in outpatients of age 12-80 y.METHODS:Each patient(totally 2000 outpatients)had both eyes tested with ETDRS chart at 4 m,5 SL chart at 5 m,and 2.5 SL chart at 2.5 m in random order.The VA values of outpatients were categorized by ages.VA values were expressed by log MAR recording method.RESULTS:The mean VA results of ETDRS charts,5 SL,and 2.5 SL chart were 0.52±0.28,0.50±0.30,and 0.46±0.28 log MAR,respectively.There was a statistically significant difference in the three eye charts in the whole group(P<0.001).For all subjects,the correlation of VA tested with three charts was statistically significant(Spearman correlation coefficient=0.944,0.937,0.946,all P<0.001).Bland–Altman analysis shows the 95%limits of agreement between the 5 SL and 2.5 SL chart were-0.182 to 0.210,-0.139 to 0.251,and-0.151 to 0.235 log MAR,respectively.CONCLUSION:The agreement between the three eye charts is not high.The VA measured by 5 SL chart is slightly better than that by ETDRS chart and 5 SL chart would be a suitable alternative when ETDRS chart are not available in the clinical situation.The VA measured by 2.5 SL chart is about 0.5 line better than VA tested with ETDRS chart,which may overestimate VA.展开更多
AIM:To evaluate the vision status and sociodemographic associations of visual acuity(VA)in an urban and rural population in a coastal province of southern China.METHODS:The Fujian Eye Study,a population-based cross-se...AIM:To evaluate the vision status and sociodemographic associations of visual acuity(VA)in an urban and rural population in a coastal province of southern China.METHODS:The Fujian Eye Study,a population-based cross-sectional study,was performed from May 2018 to October 2019.Totally 10044 participants over 50 years old from all nine cities in Fujian Province were enrolled,and underwent a questionnaire and a series of standard physical and ocular examinations.VA was measured by E Standard Logarithmic Visual Acuity Chart(GB 11533-1989).Data was double entered with Epi Data v3.1 for data collation and Stata/SE statistical software v15.1 was used to analyze the data.RESULTS:Totally 8211(81.8%)participants were finally included and were divided into urban populations(4678 subjects),rural populations(n=3533),coastal residents(n=6434),and inland residents(1777 subjects);4836 participants were female.The mean age was 64.39±8.87 y(median 64 y;range 50-98 y).The mean presenting VA was 0.61±0.30(0.23±0.27 log MAR),and the mean best correctedvisual acuity(BCVA)was 0.82±0.28(0.08±0.19 log MAR).In the multiple regression analysis,BCVA was significantly correlated with several socioeconomic and biologic factors,including age(P<0.001),education level(P<0.001),income(P=0.005),rural residency(P<0.001),inland residency(P=0.001)and refractive error(P<0.001),while sex(P=0.194)was independent with BCVA.CONCLUSION:Accessible services and eye health policies targeting the elderly,people with high myopia and people living in rural or inland areas are needed.展开更多
A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equati...A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equations which calculate the visual acuity through visual acuity factors are presented, and adaptive rendering strategy based on different visual acuity equations is given. The VE system may select one of them on the basis of the host’s load, hereby select LOD for each model which would be rendered. A coarser LOD is selected where the visual acuity is lower, and a better LOD is used where it is higher. This method is tested through experiments and the experimental results show that it is effective.展开更多
AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into ...AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into two groups randomly, the AMC group and the control group, ten patients each group. Both debridement of the infected cornea tissue and standard anti-fungus drugs treatments were given to every patients, monolayer amniotic membrane were sutured to the surface of the entire cornea and bulbar conjunctiva with 10-0 nylon suture for patients in the AMC group.The diameter of the ulcer was determined with slit lamp microscope and the depth of the infiltration was determined with anterior segment optical coherence tomography. Uncorrected visual acuity(UCVA) was tested before surgery and three month after healing of the epithelial layer. The healing time of the cornea epithelium, visual acuity(VA) was compared between the two groups using t- test.RESULTS:There was no statistical difference of the diameter of the ulcer, depth of the infiltration, height of the hypopyon and VA between the two groups beforesurgery(P 】0.05). The average healing time of the AMC group was 6.89 ±2.98 d, which was statistically shorter than that of the control group(10.23±2.78d)(P 【0.05).The average UCVA of the AMC group was 0.138 ±0.083,which was statistically better than that of the control group(0.053±0.068)(P 【0.05).CONCLUSION:AMC surgery could promote healing of cornea epithelium after debridement for fungal keratitis and lead to better VA outcome.展开更多
AIM: To evaluate contrast visual acuity(CVA) after implantation of an aspheric apodized diffractive intraocular lens(IOL) or a spherical apodized diffractive IOL in cataract surgery. ·METHODS: This prospective ra...AIM: To evaluate contrast visual acuity(CVA) after implantation of an aspheric apodized diffractive intraocular lens(IOL) or a spherical apodized diffractive IOL in cataract surgery. ·METHODS: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL(30 eyes) and a spherical AcrySof ReSTOR SN60D3 IOL(30 eyes). CVA with best distance correction was measured at 4 contrast levels(100%,25%,10% and 5%) under 3 levels of chart luminance [250,85 and 25 candelas per square meter(cd/m2)] using a multi-functional visual acuity tester(MFVA-100). ·RESULTS: At 12 months after surgery,there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m2(P100% =0.875 and P25% =0.057) and 85cd/m2(P100% =0.198 and P25% =0.193) between the aspheric group and the spherical group. However,the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m2(P10% =0.042 and P5% = 0.007) and 85cd/m2(P10% =0.002 and P5%=0.039). Under the luminance level of 25cd/m 2,no significant differences was found in the 100% CVA between the 2 group(P100% = 0.245),while aspheric group had better visual acuity in the remaining 3 contracts(P25% =0.023,P10% =0.026 and P5% = 0.002,respectively). ·CONCULSION: The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.展开更多
Dynamic visual acuity test(DVAT)plays a key role in the assessment of vestibular function,the visual function of athletes,as well as various ocular diseases.As the visual pathways conducting dynamic and static signals...Dynamic visual acuity test(DVAT)plays a key role in the assessment of vestibular function,the visual function of athletes,as well as various ocular diseases.As the visual pathways conducting dynamic and static signals are different,DVATs may have potential advantages over the traditional visual acuity tests commonly used,such as static visual acuity,contrast sensitivity,and static perimetry.Here,we provide a review of commonly applied DVATs and their several uses in clinical ophthalmology.These data indicate that the DVAT has its unique clinical significance in the evaluation of several ocular disorders.展开更多
In this study, we aimed to study the pattern visual evoked potentials （P-VEPs） in two eyes with varying visual acuity in one eye and to provide an objective estimation of visual acuity by comparing P-VEPs in one and...In this study, we aimed to study the pattern visual evoked potentials （P-VEPs） in two eyes with varying visual acuity in one eye and to provide an objective estimation of visual acuity by comparing P-VEPs in one and two eyes. Thirty subjects were chosen, who had one eye with an acuity of 5.0, 4.85, 4.6, 4.0, or scieropia and obstructed vision and the other eye with an acuity of 5.0, respectively. P-VEPs were detected under the large grating stimuli at 3x4 spatial frequency, moderate grating stimuli （12× 16 spatial frequency） and small grating stimuli （48×64 spatial frequency）. Under large grating stimuli, there was no significant difference in P100 peak latency between the groups, nor was there a significant difference between the amplitude of two eyes and the amplitude of one normal-vision eye. Under moderate and small grating stimuli, there was a significant difference in P100 peak latency between the group with both eyes having an acuity of 5.0 and the group with visual acuity below 4.0 in one eye. There was a significant difference in P100 amplitude between the group with visual acuity of 5.0 in both eyes and the group with one normal-vision eye. There was no significant difference in the amplitude of two eyes and the amplitude of one normal-vision eye between any other two groups. In forensic identification, characteristics and variability of P-VEPs in one and two eyes can be used to identify malingering or decline in visual acuity.展开更多
AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 ey...AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.展开更多
AIM：To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis（SBK）or laser in situ keratomileusis（LASIK）.· METHODS：Data from 5923 eyes in 2968 patients that received LASIK...AIM：To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis（SBK）or laser in situ keratomileusis（LASIK）.· METHODS：Data from 5923 eyes in 2968 patients that received LASIK（2755 eyes） or SBK（3168 eyes） were retrospectively analyzed.The eyes were divided into 4groups according to preoperative spherical equivalent：between-12.00 to-9.00 D,extremely high myopia（n =396,including 192 and 204 in SBK and LASIK groups,respectively）;-9.00 to-6.00 D,high myopia（n=1822,including 991 and 831 in SBK and LASIK groups,respectively）,-6.00 to-3.00 D,moderate myopia（n=3071,including 1658 and 1413 in SBK and LASIK groups,respectively）,and-3.00 to 0.00 D,low myopia（n =634,including 327 and 307 in SBK and LASIK groups,respectively）.Uncorrected logMAR visual acuity values of patients were assessed under standard natural light.Analysis of variance was used for comparisons among different groups.· RESULTS：Uncorrected visual acuity values were0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK,respectively（P〈0.01）;visual acuity values of 0.1854±0.1842,0.0615±0.1326,-0.0033±0.0978,and-0.0164±0.0972 were obtained for patients in the extremely high,high,moderate,and low myopia groups,respectively（P〈0.01）.In addition,significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup.· CONCLUSION：Compared with LASIK,SBK is safer and more effective,with faster recovery.Therefore,SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation.展开更多
AIM： To investigate the influence of astigmatism on visual acuity in school-aged children, and to define a cutoff for clinically significant astigmatism. METHODS： This is a population-based, cross-sectional study. A...AIM： To investigate the influence of astigmatism on visual acuity in school-aged children, and to define a cutoff for clinically significant astigmatism. METHODS： This is a population-based, cross-sectional study. Among 5053 enumerated children aged 5-15 y in Guangzhou, 3729（73.8%） children aged 7-15 with successful cycloplegic auto-refraction（1% cyclopentolate） and a reliable visual acuity measurement were included. Ocular measurement included external eye, anterior segment, media and fundus and cycloplegic auto-refraction. Primary outcome measures included the relationship between severity and subtypes of astigmatism and the prevalence of visual impairment. Three criteria for visual impairment were adopted： best-corrected visual acuity（BCVA） ≤0.7, uncorrected visual acuity（UCVA） ≤0.5 or 〈0.7 in the right eye.RESULTS： Increases of cylinder power was significantly associated with worse visual acuity（UCVA： β=0.051, P〈0.01; BCVA： β=0.025, P〈0.001）. A substantial increase in UCVI and BCVI was seen with astigmatism of 1.00 diopter（D） or more. Astigmatism ≥1.00 D had a greater BCVI prevalence than cylinder power less than 1.00 D（OR=4.20, 95%CI： 3.08-5.74）, and this was also true for hyperopic, emmetropic and myopic refraction categories. Oblique astigmatism was associated with a higher risk of BCVI relative to with the rule astigmatism in myopic refractive category（OR=12.87, 95%CI： 2.20-75.38）.CONCLUSION： Both magnitude and subtypes of astigmatism influence the prevalence of visual impairment in school children. Cylinder ≥1.00 D may be useful as a cutoff for clinically significant astigmatism.展开更多
AIM:To obtain the baseline data on presenting visual acuity(PVA)and evaluate the prevalence and associated factors for visual impairment based on PVA in 9070 Chinese college students.METHODS:The freshmen at a universi...AIM:To obtain the baseline data on presenting visual acuity(PVA)and evaluate the prevalence and associated factors for visual impairment based on PVA in 9070 Chinese college students.METHODS:The freshmen at a university in southern China,including 6527 undergraduate students and 2543 graduate students,were investigated for some sociodemographic characteristics and underwent routine medical examination,including measuring PVA,height,and weight.Visual impairment was defined according to the new World Health Organization criteria for blindness and visual impairment.RESULTS:In 9070 college students,the mean PVA in the better eye was 0.094±0.163 log MAR.The prevalence of visual impairment based on PVA was 2.7%.Only 38.3%college students had normal visual acuity[PVA equal to 0 log MAR(20/20)in both eyes].There were 69.8%of students wearing spectacles.Logistic regression showed that home region(non-Guangdong provinces,P<0.0001,OR=1.70)was risk factor for visual impairment while BMI(P=0.001,OR=0.92)was protective factor from visual impairment.Ethnicity(Han Chinese,P<0.0001,OR=3.17)was risk factor for wearing spectacles while age(P=0.01,OR=0.90)was protective factor from wearing spectacles.CONCLUSION:This study provides the baseline data on PVA and the prevalence of visual impairment in Chinese college students.Our analyses reveal that BMI and home region are associated factors for visual impairment based on PVA,while age and ethnicity are associated factors for wearing spectacles.展开更多
AIM: To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet’s stripping automated endothelial keratoplasty(DSAEK)one year after surgery.METHODS: DSAEK patients’ data were r...AIM: To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet’s stripping automated endothelial keratoplasty(DSAEK)one year after surgery.METHODS: DSAEK patients’ data were reviewed. Thirty seven eyes of 37 patients who underwent DSAEK for pseudophakic bullous keratopathy(PBK) were included in this study. Graft thickness was measured with optical coherence tomography(OCT) 12 mo after DSAEK. Eyes were divided into 3 groups based on the graft thickness:thick(】200 μm), medium-thick(150-200 μm) and thin(【150 μm). Best corrected visual acuity(BCVA),endothelial cells density(ECD) and complications were assessed and comparisons were done between groups.RESULTS: Median thickness of postoperative grafts was 188(range 73-317 μm). There was no significant difference in age, sex, preoperative BCVA, or follow-up period between DSAEK groups. At postoperative 12 mo,mean BCVA was 0.28±0.10 in thick graft group, 0.52±0.08 in medium-thick graft group, and 0.72 ±0.06 in thin graft group. Thin grafts showed better postoperative BCVA as compared with the medium-thick and thick grafts(P =0.001). Thick graft group had 1637.44 ±88.19-mm2,medium thick graft had 1764.50±34.28-mm2 and thin graft group had 1845.30 ±65.62-mm2. Thin graft group had better ECD at 12 mo after surgery(P =0.001).CONCLUSION: Thin grafts after DSAEK ensure better visual rehabilitation. Eyes with thin grafts had significantly lesser loss of ECD compared to eyes withmedium-thick and thick grafts one year after surgery.展开更多
This study explored the accuracy of using visual evoked potentials(VEP)technology for visual acuity estimation.The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured ey...This study explored the accuracy of using visual evoked potentials(VEP)technology for visual acuity estimation.The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group,and the healthy eyes as the control group.The least signal visual angle(LSVA),and amplitude and latency of P100 were chosen as test indexes.The results under different experimental conditions were recorded by PRVEP technology.All data collected were processed...展开更多
AIM:To Introduce a new specialized visual acuity chart for amblyopic children aged 3-5 years old and its clinical applications.METHODS:The new visual acuity chart and notations were designed based on Weber-Fechner law...AIM:To Introduce a new specialized visual acuity chart for amblyopic children aged 3-5 years old and its clinical applications.METHODS:The new visual acuity chart and notations were designed based on Weber-Fechner law.The optotypes were red against a white background and were specially shaped four basic geometric symbols:circle,square,triangle,and cross.A regular geometric progression of the optotype sizes and distribution was employed to arrange in 14 lines.The progression rate of the optotype size between two lines was 1.2589 and the testing distance was 3m.Visual acuity score could be recorded as logMAR notation or decimal notation.Agestratified diagnostic criteria for amblyopia established by consensus statement on diagnosis of amblyopia(2011)among members of the Strabismus and Pediatric Ophthalmology Group,Ophthalmology Society,Chinese Medical Association(SPOGOSCMA)were illustrated in the new visual acuity chart.RESULTS:When assessing visual acuity in children aged 3-5 years old,this new visual acuity chart that consists of four symmetrical shapes(triangle,square,cross,and circle)overcame an inability to recognize the letters of the alphabet and difficulties in designating the direction of black abstract symbols such as the tumbling’E’or Landolt’C’,which the subjects were prone to lose interest in.The visual acuity score may be recorded indifferent notations:decimal acuity and logMAR.These two notations can be easily converted each other in the new eye chart.The measurements of this new chart not only showed a significant correlation and a good consistency with the international standard logarithmic visual acuity chart(r=0.932,P【0.01),but also indicated a high test-retest reliability(89%of retest scores were within 0.1 logMAR units of the initial test score).CONCLUSION:The results of this study support the validity and reliability of distance visual acuity measurements using the new eye chart in children aged3 to 5 years over a wide range of visual acuities,and the new eye chart is great for early detection of amblyopia.It can be applied in various clinical settings.展开更多
AIM:To analyze the correlation between macular morphology and function in eyes with diabetic macular edema(DME).METHODS:Fifty-five eyes with different visual acuity(VA)of 32 patients who suffered from DME were analyze...AIM:To analyze the correlation between macular morphology and function in eyes with diabetic macular edema(DME).METHODS:Fifty-five eyes with different visual acuity(VA)of 32 patients who suffered from DME were analyzed using multifocal electroretinography(mfERG)and optical coherence tomography(OCT).The parameters of mfERG including implicit times and response amplitude were compared to those of 50 normal eyes of 36 age-matched subjects.Correlation analysis was performed between VA,the parameters of mfERG including implicit times and response amplitude,and the central macular thickness(CMT).RESULTS:The amplitude of N1 and P1 were significantly decreased and their latency were significantly increased in five ring regions of the retina in patients with DME.There was statistically significant correlation between logMAR BCVA and P1 amplitude densities in rings 1-4(r=-0.306,-0.536,-0.470,-0.362;P=0.023,<0.01,<0.01,0.007 respectively),N1 amplitude in ring 2 and ring 3(r=-0.035,-0.286;P=0.019,0.034 respectively).There was poor correlation between the CMT and best-corrected visual acuity(BCVA;r=0.288,P=0.033),but there was no significant correlation between CMT and amplitude or implicit time of N1 and P1(P>0.05)in the central macular ring.Multiple stepwise regression analysis showed that P1 amplitude density in ring 2 was the only contributor to the VA.CONCLUSION:It seems to be more appropriate of combining use of mfERG with OCT for the evaluation of macular function in eyes with DME.展开更多
文摘BACKGROUND Cataracts pose a significant clinical burden due to their complex pathogenesis.In recent years,an increase in cataracts coexisting with myopia has heightened the incidence of retinopathy and posterior vitreous detachment.Additionally,symptoms of ocular axis elongation,lens nucleus hardening,and vitreous liquefaction have become more prevalent.While conventional extracapsular cataract extraction is commonly employed,it often yields suboptimal visual outcomes.Subsequent advancements in cataract phacoemulsification and lens implantation surgeries have gained widespread acceptance for their ability to improve refraction and significantly improve uncorrected visual acuity.AIM To investigate the effect of capsular treatment after phacoemulsification lens implantation in myopic patients with cataract.METHODS We selected 110 patients(with 134 eyes)with myopia and cataracts treated.These patients were categorized into two groups:an observation group(57 patients with 70 eyes)and a control group(53 patients with 64 eyes).The control group underwent cataract phacoemulsification and lens implantation,while the observation group received a refined capsular treatment based on the control group’s procedure.We assessed the differences in visual acuity and quality between the two groups before and after surgery.RESULTS At six months post-operation,the observation group exhibited significantly improved far vision,intermediate vision,near vision,lower objective scattering index,higher Modulation transfer function cut-off frequency,and overall vision metrics at different contrast levels(100%,20%and 9%)compared to the control group(P<0.05).The total score of the National Eye Institute Visual Function Questionnaire in the observation group at 6 months after operation was significantly higher than that in the control group(P<0.05).No significant difference in the incidence of adverse reactions was observed between the observation group and control group(P>0.05).CONCLUSION Capsular treatment demonstrates efficacy in improving visual acuity and quality after phacoemulsification lens implantation in myopic patients with cataracts,warranting its clinical application.
基金Supported by Tianjin Key Medical Discipline(Specialty)Construction Project(No.TJYXZDXK-016A).
文摘AIM:To observe the retinal and choroidal circulations in patients with non-arteritic permanent central retinal artery occlusion(NA-CRAO)via optical coherence tomography angiography(OCTA)and analyze their correlation with visual acuity.METHODS:Sixty-two eyes with clinically confirmed acute NA-CRAO were included in the study and divided into:A type(mild n=29),B type(moderate n=27)and C type(severe n=6)based on the degree of visual loss,retinal edema,and arterial blood flow delay in fundus fluorescence angiography(FFA).Contralateral healthy eyes were used as the control group.Best-corrected visual acuity(BCVA),slit lamp microscopy,indirect ophthalmoscopy,fundus color photography,OCTA,and FFA were performed.Spearman’s correlation analysis was used to determine the correlations between retinal and choroidal vessels and visual acuity.RESULTS:There were no statistically significant differences in age,gender,and intraocular pressure among the three types and the control group(P>0.05).Vessel density in deep capillary plexus(VD-DCP)significantly decreased(P<0.05)in all three types of NA-CRAO patients compared to the control group.Vessel density in superficial vascular plexus(VD-SVP)significantly decreased(P<0.05)in type A patients and choriocapillaris flow area significantly decreased(P<0.05)in type B and type C patients compared to the control group;while outer retinal flow areas significantly increased in the type A(P<0.05)and decreased in type C patients(P<0.05).The retinal thickness significantly increased in type C group(P<0.05).The VD-SVP at fovea in the type A was significantly lower than both of type B and C.The VD-SVP at nasal parafovea in type A and B was significantly lower than type C(P<0.05).The logMAR BCVA of type A was significantly better than that of type B and C groups(P<0.05).Spearman’s correlation analysis showed that the logMAR BCVA was positively correlated with VD-SVP at fovea(r=0.679,P=0.031)and nasal parafovea(r=0.826,P=0.013).CONCLUSION:OCTA is valuable for assessing retinal ischemia,and evaluating visual impairment.Deep retinal vasculature is commonly affected in all NA-CRAO types.VDSVPs at fovea and nasal parafovea can serve as reliable markers of visual impairment in NA-CRAO.
基金Supported by National Key R&D Program of China(No.2022YFC3302001)the Human Injury and Disability Degree Classification(No.SF20181312)the National Natural Science Foundation of China(No.62071285)。
文摘AIM:To predict best-corrected visual acuity(BCVA)by machine learning in patients with ocular trauma who were treated for at least 6mo.METHODS:The internal dataset consisted of 850 patients with 1589 eyes and an average age of 44.29y.The initial visual acuity was 0.99 log MAR.The test dataset consisted of 60 patients with 100 eyes collected while the model was optimized.Four different machine-learning algorithms(Extreme Gradient Boosting,support vector regression,Bayesian ridge,and random forest regressor)were used to predict BCVA,and four algorithms(Extreme Gradient Boosting,support vector machine,logistic regression,and random forest classifier)were used to classify BCVA in patients with ocular trauma after treatment for 6mo or longer.Clinical features were obtained from outpatient records,and ocular parameters were extracted from optical coherence tomography images and fundus photographs.These features were put into different machine-learning models,and the obtained predicted values were compared with the actual BCVA values.The best-performing model and the best variable selected were further evaluated in the test dataset.RESULTS:There was a significant correlation between the predicted and actual values[all Pearson correlation coefficient(PCC)>0.6].Considering only the data from the traumatic group(group A)into account,the lowest mean absolute error(MAE)and root mean square error(RMSE)were 0.30 and 0.40 log MAR,respectively.In the traumatic and healthy groups(group B),the lowest MAE and RMSE were 0.20 and 0.33 log MAR,respectively.The sensitivity was always higher than the specificity in group A,in contrast to the results in group B.The classification accuracy and precision were above 0.80 in both groups.The MAE,RMSE,and PCC of the test dataset were 0.20,0.29,and 0.96,respectively.The sensitivity,precision,specificity,and accuracy of the test dataset were 0.83,0.92,0.95,and 0.90,respectively.CONCLUSION:Predicting BCVA using machine-learning models in patients with treated ocular trauma is accurate and helpful in the identification of visual dysfunction.
基金This project was supported by the National Key Research and Development Program of China during the Thirteenth Five-Year Plan period(No.2016YFC0800701-4-2).
文摘Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiological evidence for the objective evaluation of VA.Methods We recruited 32 participants with myopia-related ametropia.They reported no other ocular diseases and had an uncorrected VA of 4.0 in both eyes.We used the block letter“E”at different visual angles and orientations as the graphic stimuli.The oddball paradigm,consisting of 4 modules,was used for ERP analysis.The standard stimuli of each module were identical,with a visual angle of 1°15′.The visual angles of the target stimuli were 1°15′,55′,24′,and 15′.The VA test was performed on each eye separately for all participants,and all characteristics of the P3 component were analyzed.Results There was no significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 55′group,or between the target stimulation angle 24′group and the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 24′group as well as the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 55′group and the 24′group as well as the 15′group.No significant differences were observed in the P3 amplitude between modules.Conclusion In the oddball paradigm,P3 elicitation indicated a cognitive response to the target stimuli.These data showed that the characteristics of P3 can be used as an objective evaluation of VA.
基金Supported in part by the National Science Foundation of Liaoning Province,China(No.2020-MS-360)Shenyang Science and Technology Bureau(No.RC210267)。
文摘AIM: To compare the postoperative visual acuity among eyes with proliferative diabetic retinopathy(PDR) of different stages after pars plana vitrectomy(PPV) in type 2 diabetic patients. METHODS: A retrospective study was conducted for PDR eyes undergoing PPV in type 2 diabetic patients. All patients were divided into three groups based on Chinese Ocular Fundus Diseases Society(COFDS) classification for PDR: Group A(primary vitreous hemorrhage), Group B(primary fibrovascular proliferation) and Group C(primary vitreous hemorrhage and/or fibrovascular proliferative combined with retinal detachment). The postoperative visual acuity and the change between postoperative and preoperative visual acuity were compared among three groups. The associated risk factors for postoperative visual acuity were analyzed in the univariate and multiple linear aggression. RESULTS: In total, 195 eyes of 195 patients were collected in this study, including 71 eyes of 71 patients in Group A, 75 eyes of 75 patients in Group B and 49 eyes of 49 patients in Group C. The eyes in Group A got better postoperative best-corrected visual acuity(BCVA) compared to the eyes in Group B and C(0.48±0.48 vs 0.89±0.63, P<0.001;0.48±0.48 vs 1.04±0.67, P<0.001;respectively). The eyes in Group A got more improvement of BCVA compared to the eyes in Group B and C(1.07±0.70 vs 0.73±0.68, P=0.004;1.07±0.70 vs 0.77±0.78, P=0.024;respectively). In the multiple linear regression analysis, primary fibro-proliferative type(β=0.194, 95%CI=0.060-0.447, P=0.01), retinal detachment type(β=0.244, 95%CI=0.132-0.579, P=0.02), baseline log MAR BCVA(β=0.192, 95%CI=0.068-0.345, P=0.004), silicone oil tamponade(β=0.272, 95%CI=0.173-0.528, P<0.001) was positively correlated with postoperative log MAR BCVA. Eyes undergoing phacovitrectomy had better postoperative BCVA(β=-0.144, 95%CI=-0.389 to-0.027, P=0.025). CONCLUSION: PDR eyes of primary vitreous hemorrhage type usually have better visual acuity prognosis compared to primary fibrovascular proliferation type and retinal detachment type. COFDS classification for PDR may have a high prognostic value for postoperative visual outcome and surgical management indications.
文摘AIM:To compare the results of visual acuity(VA)measured by Early Treatment Diabetic Retinopathy Study(ETDRS)chart,5 m Standard Logarithm Visual Acuity(5 SL)chart,and 2.5 m Standard Logarithm Visual Acuity(2.5 SL)chart in outpatients of age 12-80 y.METHODS:Each patient(totally 2000 outpatients)had both eyes tested with ETDRS chart at 4 m,5 SL chart at 5 m,and 2.5 SL chart at 2.5 m in random order.The VA values of outpatients were categorized by ages.VA values were expressed by log MAR recording method.RESULTS:The mean VA results of ETDRS charts,5 SL,and 2.5 SL chart were 0.52±0.28,0.50±0.30,and 0.46±0.28 log MAR,respectively.There was a statistically significant difference in the three eye charts in the whole group(P<0.001).For all subjects,the correlation of VA tested with three charts was statistically significant(Spearman correlation coefficient=0.944,0.937,0.946,all P<0.001).Bland–Altman analysis shows the 95%limits of agreement between the 5 SL and 2.5 SL chart were-0.182 to 0.210,-0.139 to 0.251,and-0.151 to 0.235 log MAR,respectively.CONCLUSION:The agreement between the three eye charts is not high.The VA measured by 5 SL chart is slightly better than that by ETDRS chart and 5 SL chart would be a suitable alternative when ETDRS chart are not available in the clinical situation.The VA measured by 2.5 SL chart is about 0.5 line better than VA tested with ETDRS chart,which may overestimate VA.
基金Supported by the National Natural Science Foundation of China(No.81870672)National Natural Science Foundation of China Youth Fund(No.81900881)+4 种基金Natural Science Foundation of Youth Innovation Program of Fujian Province(No.2019D007No.2020D028)Xiamen Key Medical and Health Project(No.3502Z20191101)Medical and Healthcare Guiding Program of Xiamen City(No.3502Z20189018)Xiamen Science and Technology Planning Project(No.3502Z20184023)。
文摘AIM:To evaluate the vision status and sociodemographic associations of visual acuity(VA)in an urban and rural population in a coastal province of southern China.METHODS:The Fujian Eye Study,a population-based cross-sectional study,was performed from May 2018 to October 2019.Totally 10044 participants over 50 years old from all nine cities in Fujian Province were enrolled,and underwent a questionnaire and a series of standard physical and ocular examinations.VA was measured by E Standard Logarithmic Visual Acuity Chart(GB 11533-1989).Data was double entered with Epi Data v3.1 for data collation and Stata/SE statistical software v15.1 was used to analyze the data.RESULTS:Totally 8211(81.8%)participants were finally included and were divided into urban populations(4678 subjects),rural populations(n=3533),coastal residents(n=6434),and inland residents(1777 subjects);4836 participants were female.The mean age was 64.39±8.87 y(median 64 y;range 50-98 y).The mean presenting VA was 0.61±0.30(0.23±0.27 log MAR),and the mean best correctedvisual acuity(BCVA)was 0.82±0.28(0.08±0.19 log MAR).In the multiple regression analysis,BCVA was significantly correlated with several socioeconomic and biologic factors,including age(P<0.001),education level(P<0.001),income(P=0.005),rural residency(P<0.001),inland residency(P=0.001)and refractive error(P<0.001),while sex(P=0.194)was independent with BCVA.CONCLUSION:Accessible services and eye health policies targeting the elderly,people with high myopia and people living in rural or inland areas are needed.
文摘A new method of adaptable rendering for interaction in Virtual Environment(VE) through different visual acuity equations is proposed. An acuity factor equation of luminance vision is first given. Secondly, five equations which calculate the visual acuity through visual acuity factors are presented, and adaptive rendering strategy based on different visual acuity equations is given. The VE system may select one of them on the basis of the host’s load, hereby select LOD for each model which would be rendered. A coarser LOD is selected where the visual acuity is lower, and a better LOD is used where it is higher. This method is tested through experiments and the experimental results show that it is effective.
基金Supported by National Natural Science Foundation of China(No.81200661)Nature Science Foundation of Hubei Province(No.2010CDB09802)Wuhan Chenguang Plan Grant(No.201150431124)
文摘AIM:To investigate the effect of amniotic membrane covering(AMC) on the healing of cornea epithelium and visual acuity for fungal keratitis after debridement.METHODS:Twenty fungal keratitis patients were divided into two groups randomly, the AMC group and the control group, ten patients each group. Both debridement of the infected cornea tissue and standard anti-fungus drugs treatments were given to every patients, monolayer amniotic membrane were sutured to the surface of the entire cornea and bulbar conjunctiva with 10-0 nylon suture for patients in the AMC group.The diameter of the ulcer was determined with slit lamp microscope and the depth of the infiltration was determined with anterior segment optical coherence tomography. Uncorrected visual acuity(UCVA) was tested before surgery and three month after healing of the epithelial layer. The healing time of the cornea epithelium, visual acuity(VA) was compared between the two groups using t- test.RESULTS:There was no statistical difference of the diameter of the ulcer, depth of the infiltration, height of the hypopyon and VA between the two groups beforesurgery(P 】0.05). The average healing time of the AMC group was 6.89 ±2.98 d, which was statistically shorter than that of the control group(10.23±2.78d)(P 【0.05).The average UCVA of the AMC group was 0.138 ±0.083,which was statistically better than that of the control group(0.053±0.068)(P 【0.05).CONCLUSION:AMC surgery could promote healing of cornea epithelium after debridement for fungal keratitis and lead to better VA outcome.
文摘AIM: To evaluate contrast visual acuity(CVA) after implantation of an aspheric apodized diffractive intraocular lens(IOL) or a spherical apodized diffractive IOL in cataract surgery. ·METHODS: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL(30 eyes) and a spherical AcrySof ReSTOR SN60D3 IOL(30 eyes). CVA with best distance correction was measured at 4 contrast levels(100%,25%,10% and 5%) under 3 levels of chart luminance [250,85 and 25 candelas per square meter(cd/m2)] using a multi-functional visual acuity tester(MFVA-100). ·RESULTS: At 12 months after surgery,there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m2(P100% =0.875 and P25% =0.057) and 85cd/m2(P100% =0.198 and P25% =0.193) between the aspheric group and the spherical group. However,the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m2(P10% =0.042 and P5% = 0.007) and 85cd/m2(P10% =0.002 and P5%=0.039). Under the luminance level of 25cd/m 2,no significant differences was found in the 100% CVA between the 2 group(P100% = 0.245),while aspheric group had better visual acuity in the remaining 3 contracts(P25% =0.023,P10% =0.026 and P5% = 0.002,respectively). ·CONCULSION: The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.
基金Supported by Chinese Capital’s Funds for Health Improvement and Research(No.CFH2018-2-4093)National Science and Technology Major Project(No.2018ZX10101-004)。
文摘Dynamic visual acuity test(DVAT)plays a key role in the assessment of vestibular function,the visual function of athletes,as well as various ocular diseases.As the visual pathways conducting dynamic and static signals are different,DVATs may have potential advantages over the traditional visual acuity tests commonly used,such as static visual acuity,contrast sensitivity,and static perimetry.Here,we provide a review of commonly applied DVATs and their several uses in clinical ophthalmology.These data indicate that the DVAT has its unique clinical significance in the evaluation of several ocular disorders.
文摘In this study, we aimed to study the pattern visual evoked potentials （P-VEPs） in two eyes with varying visual acuity in one eye and to provide an objective estimation of visual acuity by comparing P-VEPs in one and two eyes. Thirty subjects were chosen, who had one eye with an acuity of 5.0, 4.85, 4.6, 4.0, or scieropia and obstructed vision and the other eye with an acuity of 5.0, respectively. P-VEPs were detected under the large grating stimuli at 3x4 spatial frequency, moderate grating stimuli （12× 16 spatial frequency） and small grating stimuli （48×64 spatial frequency）. Under large grating stimuli, there was no significant difference in P100 peak latency between the groups, nor was there a significant difference between the amplitude of two eyes and the amplitude of one normal-vision eye. Under moderate and small grating stimuli, there was a significant difference in P100 peak latency between the group with both eyes having an acuity of 5.0 and the group with visual acuity below 4.0 in one eye. There was a significant difference in P100 amplitude between the group with visual acuity of 5.0 in both eyes and the group with one normal-vision eye. There was no significant difference in the amplitude of two eyes and the amplitude of one normal-vision eye between any other two groups. In forensic identification, characteristics and variability of P-VEPs in one and two eyes can be used to identify malingering or decline in visual acuity.
文摘AIM:To study the effects of different flap sizes on visual acuity,refractive outcomes,and aberrations after femtosecond laser for laser in situ keratomileusis(LASIK).METHODS:In each of the forty patients enrolled,1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap,defined as the small flap,while the other eye was treated with a 8.6mm diameter corneal flap,defined as the big flap.Refractive errors,visual acuity,and higher-order aberrations were compared between the two groups at week 1,month 1 and 3 postoperatively. RESULTS:The postoperative refractive errors and visual acuity all conformed to the intended goal.Postoperative higher-order aberrations were increased,especially in spherical aberration(Z12) and vertical coma(Z7).There were no statistically significant differences between the two groups in terms of postoperative refractive errors,visual acuity,root mean square of total HOAs(HO-RMS),trefoil 30°(Z6),vertical coma(Z7),horizontal coma(Z8),trefoil 0°(Z9),and spherical aberration(Z12) at any point during the postoperative follow-up.CONCLUSION:Both the small and big flaps are safe and effective procedures to correct myopia,provided the exposure stroma meets the excimer laser ablations.The personalized size corneal flap is feasible,as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.
基金Supported by the National Natural Science Foundation of China(No.81000391,No.81370020)
文摘AIM：To compare recovery of the visual acuity in patients one day after sub-Bowman keratomileusis（SBK）or laser in situ keratomileusis（LASIK）.· METHODS：Data from 5923 eyes in 2968 patients that received LASIK（2755 eyes） or SBK（3168 eyes） were retrospectively analyzed.The eyes were divided into 4groups according to preoperative spherical equivalent：between-12.00 to-9.00 D,extremely high myopia（n =396,including 192 and 204 in SBK and LASIK groups,respectively）;-9.00 to-6.00 D,high myopia（n=1822,including 991 and 831 in SBK and LASIK groups,respectively）,-6.00 to-3.00 D,moderate myopia（n=3071,including 1658 and 1413 in SBK and LASIK groups,respectively）,and-3.00 to 0.00 D,low myopia（n =634,including 327 and 307 in SBK and LASIK groups,respectively）.Uncorrected logMAR visual acuity values of patients were assessed under standard natural light.Analysis of variance was used for comparisons among different groups.· RESULTS：Uncorrected visual acuity values were0.0115±0.1051 and 0.0466±0.1477 at day 1 after operation for patients receiving SBK and LASIK,respectively（P〈0.01）;visual acuity values of 0.1854±0.1842,0.0615±0.1326,-0.0033±0.0978,and-0.0164±0.0972 were obtained for patients in the extremely high,high,moderate,and low myopia groups,respectively（P〈0.01）.In addition,significant differences in visual acuity at day 1 after operation were found between patients receiving SBK and LASIK in each myopia subgroup.· CONCLUSION：Compared with LASIK,SBK is safer and more effective,with faster recovery.Therefore,SBK is more likely to be accepted by patients than LASIK for better uncorrected visual acuity the day following operation.
基金Supported by the World Health Organization under National Institute of Health contract N01-EY-2103Fundamental Research Funds of the State Key Laboratory in Ophthalmology+2 种基金National Natural Science Foundation of China (No.81125007)The Research Accelerator Program was at University of Melbourne and the CERA FoundationThe Centre for Eye Research Australia receives Operational Infrastructure Support from the Victorian State Government
文摘AIM： To investigate the influence of astigmatism on visual acuity in school-aged children, and to define a cutoff for clinically significant astigmatism. METHODS： This is a population-based, cross-sectional study. Among 5053 enumerated children aged 5-15 y in Guangzhou, 3729（73.8%） children aged 7-15 with successful cycloplegic auto-refraction（1% cyclopentolate） and a reliable visual acuity measurement were included. Ocular measurement included external eye, anterior segment, media and fundus and cycloplegic auto-refraction. Primary outcome measures included the relationship between severity and subtypes of astigmatism and the prevalence of visual impairment. Three criteria for visual impairment were adopted： best-corrected visual acuity（BCVA） ≤0.7, uncorrected visual acuity（UCVA） ≤0.5 or 〈0.7 in the right eye.RESULTS： Increases of cylinder power was significantly associated with worse visual acuity（UCVA： β=0.051, P〈0.01; BCVA： β=0.025, P〈0.001）. A substantial increase in UCVI and BCVI was seen with astigmatism of 1.00 diopter（D） or more. Astigmatism ≥1.00 D had a greater BCVI prevalence than cylinder power less than 1.00 D（OR=4.20, 95%CI： 3.08-5.74）, and this was also true for hyperopic, emmetropic and myopic refraction categories. Oblique astigmatism was associated with a higher risk of BCVI relative to with the rule astigmatism in myopic refractive category（OR=12.87, 95%CI： 2.20-75.38）.CONCLUSION： Both magnitude and subtypes of astigmatism influence the prevalence of visual impairment in school children. Cylinder ≥1.00 D may be useful as a cutoff for clinically significant astigmatism.
基金Supported by Science,Technology and Innovation Commission of Shenzhen Municipality(No.GJHZ20180420180937076,No.JCYJ20180228164400218)Sanming Project of Medicine in Shenzhen Grant(No.SZSM201812090)。
文摘AIM:To obtain the baseline data on presenting visual acuity(PVA)and evaluate the prevalence and associated factors for visual impairment based on PVA in 9070 Chinese college students.METHODS:The freshmen at a university in southern China,including 6527 undergraduate students and 2543 graduate students,were investigated for some sociodemographic characteristics and underwent routine medical examination,including measuring PVA,height,and weight.Visual impairment was defined according to the new World Health Organization criteria for blindness and visual impairment.RESULTS:In 9070 college students,the mean PVA in the better eye was 0.094±0.163 log MAR.The prevalence of visual impairment based on PVA was 2.7%.Only 38.3%college students had normal visual acuity[PVA equal to 0 log MAR(20/20)in both eyes].There were 69.8%of students wearing spectacles.Logistic regression showed that home region(non-Guangdong provinces,P<0.0001,OR=1.70)was risk factor for visual impairment while BMI(P=0.001,OR=0.92)was protective factor from visual impairment.Ethnicity(Han Chinese,P<0.0001,OR=3.17)was risk factor for wearing spectacles while age(P=0.01,OR=0.90)was protective factor from wearing spectacles.CONCLUSION:This study provides the baseline data on PVA and the prevalence of visual impairment in Chinese college students.Our analyses reveal that BMI and home region are associated factors for visual impairment based on PVA,while age and ethnicity are associated factors for wearing spectacles.
文摘AIM: To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet’s stripping automated endothelial keratoplasty(DSAEK)one year after surgery.METHODS: DSAEK patients’ data were reviewed. Thirty seven eyes of 37 patients who underwent DSAEK for pseudophakic bullous keratopathy(PBK) were included in this study. Graft thickness was measured with optical coherence tomography(OCT) 12 mo after DSAEK. Eyes were divided into 3 groups based on the graft thickness:thick(】200 μm), medium-thick(150-200 μm) and thin(【150 μm). Best corrected visual acuity(BCVA),endothelial cells density(ECD) and complications were assessed and comparisons were done between groups.RESULTS: Median thickness of postoperative grafts was 188(range 73-317 μm). There was no significant difference in age, sex, preoperative BCVA, or follow-up period between DSAEK groups. At postoperative 12 mo,mean BCVA was 0.28±0.10 in thick graft group, 0.52±0.08 in medium-thick graft group, and 0.72 ±0.06 in thin graft group. Thin grafts showed better postoperative BCVA as compared with the medium-thick and thick grafts(P =0.001). Thick graft group had 1637.44 ±88.19-mm2,medium thick graft had 1764.50±34.28-mm2 and thin graft group had 1845.30 ±65.62-mm2. Thin graft group had better ECD at 12 mo after surgery(P =0.001).CONCLUSION: Thin grafts after DSAEK ensure better visual rehabilitation. Eyes with thin grafts had significantly lesser loss of ECD compared to eyes withmedium-thick and thick grafts one year after surgery.
文摘This study explored the accuracy of using visual evoked potentials(VEP)technology for visual acuity estimation.The enrolled 726 patients with post-traumatic unilateral decrease in visual acuity included the injured eyes served as the experimental group,and the healthy eyes as the control group.The least signal visual angle(LSVA),and amplitude and latency of P100 were chosen as test indexes.The results under different experimental conditions were recorded by PRVEP technology.All data collected were processed...
文摘AIM:To Introduce a new specialized visual acuity chart for amblyopic children aged 3-5 years old and its clinical applications.METHODS:The new visual acuity chart and notations were designed based on Weber-Fechner law.The optotypes were red against a white background and were specially shaped four basic geometric symbols:circle,square,triangle,and cross.A regular geometric progression of the optotype sizes and distribution was employed to arrange in 14 lines.The progression rate of the optotype size between two lines was 1.2589 and the testing distance was 3m.Visual acuity score could be recorded as logMAR notation or decimal notation.Agestratified diagnostic criteria for amblyopia established by consensus statement on diagnosis of amblyopia(2011)among members of the Strabismus and Pediatric Ophthalmology Group,Ophthalmology Society,Chinese Medical Association(SPOGOSCMA)were illustrated in the new visual acuity chart.RESULTS:When assessing visual acuity in children aged 3-5 years old,this new visual acuity chart that consists of four symmetrical shapes(triangle,square,cross,and circle)overcame an inability to recognize the letters of the alphabet and difficulties in designating the direction of black abstract symbols such as the tumbling’E’or Landolt’C’,which the subjects were prone to lose interest in.The visual acuity score may be recorded indifferent notations:decimal acuity and logMAR.These two notations can be easily converted each other in the new eye chart.The measurements of this new chart not only showed a significant correlation and a good consistency with the international standard logarithmic visual acuity chart(r=0.932,P【0.01),but also indicated a high test-retest reliability(89%of retest scores were within 0.1 logMAR units of the initial test score).CONCLUSION:The results of this study support the validity and reliability of distance visual acuity measurements using the new eye chart in children aged3 to 5 years over a wide range of visual acuities,and the new eye chart is great for early detection of amblyopia.It can be applied in various clinical settings.
基金Supported by the Guangdong Medical Science and Technology Research Fund Project(No.A2018227)Shantou Science and Technology Program(No.170829231930502)。
文摘AIM:To analyze the correlation between macular morphology and function in eyes with diabetic macular edema(DME).METHODS:Fifty-five eyes with different visual acuity(VA)of 32 patients who suffered from DME were analyzed using multifocal electroretinography(mfERG)and optical coherence tomography(OCT).The parameters of mfERG including implicit times and response amplitude were compared to those of 50 normal eyes of 36 age-matched subjects.Correlation analysis was performed between VA,the parameters of mfERG including implicit times and response amplitude,and the central macular thickness(CMT).RESULTS:The amplitude of N1 and P1 were significantly decreased and their latency were significantly increased in five ring regions of the retina in patients with DME.There was statistically significant correlation between logMAR BCVA and P1 amplitude densities in rings 1-4(r=-0.306,-0.536,-0.470,-0.362;P=0.023,<0.01,<0.01,0.007 respectively),N1 amplitude in ring 2 and ring 3(r=-0.035,-0.286;P=0.019,0.034 respectively).There was poor correlation between the CMT and best-corrected visual acuity(BCVA;r=0.288,P=0.033),but there was no significant correlation between CMT and amplitude or implicit time of N1 and P1(P>0.05)in the central macular ring.Multiple stepwise regression analysis showed that P1 amplitude density in ring 2 was the only contributor to the VA.CONCLUSION:It seems to be more appropriate of combining use of mfERG with OCT for the evaluation of macular function in eyes with DME.
