Contrast Sensitivity Testing Research Articles

The Effect of Ethambutol Therapy in terms of Visual Evoked Potential, Color Vision Test, and Contrast Sensitivity Test at the Subclinical Level

Abstract
 Introduction & Objectives : Ethambutol is one of the first-line drugs in the treatment of tuberculosis and known to induce optic neuropathy. However, there are unknown protocols for detecting subclinical level of toxicity. The aim of this study was to assess the difference in amplitude and latency of visual evoked potential (VEP), color vision, and contrast sensitivity in tuberculosis patients before and after taking ethambutol for 1 and 2 months.
 Methods : This was a prospective observational cohort study of 38 eyes of 19 newly diagnosed patients with category-1 tuberculosis being treated with ethambutol. All patients were given ethambutol for 2 months at a dose of 15 - 20 mg/kg body weight/day. The participants underwent complete eye and visual function examination including pattern-reversal VEP, color vision with Farnsworth Munsell D-15 test, and contrast sensitivity with LEA Low Contrast Flip Chart before and after 1 and 2 months of treatment. Wilcoxon test was employed for data analysis.
 Results : During the study, no changes in visual acuity was observed. The results showed that the latencies of VEP after 1 month (p = 0.000) and 2 months (p = 0.000) of treatment were significantly delayed. There was a significant difference in contrast sensitivity after 2 months (p = 0.014) of treatment. However, no significant difference was found in color vision and amplitude of VEP.
 Conclusion : Latency of VEP and contrast sensitivity test could prove useful in detecting subclinical and hence very useful for monitoring patients under ethambutol therapy for ocular toxicity.

Comparative Validity of LEA Contrast Sensitivity Chart to Pelli-Robson Contrast Sensitivity Chart in Neuroophthalmology Patients

Abstract
 Introduction & Objectives : The Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrast sensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEA contrast sensitivity chart offers a reliable test in a way more practical and portable chart. This condition led to a question of whether we can predict Pelli-Robson score based on the LEA score. This study developed a conversion method to facilitate the transition from the LEA to the Pelli-Robson and validating the conversion score.
 Methods : This study retrospectively examined the relationship between LEA and Pelli-Robson Contrast Sensitivity Test. There were 120 eyes included in this study. We produced a conversion table using the equipercentile equating method. Then, we evaluated the reliability and accuracy of this algorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 Results : LEA scores were converted to Pelli-Robson scores according to a conversion table that achieved a reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6% within 1 point difference from the raw score.
 Conclusion : This study reported a reliable and comparable conversion algorithm for transforming LEA scores into converted estimated Pelli-Robson scores. This method will enhance the utility of existing data in clinical and research settings.

MANAGEMENT APPROACH OF LOW VISION IN RETINITIS PIGMENTOSA: WHAT SHOULD WE DO?

Introduction : Retinitis pigmentosa is a chronic and progressive disease throughout patient’s life. Management low vision in retinitis pigmentosa patients are to maximize their remaining vision and provision of visual aids, it can be financial dan social burden.
 Case Illustration : A 56-year-old man came with blurred vision in his both eyes for 12 years. The patient had cataract surgeries and IOLs implantation in 2022. Ophthalmologic examination revealed the right eye was 4/40 and the left eye was 3/60. Funduscopic examination revealed the bone spicule appearance, blood vessel attenuation, and waxy disc pallor in both eyes. Contrast sensitivity test decreased and Farnsworth hue test showed mild to severe. Humphrey visual field examination showed peripheral visual field defect, therefore patient diagnosed with low vision caused by retinitis pigmentosa with bilateral pseudophakia and his Low Vision Quality of Life was intermediate.
 Discussion : Treatment includes pharmacological treatment with supplementation, optical or non-optical treatment, and rehabilitation. Spectacles clarified distant and near vision with Best Corrected Visual Acuity 6/30 with photochromic lenses, for adapting the light and gave addition lens +5.00 in both eyes. Rehabilitation enhances his head tracking, scanning, and habitual spotting skills. Lighting and typoscope would help his daily reading activities as well.
 Conclusion : Low vision requires several management approach, patient with visual impairment can get low vision aids to optimize his visual function based on his needs. Managing low vision in patient with visual impairment has to be considered from multiple aspects.

Comparative Validity of LEA Contrast Sensitivity Chart to Pelli-Robson Contrast Sensitivity Chart in Neuroophthalmology Patients

Abstract
 Introduction & Objectives : The Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrast sensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEA contrast sensitivity chart offers a reliable test in a way more practical and portable chart. This condition led to a question of whether we can predict Pelli-Robson score based on the LEA score. This study developed a conversion method to facilitate the transition from the LEA to the Pelli-Robson and validating the conversion score.
 Methods : This study retrospectively examined the relationship between LEA and Pelli-Robson Contrast Sensitivity Test. There were 120 eyes included in this study. We produced a conversion table using the equipercentile equating method. Then, we evaluated the reliability and accuracy of this algorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 Results : LEA scores were converted to Pelli-Robson scores according to a conversion table that achieved a reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6% within 1 point difference from the raw score.
 Conclusion : This study reported a reliable and comparable conversion algorithm for transforming LEA scores into converted estimated Pelli-Robson scores. This method will enhance the utility of existing data in clinical and research settings.

COMPARATIVE VALIDITY OF LEA CONTRAST SENSITIVITY CHART TO PELLI-ROBSON CONTRAST SENSITIVITY CHART IN NEURO-OPHTHALMOLOGY PATIENTS

INTRODUCTION AND OBJECTIVEThe Pelli-Robson and LEA contrast sensitivity chart are widely used to measure clinical contrastsensitivity. The Pelli-Robson is a gold standard with the limitation of its bulky size. The LEAcontrast sensitivity chart offers a reliable test in a way more practical and portable chart. Thiscondition led to a question of whether we can predict Pelli-Robson score based on the LEA score.This study developed a conversion method to facilitate the transition from the LEA to the PelliRobson and validating the conversion score.
 METHODSThis study retrospectively examined the relationship between LEA and Pelli-Robson ContrastSensitivity Test. There were 120 eyes included in this study. We produced a conversion tableusing the equipercentile equating method. Then, we evaluated the reliability and accuracy of thisalgorithm to convert the LEA to the Pelli-Robson contrast sensitivity score.
 RESULTSLEA scores were converted to Pelli-Robson scores according to a conversion table that achieveda reliability of 0.91 based on intraclass correlation. The accuracy of this algorithm was 81.6%within 1 point difference from the raw score.
 CONCLUSIONSThis study reported a reliable and comparable conversion algorithm for transforming LEA scoresinto converted estimated Pelli-Robson scores. This method will enhance the utility of existing datain clinical and research settings.

Evaluation of contrast sensitivity in visually impaired individuals using K-CS test. A novel smartphone-based contrast sensitivity test-Design and validation.

To describe the development and investigate the accuracy of a novel smartphone-based Contrast Sensitivity (CS) application, the K-CS test. A total of 67 visually impaired and 50 normal participants were examined monocularly using the novel digital K-CS test and the Pelli-Robson (PR) chart. The K-CS test examines letter contrast sensitivity in logarithmic units, using eight levels of contrast from logCS = ~0,1 to logCS = ~2,1 at two spatial frequencies of 1.5 and 3 cycles per degree (cpd). The K-CS test was compared to the gold standard, PR test and intra-session test repeatability was also examined. The K-CS test in normally sighted was found to agree well with the PR, providing comparable mean scores in logCS (±SD) (K-CS = 1.908 ± 0.06 versus PR = 1.93 ± 0.05) at 1.5 cpd and mean (± SD) logCS at 3 cpd (K-CS = 1.83 ± 0.13 versus PR = 1.86 ± 0.07). The mean best corrected visual acuity of visually impaired participants was 0.67 LogMAR (SD = 0.21) and the K-CS was also found to agree well with the Pelli-Robson in this group, with an equivalent mean (±SD) logCS at 1.5 cpd: (K-CS = 1.19 ± 0.27, PR = 1.15 ± 0.31), 3 cpd: K-CS = 1.01 ± 0.33, PR = 0.94 ± 0.34. Regarding the intra-session test repeatability, both the K-CS test and the PR test showed good repeatability in terms of the 95% limits of agreement (LoA): K-CS = ±0.112 at 1.5 cpd and ±0.133 at 3 cpd, PR = ±0.143 at 1.5 cpd and ±0.183 in 3 cpd in visually impaired individuals. The K-CS test provides a quick assessment of the CS both in normally sighted and visually impaired individuals. The K-CS could serve as an alternative tool to assess contrast sensitivity function using a smartphone and provides results that agree well with the commonly used PR test.

Correlation between color vision, visual acuity, contrast sensitivity and photostress recovery in the visually impaired: a cross-sectional study

Background: To investigate the correlation of colour vision, visual acuity, contrast sensitivity, and photostress recovery time test scores in visually impaired patients. Materials and methods: A total of 133 subjects were enroled and 133 eyes were examined. The pathological group consisted of 76 (57.1%) males with an average age of 68.0 (SD=13.2) and 57 (42.9%) females, with an average age of 68.1 (SD=15.2), Mann–Whitney U test was used to evaluate the differences in K-colour tests, HRR, visual acuity, Contrast Sensitivity test and photostress recovery time test between two different groups of severity. Results: Correlations were found among colour vision tests, visual acuity, contrast sensitivity, and photostress recovery time scores in eyes with age-related macular degeneration, with diabetic retinopathy, with optic nerve diseases, and various other retinal diseases (P<0.05). In patients with moderate-visual impairments. Conclusions: The colour vision test scores correlate with the scores of visual acuity, contrast sensitivity, and photostess recovery time test. It may be a useful clinical surrogate for functional vision.

Ocular toxicity of psychotropic medications in a tertiary hospital in Lagos, Nigeria.

Objective: This study aimed to determine the ocular toxicity of the psychotropic drugs used by patients and to proffer suggestions on how to prevent visual impairment or blindness in patients on antipsychotics. Methodology: This was a prospective, hospital-based cross-sectional study. Participants were adult patients between 18 and 70 years, diagnosed with psychosis, and who had been on antipsychotic medications for at least one year. All the recruited participants had an examination of the anterior and posterior segments of the eyes done. Schirmer's test, Tear film Break-up time (TBUT), Central Corneal thickness (CCT), Colour vision test, and Contrast sensitivity test were done. The collected data was analyzed using IBM SPSS 28.0. Results: The study enrolled patients who were mainly females (55.1%). The highest age group of the cases was 29-38 years (29.7%). The examination of the eyes and investigations revealed that 10.2% of the respondents on antipsychotics had color vision deficiency and 25.4% - loss of contrast sensitivity. Lid pigmentation was observed in 20.3% and cataract in 32.2%. Degeneration of the peripheral retina was observed in 4.2% of patients on antipsychotic medication. Schirmer's test showed mild, moderate, and severe dry eyes in 11%,17.8%, and 20.3% of the participants respectively. The test for Central Corneal Thickness (CCT) showed 50.0% of the respondents had a thin cornea and 24.6% had a thick cornea. 17.8% of the surveyed respondents manifested high eye pressure. Discussion: Psychotropics are the gold standard for the treatment of psychotic episodes and disorders. The choice of drug, dosing, and mode of administration depends on the severity of the psychotic disorder. Higher doses of psychotropics were reported to cause toxicity in different organs in the body including the eyes, especially on long-term use and high dosage and this can affect the quality of life of the individual negatively. Conclusion: The earliest and most prominent side effect seen in patients on psychotic medication was dry eyes. There were a few cases of blinding eye diseases like glaucoma, and cataract. For these reasons, ophthalmic assessments should be included as part of the management of psychiatric patients early at the start of antipsychotic treatment. Abbreviations: FGA = First Generation Antipsychotics, SGA = Second Generation Antipsychotics, TCAs = Tricyclic Antidepressants, CCT = Central Corneal Thickness, IOP = Intraocular Pressure, TBUT =Tear film Break-up Time, BIO = Binocular Indirect Ophthalmoscope.

Small-Molecule-Directed Endogenous Regeneration of Visual Function in a Mammalian Retinal Degeneration Model.

Degenerative retinal diseases associated with photoreceptor loss are a leading cause of visual impairment worldwide, with limited treatment options. Phenotypic profiling coupled with medicinal chemistry were used to develop a small molecule with proliferative effects on retinal stem/progenitor cells, as assessed in vitro in a neurosphere assay and in vivo by measuring Msx1-positive ciliary body cell proliferation. The compound was identified as having kinase inhibitory activity and was subjected to cellular pathway analysis in non-retinal human primary cell systems. When tested in a disease-relevant murine model of adult retinal degeneration (MNU-induced retinal degeneration), we observed that four repeat intravitreal injections of the compound improved the thickness of the outer nuclear layer along with the regeneration of the visual function, as measured with ERG, visual acuity, and contrast sensitivity tests. This serves as a proof of concept for the use of a small molecule to promote endogenous regeneration in the eye.

Evaluating the Use of Contrast Sensitivity Tests By Orthoptists in the UK.

The importance of the use of contrast sensitivity (CS) tests in orthoptic practice is well established. However, despite the clinical relevance the implementation within clinical care is known to be variable. There are no known studies that investigate the use of CS tests in Orthoptic clinics in the UK, therefore the aim of this study is to gather information from Orthoptists in the UK on their opinion of CS and use of CS testing in clinical practice, now and in the future. An online survey was distributed via JISC to the British and Irish Orthoptic Journal newsletter three times over a period of four weeks in June 2021 inviting practising orthoptists in the United Kingdom to complete. The questionnaire comprised of a series of questions regarding current use with free text responses for additional information. There were 84 responses to the survey. The preferred test for adult and children testing is Pelli Robson with 50% reporting use of this test. 56% felt there is a need for a new CS test for young children, 12% said no and 32% were unsure. The highest percentage (57.1%) of participants were confident to some degree that their preferred test gave them useful clinical information. The result of the survey demonstrates the variability of CS testing currently in orthoptic practice in the UK. It also highlights the lack of currently available tests for children for CS testing, which may be addressed by the addition of the new Double Happy CS test.

Clinical report: Virtual reality enables comparable contrast sensitivity measurements to in-office testing (pilot study).

Vision health disparities largely stem from inaccessibility to vision specialists. To improve patient access to vision tests and to expedite clinical workflows, it is important to assess the viability of virtual reality (VR) as a modality for evaluating contrast sensitivity. This study aimed to assess the validity of a VR version of the Pelli-Robson contrast sensitivity test by comparing its results with those of the corresponding in-office test. Twenty-eight participants (mean ± standard deviation age, 37.3 ± 20.5 years) with corrected vision were recruited for testing on a voluntary basis with randomized administration of the in-office test followed by the VR analog or vice versa. Nineteen participants took each test twice to assess test-retest consistency in each modality. Virtual reality tests were conducted on a commercial Pico Neo Eye 2 VR headset, which has a 4K screen resolution. The environment for both tests was controlled by the participant for location and lighting. Similar sensitivity scores were obtained between testing modalities in both the right (n = 28 participants; Wilcoxon match-paired signed rank [SR], p=0.7) and left eyes (n = 28 participants; Wilcoxon match-paired SR, p=0.7). In addition, similar test-retest scores were found for VR (n = 19 participants; Wilcoxon match-paired SR, p=1.0) or in-office (n = 19 participants; Wilcoxon match-paired SR, p=1.0) tests. Virtual reality Pelli-Robson results correlated well with in-office test results in variably diseased participants (n = 14 eyes from 7 participants, R2 = 0.93, p<0.0001). In this pilot trial, we demonstrated that VR Pelli-Robson measurements of corrected vision align with those of in-office modalities, suggesting that this may be a reliable method of implementing this test in a more interactive and accessible manner.

Overview of biomarkers in vitreoretinal conditions

Biomarkers are measurable indicators that can be used to diagnose diseases or monitor their progression. In vitreoretinal conditions, biomarkers can be found in various structures of the eye, including the retina, vitreous, and choroid.One of the most commonly used biomarkers in vitreoretinal conditions is visual acuity, which is a measure of how well a person can see. Other biomarkers include imaging techniques, such as optical coherence tomography (OCT) and fundus photography, which can provide detailed images of the retina and vitreous.In addition to structural biomarkers, there are also functional biomarkers that can be used to evaluate visual function, such as contrast sensitivity and visual field testing. These measures are often used to monitor the progression of diseases such as macular degeneration and diabetic retinopathy.Recent advances in biomarker research have led to the discovery of new markers for vitreoretinal conditions, including genetic markers, inflammatory markers, and metabolic markers. These markers may provide new insights into the underlying mechanisms of disease and may help to identify new therapeutic targets.Overall, biomarkers are an important tool in vitreoretinal conditions for the diagnosis, monitoring, and management of a wide range of ocular diseases. They may also help to improve our understanding of these conditions and facilitate the development of new therapies.

Biomarkers in diabetic retinopathy

Diabetic retinopathy (DR) is a leading cause of blindness in working‐age adults worldwide, affecting up to 80% of patients who have had diabetes for more than 10 years. Biomarkers are measurable indicators that can be used to diagnose diseases or monitor their progression. In DR, biomarkers can be found in various structures of the eye, including the retina, vitreous, and aqueous humour.One of the most commonly used biomarkers in DR is glycated haemoglobin (HbA1c), which reflects long‐term blood glucose control. Elevated HbA1c levels are associated with an increased risk of developing DR, and strict glycemic control can help to prevent or delay its onset.Other biomarkers in DR include imaging techniques such as optical coherence tomography (OCT) and fundus photography, which can provide detailed images of the retina and allow for the detection of microaneurysms, haemorrhages, and exudates. OCT angiography (OCTA) can also visualize changes in retinal blood flow, which may be indicative of early DR.In addition to structural biomarkers, there are also functional biomarkers that can be used to evaluate visual function, such as contrast sensitivity and visual field testing. These measures are often used to monitor the progression of DR and assess the efficacy of treatment.Recent advances in biomarker research have led to the discovery of new markers for DR, including genetic markers, inflammatory markers, and metabolic markers. Genetic markers, such as single nucleotide polymorphisms (SNPs), have been associated with an increased risk of developing DR. Inflammatory markers, such as cytokines and chemokines, are elevated in the aqueous humour and vitreous of patients with DR and may contribute to the development and progression of the disease. Metabolic markers, such as advanced glycation end‐products (AGEs), are elevated in patients with DR and may play a role in the pathogenesis of the disease.Overall, biomarkers are an important tool in the diagnosis, monitoring, and management of DR. They may also help to improve our understanding of the disease and facilitate the development of new therapies. By identifying patients at high risk of developing DR, biomarkers may enable earlier interventions to prevent or delay the onset of vision loss.

NEW MEASURES AND POPULATION PREVALENCE OF VISION IMPAIRMENT IN NHATS

Abstract The National Health and Aging Trends Study (NHATS) is a nationally representative panel study of older U.S. adults that in 2021 (Round 11) added to its annual protocol a suite of objective visual function measures consisting of distance visual acuity, near visual acuity, and contrast sensitivity tests. These measures were developed to approximate clinical gold-standard tests, while allowing for administration on a tablet in participants’ homes. The tests were found to have good agreement with clinical gold-standards based on their limits of agreement, correlations, and lack of systematic bias between tests. In the initial 2021 fielding of the NHATS visual function measures, 27.8% (25.5%-30.1%) of U.S. adults over age 70 had one or more visual impairment (VI) (distance VI: 10.3% [8.9%-11.7%]; near VI: 22.3% [20.3%-24.3%]; contrast sensitivity impairment: 10.0% [8.5%-11.4%]), and the prevalence was highest among those who were older, had less education, lower income, and were of Hispanic ethnicity and non-White race. Additionally, the adjusted prevalence ratio for dementia was significantly higher among those with each type of VI compared to those with normal vision (moderate/severe distance VI=1.72 [1.26-2.35]; any near VI=1.40 [1.16-1.69]-; contrast sensitivity impairment =1.31 [1.04-1.66]). Since few other national studies of older adults include objective visual function measures, NHATS now serves as a vital resource for the study of vision epidemiology and the impact of VI and blindness on later-life health outcomes and trajectories.

Age-related changes in geometry and transparency of human crystalline lens revealed by optical signal discontinuity zones in swept-source OCT images

BackgroundThe shape and microstructure of the human crystalline lens alter with ageing, and this has an effect on the optical properties of the eye. The aim of this study was to characterise the age-related differences in the morphology and transparency of the eye lenses of healthy subjects through the optical signal discontinuity (OSD) zones in optical coherence tomography (OCT) images. We also investigated the association of those changes with the optical quality of the eye and visual function.MethodsOCT images of the anterior segment of 49 eyes of subjects (9–78 years) were acquired, and the OSD zones (nucleus, C1–C4 cortical zones) were identified. Central thickness, curvature and optical density were measured. The eye’s optical quality was evaluated by the objective scatter index (OSI). Contrast sensitivity and visual acuity tests were performed. The correlation between extracted parameters and age was assessed.ResultsThe increase in lens thickness with age was dominated by the thickening of the cortical zone C3 (0.0146 mm/year). The curvature radii of the anterior lens surface and both anterior and posterior nucleo-cortical interfaces decreased with age (− 0.053 mm/year, − 0.013 mm/year and − 0.006 mm/year, respectively), and no change was observed for the posterior lens radius. OCT-based densitometry revealed significant correlations with age for all zones except for C1β, and the highest increase in density was in the C2–C4 zones (R = 0.45, 0.74, 0.56, respectively, P < 0.001). Increase in OSI was associated with the degradation of visual function.ConclusionsOCT enables the identification of OSD zones of the crystalline lens. The most significant age-related changes occur in the C3 zone as it thickens with age at a faster rate and becomes more opaque than other OSD zones. The changes are associated with optical quality deterioration and reduction of visual performance. These findings contribute to a better understanding of the structure–function relationship of the ageing lens and offer insights into both pathological and aging alterations.

Remote Monitoring of Visual Function in Patients with Maculopathy: The Aphelion Study.

Remote monitoring of vision, using tools such as the shape discrimination hyperacuity (SDH) test, can detect disease activity in patients with maculopathy. We determined the in-clinic accuracy and repeatability of three myVisionTrack expanded version (mVTx) tests for self-testing of visual acuity (VA) and contrast sensitivity. Aphelion, a single-arm, prospective study conducted at two sites in the USA, included adults with any maculopathy and a baseline VA of 0.7 log of minimum angle of resolution (logMAR) (Snellen 20/100) or better. Participants completed the mVTx tests (tumblingE, LandoltC, contrast sensitivity, and SDH) and standard clinical tests (near and distance Early Treatment Diabetic Retinopathy Study [ETDRS] charts and the Pelli-Robson contrast sensitivity chart). Test-retest repeatability and agreement between the mVTx tests and the corresponding clinical test were assessed by Bland-Altman analyses. Participants also completed a usability survey. The mean age of the 122 participants was 67years. The most common diagnosis was age-related macular degeneration (42% of patients). The tumblingE test had a test-retest 95% limit of agreement (LoA) of ± 0.18logMAR; the LandoltC test, ± 0.23logMAR; the SDH test, ± 0.24logMAR; and the contrast sensitivity test, ± 0.32 log contrast threshold (logCT). Compared with the distance ETDRS chart, the LoA was ± 0.35logMAR for the tumblingE test (mean difference, - 0.07logMAR) and ± 0.39logMAR for the LandoltC test (mean difference, 0.03logMAR). For the contrast sensitivity test, the LoA compared with the Pelli-Robson chart was ± 0.30 logCT (mean difference, - 0.25logCT). Most participants (85%) reported that they learned the tests quickly. The tumblingE test scored the highest on ease of use. The mVTx tests of VA are accurate and repeatable, supporting their potential use alongside the SDH test to detect disease progression remotely between clinic visits.

Visual and non-visual responses of drivers to simulated LED headlights varying in correlated colour temperature

This study aimed to investigate the impact of automotive headlights of different correlated colour temperatures (CCT) on the visual and non-visual performance of drivers. Forty drivers participated in the study, driving in a simulated night road for 45 min in three sessions. The LED headlights had CCTs of 3176 K, 4358 K and 6923 K, with an illuminance of 5 lx perpendicular to the participants’ eyes. Heart rate variability (HRV), psychomotor vigilance task and Karolinska sleepiness scale were measured before and after driving. At the end of the trials, achromatic far and near visual acuity tests, as well as achromatic far and near contrast sensitivity tests, were conducted. The study revealed that CCT did not affect achromatic far and near visual acuity. However, CCT had an impact on achromatic near and far contrast sensitivity, with higher CCT resulting in improved achromatic contrast sensitivity. As the CCT decreased, participants exhibited increased reaction time, made more errors, and reported higher sleepiness. The most significant physiological changes in HRV, including alterations in low frequency (LF), high frequency (HF) and LF/HF, were observed at lower CCT. The findings of this study suggest that both the visual and non-visual performance of drivers were enhanced when high CCTs were used for automotive LED headlights.

Quantification of expected information gain in visual acuity and contrast sensitivity tests

We make use of expected information gain to quantify the amount of knowledge obtained from measurements in a population. In the first application, we compared the expected information gain in the Snellen, ETDRS, and qVA visual acuity (VA) tests, as well as in the Pelli–Robson, CSV-1000, and qCSF contrast sensitivity (CS) tests. For the VA tests, ETDRS generated more expected information gain than Snellen. Additionally, the qVA test with 15 rows (or 45 optotypes) generated more expected information gain than ETDRS, whether scored with VA threshold alone or with both VA threshold and VA range. Regarding the CS tests, CSV-1000 generated more expected information gain than Pelli–Robson, and the qCSF test with 25 trials generated more expected information gain than CSV-1000, whether scored with AULCSF or with CSF at six spatial frequencies. The active learning-based qVA and qCSF tests have the potential to generate more expected information gain than traditional paper chart tests. Although we have specifically applied it to compare VA and CS tests, expected information gain is a general concept that can be used to compare measurements in any domain.

Functional outcomes after bilateral refractive lens exchange with a continuous-range-of-vision intraocular lens.

To clinically evaluate a diffractive continuous-range-of-vision intraocular lens (IOL) that combines bifocal and extended depth-of-focus technologies in refractive lens exchange (RLE) patients. University eye clinic. Prospective interventional clinical study. Bilateral implantation of the TECNIS Synergy IOL was performed during a RLE procedure in 28 patients. At 3 months postoperatively, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected (UIVA) and distance-corrected (DCIVA) intermediate visual acuities at 80 cm, and uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuities at 40 cm were assessed. Defocus curve testing and contrast sensitivity testing were also performed. Binocular UDVA and CDVA of 56 eyes (28 patients) were -0.06 ± 0.07 logMAR and -0.13 ± 0.05 logMAR, respectively. UIVA and DCIVA were -0.06 ± 0.05 logMAR and -0.08 ± 0.06 logMAR, and UNVA and DCNVA were -0.01 ± 0.07 logMAR and -0.04 ± 0.07 logMAR. The defocus curve revealed a visual acuity of 0.10 logMAR or better from +0.50 to -3.00 diopters (D). Photopic contrast sensitivity at spatial frequencies 3.0, 6.0, 12.0, and 18.0 was 1.68 ± 0.20, 1.77 ± 0.19, 1.45 ± 0.18, and 1.02 ± 0.19 log units, respectively. Mesopic contrast sensitivity at the same frequencies was 1.56 ± 0.20, 1.44 ± 0.25, 0.92 ± 0.38, and 0.44 ± 0.37, respectively. The Synergy IOL provided very good distance, intermediate, and near visual outcomes. A visual acuity of 0.10 logMAR or better was achieved from +0.50 to -3.0 D. Contrast sensitivity was within the normal range.

Improvement of positive dysphotopsia with multifocal intraocular lenses by hormone replacement therapy

Introduction: The case of a patient with positive dysphotopsia (PD) affected by hormone replacement therapy (HRT) after multifocal intraocular lens (IOL) insertion is reported. Patient and Clinical Findings: A 66-year-old woman underwent bilateral cataract surgery and multifocal IOL implantation. Postoperatively, the uncorrected distance and near visual acuity improved bilaterally. The patient experienced mild PD symptoms in the left eye. She had been using an estradiol patch for menopausal disorders. 6 months postoperatively, the use of an estradiol patch was discontinued because of dermatitis and she noticed a marked worsening of her PD. Diagnosis, Intervention, and Outcomes: With the patient's cooperation, full-field electroretinography (ERG) and contrast sensitivity tests were performed before and after estradiol discontinuation. After the discontinuation, the amplitude of both rod and cone ERGs decreased, contrast sensitivity decreased, and PD deteriorated. There were no changes in anterior-segment condition and retinal shape. Conclusions: PD symptoms worsened after the discontinuation of estrogen hormone therapy. ERG amplitude and contrast sensitivity decreased when HRT was discontinued, suggesting that retinal function in the presence of estrogen receptors may be related to the development of PD.