Contrast Detection Learning Improves Visual Contrast Sensitivity of Cat

Psychological studies on human subjects show that contrast detection learning promote learner＇s sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats （Felis catus） were trained to perform monocularly a contrast detection task by two-altemative forced choice method. The perceptual ability of each cat improved remarkably with learning as indicated by a significantly increased contrast sensitivity to visual stimuli. The learning effect displayed an evident specificity to the eye employed for learning but could partially transfer to the naive eye, prompting the possibility that contrast detection learning might cause neural plasticity before and after the information from both eyes are merged in the visual pathway. Further, the contrast sensitivity improvement was evident basically around the spatial frequency （SF） used for learning, which suggested that contrast detection learning effect showed, to some extent, a SF specificity. This study indicates that cat exhibits a property of contrast detection learning similar to human subjects and can be used as an animal model for subsequent investigations on the neural correlates that mediate learning-induced contrast sensitivity improvement in humans.

Decreased contrast sensitivity of visual cortical cells to visual stimuli accompanies a reduction of intracortical inhibition in old cats

Psychophysical experiments on human and animal subjects have proven that aged individuals show significantly reduced visual contrast sensitivity compared with young adults.To uncover the possible neural mechanisms,we used extracellular single-unit recording techniques to examine the response of V1（primary visual cortex） neurons as a function of visual stimulus contrast in both old and young adult cats（Felis catus）.The mean contrast sensitivity of V1 neurons to visual stimuli in old cats decreased significantly relative to young adult cats,consistent with findings reported in old primates.These results indicate that aging can affect contrast sensitivity of visual cortical cells in both primate and non-primate mammalian animals,and might contribute to the reduction of perceptual visual contrast sensitivity in aged individuals.Further,V1 cells of old cats exhibited increased responsiveness,decreased signal-to-noise ratio,and enlarged receptive field（RF） size compared with that of young adult cats,which indicated that decreased contrast sensitivity of V1 neurons accompanied a reduction of intracortical inhibition during senescence.

Effects of higher-order aberrations on contrast sensitivity in normal eyes of a large myopic population

AIM：To study the relation between higher-order aberrations（HOAs）and contrast sensitivity（CS）in normal eyes among a population of laser in situ keratomileusis（LASIK）candidates.METHODS：In 6629 eyes of 3315 LASIK candidates,CS were measured under dark environment at the spatial frequencies of 1.5,3,6,12 and 18 cycles per degree（c/d）,respectively,using an Optec 6500 visual function tester.Meanwhile,ocular HOAs were measured for a 6.0 mm pupil with a Hartmann-Shack wavefront analyzer.RESULTS：In the study,the subjects with an average spherical equivalent of-4.86±2.07 D were included.HOAs decreased from the third to the sixth order aberrations with predominant aberrations of third-order coma,trefoil and fourth-order spherical aberration.At low and moderate spatial frequencies,CS was negatively correlated with the third-order coma and trefoil aberrations,and decreased with increasing Z31,but increased with increasing Z3-3and Z5-1.At high spatial frequencies,CS decreased with increasing Z3-3and increased with increasing Z5-1.CONCLUSION：At a large pupil size of 6.0 mm,the thirdorder aberrations,but not the total aberrations,are the main factors affecting CS.Vertical coma is negatively correlated with CS.

Comparison of contrast sensitivity and visual acuity between deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with keratoconus

AIM: To evaluate postoperative visual acuity and contrast sensitivity results following deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus (KC). METHODS: All the patients’ records with KC who had PK or DALK surgery between May 2010 and May 2011 were retrospectively reviewed. Sixty patients who underwent successful corneal transplantation for KC: 30 eyes underwent DALK and 30 eyes underwent PK were included in this study. Preoperative and postoperative mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA), logMAR best spectacle-corrected visual acuity (BSCVA) and intraocular pressure (IOP) were evaluated. Contrast sensitivity tests (CS) were done preoperative and 2 months after all sutures had removed. All surgeries were performed under regional anesthesia (retrobulbar anesthesia) by 1 surgeon (B.K.) who was experienced in penetrating and lamellar keratoplasty techniques. RESULTS: The mean age of the DALK group was 29.67±4.95 (range 18-40) years and the PK group was 28.7±3.53 (range 18-39) years. Preoperatively there was no significant difference in the logMAR UCVA, logMAR BSCVA and IOP between the DALK (1.281±0.56; 0.97±0.85; 12.07±2.12mmHg) and PK (1.34±0.21; 0.98±0.21; 13±2.12mmHg) groups. One-year after surgery there was no significant difference in the mean logMAR UCVA and IOP between the DALK (0.46±0.37; 11.73±2.1mmHg) and PK (0.38±0.21; 12±2.12mmHg) groups. The mean contrast sensitivity was evaluated by CC-100 Topcon LCD at 1.5, 2.52, 4.23, 7.10 and 11.91 cycles per degree (cs/deg) spatial frequencies before and 2 months after the all sutures had removed. CONCLUSION: All patients with keratoconus in both DALK and PK groups performed good visual function postoperatively. The mean contrast sensitivity increased considerably at all spatial frequencies compared with preoperative levels in the DALK and PK groups. The mean post-operative evaluation of contrast sensitivity measurements was not significantly different between the two groups.

Assessment of contrast sensitivity loss after intrastromal femtosecond laser and LASIK procedure

AIM： To assess the loss of contrast sensitivity （CS） function for INTRACOR or intrastromal femtosecond laser presbyopia procedure to conventional LASIK procedures.METHODS： Patients were recruited from a refractive surgery center for either INTRACOR or conventional LASIK. INTRACOR was performed on 8 eyes and LASIK was performed for 40 eyes in an overlapping period. Pre-operative evaluation and post-operative follow up for up to three months was done. Drops of CS in 4 spatial frequency （3 cpd, 6 cpd, 12 cpd and 18 cpd） right before and 3mo after the surgery were compared by Wilcoxon signed ranks test.RESULTS： For INTRACOR, CS threshold showed significant drop at both glare and non-glare condition, the drop was seen in all 4 spatial frequency. The averaged loss over the 4 spatial frequencies 3mo after surgery was 1.18 for non-glare and 0.71 for glare. For LASIK the CS threshold drop was most significant in 12 cpd for glare.CONCLUSION： INTRACOR procedure produces a gain of near vision for presbyopia patients but also introduces a high lost of contrast sensitivity plus worsen of vision quality. Pre-surgical patient selection and advise should be given with specific regards to night driving and glare conditions.

Age norms for grating acuity and contrast sensitivity measured by Lea tests in the first three years of life

AIM： To determine age norms in the first three years of life for grating visual acuity and contrast sensitivity obtained with Lea grating test and Hiding Heidi low contrast face test. METHODS： Lea grating test was used to estimate binocular grating acuity and Hiding Heidi low contrast face test was used to estimate contrast sensitivity in 600 healthy infants and children. Age ranged from 3 to 36 mo subdivided into 12 groups subjected for full ophthalmologic and pediatric examinations.RESULTS： The grating acuity developed along the first three years of life. It ranged from 1.88±0.32 c/d at 3mo to 30.95±0.77 c/d at 36 mo. The most rapid development was during the first 12 mo and the slowest development was from 30 to 36 mo. The contrast sensitivity showed rapid development in the first two years of life. Its mean value ranged from 4.23±1.17 at 3mo to 78.26±8.21 at 24 mo. It was constant at the highest score（80） thereafter.CONCLUSION： Age norms for grating acuity along with contrast sensitivity offer a more comprehensive measure of spatial vision and should be incorporated in clinical practice for better visual assessment in preverbal and nonverbal children.

CONTRAST SENSITIVITY IN AMBLYOPIA

Contrast sensitivity function(CSF) for sinusoid gratings of varying spatial frequencies was determined for each eye of 21 cases with unilateral amblyopia. The CSF of all amblyopic eyes, except one, showed reduced sensitivity when compared with the non-amblyopic eye of the same person. The curve showed reduction more significantly at middle and high spatial frequencies. The cut-off frequency was shifted toward lower spatial frequencies. The relationship between CSF and various degree of amblyopia was als...

Psychophysics in the ophthalmological practice—Ⅱ.Contrast sensitivity

Contrast is the differential luminance between one object and another.Contrast sensitivity(CS)quantifies the ability to detect this difference:estimating contrast threshold provides information about the quality of vision and helps diagnose and monitor eye diseases.High contrast visual acuity assessment is traditionally performed in the eye care practice,whereas the estimate of the discrimination of low contrast targets,an important complementary task for the perception of details,is far less employed.An example is driving when the contrast between vehicles,obstacles,pedestrians,and the background is reduced by fog.Many conditions can selectively degrade CS,while visual acuity remains intact.In addition to spatial CS,“temporal”CS is defined as the ability to discriminate luminance differences in the temporal domain,i.e.,to discriminate information that reaches the visual cortex as a function of time.Likewise,temporal sensitivity of the visual system can be investigated in terms of critical fusion frequency(CFF),an indicator of the integrity of the magnocellular system that is responsible for the perception of transient stimulations.As a matter of fact,temporal resolution can be abnormal in neuro-ophthalmological clinical conditions.This paper aims at considering CS and its application to the clinical practice.

AB037.Preliminary findings from the COMPASS-ND study:reading acuity and contrast sensitivity at different levels of cognitive impairment

Background:Declines in visual function have been reported in individuals with Alzheimer’s disease(AD)and other neurological disorders,and have been associated with cognitive decline seen in those disorders.Here we report preliminary visual findings from the COMPASS-ND study of the Canadian Consortium on Neurodegeneration in Aging(CCNA)in a diverse group of individuals at various stages of cognitive impairment,diagnosed via clinical consensus and stringent criteria.Methods:Participants were 109 older adults(age range,60-89,M=72.94,SD=7.01)that are part of the CCNA cohort at different stages of cognitive decline(subjective cognitive impairment,SCI,n=24;mild cognitive impairment,MCI,n=64;mild AD,n=21).Reading acuity(MNRead)and contrast sensitivity(Mars test)were tested with habitual correction.We additionally report scores on the Montreal Cognitive Assessment(MoCA)scale for the three groups.Results:Out of all the participants,25%had reduced reading acuity[>0.5 logMAR(20/63)]and 23%presented with moderate to severe loss of contrast sensitivity[<1.48 log CS(3.3%contrast)].Only 6.5%of participants had combined reduced reading acuity and moderate to severe contrast sensitivity.Notably,only 8.3%of individuals with SCI presented with reduced reading acuity,compared to 32.3%and 23.8%of those with MCI and AD,respectively(χ2=5.28,P=0.071).Lower contrast sensitivity was observed in AD participants relative to those with MCI and SCI(P=0.04,ω2=0.04;Figure 1),after adjusting for age,sex and education.No differences in reading acuity were observed(P=0.46,ω2=0.004).Conclusions:Using the Mars test,a measure of the processing of low spatial frequencies,we were able to replicate previous reports of declines in contrast sensitivity in individuals with AD compared to those with MCI and SCI.We also observed higher rates of reduced reading acuity in the AD and MCI groups relative to those reported in the general population.These results set the groundwork for examining the relationship between vision status and cognitive function,brain integrity,quality of life,in these groups.

Objective electrophysiological contrast sensitivity with monofocal and multifocal intraocular lenses:a prospective clinical study

Background:To compare objective electrophysiological contrast sensitivity function(CSF)in patients implanted with either multifocal intraocular lenses(MIOLs)or monofocal intraocular lenses(IOLs)by pattern reversal visual evoked potentials(prVEP)measurements.Methods:Fourty-five cataract patients were randomly allocated to receive bilaterally:apodized diffractive-refractive Alcon Acrysof MIOL(A),full diffractive AMO Tecnis MIOL(B)or monofocal Alcon Acrysof IOL(C).Primary outcomes:1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies.Secondary outcomes:psychophysical CSF measured with VCTS-6500,photopic uncorrected distance(UDVA),and mesopic and photopic uncorrected near and intermediate visual acuities(UNVA and UIVA respectively).Results:Electrophysiological CSF curve had an inverted U-shaped morphology in all groups,with a biphasic pattern in Group B.Group A showed a lower CSF than group B at 4 and 8 cpd,and a lower value than group C at 8 cpd.Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B.Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups.Mesopic UNVA and UIVA were better in group B.Conclusions:Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs.This may be related to the visual acuity under certain conditions or to IOL characteristics.This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.

Contrast sensitivity and higher-order aberrations in patients with astigmatism

Background Astigmatism is one of the most significant obstacles for achieving satisfactory visual function. This study was to evaluate the influence of astigmatism on contrast sensitivity （CS） and higher-order aberrations. Methods CS, accommodation response and wavefront aberration were measured in 113 patients with astigmatism, aged 18-36 years. Both single and binocular visual performance were examined under four lighting conditions： photopia, photopia with glare, scotopia and scotopia with glare respectively. Accommodation response was classified as normal, abnormal and low. The contribution of the power and axis of astigmatism to CS, accommodation response and wavefront aberration was analyzed. Results As the dioptric power of astigmatism increased, the loss of CS spatial frequency changed from high to intermediate, and then to low frequency. CS scores varied at different illuminance levels, descending in the following sequence： photopia, photopia with glare, scotopia, and scotopia with glare. However, the normal accommodation group showed better CS values under photopia with glare than without glare. The range of influenced direction of sine-wave gratings remained mostly at the meridian line of high dioptric power, which would be expanded when optical accommadation attenuated. The patients with symmetrical astigmatism got higher CS scores with binoculus vision than with dominant eye vision, while the patients with asymmetrical astigmatism did this only at scotopia with glare. Among higher-order aberrations, coma aberration, secondary coma aberration and the total higher order aberration were influenced by astigmatism, all of which rising with the power of astigmatism increased. Conclusions Reducing astigmatism might improve the performance of visual function. Not only the power of astigmatism should be cut down, but also the binocular axes should be made symmetrically.

Comparison of higher-order aberrations and contrast sensitivity between Tecnis Z9001 and CeeOn 911A intraocular lenses:a prospective randomized study

Background The advent of wavefront technology in the past five years has provided some insight into the optical outcomes of cataract surgery. The Tecnis Z9001 intraocular lens （Tecnis IOL, AMO） with a modified prolate anterior surface was claimed to reduce or even eliminate ocular spherical aberration to improve the visual quality. The purpose of this study was to determine whether Tecnis IOLs can improve the quality of vision as evaluated by measuring visual acuity, wavefront aberration, and contrast sensitivity. Methods In an intraindividual prospective study, 20 patients with bilateral cataract were randomly assigned to receive a modified prolate anterior surface IOL （Tecnis Z9001, AMO） in one eye and a biconvex spherical surface IOL （CeeOn 911A, AMO） in the other. After 3 months, the following were investigated： best corrected visual acuity, pupil diameter, photopic and mesopic contrast sensitivity, and wavefront aberration of the whole eye （ocular）, cornea, and internal plane. Results The differences in the best corrected visual acuity and pupil diameter between the two groups were not statistically significant. Negative 4th-order spherical aberration （Z4^0） was found in the Tecnis group, whereas positive Z4^0 found in the CeeOn group for the internal and ocular plane. Statistically significant differences were found at the ocular higher-aberrations between the two IOLs. Contrast sensitivity testing showed significantly better results in the Tecnis group at visual angles higher than 1.0 degree under photopic conditions and at visual angles higher than 1.6 degree under mesopic conditions both without glare and with glare in comparison with the CeeOn group. Conclusions The Tecnis Z9001 IOL with a modified prolate anterior surface produces negative spherical aberration and consequently reduces the higher-order aberrations in pseudophakic eyes. This leads to enhanced contrast sensitivity and improved functional vision compared to conventional spherical IOLs.

Avian contrast sensitivity inspired contour detector for unmanned aerial vehicle landing

Runway detection is a demanding task for autonomous landing of unmanned aerial vehicles. Inspired by the attenuation effect and surround suppression mechanism, a novel biologically computational method based on the avian contrast sensitivity is proposed for runway contour detection. For the noisy stimuli, deniosed responses of the biologically inspired Gabor energy operator are generalized followed by the denoising layer and the multiresolution fusion layer. Moreover, two factors such as contour effect and texture suppression are considered in the contrast sensitivity based surround inhibition. Different from traditional detectors, which do not distinguish between contours and texture edges, the proposed method can respond strongly to contours and suppress the texture information. Applying the contrast sensitivity inspired detector to noisy runway scenes yields effective contours, while the non-meaningful texture elements are removed dramatically at the same time. Besides the superior performance over traditional detectors, the proposed method is capable to provide insight into the attenuation effect of the avian contrast sensitivity function and has potential applications in computer vision and pattern recognition.

Correlation between contrast sensitivity and the lens opacities classification system III in age-related nuclear and cortical cataracts

Background Contrast sensitivity （CS） testing can detect differences in functional vision and is highly correlated with visual performance. This study was designed to investigate the association between CS and the grading score using the lens opacities classification system （LOCS） III as well as the association between CS and visual acuity （VA） in nuclear or cortical age-related cataract （ARC） patients. Methods A total of 270 eyes with ARC and 30 control eyes were divided into nuclear opacity （NO）, nuclear color （NC）, cortical cataract （C） based on LOCS II1. The CS values measured at all spatial frequencies under photopic and glare conditions that resulted in contrast sensitivity function （CSF） were evaluated, and LogMAR VA was tested with the Early Treatment Diabetic Retinopathy Study （ETDRS） chart. The correlation between CSF and LOCS III grading scores, and between CSF and LogMAR VA were analyzed. Results Compared to the controls, CSF of the nuclear or cortical ARC significantly declined. There are significant correlation between CSF and LogMAR VA, and between CSF and LOCS III grading scores. Compared to the VA, a stronger correlation existed between CSF and LOCS III grading score than that of LogMAR VA and LOCS III grading score. CS at some spatial frequencies is significantly influenced with LOCS III grading score. Conclusions CSF significantly declined with the increasing ARC grading scores. Comparing to VA, CSF reflected the severity of cataract more comprehensively. CS at low spatial frequency is significantly influenced by ARC. Therefore, CS is more precise than VA in assessing the visual function of ARC patients.

Impact of Lutein-Based Food Supplement on Macular Pigment, Glare and Contrast Vision

Purpose: To evaluate the impact of a specially formulated food supplement containing 20 mg free lutein and 2.8 mg zeaxanthin on macular pigment volume (MPV) and visual function. Methods: In this prospective non-comparative study healthy subjects were instructed to take one capsule of Eagle Eye Lutein 20 Vision Caps (Innomedis AG) per day with a meal for 6 months. MPV was measured with the MP-Eye system (AzulOptics) after 3 and 6 months of treatment. Mesopic vision (MV), glare sensitivity (GS) and contrast vision threshold (CVT) were measured with the Binoptometer 4P system (OCULUS Optikgeräte). Results: Twenty-three healthy subjects between 19 and 56 years were enrolled. A significant increase was observed in MPV (p Conclusions: The specially formulated food supplement containing lutein and zeaxanthin induced a significant increase in MPV, and consequently an improvement in the visual function after 3 and 6 months in healthy subjects.

Impact of Lutein-Based Food Supplement on Macular Pigment, Glare and Contrast Vision

Purpose: To evaluate the impact of a specially formulated food supplement containing 20 mg free lutein and 2.8 mg zeaxanthin on macular pigment volume (MPV) and visual function. Methods: In this prospective non-comparative study healthy subjects were instructed to take one capsule of Eagle Eye Lutein 20 Vision Caps (Innomedis AG) per day with a meal for 6 months. MPV was measured with the MP-Eye system (AzulOptics) after 3 and 6 months of treatment. Mesopic vision (MV), glare sensitivity (GS) and contrast vision threshold (CVT) were measured with the Binoptometer 4P system (OCULUS Optikgeräte). Results: Twenty-three healthy subjects between 19 and 56 years were enrolled. A significant increase was observed in MPV (p Conclusions: The specially formulated food supplement containing lutein and zeaxanthin induced a significant increase in MPV, and consequently an improvement in the visual function after 3 and 6 months in healthy subjects.

Contrast visual acuity after multifocal intraocular lens implantation: aspheric versus spherical design

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.

Visual perception alterations in COVID-19:a preliminary study

AIM:To compare the visual perception(color and chromatic-achromatic contrast vision)of a small cohort of COVID-19 patients at the time of infection and after 6mo with that of a healthy population matched for sex and age.METHODS:A total of 25 patients(9 females,16 males,mean age:54±10y)with COVID-19 hospitalized in the COVID-19 Unit of the University Clinical Hospital of Valladolid were recruited for this preliminary study.Visual perception,as determined by monocular measurement of contrast sensitivity function(CSF)and color vision was assessed in each patient using the Optopad test.The results obtained were then compared with those of a sample of 16 age-and sex-matched healthy controls(5 females,11 males,mean age:50±6y)in which the same measurement procedure was repeated.Statistically significant differences between groups were assessed using the Mann-Whitney U test.Measurements were repeated after a minimum follow-up period of 6mo and statistically significant differences between the two time points in each group were assessed using the Wilcoxon signed rank test.RESULTS:Discrimination thresholds(color and chromatic-achromatic contrast vision)and their corresponding sensitivity,calculated as the inverse of the discrimination threshold,were evaluated.Analysis of the data revealed higher contrast threshold results(i.e.,worse contrast sensitivity)in the COVID-19 group than in the control group for all spatial frequencies studied in the Optopad-CSF achromatic test and most of the spatial frequencies studied in the Optopad-CSF chromatic test for the red-green and blue-yellow mechanisms.In addition,color threshold results in the COVID-19 group were also significantly higher(i.e.,worse color sensitivity)for almost all color mechanisms studied in the Optopad-Color test.At 6mo,most of the differences found between the groups were maintained despite COVID-19 recovery.CONCLUSION:The present results provide preliminary evidence that visual perception may be impaired in COVID-19,even when the infection has passed.Although further research is needed to determine the precise causes of this finding,analysis of CSF and color vision could provide valuable information on the visual impact of COVID-19.

One-year outcomes of resveratrol supplement with aflibercept versus aflibercept monotherapy in wet agerelated macular degeneration

AIM:To determine the one-year outcomes of resveratrol oral supplement in patients suffering from wet age-related macular degeneration(AMD).METHODS:Fifty naïve and previously untreated patients suffering from wet AMD,were randomly assigned in two subgroups of 25 patients each.All the participants were treated with 3 monthly intravitreal injections of 2.0 mg aflibercept(IAIs)followed by injections“according to need”,while in one group the patients also received daily two tablets of resveratrol oral supplement.Prior to treatment initiation,a complete ophthalmological examination,including best corrected visual acuity(BCVA)and contrast sensitivity evaluation,optical coherence tomography(OCT)scans,fundus autofluorescence(FAF),fluorescein angiography,indocyanine green angiography,and OCT angiography(OCTA),was performed to every participant,while all of them completed the Hospital Anxiety and Depression Scale(HADS)questionnaire,in order to assess their quality of life(QoL)status.The patients were assessed monthly for 1y with FAF,and OCT or OCTA;the main endpoints were the number IAIs,the changes in BCVA,in contrast sensitivity,and in patients’QoL status.RESULTS:No significant differences were present between the groups regarding the baseline demographic and clinical data.Over the 12-month period,a similar number of IAIs was applied in both groups(4.52±1.00 vs 4.28±0.90,P=0.38),while the rest of the clinical data also did not differ significantly after the completion of the study period.However,for HADS Depression(11.88±2.51 vs 8.28±1.54,P<0.001)and HADS Anxiety(11.92±2.52 vs 7.76±1.51,P<0.001)questionnaires values,the score was significantly better in patients who received resveratrol supplements.Moreover,a statistically significant difference was detected in the mean change from baseline values of contrast sensitivity(0.17±0.19 vs 0.35±0.24,P=0.005),HADS Depression(0.08±1.38 vs-3.88±1.48,P<0.001),and HADS Anxiety(0.36±1.98 vs-5.12±2.70,P<0.001)scores,in favour of the patients treated with resveratrol supplements.CONCLUSION:The resveratrol oral supplement is a complementary treatment in cases of wet AMD,highlighting its effectiveness in improving patients’QoL status.

Effect of changing mesopic and photopic light conditions on visual functions

AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022.All of them had eye health and normal visual function and could have refractive errors or not.Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition.The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured.Also,visual acuity,stereopsis and contrast sensitivity(in five spatial frequencies of 1.5,3,6,12,and 18 cycles per degree),were measured first in photopic light condition and then in mesopic light condition,by Snellen control vision chart,stereo butterfly test and the M&S technology monitor test respectively.RESULTS:In the 48 student subjects with an average age of 22.69±3.56y,mean of refractive error as sphere equivalent,visual acuity and stereopsis were-1.25±1.74 diopters,0 logMAR,44.37±13.03 seconds of arc,respectively in photopic light condition while in mesopic light was equal to-1.56±1.75 diopters,0.12±0.09 logMAR and 50.62±33.35 seconds of arc,respectively.The mean of contrast sensitivity measured at spatial frequencies of 1.5,3,6,12,and 18 cycles per degree in photopic condition was equal to 2.38±0.04,2.37±0.07,2.04±0.21,1.27±0.32,0.82±0.27 logarithm of contrast sensitivity,respectively and in mesopic lighting condition was equal to 2.34±0.12,2.30±0.16,1.84±0.28,1.02±0.28,0.63±0.24 logarithm of contrast sensitivity,respectively.Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables[refractive error(P<0.001),visual acuity(P<0.001),stereopsis(P=0.008)and contrast sensitivity(P<0.001)].CONCLUSION:The refractive error of the student subjects in mesopic light condition change towards myopia,and its amount is clinically significant.Also,the examination and comparison of the factors of visual acuity,stereopsis and contrast sensitivity in these two lighting conditions show that the decrease in brightness level to the mesopic level causes a decrease in the aforementioned visual functions.