Fluorescent MnO2@DEHP Nanoprobe for Rapid and Selective Detection of Fe(III) ions.

Particle extraction via the liquid-liquid interface (PELLI) method has been utilized to produce Di-(2-ethylhexyl) phosphate (DEHP) coated MnO2 fluorescent nanoprobe denoted as MnO2@DEHP for the selective detection of Fe3+ ions. The synthesized MnO2@DEHP nanoprobe was characterized by various instrumental techniques such as FT-IR, PXRD, TEM, EDAX, HRTEM, DLS, and XPS. Since the high concentration of Fe3+ in waste water leads to water pollution, which in turn affects the ecosystem, and causes severe health hazards. Therefore, accurate detection of Fe3+ ions in the aqueous systems is essential as they are involved in various chemical and biological processes in living things. Here, the synthesized MnO2@DEHP nanoprobe selectively detects Fe3+ ions in the presence of various metal ions in an aqueous media by fluorescence quenching (turn-off) mechanism. The limit of detection (LOD) of MnO2@DEHP nanoprobe for Fe3+ was found to be 0.49 µM. The test-strip method and real water sample analysis were also used to demonstrate the viability of MnO2@DEHP as a fluorescent nanoprobe to detect Fe3+ ions visually and in environment monitoring applications.

Evaluation of the SpotChecks contrast sensitivity test in healthy adults.

PURPOSE: SpotChecks is a new contrast sensitivity (CS) test designed for self-monitoring of vision. This study assessed the test-retest repeatability of take-home SpotChecks, in-office SpotChecks and near Pelli-Robson charts in healthy adults. METHODS: One eye of 61 healthy adults with near visual acuity (VA) of 6/9 or better (age range 22-84, mean 49 [18] years) was tested during two office visits (mean 10 [8] days apart). Each visit included high-contrast VA, then 12 randomly ordered CS tests (6 different SpotChecks and 6 different Pelli-Robson) under the same lighting (luminance 110 cd/m2), all at near in the same eye with habitual correction. The same eye was self-tested with take-home SpotChecks once a day on 6 days between the office visits. SpotChecks was scored by the logCS at the highest line with ≥2 errors. Pelli-Robson was scored by [0.05 × number of letters read correctly - 0.15]. Repeatability of logCS was defined as 1.96 2 Sw, Sw representing within-subject standard deviation. Comparison for repeatability was performed with Bootstrap hypothesis test. RESULTS: SpotChecks and Pelli-Robson showed similar intra-session or inter-visit repeatability (p = 0.14-0.81). Inter-day repeatability for take-home SpotChecks was 0.18 logCS, the same as that from the first measurements of two office visits with SpotChecks or Pelli-Robson. Inter-visit repeatability improved to 0.15 by using the average of two repeated measurements for SpotChecks (p = 0.02) or three repeated measurements for Pelli-Robson (p = 0.04). Age showed a small effect on logCS (-0.015/decade, p = 0.02) for both SpotChecks and Pelli-Robson. Mean logCS was 0.05 lower in those ≥50 years (SpotChecks 1.84 [0.10] and Pelli-Robson 1.77 [0.10]) compared with those <50 years of age (SpotChecks 1.89 [0.07] and Pelli-Robson 1.83 [0.07]). CONCLUSIONS: SpotChecks showed good repeatability with take-home and in-office testing in healthy adults, making it a promising tool for monitoring disease progression at home.

Clinical outcomes in eyes with diffractive continuous depth-of-focus intraocular lenses enhanced for near vision: comparison with trifocal intraocular lenses.

BACKGROUND: To prospectively evaluate visual functions and patient satisfaction after bilateral implantation of diffractive continuous depth-of-focus intraocular lens (CDF IOL) compared with trifocal IOLs. METHODS: This investigator-initiated study was approved by a certified local review board (registered: jRCTs032210305). CDF IOL (Synergy, J&J, group S) and trifocal IOL (AcrySof PanOptix, Alcon, group P) were implanted bilaterally in 30 patients each. Three months postoperatively, binocular outcomes of uncorrected (BUCVA) and distance-corrected (BDCVA) visual acuities at distances of 0.3, 0.4, 0.5, 0.7, and 5 m were measured. Contrast sensitivities were binocularly measured using CSV-1000 (2.5 m) and Pelli-Robson charts at distances of 0.4 and 1 m. Symptoms of glare, halo, starburst, and waxy vision, and satisfaction for near, intermediate, and far visions were assessed with questionnaires. Differences between the two groups were examined. RESULTS: Twenty-seven patients each completed the follow-up. The mean age of the group S was lower than that of the group P (P < 0.001). The BUCVA at 0.4 m was better in the S group, while the mean manifest refraction of the P group showed a significant hyperopic shift (P < 0.001). BDCVA was significantly better in the S group. The contrast sensitivity results at three distances showed no discernible differences. Although more patients in the S group reported significant glare and halo, their satisfaction with near vision was higher. CONCLUSIONS: The binocular visual function of patients with CDF IOLs was comparable to or better than that of patients with trifocal IOLs. The patients were satisfied with near vision, despite the enhanced glare and halo. Understanding the differences between the two types of presbyopia-correcting IOLs is important to ensure patient satisfaction. TRIAL REGISTRATION: This clinical trial was registered in the Japan Registry for Clinical Research (identifier: jRCTs032210305) on September 13, 2021.

Comparing the CamBlobs2 contrast sensitivity test to the near Pelli-Robson contrast sensitivity test in normally-sighted young adults.

PURPOSE: Contrast sensitivity (CS) has been proposed as a potential method for patients to assess their vision at home. The CamBlobs2 contrast sensitivity test is meant to be performed easily in the clinic or at home. The purpose of this study was to determine the intra-visit coefficient of repeatability of the CamBlobs2 compared with the near Pelli-Robson test, and the limits of agreement between these two tests on normally-sighted subjects. METHODS: Twenty-two normally-sighted subjects (mean age 28 ± 4 years) completed two trials of the near Pelli-Robson and CamBlobs2 contrast sensitivity tests within a single visit. Tests were performed monocularly on each eye in random order. Pelli-Robson tests were scored as 0.05 logCS for each letter read correctly after deducting the first triplet. CamBlob2 tests were scored as the highest line where two or fewer blobs were marked correctly. The coefficient of repeatability was determined as 1.96 times the standard deviation of the difference between the two measurements using the same type of chart on the same eye. The limits of agreement between the two tests were evaluated using Bland-Altman analysis. RESULTS: The mean difference between intra-visit measurements for both the near Pelli-Robson and CamBlobs2 was less than 0.05 logCS and the coefficient of repeatability was within ±0.20 log CS for both left and right eyes. The mean ± standard deviation differences between near Pelli-Robson and CamBlobs2 scores was -0.08 ± 0.08 (limits of agreement: -0.24 to 0.09) for right eyes and -0.05 ± 0.10 (limits of agreement: -0.23 to 0.14) logCS for left eyes based on average measurements. CONCLUSIONS: The intra-visit repeatability of CamBlobs2 was consistent with the near Pelli-Robson contrast sensitivity test (±0.20 logCS). With a 0.05 correction, the CamBlobs2 scores showed excellent agreement with the near Pelli-Robson contrast sensitivity test.

How accurate is an LCD screen version of the Pelli-Robson test?

PURPOSE: To evaluate the accuracy and repeatability of a computer-generated Pelli-Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli-Robson chart. METHODS: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli-Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. RESULTS: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli-Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland-Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli-Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland-Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. CONCLUSIONS: Computer-generated versions of Pelli-Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli-Robson printed version. Clinicians should consider that Pelli-Robson computer-generated versions could be non-interchangeable to the printed version.

Foveal crowding in children with developmental dyslexia.

Excessive crowding in the visual periphery has been demonstrated in children with developmental dyslexia (DD). However, less is known about crowding in the fovea, even though foveal crowding is at least equally important, as reading is mostly accomplished through foveal vision. Here we used a special set of digit stimuli (Pelli fonts) to measure foveal crowding in DD and DD + ADHD children, and compared it to that in TD (typically developing) and ADHD children. We also used the Chinese reading acuity charts (C-READ) to assess the maximum reading speed and reading acuity, along with tests to evaluate cognitive attributes including phonological awareness, rapid automatized naming, morphological awareness, and orthographic knowledge. The results indicate significantly stronger foveal crowding in the DD and DD + ADHD groups, as well as in the ADHD group, than in the TD group. Furthermore, the DD and DD + ADHD groups exhibited poorer maximum reading speed and reading acuity compared to the ADHD and TD groups. Within the two DD groups, the slower maximum reading speed and higher reading acuity can be predicted by stronger foveal crowding. In addition, the DD and DD + ADHD groups performed the worst in four cognitive skills, with the DD group showing negative correlations between foveal crowding and performances across all these skills. Our findings thus move beyond previously well-documented peripheral crowding in dyslexia, and the easy administration of the Pelli-font-based crowding test may be useful for early diagnosis of developmental dyslexia in young children.

The Effect of Yellow Filter Use on Standard Automated Perimetry and Contrast Sensitivity in Healthy Individuals.

Purpose The purpose of this study is to investigate the effect of two yellow filters (category 1: visible light transmission {VLT} from 80% to 43%) of Essilor (Kiros® and Lumior®) on standard automated perimetry (SAP) indices and Pelli-Robson (PR) contrast sensitivity (CS) testing in healthy individuals. Materials and methods This study is a prospective comparative study of 31 eyes of 31 healthy individuals aged 32.14 (8.13) years (14 males and 17 females). All participants underwent a series of three visual field (VF) examinations (24-2, Swedish Interactive Thresholding Algorithm {SITA} standard) with the Humphrey field analyzer (HFA II 740, Carl Zeiss Meditec, Jena, Germany) and three CS examinations with the PR chart (Precision Vision, Inc., Woodstock, IL). VF and CS examinations were carried out as follows: (a) no filter (NF), (b) with the yellow filter Kiros® (KIROS), and (c) with the yellow-orange filter Lumior® (LUMIOR). The effect of the two yellow filters on global VF indices (glaucoma hemifield test {GHT}, mean deviation {MD}, pattern standard deviation {PSD}, and visual field index {VFI}) and on CS score was evaluated and compared. Results When comparing the three pairs NF-KIROS, NF-LUMIOR, and KIROS-LUMIOR, no difference was presented on the global VF indices. However, a statistically significant difference was detected in the CS scores for all three pairs, favoring KIROS. It is important to note that while this difference was statistically significant, it did not reach clinical significance. Conclusions The use of yellow filters (category 1: VLT of 75% and 65%) does not affect the global VF indices and the CS of healthy individuals but significantly improves their CS score. Further studies are required to explore the clinical significance of these findings.

Digital contrast sensitivity chart with varying visual acuity: Development and validation.

BACKGROUND: Contrast sensitivity (CS) evaluation is very much necessary for the diagnosis and management of eye conditions. Several disadvantages seen in the traditionally used Pelli-Robson (PR) chart persuaded us to develop a novel digital device for the evaluation of CS at various levels of visual acuity (VA) for early detection of deteriorating vision. MATERIALS AND METHODS: The new chart was constructed on the Debian software. Letters were constructed at each level of VA from 6/60 to 6/6 with a contrast of 0-2.25 logCS. The newly constructed chart was validated against the PR chart. The data were analyzed on the SPSS software version 23. The Pearson's correlation test was used to find out the correlation between the digital CS chart (DCSC) and PR charts. RESULTS: On successful construction of a DCSC with varying VA, 56 participants were examined with a mean age of 20.43 ± 1.44 years. The mean CS with PR was 1.84 ± 0.13 logCS, whereas DCSC was 2.09 ± 0.14 logCS. The correlation between the two charts was moderate having r = 0.489 with P = 0 (confidence interval 95%). CONCLUSION: A newly developed CS chart is efficient in examining the CS in clinical practice and has good repeatability; it may help in the early detection and monitoring of ocular diseases.

Change in contrast sensitivity and OCT parameters in idiopathic intracranial hypertension.

Background: Deterioration in peripheral contrast sensitivity (CS) can be an indicator to detect progressive deterioration of visual function in patients with idiopathic intracranial hypertension (IIH). Objectives: The aim of this study was to evaluate the changes in central and peripheral CS and optical coherence tomography (OCT) parameters and in patients with IIH. Design and Methods: In this pilot observational study, data of 20 eyes of 10 'treatment-naïve' IIH patients were analyzed. Detailed ocular examination was performed including CS assessment using both Pelli-Robson (PR) test and Spaeth-Richman Contrast Sensitivity Test (SPARCS) along with the OCT for macular and optic nerve head (ONH) parameters. A comparative analysis was done for CS and OCT parameters from baseline to a follow-up visit > 12 months (range: 18-24 months). Results: The study population had a female preponderance (80%, n = 8), and mean age at diagnosis was 31.9 ± 10.3 years. Mean follow-up period was 21.2 months (range: 15-24 months). At presentation, 6/6 visual acuity was noted in 75% eyes (n = 15) while all eyes had 6/6 vision at the last follow-up. Average PR score increased from 1.96 ± 0.36 to 2.30 at the last visit (Wilcoxon test: V = 0.0, p ⩽ 0.001) while average SPARCS score (total) increased from 71.85 ± 9.10 to 77.55 ± 6.20 (Paired t-test: t = -2.3, p = 0.035). Change in SPARCS score was significant in average total score (p = 0.035), and quadrant-wise score in superonasal (p = 0.014), inferonasal (p = 0.001), and inferotemporal (p = 0.021) quadrants. Same trend in SPARCS scores was observed when eyes with and without recurrence were analyzed. Statistically significant difference in retinal nerve fiber layer (RNFL) thickness (p = 0.007) and macular thickness (MT) in nasal quadrant (p = 0.006) was seen between the eyes with recurrence and without recurrence. Conclusion: Peripheral CS showed significant difference in all eyes over time. It showed significant change in eyes with recurrence, even in the presence of intact visual acuity and preserved central CS. Changes in RNFL thickness and nasal MT could differentiate eyes which developed recurrence from normal eyes.

Contrast sensitivity assessment for early detection of hydroxychloroquine toxicity.

INTRODUCTION: Hydroxychloroquine (HCQ), is known to cause visual dysfunction during its prolonged course of administration. Optical Coherence Tomography (OCT) and field tests are the commonly used screening tests. Not much is known about the role of contrast sensitivity (CS) as method for early detection of HCQ toxicity. This pilot study was designed to study the change in central and peripheral contrast sensitivity for detecting early signs of HCQ toxicity. DESIGN: Prospective study conducted at Government Medical College & Hospital, Chandigarh, India. PARTICIPANTS: Twenty eyes of 10 treatment naïve, autoimmune patients. METHODS: All patients underwent functional tests, contrast sensitivity tests: Pelli Robson and Spaeth Richman Contrast Sensitivity (SPARCS). Average and quadrant wise SPARCS score; Pelli Robson score and structural parameters viz., macular OCT parameters were compared at baseline, 3- and 6-month post treatment with HCQ. MAIN OUTCOME MEASURES: Change in CS using SPARCS and Pelli Robson were recorded at each visit and compared with the baseline. Structural and functional parameters were correlated. RESULTS: The average SPARCS scores at baseline, 3-month post HCQ and at 6-month post HCQ were 82.37 ± 8.40, 73.17 ± 9.63 and 70.37 ± 10.08, respectively. Quadrant wise change from first visit to third visit was statistically significant only in superotemporal (p = 0.002), inferotemporal (p = 0.02) and central (p = 0.01) quadrants. There was no correlation between SPARCS and Pelli Robson (S = 0.1454, p = 0.466). Similarly, there was no significant correlation between the structural and functional parameters. CONCLUSIONS: HCQ affect the CS by virtue of its action on bipolar and ganglion cells. Decrease in central and peripheral CS as measured by SPARCS can be a sign of early visual dysfunction, hence must be considered as an early indicator of HCQ toxicity.

Longitudinal study of visual function in patients with relapsing-remitting multiple sclerosis with and without a history of optic neuritis. / Estudio longitudinal de la función visual en pacientes con esclerosis múltiple remitente-recurrente con y sin antecedentes de neuritis óptica.

INTRODUCTION: The contrast sensitivity test determines the quality of visual function in patients with multiple sclerosis (MS). The purpose of this study is to analyse changes in visual function in patients with relapsing-remitting MS with and without a history of optic neuritis (ON). METHODS: We conducted a longitudinal study including 61 patients classified into 3 groups as follows: a) disease-free patients (control group); b) patients with MS and no history of ON; and c) patients with MS and a history of unilateral ON. All patients underwent baseline and 6-year follow-up ophthalmologic examinations, which included visual acuity and monocular and binocular Pelli-Robson contrast sensitivity tests. RESULTS: Monocular contrast sensitivity was significantly lower in MS patients with and without a history of ON than in controls both at baseline (P=.00 and P=.01, respectively) and at 6 years (P=.01 and P=.02). Patients with MS and no history of ON remained stable throughout follow-up whereas those with a history of ON displayed a significant loss of contrast sensitivity (P=.01). Visual acuity and binocular contrast sensitivity at baseline and at 6 years was significantly lower in the group of patients with a history of ON than in the control group (P=.003 and P=.002 vs P=.006 and P=.005) and the group with no history of ON (P=.04 and P=.038 vs P=.008 and P=.01). However, no significant differences were found in follow-up results (P=.1 and P=.5). CONCLUSIONS: Monocular Pelli-Robson contrast sensitivity test may be used to detect changes in visual function in patients with ON.

Mobile app Aston contrast sensitivity test.

BACKGROUND: Contrast detection is an important aspect of the assessment of visual function; however, clinical tests evaluate limited spatial frequencies and contrasts. This study validates the accuracy and inter-test repeatability of a swept-frequency near and distance mobile app Aston contrast sensitivity test, which overcomes this limitation compared to traditional charts. METHOD: Twenty subjects wearing their full refractive correction underwent contrast sensitivity testing on the new near application (near app), distance app, CSV-1000 and Pelli-Robson charts with full correction and with vision degraded by 0.8 and 0.2 Bangerter degradation foils. In addition repeated measures using the 0.8 occluding foil were taken. RESULTS: The mobile apps (near more than distance, p = 0.005) recorded a higher contrast sensitivity than printed tests (p < 0.001); however, all charts showed a reduction in measured contrast sensitivity with degradation (p < 0.001) and a similar decrease with increasing spatial frequency (interaction > 0.05). Although the coefficient of repeatability was lowest for the Pelli-Robson charts (0.14 log units), the mobile app charts measured more spatial frequencies, took less time and were more repeatable (near: 0.26 to 0.37 log units; distance: 0.34 to 0.39 log units) than the CSV-1000 (0.30 to 0.93 log units). The duration to complete the CSV-1000 was 124 ± 37 seconds, Pelli-Robson 78 ± 27 seconds, near app 53 ± 15 seconds and distance app 107 ± 36 seconds. CONCLUSIONS: While there were differences between charts in contrast levels measured, the new Aston near and distance apps are valid, repeatable and time-efficient method of assessing contrast sensitivity at multiple spatial frequencies.

A modified Middle Eastern contrast sensitivity chart.

The contrast sensitivity test has been used to examine vision in different clinical circumstances. Moreover, as contrast sensitivity is affected by several ocular states, its measurement has been considered practically for monitoring and assessment of a wide range of visual functions, predicting vision related abilities, diagnosing several ophthalmic conditions, and evaluating many ocular disorders including glaucoma, cataracts, diabetic retinopathy, optic neuritis and age-related degeneration. The Pelli-Robson standard chart has been translated and modified using Persian-Arabic characters since illiterates and children in the Middle East, Central Asia, and Africa are more likely to distinguish Arabic characters instead of English ones. The translation of these characters is expected to have more precise results, thereby improving the test's validity and provide early diagnoses of ocular problems. This manuscript is focused on conceptions relating to the project. Further studies are required to evaluate the sensitivity, specificity, and reliability of the revised chart to best compare it to the standard Pelli-Robson one.

Relationship between contrast sensitivity test and disease severity in multiple sclerosis patients.

OBJECTIVE: To assess the importance of the Pelli-Robson contrast sensitivity test in multiple sclerosis patients according to the Expanded Disability Status Scale (EDSS). MATERIAL AND METHODS: A total of 62 patients with multiple sclerosis were included in a retrospective study. Patients were enrolled from the Neurology Department to Neuroophthalmology at Virgen de la Victoria Hospital. Patients were classified into 3 groups according to EDSS: group A) lower than 1.5, group B) between 1.5 and 3.5 and group C) greater than 3.5. Visual acuity and monocular and binocular contrast sensitivity were performed with Snellen and Pelli-Robson tests respectively. Twelve disease-free control participants were also recruited. Correlations between parameter changes were analyzed. RESULTS: The mean duration of the disease was 81.54±35.32 months. Monocular and binocular Pelli-Robson mean values in the control group were 1.82±0.10 and 1.93±0.43 respectively, and 1.61±0.29 and 1.83±0.19 in multiple sclerosis patients. There were statistically significant differences in the monocular analysis for a level of significance P<.05. Mean monocular and binocular Pelli-Robson values in relation to gravity level were, in group A: 1.66±0.24 and 1.90±0.98, group B: 1.64±0.21 and 1.82±0.16, and group C: 1.47±0.45 and 1.73±0.32 respectively. Group differences were statistically significant in both tests: P=.05 and P=.027. CONCLUSIONS: Monocular and binocular contrast discrimination analyzed using the Pelli-Robson test was found to be significantly lower when the severity level, according EDSS, increases in multiple sclerosis patients.