Pilot Study Assessing the Safety and Acceptance of a Novel Virtual Reality System to Improve Visual Function.

PURPOSE: To assess the feasibility of the clinical use of a novel Virtual Reality (VR) training software designed to be used for active vision therapy in amblyopic patients by determining its preliminary safety and acceptance on the visual function of healthy adults. METHODS: Pilot study enrolling 10 individuals (3 men, 7 women, mean age: 31.8 ± 6.5 years) with a best-corrected visual acuity (BCVA) of ≥ .90 (decimal) in both eyes were evaluated before and after 20 minutes of exposure to the NEIVATECH VR system using the HTC Vive Pro Eye head mounted display. Visual function assessment included near (40 cm) and distance (6 m) cover test (CT), stereopsis, binocular accommodative facility (BAF), near point of convergence (NPC), near point of accommodation (NPA), accommodative-convergence over accommodation (AC/A) ratio and positive and negative fusional vergences. Safety was assessed using the VR Sickness Questionnaire (VRSQ) and acceptance using the Technology Acceptance Model ;(TAM). Changes in all these variables after VR exposure were analyzed. RESULTS: Short-term exposure to the NEIVATECH VR system only induced statistically significant changes in distance phoria (p = .016), but these changes were not clinically relevant. No significant changes were observed in VRSQ oculo-motricity and disorientation scores after exposure (p = .197 and .317, respectively). TAM scores showed a good acceptance of the system in terms of perceived enjoyment and perceived ease of use, although some concerns were raised in relation to the intention-to-use domain. CONCLUSION: Exposure to the NEIVATECH VR system does not seem to adversely affect the visual function in healthy adults and its safety and acceptance profile seems to be adequate for supporting its potential use in other populations, such as amblyopic patients.

Safety, Efficacy, and Visual Performance of an Orthokeratology Lens with Increased Compression Factor.

The aim was to evaluate the safety, efficacy, and visual performance of an orthokeratology lens with an increased compression factor (ICF) of 1.25 D in a 3-month follow-up. Thirty-six myopic patients (5 males and 31 females; 24.2 ± 5.8 years) were fitted with Alexa AR (Tiedra Farmacéutica S.L., Madrid, Spain) contact lenses (CLs) and twenty participants finished the follow-up. Visual acuity (VA), subjective refraction, primary spherical and primary coma aberrations, keratometry, central pachymetry, and ocular surface evaluation were performed at baseline and after 1 night, 1 week, 1 month, and 3 months of CL wear. The differences among visits were analyzed using a repeated-measures analysis of variance or the Friedman test. The spherical equivalent decreased (p ≤ 0.005), and the uncorrected VA improved (p < 0.001) until the first week. Corneal and ocular aberrations showed a significant increase (p ≤ 0.02). A significant decrease (p < 0.001) was found for keratometry values. No significant changes were observed in either central pachymetry or ocular surface parameters among study visits. In conclusion, an orthokeratology CL with an ICF of 1.25 D provides good safety, efficacy, and visual performance in a 3-month follow-up. Seven days of orthokeratology wear are enough to achieve the full myopic compensation, resulting in satisfactory VA.

Orthokeratology effect on the corneoscleral profile: Beyond the bull's eye.

PURPOSE: To assess the impact of 3 months of orthokeratology (ortho-k) contact lenses (CLs) for myopia correction on the corneoscleral profile, as changes in scleral geometry could serve as indirect evidence of alteration in the corneal biomechanical properties. METHODS: Twenty subjects (40 eyes) were recruited to wear ortho-k lenses overnight; however, after discontinuation (two CL fractures, one under-correction and two non-serious adverse events), 16 subjects (31 eyes) finished a 3-month follow-up. Corneoscleral topographies were acquired using the Eye Surface Profiler (ESP) system before and after 3 months of lens wear. Steep (SimKs) and flat (SimKf) simulated keratometry and scleral sagittal height measurements for 13-, 14- and 15-mm chord lengths were automatically calculated by the ESP software. Additionally, sagittal height and slope were calculated in polar format from 21 radii (0-10 mm from the corneal apex) at 12 angles (0-330°). Linear mixed models were fitted to determine the differences between visits. RESULTS: SimKs and SimKf were increased significantly (p ≤ 0.02). The sagittal height in polar format increased significantly (p = 0.046) at a radius of 2.5 mm for 150°, 180°, 210° and 240° orientations and at a radius of 3.0 mm for 210°. Additionally, the slope in polar format significantly decreased (p ≤ 0.04) at radii ranges of 0.0-0.5, 0.5-1.0 and 1.0-1.5 mm for multiple angles and at a radii range of 5.0-5.5 mm for 90°. It also increased significantly (p ≤ 0.045) at a radii range of 1.5-2.0 mm for 30° and at radii ranges of 2.0-2.5, 2.5-3.0 and 3.0-3.5 mm for multiple angles. No significant changes were found for any parameter measured from the scleral area. CONCLUSIONS: Three months of overnight ortho-k lens wear changed the central and mid-peripheral corneal geometry as expected, maintaining the peripheral cornea and the surrounding sclera stability.

Professional perspective and practice patterns of vision therapy in Spain.

CLINICAL RELEVANCE: An analysis of the professional perspective of vision therapy (VT) by eye care professionals allows understanding the current controversies about this therapeutic option of which aspects can be improved for its correct application in clinical practice. BACKGROUND: The aim of the current study was to analyse the perception of VT and the clinical protocols in this context followed among optometrists and ophthalmologists in Spain. METHODS: A cross-sectional survey among Spanish optometrists and ophthalmologists. Google Forms tool was used to collect data via an online questionnaire divided into 4 sections (40 questions): consent to participate, demographic characteristics, opinion of the professional perspective of VT, and protocols. Only one submission from each email address was permitted by the survey tool. RESULTS: A total of 889 Spanish professionals answered (age, 25-62 years): 848 optometrists (95.4%) and 41 ophthalmologists (4.6%). VT was considered as a scientifically-based procedure by 95.1% of participants, but its recognition and prestige was considered as low. The main cause reported for this was bad reputation or perception of placebo therapy (27.3%). The main indication of VT according to the surveyed professionals was convergence and/or accommodation problems (72.4%). Significant differences were found in the perception of VT among optometrists and ophthalmologists (p ≤ 0.027). A total of 45.3% of professionals reported performing VT in their current clinical practice. A combination of training sessions in office and home was regularly prescribed by 94.5% of them, but with significant variability in the duration of such sessions. CONCLUSIONS: VT is perceived by Spanish optometrists and ophthalmologists as a therapeutic option with scientific basis, but with limited recognition and prestige, although with more negative perception among ophthalmologists. A great variability was found in the clinical protocols followed between specialists. Future efforts should be focused on creating internationally recognised evidence-based protocols for this therapeutic option.

Reliability and Agreement of Keratometry Measurements Obtained With Eye Surface Profilometry and Partial Coherence Interferometry.

PURPOSE: The aim of this study was to assess the repeatability of keratometry parameters obtained using the Eye Surface Profiler (ESP) system and their agreement with the IOL Master 500 device. METHODS: Seventy-one eyes of 71 healthy participants were evaluated. Three repeated measurements were performed using the ESP system. Simulated keratometry in the flat (SimKf) and steep (SimKs) meridians, astigmatism, and axis were obtained. The same parameters were measured using the IOL Master 500 device. The J0 and J45 vector components of the astigmatism were calculated. The intrasession repeatability was analyzed using within-subject SD (Sw) and intraclass correlation coefficient (ICC). Agreement was assessed using paired statistical tests and the Bland-Altman method. RESULTS: The Sw was 0.07 mm, 0.04 mm, 0.51 D, 0.33 D, and 0.22 D, and the ICC was 0.96, 0.98, 0.74, 0.61, and 0.55 for SimKf, SimKs, astigmatism, J0, and J45, respectively. The mean difference and limits of agreement when comparing the ESP system with the IOL Master 500 device were 0.37 mm (0.08/0.66) for SimKf ( P < 0.001), 0.18 mm (0.00/0.35) for SimKs ( P < 0.001), -0.93 D (-2.42/0.56) for astigmatism ( P < 0.001), 0.51 D (-0.22/1.24) for J0 ( P < 0.001), and 0.06 D (-0.48/0.60) for J45 ( P = 0.09). CONCLUSIONS: The ESP system provides consistent values for simulated keratometry, showing moderate consistency for astigmatism parameters. Contact lens practitioners should be aware that the ESP system and IOL Master 500 device provide different simulated keratometry from a clinically viewpoint.

Efficacy of Soft Contact Lenses for Myopia Control: A Systematic Review.

PURPOSE: To summarize and analyze critically the scientific evidence focused on the effectiveness of the use of hydrophilic contact lenses (HCLs) in myopia control, as well as their impact on visual quality and the involvement on the accommodative and binocular function. METHODS: This systematic review was developed selecting all original studies which evaluated HCLs for myopia control with follow-up of at least 1 year. Eligible randomized controlled trials (RCTs) were retrieved from PubMed MEDLINE and Scopus. Methodological quality of the studies was assessed using the Critical Appraisal Skills Programme (CASP) for RCTs. RESULTS: The search provided a total of 276 articles, selecting 13 according to the inclusion and exclusion criteria. The majority of studies evaluating the effectiveness of HCL showed a good efficacy in myopia progression, providing a good quality of vision. The quality of these studies was found to be suitable according to the CASP tool. The accommodative and binocular function with these lenses was evaluated in few studies, reporting a trend to an increase in the accommodative response and exophoria in near vision, while maintaining good level of stereopsis. Aberrometry and pupillometry were only studied in one trial, in which the authors did not find changes in these variables after the use of a myopia control HCL. CONCLUSIONS: There is a strong evidence about the effectiveness of different HCLs designs for slowing down myopia progression in children, providing all of them good levels of visual quality. However, there is still poor evidence about changes in accommodation and binocular function, as well as in pupil size and aberrometry with myopia control HCLs, being necessary more studies focused on this issue.

Dynamic Pupillary Response in Multiple Sclerosis Patients with and without Optic Neuritis.

Multiple sclerosis (MS) is a neurodegenerative disease that affects the central nervous system which produces abnormalities in visual function, as disturbed pupillary responses, even after an episode of optic neuritis (ON). The aim was to assess different parameters of the pupillary response in MS subjects with and without ON. Therefore, 24 eyes of healthy age-matched subjects were included, 22 eyes of subjects with MS (MS group), and 13 subjects with MS with previous ON (MSON group). Pupillary parameters (ratio pupil max/min; latency; velocity and duration; contraction and dilation; and amplitude of contraction) were recorded with the MYAH topographer. Statistical analysis was performed by IBM SPSS Statistics, and parametrical or non-parametrical tests were used according to the normality of the data. MS patients did not significantly differ from healthy patients in any of the parameters analyzed (p > 0.05). Only patients with previous ON were different from healthy patients in the amplitude (40.71 ± 6.73% vs. 45.22 ± 3.29%, respectively) and latency of contraction (0.35 ± 0.13 s vs. 0.26 ± 0.05 s, respectively). The time to recover 75% of the initial diameter was abnormal in 9% of the MS subjects and 12% of MSON subjects. Based on the results of this study, the contraction process, especially latency and amplitude, was found to be affected in subjects with MS and previous ON. The degree of disability and the relation of the decrease in pupil response with other indicators of MS disease should be further investigated considering other comorbidities such as ON in the affection.

Binocular vision measurements with a new online digital platform: comparison with conventional clinical measures.

CLINICAL RELEVANCE: New digital systems are being developed for evaluating different aspects of the visual function, such as binocularity, and it is important to know their real performance in clinical practice in order to use them appropriately. BACKGROUND: The aim was to compare binocular vision measures obtained with an online digital platform with conventional measures using prisms and printed tests. METHODS: Prospective study enrolling 49 healthy patients (mean age: 35.5 ± 13.6 years). A complete visual examination was performed including measurement of near phoria (cover test), negative fusional vergence (NFV) and positive fusional vergence (PFV) ranges (prism bar), and stereopsis (24 patients Randot Stereo Test and 25 patients TNO Random Dot Test 19th edition). These same parameters were also measured with the Bynocs system (Kanohi Eye Pvt Ltd). Bland - Altman plots were used to analyse the agreement between methods. RESULTS: Digital measurement of near phoria was significantly lower than that obtained with the cover test, with a median difference (MD) of 4.71 (-0.07-20.07) prism dioptres (pd) (p < 0.001). No significant differences were found between Bynocs and prism bar methods in NFV break (MD 2.00, range -21-26 pd, p = 0.584) and recovery points (MD 0.00, range -16-24 pd, p = .571). Near PFV were significantly lower with Bynocs (break: MD -9.00, range -38-12 pd; recovery: MD -14.00, range -43-20 pd; p < 0.001). Bynocs stereoacuity threshold was significantly lower than that obtained with TNO (p = 0.004), but significantly higher compared to Randot (p < 0.001). Large and clinically relevant confidence intervals for the comparison between digital and conventional measures were detected in Passing-Bablok analysis. CONCLUSIONS: Digital measures of near phoria, NFV, PFV, and stereopsis with the Bynocs platform cannot be used interchangeably with conventional measures. The normal ranges of normality for this new tool are defined.

Efficacy of Presbyopia-Correcting Contact Lenses: A Systematic Review.

PURPOSE: To analyze critically the clinical trials on presbyopia correction with contact lenses (CLs) to investigate the quality of the research performed. METHODS: A search was performed in PubMed database on clinical trials evaluating the efficacy of the presbyopia correction with different CLs, including multifocal or simultaneous vision contact lenses (MCLs). After a comprehensive analysis of the relevant publications found, quality assessment of such publications was performed by means of Critical Appraisal Skills Programme checklist tool according to the five types of evaluations: MCL versus spectacles, MCL versus pinhole CLs, MCL versus monovision, comparison between MCL designs, and MCL versus extended depth of focus CLs. RESULTS: A total of 16 clinical trials were selected for evaluation. All evaluated studies addressed a clearly focused research question and were randomized, with a crossover design in most of the cases. Blinding was not possible in all cases due to the physical appearance of some of the CLs evaluated (pinhole or hybrid designs). Most of studies analyzed reported outcomes with complete data, providing the statistical tests used and the P -values, but some of the authors did not provide the statistical power associated to the sample size evaluated. The small sample size in some trials as well as the scarce information about the effect of addition on visual performance was the main limitations found in the peer-reviewed literature revised. CONCLUSIONS: There is a high-quality scientific evidence supporting the use of presbyopia-correcting CLs, with several randomized controlled clinical trials conducted to this date.

Randomised placebo-controlled clinical trial evaluating the impact of a new visual rehabilitation program on neuroadaptation in patients implanted with trifocal intraocular lenses.

PURPOSE: To evaluate the efficacy of a new visual training program for improving the visual function in patients implanted with trifocal intraocular lenses (IOLs). METHODS: Randomised placebo-controlled clinical trial enrolling 60 subjects (age, 47-75 years) undergoing cataract surgery with implantation of trifocal diffractive IOL. Home-based active visual training was prescribed immediately after surgery to all of them (20 sessions, 30 min): 31 subjects using a serious game based on Gabor patches (study group) and 29 using a placebo software (placebo group). Visual acuity, contrast sensitivity (CS), and perception of visual disturbances (QoV questionnaire) were evaluated before and after training. Likewise, in a small subgroup, resting-state functional magnetic resonance imaging (rs-fMRI) analysis was performed. RESULTS: No significant differences were found between groups in compliance time (p = 0.70). After training, only significant improvements in monocular uncorrected intermediate visual acuity were found in the study group (p ≤ 0.01), although differences between groups did not reach statistical significance (p ≥ 0.11). Likewise, significantly better binocular far CS values were found in the study group for the spatial frequencies of 6 (p = 0.01) and 12 cpd (p = 0.03). More visual symptoms of the QoV questionnaire experienced a significant change in the level of bothersomeness in the study group. Rs-fMRI revealed the presence significant changes reflecting higher functional connectivity after the training with the serious game. CONCLUSIONS: A 3-week visual training program based on the use of Gabor patches after bilateral implantation of trifocal diffractive IOLs may be beneficial for optimising the visual function, with neural changes associated suggesting an acceleration of neuroadaptation. Trial registration ClinicalTrials.gov, NCT04985097. Registered 02 August 2021, https://clinicaltrials.gov/(NCT04985097 ).

Amblyopia Treatment through Immersive Virtual Reality: A Preliminary Experience in Anisometropic Children.

The use of digital devices provides a wide range of possibilities for measuring and improving visual function, including concepts such as perceptual learning and dichoptic therapy. Different technologies can be used to apply these concepts, including, in recent years, the introduction of virtual reality (VR) systems. A preliminary experience in treating anisometropic amblyopia through an immersive VR device and using prototype software is described. A total of 4 children were treated by performing 18 office-based sessions. Results showed that distance VA in amblyopic eyes remained constant in two subjects, whereas the younger subjects improved after the training. Near VA improved in three subjects. All subjects showed an increase in the stereopsis of at least one step, with three subjects showing a final stereopsis of a 60 s arc. A total of three subjects showed an increase of approximately 0.5 CS units for the spatial frequency of 3 cpd after the training. Results from this pilot study suggest that visual training based on perceptual learning through an immersive VR environment could be a viable treatment for improving CS, VA, and stereopsis in some children with anisometropic amblyopia. Future studies should support these preliminary results.

Visual perception alterations in COVID-19: a preliminary study.

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

Modeling and Prediction of the Immediate and Short-Term Effect of Myopic Orthokeratology.

PURPOSE: To characterize the clinical changes occurring in the initial phase of the orthokeratology (OK) treatment for myopia correction, developing a model of prediction of the refractive changes in such phase. METHODS: Prospective study enrolling 64 eyes of 32 patients (range, 20-40 years) undergoing myopic OK treatment with the reverse geometry contact lens CRT (Paragon Vision Science). Changes in uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), refraction, corneal topography, ocular aberrations, and corneal epithelial thickness were evaluated during the first hour of OK lens wear and after 1 week of OK treatment. Multiple linear regression analysis was used to obtain a model to predict the short-term refractive effect of OK. RESULTS: The UCVA improved at each visit, reaching normal visual acuity values after a week (P<0.001) of OK treatment, which was consistent with the significant spherical equivalent (SE) reduction and central flattening (P<0.001). Multiple linear regression analysis revealed that one night change in refraction (ΔR×1N) could be predicted according to the following expression (P<0.001, R2=0.686): ΔR×1N=1.042+0.028×Age+1.014×BCET (baseline central epithelium thickness)-0.752×BKm (baseline mean keratometry)-1.405×BSE (baseline SE)+1.032×ΔR×1 h (change in SE after 1 hr of OK lens use). Similarly, a statistically relevant linear relationship was obtained for predicting the refractive change after 1 week (ΔR×1W) of OK use (P<0.001, R2=0.928): ΔR×1W=3.470-1.046×BSE-1.552×BBCVA (baseline BCVA)-0.391×BKm+0.450×ΔR×1 h. CONCLUSIONS: The immediate and short-term refractive effects of myopic OK with the reverse geometry contact lens CRT can be predicted with enough accuracy from baseline and first trial visits data.

Clinical outcomes of presbyopia correction with the latest techniques of presbyLASIK: a systematic review.

The aim of this study was to collect the scientific literature on the correction of presbyopia with laser in situ keratomileusis (presbyLASIK) in last years and to analyse the quality of such scientific evidence using a validated methodology for conducting a systematic review. A total of 42 articles were initially identified, but after applying the selection criteria and an additional manual search a total of 23 articles were finally included: 2 non-randomized controlled clinical trials (NRCT) and 21 case series. Quality assessment of NRCTs and case series was performed with the ROBINS-I and the 20-criterion quality appraisal checklist defined by Moga et al. (IHE Publ 2012), respectively. For NRCT, the risk of bias was moderate in one study and serious in the other NRCT, being the main sources of risk, the domains related to confounding, selection of participants and measurement of outcomes. For case series studies, the main source of risk of bias was subjects not entering the study at the same point of the conditions (different levels of presbyopia). Likewise, a significant level of uncertainty was detected for the following items: consecutive recruitment of patients, blinding of outcome assessors to the intervention that the patient received, and conclusions of the study not supported by the results. Research on presbyLASIK to this date is mainly focused on case series generating a limited level of scientific evidence. The two NRCTs identified only demonstrated the potential benefit of combining the multiaspheric profile with some level of monovision in the non-dominant eye.

Clinical Validation of a New Optical Biometer for Myopia Control in a Healthy Pediatric Population.

To assess the clinical validation of the Myah device in a pediatric population by evaluating the repeatability of biometric evaluations and analyzing its agreement with the Myopia Master system. A total of 51 children (51 eyes) were enrolled. Repeated measurements of flat (K1) and steep (K2) corneal radius, white-to-white (WTW) distance and axial length (AL) were performed with the Myah device. The same parameters were obtained from a subgroup (30 eyes) with the Myopia Master for the agreement analysis. The repeatability was assessed using the intrasubject standard deviation (Sw) and the intraclass correlation coefficient (ICC). The agreement was analyzed using the Bland−Altman method and the paired Student t-test. The Sw was 0.018 D, 0.021 D, 0.071 mm and 0.017 mm for K1, K2, WTW and AL, respectively (ICC ≥ 0.971). The mean difference and limits of agreement when comparing instruments were −0.013 (−0.102/0.077) for K1 (p = 0.16), −0.058 (−0.127/0.012) for K2 (p < 0.001), 0.151 (−0.370/0.673) for WTW (p < 0.001) and 0.030 (−0.091/0.151) for AL (p = 0.009). In conclusion, the Myah device provides consistent measurements of corneal radius, WTW distance and AL in a healthy pediatric population, validating their usefulness in clinical practice. These measurements could be used interchangeably with those provided by the Myopia Master device, although with some caution.

Long-Term Efficacy of the Combination of Active Vision Therapy and Occlusion in Children with Strabismic and Anisometropic Amblyopia.

This retrospective study was conducted to evaluate the efficacy of the combined treatment of occlusion and active vision therapy in a total of 27 amblyopic children, including 14 strabismic and 13 anisometropic cases. For such purpose, changes in distance and near visual acuity as well as in the binocular function was evaluated during a two-year follow-up. In both amblyopia groups, significant improvements were found in distance and near visual acuity in the non-dominant eye (p < 0.001). In the strabismic amblyopia group, the percentage of patients with binocular function score (BF) > 3.3 decreased significantly from a baseline value of 64.3% to a two-year follow-up value of 7.1% (p < 0.001). In the anisometropic amblyopia group, this percentage also decreased significantly from a baseline value of 15.4% to a two-year follow-up value of 0.0% (p < 0.001). No recurrences were observed in the anisometropic amblyopia group, whereas recurrence occurred in two cases of the strabismic amblyopia group after finishing the vision rehabilitation process. In conclusion, the combined approach of the treatment evaluated is efficacious for providing an improvement in visual acuity and binocular function in both anisometropic and strabismic amblyopia, which was maintained over time.

Developmental Eye Movement (DEM) and King-Devick (K-D) Performance in Multiple Sclerosis.

Eye movement disorders have been reported in patients with multiple sclerosis (MS) as saccadic disturbances. Several methods have been described for the assessment of saccades, including the K-D and DEM tests. The performance of these tests also involves attention, language, and other brain areas which have been reported to be altered in MS patients. The aim of the study was to determine how developmental eye movement (DEM) and King-Devick (K-D) tests are affected in MS-patients. It was also to analyze whether a resolved episode of optic neuritis (ON) has a negative influence. Subjects with MS showed worse outcomes (higher times) in DEM test (72 (26) s and a K-D test (56 (22) s compared to healthy subjects (64 (7) s and 55 (11) s, respectively). However, a previous ON episode did not worsen the MS-times of DEM (80 (33) s or of K-D (62 (33) s. Horizontal saccades with the DEM showed differences between subjects with MS (with and without ON) and healthy ones (p < 0.05), whereas no such differences were found in the vertical saccades. According to the DEM instructions, MS patients would present heterogeneous oculomotor and non-visual disturbances. Regarding the K-D test, only the third card (the most complex one) showed differences (p < 0.05) between groups. These tests can capture impairment of attention, language, and other areas that correlate with suboptimal brain function in addition to the oculomotor dysfunctions present in subjects with MS.

Fixation Pattern Analysis With Microperimetry In Strabismic Subjects: A Pilot Study.

OBJECTIVE: Strabismic amblyopia is a motor and sensory deficit produced by unilateral constant strabismus and binocular imbalance. The aim of this study was to analyse the retinal fixation pattern using microperimetry in subjects with strabismus with and without amblyopia associated, and to compare the results with those obtained in normal subjects. METHODS: Prospective comparative study conducted at the Optometric Clinic of the University of Valencia and Oftalvist Alicante (Spain) including 46 eyes with ages from 3 to 16 years. Three groups were differentiated: patients with persistent strabismic amblyopia after occlusion and active therapy (group 1, 7 patients, 30.4%), strabismic patients without amblyopia (group 2, 8 patients, 34.8%) and a control group (8 patients, 34.8%). Microperimetric analysis was performed with the Macular Integrity Assessment (MAIA) system (Centervue, Padova, Italy) and using the following parameters: P1% and P2% fixation indexes, and the ellipse areas (BCEA) for 95% and 63% of points for the first 10 seconds, 30 seconds, 60 seconds, and the total examination time. RESULTS: Significant differences were found between groups for dominant eyes in P2 calculated at 30 (p = .04) and 60 seconds (p = .03). However, these differences between groups in non-dominant eyes were close to statistical significance (p = .07 and p = .08). Specifically, P2 was significantly lower in group 1 compared to control group (p = .01). Best corrected visual acuity was found to be significantly correlated (p ≤ .04) with total P1 (dominant eye, r = -0.51; non-dominant eye, r = -0.50), total P2 (dominant eye, r = -0.50; non-dominant eye, r = -0.50), and BCEA63 (dominant eye, r = 0.50; non-dominant eye, r = 0.40) and BCEA95 (dominant eye, r = 0.50; non-dominant eye, r = 0.40) measured at 10 seconds. CONCLUSIONS: The preliminary results of this study seem to indicate that subjects with strabismus have fixation instability regardless of the presence or absence of amblyopia.

Characterization of Dysfunctional Lens Index and Opacity Grade in a Healthy Population.

This study enrolled 61 volunteers (102 eyes) classified into subjects < 50 years (group 1) and subjects ≥ 50 years (group 2). Dysfunctional Lens Index (DLI); opacity grade; pupil diameter; and corneal, internal, and ocular higher order aberrations (HOAs) were measured with the i-Trace system (Tracey Technologies). Mean DLI was 8.89 ± 2.00 and 6.71 ± 2.97 in groups 1 and 2, respectively, being significantly higher in group 1 in all and right eyes (both p < 0.001). DLI correlated significantly with age (Rho = −0.41, p < 0.001) and pupil diameter (Rho = 0.20, p = 0.043) for all eyes, and numerous internal and ocular root-mean square HOAs for right, left, and all eyes (Rho ≤ −0.25, p ≤ 0.001). Mean opacity grade was 1.21 ± 0.63 and 1.48 ± 1.15 in groups 1 and 2, respectively, with no significant differences between groups (p ≥ 0.29). Opacity grade significantly correlated with pupil diameter for right and all eyes (Rho ≤ 0.33, p ≤ 0.013), and with some ocular root-mean square HOAs for right and all eyes (Rho ≥ 0.23, p ≤ 0.020). DLI correlates with age and might be used complementary to other diagnostic measurements for assessing the dysfunctional lens syndrome. Both DLI and opacity grade maintain a relationship with pupil diameter and internal and ocular HOAs, supporting that the algorithms used by the device may be based, in part, on these parameters.

Are near visual signs and symptoms in multiple sclerosis compatible with convergence insufficiency?

CLINICAL RELEVANCE: Optometric management of neurodegenerative diseases is essential since visual signs, such as double vision, visual acuity reduction, or oculomotricity dysfunctions, are usually present in these subjects over the course of the disease. The present paper can guide clinicians in better managing their patients with multiple sclerosis. BACKGROUND: Patients with multiple sclerosis present near vision symptoms that may be related to binocular anomalies, but these symptoms have not been investigated and related to specific signs. The aim of the present study was to evaluate the binocular vision in subjects with multiple sclerosis, and to analyse if the near visual signs and symptoms observed are compatible with those found in convergence insufficiency, as occurs in other neurodegenerative diseases. METHODS: A total of 57 multiple sclerosis patients and 26 healthy controls were examined and classified as potentially compatible with convergence insufficiency according to the signs and symptoms. Clinical diagnosis of convergence insufficiency was established when subjects met the following criteria: NPC breakpoint more than 6 cm, PFV ≤ than 15Δ (base-out), and exophoria greater at near than at distance at least 4Δ. Convergence Insufficiency Symptom Survey (CISS) was administered to assess the symptomatology considering a score ≥16 as positive. RESULTS: According to the CISS score, 54,4% of the multiple sclerosis subjects revised showed a suspect of convergence insufficiency, with a median score of 27 (IQR 9), whereas only one subject from control group (3.8%) showed this suspect. According to the diagnostic criteria based on signs, only 15.8% of multiple sclerosis patients had a real diagnosis of convergence insufficiency. CONCLUSION: Multiple sclerosis patients showed symptomatology compatible with convergence insufficiency, but this was not supported by the signs which showed a more esophoric tendency. The discrepancies between the signs and symptoms could be due to the questionnaire used including items that are also related to the cognitive function and other ocular abnormalities.