Decreased Contrast Sensitivity Research Articles

Impaired Visual Function in Posterior Vitreous Detachment Assessed With the Active-Learning Quantitative Contrast Sensitivity Function Test.

Introduction: To investigate whether there is visual function impairment in patients with posterior vitreous detachment (PVD) using the active-learning quantitative contrast sensitivity function test. Methods: In this cross-sectional study, contrast sensitivity was measured in eyes with PVD and eyes without PVD using the quantitative contrast sensitivity function algorithm on the Adaptive Sensory Technology platform. Outcomes included the area under the log contrast sensitivity function curve, contrast acuity, and contrast sensitivity thresholds at 1 to 18 cycles per degree (cpd). Snellen visual acuity (VA) was also measured. Mixed-effects multiple linear regression analyses were performed to evaluate the association between the presence of PVD and visual function, controlling for age and lens status. Results: The cohort comprised 232 healthy eyes of 205 participants; of these, 80 eyes of 69 patients had PVD. There was no significant association between VA and PVD presence. However, PVD was significantly associated with decreased contrast sensitivity thresholds at 1.5 cpd (β, -0.058; P = .003) and 3 cpd (β, -0.067; P = .004). Contrast sensitivity thresholds at lower (1 cpd) or higher (6, 12, 18 cpd) spatial frequencies did not significantly correlate with PVD presence. Even in the subgroup of symptomatic PVD eyes, VA was not significantly decreased, while quantitative contrast sensitivity function outcomes showed visual function deficits at low spatial frequencies (1.5 cpd and 3 cpd). Conclusions: Contrast sensitivity measured with the quantitative contrast sensitivity function test showed visual function deficits in eyes with PVD that would have been missed with VA testing alone. Incorporating this test in the retina clinic might offer a more comprehensive functional assessment of eyes with PVD, serving as an adjunct outcome metric in clinical decision-making.

Evaluation of the effects of blue-enriched white light on cognitive performance, arousal, and overall appreciation of lighting.

Light's non-visual effects on the biological clock, cognitive performance, alertness, and mental health are getting more recognized. These are primarily driven by blue light, which triggers specific retinal cells containing melanopsin. Traditionally, research on light has relied on correlated color temperature (CCT) as a metric of its biological influence, given that bluer light corresponds to higher Kelvin values. However, CCT proves to be an inadequate proxy of light's biological effects. A more precise metric is melanopic Equivalent Daylight Illuminance (mel-EDI), which aligns with melanopsin spectrum. Studies have reported positive cognitive impacts of blue-enriched white light. It's unclear if the mixed results are due to different mel-EDI levels since this factor wasn't assessed. Given recent recommendations from experts to aim for at least 250 mel-EDI exposure daily for cognitive benefits, our aim was to assess if a 50-minute exposure to LED light with 250 mel-EDI could enhance concentration and alertness, without affecting visual performance or comfort compared to conventional lighting producing around 150 mel-EDI. To ensure mel-EDI's impact, photopic lux levels were kept constant across conditions. Conditions were counterbalanced, parameters included subjective sleepiness (KSS; Karolinska Sleepiness Scale), concentration (d2-R test), visual performance (FrACT; Freiburg Visual Acuity and Contrast Test), general appreciation (VAS; Visual Analogous Scale), preferences and comfort (modified OLS; Office Lighting Survey). The experimental light significantly reduced sleepiness (p = 0.03, Cohen's d = 0.42) and also decreased contrast sensitivity (p = 0.01, Cohen's d = 0.50). The conventional light was found to be more comfortable (p = 0.002, Cohen's d = 0.62), cheerful (p = 0.02, Cohen's d = 0.46) and pleasant (p = 0.005, Cohen's d = 0.55) while the experimental light was perceived as brighter (p = 0.004, Cohen's d = 0.58) and tended to be more stimulating (p = 0.10). Notably, there was a preference for conventional lighting (p = 0.004, Cohen's d=0.56) and concentration was equally improved in both conditions. Despite the lack of further improvement in concentration from exposure to blue-enriched light, given the observed benefits in terms of vigilance, further research over an extended period would be justified. These findings could subsequently motivate cognitive optimization through lighting for workers that would benefit from artificial lighting such as in northern regions.

Effects of fluorescent protein tdTomato on mouse retina

Fluorescent proteins (FPs) have been widely used to investigate cellular and molecular interactions and trace biological events in many applications. Some of the FPs have been demonstrated to cause undesirable cellular damage by light-induced ROS production in vivo or in vitro. However, it remains unknown if one of the most popular FPs, tdTomato, has similar effects in neuronal cells. In this study, we discovered that tdTomato expression led to unexpected retinal dysfunction and ultrastructural defects in the transgenic mouse retina. The retinal dysfunction mainly manifested in the reduced photopic electroretinogram (ERG) responses and decreased contrast sensitivity in visual acuity, caused by mitochondrial damages characterized with cellular redistribution, morphological modifications and molecular profiling alterations. Taken together, our findings for the first time demonstrated the retinal dysfunction and ultrastructural defects in the retinas of tdTomato-transgenic mice, calling for a more careful design and interpretation of experiments involved in FPs.

Reduced contrast sensitivity function is correlated with changes to cone photoreceptors in simple high myopia.

To investigate the contrast sensitivity function (CSF) changes in simple high myopia (SHM) and evaluate the correlations between these changes with the early changes in the retinal microstructure. This prospective study comprised 81 subjects, 20 with emmetropia (EM), 26 with low myopia and moderate myopia (LM/MM), and 35 with SHM. The area under the log CSF curve (AULCSF) and the cut-off spatial frequency (Cut-off SF) were employed as measures of CSF. Adaptive optics (AO) was employed to quantify the cone density, spacing, and regularity. The thickness and blood flow of the retinal sublayers were determined from vertical and horizontal optical coherence tomography angiography (OCTA) A-scans. Swept-source optical coherence tomography (SS-OCT) was employed to analyze the choroidal thickness (CT) and choroidal vascularity using a custom algorithm. Differences in the retinal and choroidal parameters, cone distribution, AULCSF, and Cut-off SF were compared among the three groups. Multivariate linear mixed models were used to elucidate the associations between photoreceptor morphological alterations, retinal and choroidal parameters, and AULCSF. The AULCSF and Cut-off SF were significantly lower in the SHM group compared to the EM and LM groups (p < 0.05). The SHM group had less cone density, larger cone spacing, and lower cone regularity than the EM and LM/MM groups (p < 0.05). Moreover, the thickness of the inner segment of photoreceptors (IS), retinal pigment epithelium (RPE) layer and choroid were reduced, and the outer segment of photoreceptors (OS) was thicker in the SHM group compared to the EM and LM/MM groups (all p < 0.05). A longer axial length (AL) was correlated with decreased AULCSF, cone density, and cone spacing (r = -0.800 to 0.752, all p < 0.050). Additionally, decreased CSF was correlated with lower cone density (r = 0.338, p = 0.035). Decreased contrast sensitivity was observed in patients with SHM and cone density was significantly correlated with reduced AUCSF.

Photoreceptor deficits appear at eye opening in Rs1 mutant mouse models of X-linked retinoschisis

X-linked retinoschisis (XLRS) is an early onset degenerative retinal disease characterized by cystic lesions in the middle layers of the retina. These structural changes are accompanied by a loss of visual acuity and decreased contrast sensitivity. XLRS is caused by mutations in the gene Rs1 which encodes the secreted protein Retinoschisin 1. Young Rs1-mutant mouse models develop key hallmarks of XLRS including intraretinal schisis and abnormal electroretinograms. The electroretinogram (ERG) comprises activity of multiple cellular generators, and it is not known how and when each of these is impacted in Rs1 mutant mice. Here we use an ex vivo ERG system and pharmacological blockade to determine how ERG components generated by photoreceptors, ON-bipolar, and Müller glial cells are impacted in Rs1 mutants and to determine the time course of these changes. We report that ERG abnormalities begin near eye-opening and that all ERG components are involved.

Comparison of Distance-Based Uncorrected Visual Acuity Based on the Optical Profile of Same Platform IOLs.

To compare and evaluate uncorrected visual acuity (UCVA) from far to near distance for four different optical designs of intraocular lenses (IOLs), developed on the same IOL platform. In a cohort of 121 patients, who underwent uncomplicated cataract surgery in Zengyo Suzuki Eye Clinic, Japan, between June 2018 and November 2023, and who received a single-piece TECNIS OptiBlue™ platform series IOL, the following four groups were established based on the IOL implant type: ZCB00V (TE), ZXR00V (SF), DFR00V (SG), and DIB00V (EH). UCVA at 5 m, 1 m, 70 cm, 50 cm, 40 cm, and 30 cm, as well as contrast sensitivity (with and without glare), was compared at one month post-operation. Regarding diffractive IOLs, patients in the SG group demonstrated significantly improved visual acuity at 5 m, 50 cm, 40 cm, and 30 cm, while those in SF group performed significantly better at 1 m. Among non-diffractive IOLs, patients in the EH group demonstrated significantly improved visual acuity scores at 1 m, 70 cm, 40 cm, and 30 cm, compared to individuals in the TE group, with comparable results between the two groups at 5 m and 50 cm. Patients in the SF and EH groups achieved similar results for visual acuity and contrast sensitivity, while those in the SG group exhibited a distinctive decrease in contrast sensitivity (with glare) relative to the other three groups. DFR00V seemingly provides excellent UCVA from near to far distances, aiming for spectacle independence, although at the potential cost of decreased contrast sensitivity compared to the other three IOL types. Furthermore, although ZXR00V and DIB00V differ lens structures, they may nonetheless provide similar visual quality and spectacle independence in daily life.

Pattern electroretinography response in amblyopic adults

IntroductionAmblyopia is generally a unilateral disorder, defined by at least a difference of two lines of visual acuity between both eyes with the best-corrected visual acuity, a decrease in contrast sensitivity, and a decrease in stereopsis. Pattern electroretinogram (PERG) is a noninvasive technique that provides a retinal biopotential and is a highly sensitive indicator of changes in the macular area. Our aim was to evaluate if there are differences in the retinal response of an amblyopic eye compared with a normal eye (NE).MethodsWe evaluated twenty-four adult volunteers, twelve amblyopes (mean 43.42 ± 12.72 years old), and twelve subjects with NE (mean 35.58 ± 12.85 years old). None of the subjects in the two groups had comorbidities. A complete optometric examination was performed including parameters such as visual acuity (VA) by far and near with ETDRS chart, eye alignment with cover test, and evaluation of retinal cells response with PERG.ResultsThe refractive error found in the NE group of subjects had a mean of − 0.95 ± 1.65D, while the amblyopic group showed a mean of − 2.03 ± 4.29D. The VA in amblyopic eyes had a mean of 0.38 ± 0.20 logMAR. Analyzing PERG data, we observed significant differences in the P50-N95 amplitudes of the amblyopic group compared with the NE group (p < 0.0001–amblyopic eye vs. NE; p = 0.039–fellow eye vs. NE).DiscussionThese findings suggest that amblyopic patients may also present other impairments beyond the visual cortex. PERGs seem to be an important complementary examination in the diagnosis of other impairments in amblyopia.

LOW VISION IN RETINITIS PIGMENTOSA: HOW TO ENHANCE FUNCTIONAL VISION IN PSEUDOPHAKIC PATIENT

Introduction : Retinitis Pigmentosa (RP) could lead to various visual impairments, including decreased visual acuity, poor dark adaptation, decreased contrast sensitivity, poor color vision, visual field constriction, leading to low vision (LV). LV in RP decreases patient’s quality of life (QoL) and Independence. We aim to report a successful case of LV management in a bilateral pseudophakic patient with RP.&#x0D; Case Illustration : A 33-year-old man came with progressively blurred vision in both eyes (BE) that worsen 6 months ago. Ophthalmologic examination revealed his uncorrected visual acuity for right eye (RE) and left Eye (LE) was 6/60 and 4/60. The patient had cataract surgeries and IOLs implantation on BE in 2021. Funduscopic examination revealed the bone spicule appearance, blood vessel attenuation, and waxy disc pallor on BE. Humphrey's examination showed a peripheral visual field defect. Decreased contrast sensitivity and poor color vision were also found.&#x0D; Discussion : The patient was managed by LV aids and rehabilitation. Spectacle clarified distant and near vision with best corrected visual acuity (BCVA) 6/21 and 0.8 M on BE, photochromic lenses aided in adapting to various lighting levels and as a UV protection, and the addition of illumination and color contrast enhancement improved vision in dim light. A convex mirror to be used as a field- enhancement spotting tool. Rehabilitation enhances his head tracking, scanning, and habitual spotting skills. Improvement of QoL has been recorded using LVQoL questionnaires.&#x0D; Conclusion : LV management are vary based on an individual’s level of functional vision and personal preferences. Optimal LV management could enhance patient QoL and Independence.

ANALYSING THE SIDE EFFECT OF AMIODARONE N CONSUMPTION ON OPTIC NERVE HEAD, CONTRAST SENSITIVITY AND COLOR VISION IN ARRYTHMIA PATIENT

Abstract&#x0D; Introduction &amp; Objectives : To analyze the side effect of duration consumption of amiodarone on ONH, contrast sensitivity and color vision in arrythmia patient&#x0D; Methods : This study was an analytical observational study with cross sectional design. A total of 23 subjects with arrhythmias taking amiodarone were included in the study. Sampling was carried out from April 2022-August 2022 at the Eye Polyclinic and Cardiology Polyclinic.&#x0D; Results : Most of the subjects were female, 12 people (52.2%) with a mean age of 59 years. The results of the examination showed that two subjects had decreased vision, ONH edema and decreased contrast sensitivity in the right eye where the mean duration of amiodarone consumption was 4.5 months. The results of binocular color vision examination were normal in all study subjects. There was a significant effect of the consumption duration of amiodarone on ONH (p=0.024) and on contrast sensitivity (p=0.022)&#x0D; Conclusion : There was a significant effect of the duration consumption of amiodarone on ONH and contrast sensitivity in arrythmia patient

Comparison of contrast sensitivity among strabismic and anisometropic amblyopes and its association with disease-related parameters.

To evaluate and contrast the contrast sensitivity defects present in strabismic and anisometropic amblyopes. And to find out the association of contrast deterioration with the visual acuity of the amblyopic eye, the magnitude of strabismus, and the amount of anisometropia in both groups. This cross-sectional study was carried out in the orthoptics unit of a tertiary eye care facility between October 2021 and December 2021. There were 45 patients altogether. In the first phase, the patient's history and ocular examination data were recorded after informed consent. The Pelli-Robson chart was used to measure contrast sensitivity. In the second phase, results were interpreted using the SPSS (Statistical Package for the Social Sciences) version 26.0. Strabismic amblyopes were 24 and anisometropic amblyopes were 21. A significant positive association existed between both groups' contrast sensitivity and visual acuity (P = 0.000). A moderately negative correlation between contrast and anisometropia was statistically significant (P = 0.025) in anisometropic amblyopes. However, no association (P > 0.050) existed between the contrast and magnitude of strabismus in any group. The study concluded that contrast sensitivity decreases in both groups, whereas anisometropic amblyopes have poorer contrast than strabismic amblyopes. Excessively decreased contrast sensitivity among anisometropic amblyopes was solely because of the worst amblyopia in this group, whereas the magnitude of strabismus does not affect contrast sensitivity.

Dynamics of retinal perfusion parameters in patients with post-COVID syndrome

BACKGROUND: A major current health issue is the rehabilitation of patients who previously had a coronavirus infection (COVID-19), as well as the treatment of patients with post-COVID syndrome. For a long time after COVID-19, patients may have complaints, including vision-related ones. One of the theories is that this may be due to long-term persistent microcirculatory retinal changes.&#x0D; AIM: To assess the long-term dynamics of retinal microcirculation changes in patients with post-COVID syndrome and to evaluate the relationship of these parameters with visual functions.&#x0D; MATERIALS AND METHODS: The main group consisting of 41 patients (82 eyes) was divided into groups depending on the severity of COVID-19: mild, moderate and severe. The control group included 13 people (26 eyes) who did not have COVID-19 to the time of the examination. All patients underwent an ophthalmological examination, including low-contrast visual acuity testing and optical coherence tomography-angiography. Vessel density (VD) was examined within the superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary capillaries (RPC). The following structural indicators were also measured: the retinal thickness, the retinal nerve fiber layer thickness and the ganglion cell complex. All patients were examined twice: 6 weeks after COVID-19 and in 27 weeks (6 months after the first visit).&#x0D; RESULTS: Patients who went through moderately severe and severe COVID-19 showed a significant decrease in low-contrast visual acuity in comparison to the control group at Visit 1 (p .001 in both cases), which totally recovered to the Visit 2. In the same group of patients, there was a significant decrease in VD SCP (p .001) and VD DCP (p .001) in comparison to the control group, and these parameters significantly decreased at visit 2 (p .001 in both cases). In the group of patients with moderate COVID-19, there was also a decrease in VD SCP and VD DCP in comparison to the control group (p .001 in both cases), while the indicators remained stable during 6 months of follow-up (p = .082). There were no significant changes in VD RPC and main morphometric parameters during 6 months of follow-up.&#x0D; CONCLUSIONS: In patients with COVID-19 from moderate severity to severe, there is a significant decrease in contrast sensitivity, which is temporary and fully recovers after 6 months. In patients with severe COVID-19, there was a negative dynamic of retinal perfusion during 6 months, both in deep and superficial capillary plexuses. Patients with post-COVID syndrome, or those who have had COVID-19 and present with visual complaints, need a deep ophthalmological examination including optical coherence tomography-angiography, with a possible involvement of related specialists.

Наш опыт имплантации ИОЛ AcrySof IQ Vivity®. Предварительные результаты

AcrySof IQ PanOptix® multifocal IOLs provide patients with far, near and intermediate vision. But this type of IOL is characterized by various undesirable optical phenomena and a decrease in contrast sensitivity. A new type of IOL with an extended depth of focus, like the AcrySof IQ Vivity ® overcomes these disadvantages and should also give patients freedom from the use of glasses. Aim. The aim of our study was to analyze the results of implantation of the AcrySof IQ Vivity ® IOL with extended depth of focus up to 6 months after surgery аnd also to compare the studied parameters with those after implantation of the AcrySof IQ PanOptix ® IOL. Methods. The study group included 20 eyes (13 patients) with an implanted AcrySof IQ Vivity® IOL. Patients were examined for distance UCVA and BCVA, and, for a period of 6 months, UCVA for near (40 cm) and for intermediate distance (60 cm) were additionally studied. Patients' satisfaction was determined using the VF-14 questionnaire. Presence of undesirable optical phenomena was also determined. Spatial contrast sensitivity was determined under photopic and mesopic conditions. The comparison group of AcrySof IQ PanOptix ® is taken from a study by our colleagues (108 eyes of 71 patients). Comparison was carried out according to the specified parameters. Results. 6 months after IOL implantation, UCVA and BCVA in both groups was comparably high (in the study group AcrySof IQ Vivity ® UCVA 0.95±0.29; BCVA 1.06±0.1; in the comparison group AcrySof IQ PanOptix® – UCVA 0.93±0.18, BCVA 1.0±0.04). UCVA for near in the study group was 0.41±0.16; in the comparison group 0.85±0.22. UCVA for intermediate distance 0.52±0.17; in the comparison group 0.84±0.24. Satisfaction on the VF-14 scale: 83.0±6.5 points in the AcrySof IQ Vivity ® group, 97.9±1.2 points in the AcrySof IQ PanOptix ® group. In the study group, only one patient complained of glare, in the comparison group, such complaints were significantly more frequent. Spatial contrast sensitivity was superior in the AcrySof IQ Vivity ® group at all frequencies both under photopic and mesopic conditions. Conclusion. At a period of 6 months after phacoemulsification with implantation of the AcrySof IQ Vivity ® IOL, it is possible to achieve high distance visual acuity, as well as with the implantation of the AcrySof IQ PanOptix ® IOL. However, near visual acuity is significantly lower, which required the use of glasses by patients. Visual acuity at an intermediate distance is more comparable. In the AcrySof IQ Vivity® group, spatial contrast sensitivity is higher and the rate of optical adverse events is much lower. Key words: phaco emulsification; trifocal IOL; EDOF IOL; Vivity; PanOptix; contrast sensitivity

Characterization of vision in pediatric retinoblastoma survivors beyond visual acuity

Retinoblastoma (RB) and its associated treatments can significantly impact visual acuity. However, little is known regarding other measures of vision, such as contrast sensitivity or saccades. The aim of this study was to describe contrast sensitivity and saccades in children treated for retinoblastoma. This cross-sectional study included children aged 5-17 years who had completed treatment for RB. Visual acuity, saccades via fixation analysis, and contrast sensitivity by Cardiff contrast sensitivity were assessed, and multivariable linear regression was performed. Eleven children were enrolled (mean age, 10.7 ± 3.9 years). Treatment included enucleation (8 children [73%]) and chemotherapy (10 [91%]). Of the 11, one participant was unable to complete testing of saccades, and another was unable to complete contrast sensitivity testing. Decreased saccade parameters (velocity, latency, or accuracy) and impaired contrast sensitivity were observed in all 10 participants who underwent visual testing. Multivariable analysis revealed that worse logMAR visual acuity (B, -4.54 [-6.8, -2.2]; P = 0.004) and bilateral disease (B, -3.9 [-6.4, -1.4]; P = 0.009) were associated with worse contrast sensitivity. Germline disease was associated with decreased vertical saccade accuracy (P = 0.02). Decreased contrast sensitivity and impaired saccades were universally observed in this cohort of RB survivors. Comprehensive visual evaluation should be considered for all RB survivors to provide optimal rehabilitative services for these patients.

Eye-related quality of life and activities of daily living in pediatric retinoblastoma patients: A single-center, non-controlled, cross-sectional analysis.

Childhood retinoblastoma (RB) survivors are known to experience long-term morbidity; however, eye-related quality of life (QoL), which may significantly impact activities of daily living (ADL), has not been extensively studied in this population. The purpose of this cross-sectional study was to assess QoL and ADL morbidity among school-age RB survivors. The Pediatric Eye Questionnaire (PedEyeQ) and Roll Evaluation Activities of Life (REAL) were administered to childhood RB survivors between ages 5 and 17 followed at St. Louis Children's Hospital. Visual outcomes and demographic predictors of ADL and QoL were examined. Total 23 patients (mean age 9.6years) consented for participation in this study. All children experienced at least one domain on the PedEyeQ≤80%. Subjects and parents marked functional vision to be the most impacted domain with a median score of 82.5 and 83.4, respectively. Only 10.5% of participants scored above 75% on the ADL percentile rank. On multivariable analysis, decreased visual acuity (VA) was associated with worse "Child Functional" (odds ratio [OR] -59.2, p=.004) and "Parent Worry Function" (OR -66.5, p=.03) metrics. Decreased contrast sensitivity was associated with worse "Parent Impact" (OR 21.0, p = .02) and "Parent Worry Function" (OR 3.70, p=.04) metrics. Longer saccade horizontal latency was associated with a worse "Parent Worry Function" metric (OR 43.0, p=.009). On multivariable analysis, no variable was significantly associated with ADL. RB survivors have impaired QoL and ADL. Screening for such difficulties should strongly be considered for all RB patients. Additional studies may help predict morbidity based on visual metrics and demographic data.

Bilateral Implantation of Multifocal Intraocular Lenses: 10-Year Follow-Up

To evaluate and compare the long-term results after bilateral implantation of different multifocal intraocular lenses (MIOLs). This retrospective comparative study included 42 patients who underwent cataract surgery with bilateral MIOL implantation. Patients were divided into 5 groups: Group 1 received a refractive ReZoom NGX1 IOL (AMO), Group 2 a diffractive Acrysof ReSTOR SA60D3 IOL (Alcon), and Group 3 a diffractive Tecnis ZM900 IOL (AMO). Group 4 and Group 5 were implanted using the mix and match approach with refractive ReZoom-diffractive ReSTOR IOL and refractive ReZoom-diffractive Tecnis ZM900 IOL, respectively. Primary outcome measures were distance, near, and intermediate distance visual acuity measured 6 months (T0) and 10 years (T1) after surgery. Secondary outcomes were defocus curves, contrast sensitivity, patients' satisfaction, and spectacle independence. All patients achieved best-corrected distance visual acuity (BCDVA) greater than 0.11 logMAR and uncorrected distance visual acuity (UCDVA) greater than 0.14 logMAR at both time points. A decrease in contrast sensitivity was evident, particularly at high spatial frequencies; at T1, Group 4 reported statistically higher values than Group 2 at 12 cycles/degree and 18 cycles/degree and statistically higher values than Group 3 at 18 cycles/degree. Great overall satisfaction was reported even in the presence of dysphotopsia. Tecnis ZM900 IOL showed the lowest incidence of posterior capsular opacification. MIOLs could provide adequate functional vision and patient satisfaction, despite the incidence of side effects, in carefully selected patients desiring spectacle independence.

Higher order aberrations and visual function in a young Asian population of high myopes

PurposeTo examine the associations between higher order aberrations (HOAs), visual performance, demographics, and ocular characteristics in a young Asian population with high myopia. MethodsThis was a retrospective review of military pre-enlistees conducted between March 2014 to September 2018. Visual acuity and contrast sensitivity were tested under photopic, mesopic and simulated night conditions. Ocular, corneal and internal HOAs were measured with a Hartmann–Shack wavefront aberrometer (KR-1W, Topcon Co., Tokyo, Japan). Results522 eyes of 263 consecutive subjects with severe high myopia (defined as spherical equivalent refraction [SER] ≤ −10.00D) in at least one eye, and high myopia (SER ≤ −6.00D) in the fellow eye, [mean (SD) SER −11.85 (2.03D)] were analysed. The mean (SD) age of subjects was 18.5 (1.6) years. Chinese eyes had significantly greater internal total HOA root-mean-square (RMS) compared to Malay eyes [mean difference (SD) 0.0246 (0.007) μm, p < 0.001). More negative SER was associated with greater ocular total HOA (p = 0.038), primary coma (p = 0.003) and tetrafoil (p = 0.025) RMS, as well as more positive ocular (p = 0.003) and internal primary spherical aberration (p = 0.009). Greater ocular total HOAs was associated with reduced visual acuity in simulated night conditions and low contrast, decreased contrast sensitivity under mesopic and simulated night conditions (all p < 0.05). ConclusionsGreater HOAs were associated with Chinese ethnicity and more negative SER in a young Asian population with high myopia. Greater HOAs were associated with poorer visual performance in low luminance and reduced contrast conditions.

Correlation Between Contrast Variability and Refractive Error

Background: Contrast sensitivity, is defined as the ability to detect the lowest lumination difference between an object and the background. It is one of the main requisites for good quality vision as the eye works by perceiving an object by comparing the difference between the target and the background contrast difference. Aims and Objectives: To assess patterns of contrast sensitivity functions in patients in different types of refractive errors using Pelli Robson chart and also to measure the severity of refractive error within each group and compared the contrast sensitivity function with severity in different types of refractive errors. Material and Method: This cross-sectional study was conducted on 500 patients (Age range from 10 to 80 years) who presented with chief complaint of refractive errors mainly myopia and hypermetropia. Patients who had previous history of ocular surgery and other ocular co- morbidity were excluded from study. Selected patients were enrolled for the study after taking a written informed consent. The patterns of contrast sensitivity function in different types of refractive errors were recorded on a prescribed proforma with respect to: Visual acuity, type of refractive error, severity of refractive error, duration of refractive error, age of the patient, fundus examination and Contrast sensitivity. Statistical analysis was undertaken with P&lt;0.05 significant. Results: A mild decrease in contrast sensitivity was recorded in majority of patients i.e 250 patients (50%). Maximum decrease in contrast sensitivity was seen in 31-60 years age group. A statistically significant direct correlation (P&lt;0.05) was observed between duration and variation in contrast sensitivity. Both the refractive error showed definite decrease in contrast sensitivity and compound astigmatism showed severe decrease in contrast sensitivity. Conclusion: Despite having BCVA of 6/6, patients showed reduced contrast sensitivity, even without any retinal pathology, making it an essential part of a routine ophthalmic examination.

Patients with Ethambutol-Induced Ocular Toxicity Receiving "Directly Observed Treated Short-Course"

Objective: Determine the total number of Category-1 patients with ocular toxicity from Ethambutol after DOTS therapy. Methodology: This study conducted in department of Ophthalmology of abaseen hospital and Khyber medical center Peshawar over the one year, from May 2021 to April 2022 included Category-1 TB patients (both genders) aged 14 and 65 who had normal ocular parameters on an ophthalmological examination when starting DOTS treatment. The frequency of any vision change, optical symptom, including color vision, contrast sensitivity while receiving Ethambutol medication was examined in 240 eyes (120 patients). At the end of the first month and again at the end of the second month of therapy, Each patient's compliance with Ethambutol was examined, and all tests for ocular toxicity were repeated for each chosen patient. The study did not include patients in category-2 with positive sputum smears who had relapsed, had therapy fail, or was getting treatment after a break in treatment. Results: Out of 120 patients (240 eyes), 62 (51.6%) of them were male, and 58 (48.4%) of them were female patients. After a month, there was no sign of ocular toxicity. Ocular toxicity, on the other hand, appeared in 3 (2.5%) of the patients after the second month. Moreover, these three patients showed decreased visual acuity, poor color vision, decreased contrast sensitivity, and optic disc abnormalities. Conclusion: Patients with tuberculosis who use Ethambutol are at risk of developing ocular toxicity. As a result, it is essential to identify visual symptoms and signs as soon as possible to avoid unnecessary diagnostic delays and maybe irreversible vision loss. Keywords: Tuberculosis, Color Vision, Contrast Sensitivity, Optic Disc, Ethambutol-induced ocular toxicity, visual acuity, treatment strategies

A novel quick contrast sensitivity function test in Chinese adults with myopia and its related parameters

PurposeThis study is to investigate the contrast sensitivity function (CSF) using the quick CSF (qCSF) test in Chinese adults with myopia.MethodsThis case series study included 320 myopic eyes of 160 patients (mean age 27.75 ± 5.99 years) who underwent a qCSF test for acuity, area under log CSF (AULCSF), and mean contrast sensitivity (CS) at 1.0, 1.5, 3.0, 6.0, 12.0, and 18.0 cycle per degree (cpd). Spherical equivalent, corrected-distant visual acuity (CDVA), and pupil size were recorded.ResultsThe spherical equivalent, CDVA (LogMAR), spherical refraction, cylindrical refraction, and the scotopic pupil size of the included eyes were − 6.30 ± 2.27 D (− 14.25 to − 0.88 D), 0 ± 0.02, − 5.74 ± 2.18 D, − 1.11 ± 0.86 D, and 6.77 ± 0.73 mm, respectively. The AULCSF and CSF acuity were 1.01 ± 0.21 and 18.45 ± 5.39 cpd, respectively. The mean CS (log units) at six different spatial frequencies were 1.25 ± 0.14, 1.29 ± 0.14, 1.25 ± 0.14, 0.98 ± 0.26, 0.45 ± 0.28, and 0.13 ± 0.17, respectively. A mixed effect model showed significant correlations between age and acuity, AULCSF, and CSF at 1.0, 12.0, and 18.0 cpd. Interocular CSF differences were correlated with the interocular difference of spherical equivalent, spherical refraction (at 1.0 cpd, 1.5 cpd), and cylindrical refraction (at 12.0 cpd, 18.0 cpd). The lower cylindrical refraction eye had higher CSF compared with the higher cylindrical refraction eye (0.48 ± 0.29 vs. 0.42 ± 0.27 at 12.0 cpd and 0.15 ± 0.19 vs. 0.12 ± 0.15 at 18.0 cpd).ConclusionsThe age-related decrease in contrast sensitivity is at low and high spatial frequencies. Higher-degree myopia may show a decrease in CSF acuity. Low astigmatism was noted to affect the contrast sensitivity significantly.

Features of visual, cognitive and neuroimaging changes in Parkinson’s disease patients with freezing of gait

To determine visual and cognitive impairments in relation to MRI changes in patients with freezing of Gait (FOG) in Parkinson's disease (PD). We examined 78 patients with PD without dementia, who were divided into groups according to the presence (FOG«+» group) or absence (FOG«-» group) of «freezing» episodes. A decrease in contrast sensitivity (CS) and retinal photosensitivity was determined in all subjects with PD, but in patients with FOG, the decrease in CS was more pronounced. There was a significant decrease in the volume of the cuneus, lingual gyrus, posterior cingulate gyrus, superior parietal lobe and middle frontal gyrus in the FOG«+» group. It was revealed that patients with FOG had cognitive impairments of both the frontal and posterior cortical subtypes, while in the FOG«-» group, only visuospatial deficit prevailed. A direct correlation was determined between the severity of FOG and part I of the UPDRS scale, between a decrease in CS and cortical areas related to the dorsal and ventral visual information processing systems. The presence of a negative relationship between the scores of the FOG-Q, Timed Up and Go test and the volume of cortical areas of the frontal lobe responsible for planning and programming of movements indicates their role in the development of FOG in PD. Thus, visual impairments associated with PD, along with a heterogeneous profile of cognitive impairment, make a significant contribution to the development of FOG.