Low-contrast Acuity Research Articles

Retinal Function in Advanced Multiple Sclerosis.

People with multiple sclerosis (pwMS) experience autoimmunity-mediated inflammation and neurodegeneration throughout the central nervous system. There remains a need for clinically accessible, reliable functional markers of neurodegeneration in MS. Previous research has described changes to electroretinography (ERG)-derived measures of retinal bipolar cell function in pwMS early in the disease course. We, therefore, investigated ERG as a potential outcome measure in individuals with more advanced disease. This cross-sectional observational study included pwMS with Expanded Disability Status Scale (EDSS) scores of ≥3.0 and healthy control (HC) participants who underwent ERG, optical coherence tomography, high- and low-contrast visual acuity measurement, and an ophthalmological examination. ERG findings in MS eyes with and without previous optic neuritis (MS +ON; MS -ON) were compared with those in HC eyes. Effects of EDSS, disease duration, ON, and treatment status on selected ERG outcomes were measured. Additional exploratory analyses assessed potential influences of MS phenotype and disease status (clinically active, radiologically active, and disease progression). Delays to two ERG peak times (dark-adapted 3.0 b-wave; light-adapted flicker) were recorded in MS +ON and MS -ON eyes. No influences of EDSS score, disease duration, previous ON, or treatment status were observed. Exploratory analyses were consistent with no effects of MS phenotype or disease status. ERG findings are abnormal in individuals with moderate-severe disability caused by MS; however, these findings are not distinct from those observed earlier in the disease course. Although bipolar dysfunction appears to be common in pwMS throughout the disease course, ERG is likely not useful in monitoring or prognostication of MS.

Retinal Damage and Visual Network Reconfiguration Defines Visual Function Recovery in Optic Neuritis.

Recovery of vision after acute optic neuritis (AON) is critical to improving the quality of life of people with demyelinating diseases. The objective of the study was to prospectively assess the changes in visual acuity, retinal layer thickness, and cortical visual network in patients with AON to identify the predictors of permanent visual disability. We studied a prospective cohort of 88 consecutive patients with AON with 6-month follow-up using high and low-contrast (2.5%) visual acuity, color vision, retinal thickness from optical coherence tomography, latencies and amplitudes of multifocal visual evoked potentials, mean deviation of visual fields, and diffusion-based structural (n = 53) and functional (n = 19) brain MRI to analyze the cortical visual network. The primary outcome was 2.5% low-contrast vision, and data were analyzed with mixed-effects and multivariate regression models. We found that after 6 months, low-contrast vision and quality of vision remained moderately impaired. The thickness of the ganglion cell layer at baseline was a predictor of low-contrast vision 6 months later (ß = 0.49 [CI 0.11-0.88], p = 0.012). The structural cortical visual network at baseline predicted low-contrast vision, the best predictors being the betweenness of the right parahippocampal cortex (ß = -036 [CI -0.66 to 0.06], p = 0.021), the node strength of the right V3 (ß = 1.72 [CI 0.29-3.15], p = 0.02), and the clustering coefficient of the left intraparietal sulcus (ß = 57.8 [CI 12.3-103.4], p = 0.015). The functional cortical visual network at baseline also predicted low-contrast vision, the best predictors being the betweenness of the left ventral occipital cortex (ß = 8.6 [CI: 4.03-13.3], p = 0.009), the node strength of the right intraparietal sulcus (ß = -2.79 [CI: -5.1-0.4], p = 0.03), and the clustering coefficient of the left superior parietal lobule (ß = 501.5 [CI 50.8-952.2], p = 0.03). The assessment of the visual pathway at baseline predicts permanent vision disability after AON, indicating that damage is produced early after disease onset and that it can be used for defining vision impairment and guiding therapy.

Clinical Evaluation of Violet Light Filtration and High-Resolution Lathing on a Diffractive Extended Depth of Focus IOL.

This study is a prospective, randomized, subject/evaluator-masked clinical trial in a single-center clinical setting. The purpose of the study is to compare the clinical performance of Tecnis Symfony Optiblue IOL (models ZXR00V and ZXW150) with violet light filter (VLF) and manufacturing improvements versus Tecnis Symfony IOL (models ZXR00 and ZXT150) with ultraviolet light filter (UVF) in patients undergoing cataract surgery. Patients with cataracts aged ≥ 22years were randomly assigned 1:1 to bilateral implantation with ZXR00V/ZXW150 (VLF group) or ZXR00/ZXT150 (UVF group). Key endpoints at 6months postoperative included patient reported nighttime dysphotopsia symptoms, 25% low contrast visual acuity with glare, and patient satisfaction. Sixty patients were implanted with ZXR00V/ZXW150 (30) or ZXR00/ZXT150 (30). At 6months, the VLF group did not show a statistically significant differences in mean monocular photopic uncorrected distance visual acuity (UCDVA), best-corrected distance visual acuity (BCDVA), uncorrected near visual acuity (UCNVA) (40cm), or distance-corrected near visual acuity (DCNVA) (40cm) compared to the UVF group. At 1month, patients in the VLF group reported significantly less difficulty due to halo (p = 0.016) and starburst (p = 0.028) symptoms. By the 6months, dysphotopsia complaints were no longer significantly different between the groups. Although the VLF group trended toward better low contrast visual acuity and patient satisfaction, statistical significance was not reached. Managing the patients' expectations is key to achieving success. At the 1-month visit the patients who reported dysphotopsia complaints in the VLF group had significantly less difficulty with starbursts and halos as compared to the UVF group. By the 6-month visit, there was no significant difference between the two groups in the difficulty with starbursts and halos. ClinicalTrials.gov identifier, NCT06567834.

Impact of Scleral Lenses on Visual Acuity and Ocular Aberrations in Corneal Ectasia: A Comprehensive Review.

Corneal ectasias, including keratoconus (KC), pellucid marginal degeneration (PMD), and post-LASIK ectasia, poses significant visual rehabilitation challenges due to the resultant irregular astigmatism, myopia, and higher-order aberrations (HOAs). These conditions often resist traditional corrective methods, necessitating advanced optical solutions. Scleral lenses (SLs) have emerged as a primary non-surgical option for managing these complex corneal irregularities. SLs form a smooth optical interface by forming a tear-filled chamber between the lens and the cornea, effectively mitigating HOAs and improving both high-contrast and low-contrast visual acuity (VA). This review evaluates the efficacy of SLs in enhancing VA and reducing aberrations in patients with corneal ectasia. It also explores the technological advancements in SLs, such as profilometry and wavefront-guided systems, which enable more precise and customized lens fittings by accurately mapping the eye's surface and addressing specific visual aberrations. The current body of evidence demonstrates that custom SLs significantly improve visual outcomes across various ectatic conditions, offering superior performance compared to conventional correction methods. However, challenges such as the complexity of fitting and the need for precise alignment remain. Ongoing innovations in SL technology and customization are likely to further enhance their clinical utility, solidifying their role as an indispensable tool in the management of corneal ectasias.

Evaluating the effectiveness of simvastatin in slowing the progression of disability in secondary progressive multiple sclerosis (MS-STAT2): protocol for a multicentre, randomised controlled, double-blind, phase 3 clinical trial in the UK

IntroductionThere remains a high unmet need for disease-modifying therapies that can impact disability progression in secondary progressive multiple sclerosis (SPMS). Following positive results of the phase 2 MS-STAT study, the...

Visual impact of diffusion optic technology lenses for myopia control.

To assess the visual impact of Diffusion Optics Technology™ 0.2 DOT lenses (SightGlass Vision Inc.) designed for myopia control on primary gaze. DOT spectacle lenses contain light scattering elements that scatter light as it passes through the lens which, in turn, reduces retinal image contrast. Fifty-one children (12.2 ± 1.3, range 10-14 years; 51% females) were randomly assigned to wear DOT spectacle (n = 27) or single vision lenses (n = 24) across six investigational sites in North America. Binocular high- and low-contrast distant visual acuities, near visual acuity, reading speed, contrast sensitivity, stereoacuity and glare were assessed in primary gaze after at least 3 years of wear, with the study 95% powered in all metrics to detect significant differences between the groups. Mean binocular distance high-contrast (-0.09 ± 0.02 vs. -0.08 ± 0.02 logMAR, p = 0.81), low-contrast (0.05 ± 0.02 vs. 0.07 ± 0.02 logMAR, p = 0.52) and near visual acuity with glare sources (-0.06 ± 0.03 vs. -0.09 ± 0.03 logMAR, p = 0.32) were similar for DOT and single vision lens wearers, respectively. Contrast sensitivity was similar between children wearing DOT or single vision lenses across 11 of the 16 spatial frequencies (p > 0.05). Mean stereopsis was similar (p = 0.30) with the DOT lenses (33.2 ± 12.5″) and single vision lenses (38.1 ± 14.2″). Functional reading speed metrics were similar in both study groups, as was the objectively measured head tilt during reading (p > 0.05). The mean halo radius was 0.56° ± 0.17° with the DOT lenses compared with 0.50° ± 0.12° with single vision lenses (p = 0.02), but the statistically significant difference was smaller than the non-inferiority bound of 0.4°. Diffusion optics technology lenses provide a clinically equivalent visual experience to a standard single vision lens.

Low Contrast Acuity Outcomes After SMILE and LASIK.

To compare early visual quality of small incision lenticule extraction (SMILE) versus laser in situ keratomileusis (LASIK) in terms of low contrast acuity. A secondary analysis was performed using a harmonized dataset derived from two completed prospective cohort studies on active-duty military service members undergoing either SMILE (n = 37), wavefront-guided (WFG) LASIK (n = 51), or wavefront-optimized (WFO) LASIK (n = 56). Night vision and photopic and mesopic low contrast visual acuity (LCVA) up to 3 months postoperatively were compared between groups. Compared to SMILE-treated eyes, WFG LASIK-treated eyes had significantly better night vision and photopic LCVA at 1 month postoperatively (beta = -0.039, P = .016; beta = -0.043, P = .007, respectively). WFO LASIK-treated eyes had significantly better photopic LCVA at 1 month postoperatively (beta = -0.039, P = .012) but had worse mesopic LCVA at 3 months postoperatively (beta = 0.033, P = .015) versus SMILE-treated eyes. SMILE and LASIK, on either a WFG or WFO laser platform, yielded excellent outcomes, but LCVA seemed to recover quicker following LASIK compared to SMILE. [J Refract Surg. 2024;40(9):e667-e671.].

ASTM International Subcommittee E07.02 on Reference Radiological Images: A brief history and update of recent work

Radiographic interpretation is a combination of art and science. The radiograph interpreter must be well versed in x-ray physics, conditions of the exposure, characteristics of the source and image detector, the design of the part, its specifications, and potential flaws. But there is also an art to interpretation that is gained over years of looking at many radiographs taken in many different conditions. As an aid to interpretation, reference radiographs have been developed and well accepted as means of identifying different types of indications and grading those indications for accept/reject decisions. Industrial radiography began in 1922 under the direction of HH Lester at the US Army Watertown Arsenal. The first radiography standards and reference radiographs appeared in the 1930s. ASTM International Committee E07 on Nondestructive Testing was formed out of Committee E04 on Metallography X-ray Methods subcommittee in 1938 when ASTM was the American Society for Testing Materials. An ASTM Subcommittee on Reference Radiographs was formed in 1950 and immediately adopted some of these first reference films as consensus standards. Since those first reference radiograph standards ASTM has developed both film and digital radiograph standards for 11 types of castings and 3 types of welds, several radiographic parameter demonstration films, a standard film for measuring film digitization performance, and films for evaluating visual acuity of radiograph interpreters. This paper discusses the history of reference films and the recent development of digital reference images, film digitizer performance film, and the visual acuity standard. The just-approved ASTM E3168 Standard Practice for Determining Low-Contrast Visual Acuity of Radiographic Interpreters is the first standard containing actual radiographic images of varying sharpness, contrast, and noise that can be used to evaluate interpreters and/or interpretation environments. This paper documents the initial statistical study performed on the visual acuity standard films.

Contrast Sensitivity and Low Contrast Visual Acuity in Children With Normal Visual Acuity

To measure and report the distribution of distance and near contrast sensitivity (CS) and low contrast visual acuity (LCVA) at 5% and 2.5% contrast in children aged 5-15 years with normal visual acuity (VA). Prospective, cross-sectional study. Schools in Southern India. One thousand fifty-two children aged 5 to 15 years (mean age 10.61 ± 2.85 years) with a presenting visual acuity of 0.00 logMAR or better in both eyes and a stereo acuity of 40 seconds of arc or better were recruited from nine schools. Repeatability of contrast sensitivity and low contrast visual acuities were tested in 246 children. Pelli-Robson charts were used to measure the distance and near contrast sensitivity at 1 m and 40 cm, respectively. The low contrast visual acuity was recorded at 5% and 2.5% contrast using LEA Symbols at 3 m. Overall, the mean ± SD, (95% CI) monocular distance and near CS were 1.75 ± 0.11 (1.76-1.75) logCS and 1.72 ± 0.10 (1.73-1.71) logCS, respectively. The mean LCVA at 5% and 2.5% contrasts were 0.20 ± 0.10 (0.21-0.20) logMAR and 0.39 ± 0.11 (0.40-0.39) logMAR, respectively. Distance and near CS gradually improved till the ages of 11 and 13, respectively, and then plateaued. Similarly, LCVA at 5% and 2.5% contrasts gradually improved till age ten before plateauing. The Coefficient of Repeatability (CoR) for CS was ±0.02 logCS for distance, ±0.05 logCS for near, and ±0.01 logMAR for both LCVA contrasts. The study provides age-specific normative values for distance and near CS, and LCVA in a cohort of children aged 5-15 years. These results are important to understand the impact of ocular conditions on CS in children and have utility in clinical evaluations.

Randomized clinical trial comparing customized corneal crosslinking: epi-on in high oxygen and epi-off in room air for keratoconus.

To compare clinical outcomes of customized transepithelial (epi-on) corneal crosslinking (CXL) in high oxygen and customized CXL with epithelial removal (epi-off) in room air for keratoconus (KC). Umeå University Hospital, Umeå, Sweden. Prospective, randomized, single-masked, intraindividually comparing study. 32 participants with bilateral progressive KC were treated with bilateral customized topography-guided CXL, 30 mW/cm 2 ; 7.2 to 15 J/cm 2 and were randomized to epi-on in one eye (32 eyes) and epi-off in the fellow eye (32 eyes). Uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), maximal keratometry (Kmax), subjective ocular discomfort, low-contrast visual acuities (LCVAs) at 10% and 2.5% contrast, ocular and anterior corneal wavefront aberrations, manifest refractive spherical equivalent, endothelial cell count (ECC), and adverse events were assessed through 24 months. Both treatments showed improvements at 24 months in UDVA; -0.16 ± 0.24 ( P < .001) and -0.13 ± 0.20 logMAR ( P = .006), respectively, CDVA; -0.10 ± 0.11 ( P < .001) and -0.10 ± 0.12 ( P = .001), Kmax; -1.74 ± 1.31 ( P < .001) and -1.72 ± 1.36 D ( P < .001). LCVA 10% improved for both protocols ( P < .001), but LCVA 2.5% improved for epi-on CXL only ( P = .001). ECC was unaltered, and no adverse events occurred. The epi-on eyes had significantly less discomfort symptoms during the whole first week posttreatment ( P < .05). High-oxygen customized epi-on CXL is a viable alternative to room air customized epi-off CXL, with faster improvements in CDVA and LCVA and less early ocular discomfort.

Influence of midday removal and re-application of a scleral lens on fluid reservoir thickness, pre-lens tear film quality and visual acuity

PurposeTo investigate whether the midday removal and re-application of scleral lenses (SL) influences fluid reservoir (FR) thickness, pre-lens tear film quality and visual acuity. MethodsTwo clinical experiments were conducted. A total of 49 keratoconic eyes were evaluated for Part1(tear film and visual acuity analysis) and 12 keratoconic eyes for Part2 (FR thickness analysis). All subjects were wearing 16.4 mm SL for more than 12-months. Tear Film Surface Quality (TFSQ) was evaluated with Medmont E300 at more than 120 min of SL wear, 10 min after SL removal (pre-corneal TFSQ) and 5 min after re-apply the same SL. High and Low Contrast Visual Acuity (HCVA and LCVA) were also assessed with the SL on eye (before and after re-application). For Part2, Anterior OCT (MOptim MOcean4000, China) measurements were taken with and without the SL (at the same time points of Part1) and three outcomes were evaluated: FR thickness, SL thickness (control measurement) and corneal thickness. ResultsRemoving and re-applying a SL had a statistically significant positive impact on TFSQ, with an improvement from 0.26 ± 011 to 0.16 ± 0.08 (p = 0.001). This was accompanied by a statistically significant improvement in LogMAR HCVA (from 0.10 ± 0.09 to 0.08 ± 0.08, p < 0.001) and LCVA (from 0.39 ± 0.13 to 0.36 ± 0.13, p < 0.001). Regarding Part2 of the study, a statistically significant increase in FR thickness was observed after SL re-application (from 223.64 ± 48.08 µm to 267.81 ± 80.03 µm, p = 0.007). No changes in corneal thickness were observed. ConclusionsMidday removal and re-application of a scleral lens positively impacted pre-lens tear film surface quality, although the observed improvement in visual acuity does not constitute a clinically significant change. Clinicians should consider that removing and reapplying a scleral lens may result in an overestimation of the fluid reservoir thickness, which could affect clinical assessments and treatment decisions.

Assessment of large-diameter and small-diameter SoftK specialty contact lenses for early-stage keratoconus.

Soft contact lenses may be a good alternative for early-stage keratoconus (KC) patients who do not tolerate rigid gas permeable (RGP) lenses due to ocular discomfort or complications. This prospective study compared outcomes obtained after 2 weeks of wearing two types of soft silicone hydrogel contact lenses for keratoconus that varied in their diameter and central thickness (cc). Patients with Amsler-Krumeich grades I or II KC were fitted with small-diameter (14.2 or 14.8 mm) SoftK (SD-SoftK, cc = 0.48 mm) and large-diameter (17 mm) SoftK (LD-SoftK, cc = 0.60 mm) lenses, each worn for 2 weeks in a crossover design. Low (10%;10VA) and high (100%;100VA) contrast visual acuity, contrast sensitivity (CS, Pelli-Robson), higher order aberrations (HOAs, Visionix Vx130), the number of trial lens modifications during fitting and the subjectively preferred lens were compared using Friedman tests with post-hoc analysis. Forty eyes (N = 20, 10 males, mean age: 39.0 ± 9.9 years, range: 23-55 years) were examined. Their habitual median (interquartile1, interquartile3) 10VA (LogMAR), 100VA (LogMAR) and CS (LogCS) were 0.52 (0.30, 0.50), 0.14 (0.10, 0.15) and 1.35 (1.35, 1.50), respectively. For the SD-SoftK condition, the values were 0.23 (0.17, 0.30), 0.02 (0.00, 0.05) and 1.50 (1.50, 1.65), respectively. For the LD-SoftK condition, the respective values were 0.36 (0.27, 0.44), 0.09 (0.05, 0.13) and 1.50 (1.50, 1.60). SD-SoftK lenses significantly improved 10VA compared with habitual and LD-SoftK. SD-SoftK also significantly improved CS compared with habitual, but not LD-SoftK. LD-SoftK significantly improved spherical aberration compared with uncorrected (0.03 ± 0.10 μ vs. 0.07 ± 0.13 μ) but not SD-SoftK (0.04 ± 0.07 μ). Both lenses required a mean of 1.5 modifications prior to final lens fitting. Fewer adverse events were seen with SD-SoftK (N = 3) compared with LD-SoftK (N = 8), and 75% of participants preferred SD-SoftK lenses. SD-SoftK lenses were preferred by 75% of subjects, were associated with fewer adverse events and significantly improved 10VA compared with LD-SoftK lenses. SD-SoftK lenses also significantly improved CS compared with the habitual correction, but this did not differ significantly from the LD-SoftK lenses.

Disease Course of Clinically Isolated Optic Neuritis.

Optic neuritis is the most common optic neuropathy in young adults and a frequent manifestation of multiple sclerosis. Its clinical course is pertinent to the design of visual pathway neuroprotection trials. This is a secondary analysis of longitudinal data from the TONE trial, which included 103 patients from 12 German academic tertiary centers with acute unilateral optic neuritis as a clinically isolated syndrome and baseline high-contrast visual acuity <0.5 decimal. Patients were randomized to 1,000 mg methylprednisolone i.v./d plus either erythropoietin (33,000 IU/d) or placebo (saline solution) for 3 days. They were followed up at standardized intervals with a battery of tests including high-contrast visual acuity, low-contrast letter acuity, contrast sensitivity, visual fields, visual evoked potentials, and retinal optical coherence tomography. At 6 months, participants answered a standardized questionnaire on vision-related quality of life (NEI-VFQ 25). We describe the disease course with mixed-effects piecewise linear models and calculate structure-function correlations using Pearson r. Because erythropoietin had no effect on the visual system, we use pooled (treatment-agnostic) data. Patients experienced initial rapid and then decelerating improvements of visual function with thinning of inner and thickening of outer retinal layers. At 6 months, visual parameters were positively correlated with inner and negatively correlated with outer retinal thickness changes. Peripapillary retinal nerve fiber layer thinning predominantly occurred in sectors without previous swelling. At 6 months, macular ganglion cell and inner plexiform layer thinning was weakly correlated with the P100 peak time (r = -0.11) and moderately correlated with the amplitude of visual evoked potentials (r = 0.35). Only functional outcomes were at least moderately correlated with vision-related quality of life. The longitudinal data from this large study cohort may serve as a reference for the clinical course of acute optic neuritis. The pattern of correlation between visual evoked potentials and inner retinal thinning may argue that the latter is mostly due to ganglion cell loss, rather than dysfunction. Visual pathway neuroprotection trials with functional outcomes are needed to confirm that candidate drugs will benefit patients' vision-related quality of life. ClinicalTrials.gov, NCT01962571.

Efficacy and safety of artificial tears containing Artemia salina extract with dinucleotides for dry eye

ABSTRACT Clinical relevance This clinical trial was conducted as part of the marketing procedures for a medical device comprising artificial tears containing Artemia salina extract with dinucleotides. These molecules previously demonstrated secretagogue properties by enhancing the production of aqueous, mucinous, and lipidic components of the tears. Background After confirming the efficacy of artificial tears containing Artemia salina extract in an animal model, this study proceeded to evaluate their efficacy and safety on dry eye participants. Methods A randomised controlled clinical trial was performed on 36 dry eye participants (41.6 ± 20.6 years). Half of the participants were treated with saline solution as a placebo for four weeks, while the other half were treated with artificial tears containing Artemia salina, randomly assigned. After a wash-out period of two weeks, the treatments were crossed for another four weeks. Participants were assessed at baseline and after one week, two weeks, and four weeks. Efficacy variables were: eye dryness frequency (primary), eye comfort, visual satisfaction, tear secretion, tear break-up time, corneal staining, conjunctival staining, and conjunctival hyperaemia. Safety variables were: high- and low-contrast visual acuity, intraocular pressure, and eye fundus images analysis. Results Compared with the baseline, the saline solution showed no significant changes in any of the studied variables after four weeks of treatment (p ≥ 0.05). However, the topical instillation of the artificial tears with Artemia salina for four weeks significantly improved eye dryness frequency (p = 0.014) and corneal staining (p = 0.010). No systemic or ocular adverse events were reported during the clinical trial. Conclusion The topical instillation of artificial tears containing Artemia salina in mild to moderate dry eye participants for four weeks slightly improved their symptoms related to eye dryness frequency and reduced corneal damage, with no undesirable side effects observed.

Daytime Changes in Tear Film Parameters and Visual Acuity with New-Generation Daily Disposable Silicone Hydrogel Contact Lenses-A Double-Masked Study in Symptomatic Subjects.

This prospective, double-masked, contralateral study aimed to analyze and compare daytime changes in pre-lens tear film (PLTF) stability and optical quality in symptomatic subjects wearing two contact lenses (CL). A secondary goal was to assess the performance of the PLTF by using dynamic topography techniques and analyzing surface asymmetry and irregularity indexes (SAI and SRI, respectively). Measurements were conducted on 20 symptomatic subjects (OSDI score > 13). Participants were fitted contralaterally and randomly with spherical Delefilcon A and Stenfilcon A CLs and underwent a series of measurements over 3 consecutive days: three in the morning (after 1-2 h of CL wear) and three in the afternoon (after 7-9 h of CL wear). High- and low-contrast visual acuity (HCVA and LCVA, respectively), pre-lens NIBUT, and dynamic topography were assessed. The contralateral fit of the two lenses allowed a direct and better comparison between them since they were exposed to the same conditions during the day. Consequently, both lenses demonstrated similar performance in HCVA, LCVA, and PLTF stability, with no statistically significant differences between them, although some fluctuations were observed throughout the day. Dynamic topography proved sensitive in evaluating temporal changes in the PLTF. The SRI index showed greater sensitivity to topographic changes due to lacrimal destabilization, making it potentially valuable for evaluating dry eye patients.

Low-contrast visual acuity test is associated with central inflammation and predicts disability development in newly diagnosed multiple sclerosis patients.

The visual system is a prominent site of damage in MS since the earliest phases of the disease. Altered low-contrast visual acuity (LCVA) test has been associated with visual impairment and retinal degeneration, predicting medium- and long-term disability. However, it is unclear whether LCVA may also represent a reliable measure of neuroinflammation and a predictor of disease evolution in the very early stages of MS. We explored in a group of 76 consecutive newly diagnosed relapsing-remitting MS (RR-MS) patients without visual impairment or altered visual evoked potentials, the association between LCVA scores at 2.5% and 1.25% and clinical characteristics, including prospective disability evaluated after 1- and 2 years of follow-up. Associations between LCVA and the CSF levels of IL-10 at diagnosis were also analyzed. A negative correlation was found between LCVA at 2.5% and Expanded Disability Status Scale (EDSS) evaluated at first (Spearman's Rho = -0.349, p = 0.005, n = 62) and second year (Spearman's Rho = -0.418, p < 0.001, n = 62) of follow-up, and negative correlations were found with Multiple Sclerosis Severity Score (MSSS) at first (Spearman's Rho = -0.359, p = 0.004, n = 62) and second year (Spearman's Rho = -0.472, p < 0.001, n = 62). All the data were confirmed by a mixed effect model, considering other clinical variables. A positive correlation was found between the CSF concentrations of IL-10 and LCVA at 2.5% (Spearman's Rho = 0.272, p = 0.020, n = 76), and 1.25% (Spearman's Rho, = 0.276, p = 0.018, n = 76), also evidenced in a linear regression. In MS patients at diagnosis, altered LCVA may be associated with CSF inflammation and represent a useful parameter to identify patients with worse disease course.

Effect of obesity, dietary habits and physical exercise on visual acuity in healthy young subjects

Aims/Purpose: To explore the effect of obesity, dietary habits, and physical exercise on high‐contrast visual acuity (HC‐VA) and low‐contrast visual acuity (LC‐VA) in healthy young subjects.Methods: A cross‐sectional pilot study was performed in 64 apparently healthy subjects (mean 21.6 ± 2.2 years of age; 24 men and 40 women). Best‐corrected distance HC‐VA and LC‐VA were measured using logMAR letter charts. Weight, height, and waist circumference (WC) were measured, and body mass index (BMI) and waist‐to‐height ratio (WHtR) calculated. A lifestyle questionnaire was used to investigate weekly physical activity (sedentary, active, and very active), the intake of fruits and vegetables per day (0–1 serving, 2–4 servings and 5 or more servings) and the consumption of saturated fat per day (0–1 serving and 2–4 servings). In addition, systolic (SBP) and diastolic blood pressure (DBP) were measured, and cardiovascular risk (CVR) was calculated using the Framingham calculator.Results: Mean CVR was normal (3.07 ± 2.2%) and spherical equivalent was −0.55 ± 0.88 dioptres. 7.8% of the subjects was underweight, 57.8% had normal weight (18.5 ≤ BMI &lt; 25), 23.4% overweight (25 ≤ BMI &lt; 30), and 10.9% obesity. Abdominal obesity was normal (WHtR &lt; 0.5) in 76.5% and 23.4% had abdominal obesity (WHtR ≥ 0.5). WHtR and BMI were not significantly correlated with HC‐VA and LC‐VA. No significant differences were found in the means of HC‐AV and LC‐AV between the physical exercise groups and according to the daily intake of fruits and vegetables. In the group consuming higher servings of saturated fat, mean HC‐VA was 0.03 logMAR worse (p = 0.0474) and mean LC‐VA was 0.05 logMAR worse (p = 0.0068) than in the group that reported consuming lower servings of saturated fat.Conclusions: Obesity, physical exercise and fruit and vegetable consumption were not associated with HC‐VA and LC‐VA. Conversely, higher saturated fat intake was associated with worse HC‐VA and LC‐VA in young adults.

The Canadian Prospective Cohort Study to understand progression in multiple sclerosis: baseline characteristics.

Disease progression is observed across the spectrum of people with multiple sclerosis (MS) and identification of effective treatment strategies to halt progression remains one of the greatest unmet clinical needs. The Canadian Prospective Cohort Study to Understand Progression in MS (CanProCo) was designed to evaluate a wide range of factors associated with the onset and rate of clinical disease progression in MS and to describe the interplay between these factors. A prospective cohort study. CanProCo is a national, prospective, observational cohort study that has recruited 944 individuals from 5 large academic MS centers in Canada. Participants include people with radiologically isolated syndrome (RIS), early relapsing-remitting and primary progressive MS (RRMS, PPMS), and healthy controls (HCs). Annually, participants complete self-reported questionnaires, undergo clinical evaluation and, if clinically indicated, magnetic resonance images (MRIs) of the brain and cervical spinal cord; in a subset of participants (n = 399), blood, and research MRIs of the brain and cervical spinal cord are collected. Linkages to health administrative databases are available at three sites. Overall, 944 participants were recruited (53 HCs, 63 RIS, 751 RRMS, 77 PPMS). RIS and MS participants had a mean age of 39.0 years and 70.5% female. The mean time since diagnosis was 2.7 years. There were differences observed in the Expanded Disability Status Scale score and components of the MS performance test (walking speed test, manual dexterity test, processing speed test, and low-contrast visual acuity) between RIS and MS subtypes. Questionnaires revealed more symptoms of depression and anxiety and impaired physical and mental quality of life in people with RIS/MS versus HCs and differences across RIS/MS subtypes. Physical and mental neurological disability is prevalent even in the earliest stages of MS. Transdisciplinary approaches such as those used in CanProCo are needed to better characterize clinical progression in MS. Additional CanProCo results, including MRI, biological, and pharmaco-economic data will be forthcoming. Going forward, CanProCo's data sharing and collaborative vision will facilitate numerous global collaborations, which will inform the development and implementation of effective interventions for people with MS around the world.

Study of peripheral blur in retinal electrical activity

Aims/Purpose: The aim of this study was to evaluate changes in peripheral refraction by the use of a contact lens to control the progression of myopia. In addition, the response of electrophysiological activity in different areas of the retina with and without contact lens was also determined.Methods: We recruited 7 myopic individuals (23.71 ± 5.41 years) with refraction up to −4.50D (spherical equivalent), without eye pathologies and surgeries. Visual acuity was recorded, high and low contrast, with the updated refraction and with the Misight 1 Day contact lens. Peripheral refraction measurements were obtained using an open‐field autorefractometer. Multifocal electrophysiology measurements were performed binocularly with and without contact lens, with dilated pupil. Topography and aberrometry values were also recorded.Results: lens, peripheral refractions become significantly more myopic. The change in peripheral refraction induced at 30° Nasal is −0.66D. High Contrast Visual Acuity was always superior to Low Contrast VA in both conditions. The Misight 1 Day contact lens manifests a different behaviour along the anterior surface of the cornea. LC induces a significant increase in high‐order aberrations, especially in comatic aberrations, which increase three times their initial value.Conclusions: Regarding the electrophysiological response of the retina, with the use of the LC Misight 1 Day, it presented a greater implicit time and amplitude of the P1 component, in the superior temporal retina, these differences being statistically significant. The implicit time of the P2 component increased in the temporal retina and in the retinal area delimited by Rings 3, 4 and 5.

Visual quality assessment and comparison of two multifocal scleral lens designs

PurposeTo analyze the visual quality of a new multifocal scleral lens with a customized decentred optic zone compared to a conventional design by measuring visual acuity, contrast sensitivity function, stereopsis, subjective vision and comfort after one month of wear. MethodsNineteen presbyopic subjects were fitted with two multifocal scleral lens designs: a conventional multifocal and a customized decentred optical zone design. All subjects wore both scleral lens designs for one month with a two-week washout period. The main variables evaluated included high and low-contrast visual acuity under photopic and mesopic light conditions, binocular defocus curves, contrast sensitivity function and a visual analogue scale (VAS) for subjective vision and comfort. ResultsComparing the two scleral lens designs, statistically significant differences in visual acuity were found, highlighting the improvement in more than one chart line (6 letters) for low contrast near tests under photopic light conditions with the decentred optics lens design. VAS questionnaire scores also showed a significant improvement in distance and overall subjective vision with the decentred optics lenses. Contrast sensitivity function showed an improvement with decentred multifocal lenses at all spatial frequencies measured, being statistically significant for 12 cycles per degree. No differences in stereoacuity were found. ConclusionMultifocal scleral lenses with a customized decentred optical zone proved to be a promising refractive correction in presbyopic subjects after one month of wear, offering good comfort and visual quality under photopic and mesopic light conditions.