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 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. Amo...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
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
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 and analyzed by SPSS software.The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group,but there was very significant difference in experimental group.It was concluded that with the regression formulation for the amplitude of P100 and vision under LSVA,visual acuity can be estimated more accurately and impartially.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
AIM:To validate a visual acuity(VA)test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.METHODS:A cohort of 101 patients,44 girls and 57 boys w...AIM:To validate a visual acuity(VA)test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.METHODS:A cohort of 101 patients,44 girls and 57 boys with a median of 6.5 years old(3-10 years of age),presenting for eye examinations in Ophthalmology Department(Strasbourg,France)between November 1st,2018,and February 1st,2019 were enrolled.Monocular and binocular VA testing was performed on the subject using both a standard test and the touchpad application(Monoyer,"E"or,Pigassou depending of children s capacities).Patients were excluded if they were physically or mentally unable to use the touchpad.The duration of each tests,the painfulness,the comprehension,the attention of children during the test and test’s preferences were also evaluated.RESULTS:There was a good linear correlation and intra-class correlation coefficient[ICC=0.50(0.34.0.64)for binocular acuity,0.74(0.64.0.82)for right eyes and 0.525(0.37.0.66)for left eye].The standard errors of measurement were very low(0.08.0.05.0.08 for binocular VA,right eyes VA and left eyes VA,respectively).There was no difference between two tests for right eye(P=0.126);left eye(P=0.098)and binocular acuity(P=0.085).Non inferiority was proved for all binocular[-0.06(-0.09.-0.03)],right eye[-0.04(-0.07.-0.01)]and left eye[-0.06(-0.09,-0.02)]VA.The sensitivity and specificity,which correspond to the ability for our app to detect amblyopia,were 92%and 80%respectively.CONCLUSION:Our touchpad application represents an efficient and valid test of VA in children with a high specificity to detect visual impairment.展开更多
Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of catar...Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ...展开更多
The objective was to measure the visual acuity (VA) of children with the diagnosis of hydrocephalus with or without peritoneal-ventricular shunt (PVS). A total of 55 children were included in the study (34 Female), wi...The objective was to measure the visual acuity (VA) of children with the diagnosis of hydrocephalus with or without peritoneal-ventricular shunt (PVS). A total of 55 children were included in the study (34 Female), with an age range of 0 to 291 weeks. The VA was measured by the sweep visual evoked potential technique. Of those with a PVS, in 31 the ventricular valve was inserted before 15 days after the diagnosis whereas in 14 the ventricular valve was inserted after 15 days. The sweep VEP was performed in all children, 95 exams (94%) were abnormal and only 6 were normal. There was a statistical difference in the VA between children with a PVS inserted before 15 days of the diagnosis and children with a PVS after 15 days (p = 0.038) or those without a shunt (p = 0.031). Children with no complications of the PVS had a better VA as compared to those with shunt complications (p < 0.001). In the group of children with complications, again those who had a shunt inserted be-fore 15 days had better VA results in com- parison to those in whom the shunt was inserted after 15 days (p = 0.029). No statistical difference in the VA was found between children without the PVS and with those in which the shunt was inserted after 15 days of the di-agnosis of hydrocephalus (p = 0.699). We conclude that the delayed insertion of the PVS may compromise the visual development of these children.展开更多
Transcorneal Electrical Stimulation (TES) was applied to a group of volunteer patients suffering from Retinitis Pigmentosa (RP), in order to investigate the effect of TES in Visual Acuity (VA). 28 partial blind patien...Transcorneal Electrical Stimulation (TES) was applied to a group of volunteer patients suffering from Retinitis Pigmentosa (RP), in order to investigate the effect of TES in Visual Acuity (VA). 28 partial blind patients with diagnosis of classic RP, Usher syndrome I and/or II were stimulated transcornealy, during a period of 52 weeks using a non conventional waveform, only in the lowest visually capable eye. The proposed waveform has been modeled from the natural response of human retina and delivered by means of an adaptive generator designed and built for tissue stimulation. Statistical results show the improvement of average VA or at least the contention of the disease natural progress. Categorized analysis of results indicates the same effect that if the age of patients, time since diagnosis and genetic disorder variation (classic RP, Usher syndrome I and/or II) are considered, in this case clinical and electrophysiological follow-up parameters were statistically analyzed in order to know the effect of TES. General results yield an improvement of 48.15% in the average of VA for stimulated eyes against an average degreasing of -8.06% in the same scale, with respect to their basal condition before the start of the experiment.展开更多
The retinal structure and visual acuity in Japanese flounder Paralichthys olivaceus at different stages of development were examined by light microscopy. The resolving power of the retina, the visual axis and the best...The retinal structure and visual acuity in Japanese flounder Paralichthys olivaceus at different stages of development were examined by light microscopy. The resolving power of the retina, the visual axis and the best visual field were estimated based on the distribution of cone cells in the retina. The visual system of the larvae appears poorly developed at hatching. The larvae with total length (TL) of less than 10 mm, have single cones only and the eyes were well pigmented. At 10-11 mm TL, most single cones fused to form double cones, with the single and double cones forming a mosaic pattern. From larvae to early juvenile the retina stretches, the cones increase in diameter and rods increase in number. Based on the highest density of the cones in the ventro temporal region, the visual axis was orientated up forward. The resolving power of the retina in 40-530 mm TL Japanese flounder was found to range from 25.1 to 11.5 min. The results indicated continual improvements in the visual system of the growing fish towards higher resolving power, visual acuity and sensitivity.展开更多
Objective: The current study aimed to assess the association between the type of anisometropia and its effects on monocular and binocular best-corrected vision acuity (BCVA), aniseikonia, and stereopsis in the absence...Objective: The current study aimed to assess the association between the type of anisometropia and its effects on monocular and binocular best-corrected vision acuity (BCVA), aniseikonia, and stereopsis in the absence of strabismus. Methods: In total, 162 individuals with anisometropia and healthy eyes and without a previous history of amblyopia therapy and eye surgery were included in the analysis. According to spherical and cylindrical components and spherical equivalent, they were divided into the spherical hyperopic anisometropia (SHA, n = 31), spherical myopic anisometropia (SMA, n = 45), astigmatic or cylindrical hyperopic anisometropia (CHA, n = 22), and astigmatic or cylindrical myopic anisometropia (CMA, n = 64) groups. Patients without anisometropia (NA, n = 188) were classified under the control group. The effects of anisometropia on monocular and binocular BCVA, aniseikonia, and stereoacuity were examined. Results: The NA group had a significantly lower LogMAR of BCVA of the right eye (RE), left eye (LE), worse eye than the SHA, SMA, CMA, and CHA groups. Moreover, the SMA group had significantly lower LogMAR of BCVA than the CHA group (p Conclusion: Worse visual levels of the RE, LE, worse eye, BCVA difference, and lower stereopsis were evidenced in each type of anisometropia defined in this study. Cylindrical hyperopic anisometropia (CHA) resulted in a statically significant worsening VA level and stereopsis than cylindrical myopic (CMA) or spherical myopic anisometropia.展开更多
Perception is the ability to see,hear,or become aware of external stimuli through the senses.Visual stimuli are electromagnetic waves that interact with the eye and elicit a sensation.Sensations,indeed,imply the detec...Perception is the ability to see,hear,or become aware of external stimuli through the senses.Visual stimuli are electromagnetic waves that interact with the eye and elicit a sensation.Sensations,indeed,imply the detection,resolution,and recognition of objects and images,and their accuracy depends on the integrity of the visual system.In clinical practice,evaluating the integrity of the visual system relies greatly on the assessment of visual acuity,that is to say on the capacity to identify a signal.Visual acuity,indeed,is of utmost importance for diagnosing and monitoring ophthalmological diseases.Visual acuity is a function that detects the presence of a stimulation(a signal)and resolves its detail(s).This is the case of a symbol like“E”:the stimulus is detected,then it is resolved as three horizontal bars and a vertical bar.In fact,within the clinical setting visual acuity is usually measured with alphanumeric symbols and is a three-step process that involves not only detection and resolution,but,due to the semantic content of letters and numbers,their recognition.Along with subjective(psychophysical)procedures,objective methods that do not require the active participation of the observer have been proposed to estimate visual acuity in non-collaborating subjects,malingerers,or toddlers.This paper aims to explain the psychophysical rationale underlying the measurement of visual acuity and revise the most common procedures used for its assessment.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
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 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.
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 and analyzed by SPSS software.The results showed that the coincidence between subjective and VEP visual acuity was 96.7% in control group,but there was very significant difference in experimental group.It was concluded that with the regression formulation for the amplitude of P100 and vision under LSVA,visual acuity can be estimated more accurately and impartially.
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.
文摘AIM:To validate a visual acuity(VA)test application on touchpad in the screening of pediatric population by comparing VA results obtained with conventional tests.METHODS:A cohort of 101 patients,44 girls and 57 boys with a median of 6.5 years old(3-10 years of age),presenting for eye examinations in Ophthalmology Department(Strasbourg,France)between November 1st,2018,and February 1st,2019 were enrolled.Monocular and binocular VA testing was performed on the subject using both a standard test and the touchpad application(Monoyer,"E"or,Pigassou depending of children s capacities).Patients were excluded if they were physically or mentally unable to use the touchpad.The duration of each tests,the painfulness,the comprehension,the attention of children during the test and test’s preferences were also evaluated.RESULTS:There was a good linear correlation and intra-class correlation coefficient[ICC=0.50(0.34.0.64)for binocular acuity,0.74(0.64.0.82)for right eyes and 0.525(0.37.0.66)for left eye].The standard errors of measurement were very low(0.08.0.05.0.08 for binocular VA,right eyes VA and left eyes VA,respectively).There was no difference between two tests for right eye(P=0.126);left eye(P=0.098)and binocular acuity(P=0.085).Non inferiority was proved for all binocular[-0.06(-0.09.-0.03)],right eye[-0.04(-0.07.-0.01)]and left eye[-0.06(-0.09,-0.02)]VA.The sensitivity and specificity,which correspond to the ability for our app to detect amblyopia,were 92%and 80%respectively.CONCLUSION:Our touchpad application represents an efficient and valid test of VA in children with a high specificity to detect visual impairment.
文摘Tests of preoperative visual function and prediction of postoperative E chart visual acuity(ECVA) using laser interferometric visual acuity(LIVA) and electroretinogram(ERG) were performed in 16 cases(19 eyes) of cataract. The results showed that the coincident rate between preoperative LIVA and postoperative ECVA was 63.2%, and there was a parallel correlation between preoperative amplitude of photopic ERG b-wave and postoperative ECVA in 79.0% of the eyes. Comparing these two methods, the test of LIVA ...
基金supported by grants to MFC from CNPq 401153/2009-6 Ciencias Humanas.MFC is CNPq research fellow.
文摘The objective was to measure the visual acuity (VA) of children with the diagnosis of hydrocephalus with or without peritoneal-ventricular shunt (PVS). A total of 55 children were included in the study (34 Female), with an age range of 0 to 291 weeks. The VA was measured by the sweep visual evoked potential technique. Of those with a PVS, in 31 the ventricular valve was inserted before 15 days after the diagnosis whereas in 14 the ventricular valve was inserted after 15 days. The sweep VEP was performed in all children, 95 exams (94%) were abnormal and only 6 were normal. There was a statistical difference in the VA between children with a PVS inserted before 15 days of the diagnosis and children with a PVS after 15 days (p = 0.038) or those without a shunt (p = 0.031). Children with no complications of the PVS had a better VA as compared to those with shunt complications (p < 0.001). In the group of children with complications, again those who had a shunt inserted be-fore 15 days had better VA results in com- parison to those in whom the shunt was inserted after 15 days (p = 0.029). No statistical difference in the VA was found between children without the PVS and with those in which the shunt was inserted after 15 days of the di-agnosis of hydrocephalus (p = 0.699). We conclude that the delayed insertion of the PVS may compromise the visual development of these children.
文摘Transcorneal Electrical Stimulation (TES) was applied to a group of volunteer patients suffering from Retinitis Pigmentosa (RP), in order to investigate the effect of TES in Visual Acuity (VA). 28 partial blind patients with diagnosis of classic RP, Usher syndrome I and/or II were stimulated transcornealy, during a period of 52 weeks using a non conventional waveform, only in the lowest visually capable eye. The proposed waveform has been modeled from the natural response of human retina and delivered by means of an adaptive generator designed and built for tissue stimulation. Statistical results show the improvement of average VA or at least the contention of the disease natural progress. Categorized analysis of results indicates the same effect that if the age of patients, time since diagnosis and genetic disorder variation (classic RP, Usher syndrome I and/or II) are considered, in this case clinical and electrophysiological follow-up parameters were statistically analyzed in order to know the effect of TES. General results yield an improvement of 48.15% in the average of VA for stimulated eyes against an average degreasing of -8.06% in the same scale, with respect to their basal condition before the start of the experiment.
基金Project 39970578 supported by the NSFCsupported by the Ministry of Education Foundation for University Key Teachers.
文摘The retinal structure and visual acuity in Japanese flounder Paralichthys olivaceus at different stages of development were examined by light microscopy. The resolving power of the retina, the visual axis and the best visual field were estimated based on the distribution of cone cells in the retina. The visual system of the larvae appears poorly developed at hatching. The larvae with total length (TL) of less than 10 mm, have single cones only and the eyes were well pigmented. At 10-11 mm TL, most single cones fused to form double cones, with the single and double cones forming a mosaic pattern. From larvae to early juvenile the retina stretches, the cones increase in diameter and rods increase in number. Based on the highest density of the cones in the ventro temporal region, the visual axis was orientated up forward. The resolving power of the retina in 40-530 mm TL Japanese flounder was found to range from 25.1 to 11.5 min. The results indicated continual improvements in the visual system of the growing fish towards higher resolving power, visual acuity and sensitivity.
文摘Objective: The current study aimed to assess the association between the type of anisometropia and its effects on monocular and binocular best-corrected vision acuity (BCVA), aniseikonia, and stereopsis in the absence of strabismus. Methods: In total, 162 individuals with anisometropia and healthy eyes and without a previous history of amblyopia therapy and eye surgery were included in the analysis. According to spherical and cylindrical components and spherical equivalent, they were divided into the spherical hyperopic anisometropia (SHA, n = 31), spherical myopic anisometropia (SMA, n = 45), astigmatic or cylindrical hyperopic anisometropia (CHA, n = 22), and astigmatic or cylindrical myopic anisometropia (CMA, n = 64) groups. Patients without anisometropia (NA, n = 188) were classified under the control group. The effects of anisometropia on monocular and binocular BCVA, aniseikonia, and stereoacuity were examined. Results: The NA group had a significantly lower LogMAR of BCVA of the right eye (RE), left eye (LE), worse eye than the SHA, SMA, CMA, and CHA groups. Moreover, the SMA group had significantly lower LogMAR of BCVA than the CHA group (p Conclusion: Worse visual levels of the RE, LE, worse eye, BCVA difference, and lower stereopsis were evidenced in each type of anisometropia defined in this study. Cylindrical hyperopic anisometropia (CHA) resulted in a statically significant worsening VA level and stereopsis than cylindrical myopic (CMA) or spherical myopic anisometropia.
文摘Perception is the ability to see,hear,or become aware of external stimuli through the senses.Visual stimuli are electromagnetic waves that interact with the eye and elicit a sensation.Sensations,indeed,imply the detection,resolution,and recognition of objects and images,and their accuracy depends on the integrity of the visual system.In clinical practice,evaluating the integrity of the visual system relies greatly on the assessment of visual acuity,that is to say on the capacity to identify a signal.Visual acuity,indeed,is of utmost importance for diagnosing and monitoring ophthalmological diseases.Visual acuity is a function that detects the presence of a stimulation(a signal)and resolves its detail(s).This is the case of a symbol like“E”:the stimulus is detected,then it is resolved as three horizontal bars and a vertical bar.In fact,within the clinical setting visual acuity is usually measured with alphanumeric symbols and is a three-step process that involves not only detection and resolution,but,due to the semantic content of letters and numbers,their recognition.Along with subjective(psychophysical)procedures,objective methods that do not require the active participation of the observer have been proposed to estimate visual acuity in non-collaborating subjects,malingerers,or toddlers.This paper aims to explain the psychophysical rationale underlying the measurement of visual acuity and revise the most common procedures used for its assessment.
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.
