An evaluation of the Mars Letter Contrast Sensitivity Test

BCLA CLEAR Presbyopia: Evaluation and diagnosis

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Contrast sensitivity and low contrast visual acuity in children with normal visual acuity

PURPOSE

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).

DESIGN

Prospective, Cross-sectional study.

SETTING

Schools in Southern India.

STUDY POPULATION

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.

RESULTS

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.

CONCLUSIONS

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.

Additional measures of macular function beyond visual acuity

PURPOSE

Visual function is a complex process in which external visual stimuli are interpreted. Patients with retinal diseases and prolonged follow-up times may experience changes in their visual function that are not detected by the standard visual acuity measure, as they are a result of other alterations in visual function. With the advancement of different methods to evaluate visual function, additional measurements have become available, and further standardization suggests that some methods may be promising for use in clinical trials or routine clinical practice. The objectives of this article are to review these additional measurements and to provide guidance on their application.

METHODS

The Vision Academy's membership of international retinal disease experts reviewed the literature and developed consensus recommendations for the application of additional measures of visual function in routine clinical practice or clinical trials.

RESULTS

Measures such as low-luminance visual acuity, contrast sensitivity, retinal fixation and microperimetry, and reading performance are measures which can complement visual acuity measurements to provide an assessment of overall visual function, including impact on patients' quality of life. Measures such as dark adaptation, color vision testing, binocular vision testing, visual recognition testing, and shape discrimination require further optimization and validation before they can be implemented in everyday clinical practice.

CONCLUSION

Additional measurements of visual function may help identify patients who could benefit from earlier diagnosis, detection of disease progression, and therapeutic intervention. New and additional functional clinical trial endpoints are required to fully understand the early stages of macular disease, its progression, and the response to treatment.

Contrast Sensitivity Better Reflects Wide-Field Swept-Source Optical Coherence Tomography Angiography Vascular Metrics Among Healthy Eyes Compared to Visual Acuity

BACKGROUND AND OBJECTIVE

To evaluate the association between widefield swept-source optical coherence tomography angiography (WF SS-OCTA) and visual function in healthy eyes.

PATIENTS AND METHODS

Fifty-seven eyes of 45 patients were evaluated with visual acuity (VA), contrast sensitivity (CS), and WF SS-OCTA (3 × 3, 6 × 6, and 12 × 12 mm images) on the same day. Mixed-effects multivariable regression analyses were performed.

RESULTS

Contrast sensitivity metrics, including CS between 6 to 18 cycles per degree (cpd) and area under the logarithm CS function, were significantly associated with vessel density (VD) and vessel skeletonized density (VSD), whereas VA was not. The largest effect size was between CS at 18 cpd and VD (β = 0.41, P = 0.007) and VSD (β = 0.42, P = 0.006) on 12 × 12 mm images.

CONCLUSIONS

Reduced VSD and VD on WF SSOCTA was significantly associated with decreased CS, whereas VA was not. These results suggest CS could serve as a screening tool for early stage retinal and neurologic disorders. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Test-retest repeatability and agreement of the quantitative contrast sensitivity function test: towards the validation of a new clinical endpoint

PURPOSE

The purpose of this study is to investigate test-retest reliability and agreement of the quantitative contrast sensitivity function test (qCSF) in the retina clinic.

METHODS

A total of 121 right eyes of 121 patients were tested and consecutively re-tested with qCSF in the retina clinic. Outcomes included area under the logarithm of contrast sensitivity function curve (AULCSF), contrast acuity, and contrast sensitivity thresholds at 1-18 cycles per degree (cpd). Test-retest means were compared with paired t-test, variability was compared with the Brown-Forsythe test, and intraclass correlation coefficient (ICC) and Bland Altman plots evaluated reliability and agreement.

RESULTS

Mean test-retest differences for all qCSF metrics ranged from 0.02 to 0.05 log units without statistically significant differences in variability. Standard deviations ranged from 0.08 to 0.14. Coefficients of repeatability ranged from 0.16 to 0.27 log units. ICC > 0.9 for all metrics except 1cpd (ICC = 0.84, all p < 0.001); AULCSF ICC = 0.971.

CONCLUSION

qCSF-measured contrast sensitivity shows great test-retest repeatability and agreement in the retina clinic.

Status of Vision and Eye Care Among Patients in Rehabilitation Hospital Units: A Cross-Sectional Study

OBJECTIVES

The prevalence of vision disorders is high among geriatric and hospital inpatient populations, yet they often go undetected, resulting in consequences such as falls or prolonged recovery time. A needs assessment study was conducted to investigate levels of vision and the potential prevalence of unmanaged/undiagnosed ocular disorders among adult inpatients in a hospital-based rehabilitation unit.

DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

Inpatient rehabilitation units of an acute care hospital system in Ontario, Canada. Adults (n = 112) in a hospital inpatient rehabilitation unit participated from October 2018 to February 2019.

METHODS

Participants were surveyed regarding their demographic, ocular, and medical data and spectacle wear. Visual acuity, contrast sensitivity, visual fields, and stereoacuity plus the spectacle condition were directly assessed.

RESULTS

The majority (75%) were found to have reduced habitual vision while in hospital. Nearly 60% of participants reported at least some difficulty reading a newspaper or distinguishing a face or were "not happy with their vision." This was despite 80% of participants reporting that they had an eye care practitioner and 70% that they had an eye examination within the last 2 years. More than half (51.8%) of the participants received the recommendation to follow up with their eye care practitioner on discharge from the hospital.

CONCLUSIONS AND IMPLICATIONS

Reduced vision and vision disorders has a high prevalence among hospital patients in rehabilitation units and should be evaluated at or soon after hospital intake. By incorporating vision screening tools, necessary precautions may be taken to avoid possible falls and promote recovery.

An Evaluation of the Repeatability of Visual Function Following Surgical Repair of Macula-Off Rhegmatogenous Retinal Detachment

Purpose

To evaluate the reliability and reproducibility of visual function assessments for patients with macula-off rhegmatogenous retinal detachment (RRD).

Methods

This prospective study included patients with unilateral macula-off RRD of <10-day duration successfully treated with a single, uncomplicated surgery at least 1 year following repair. Visual function assessments were performed at time of enrollment and 1 month later. Testing included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), low-contrast visual acuity (VA) 2.5% and 5%, contrast sensitivity assessment with Mars and Gabor patches, reading speed (acuity, speed, and critical print size), color vision testing (protan, deutan, and tritan), and microperimetry. Spectral-domain ocular coherence tomography (SD-OCT) was performed. Paired t-statistics were used to compare values between visits and between the study and fellow eyes.

Results

Fourteen patients (9 male, 5 female) with a mean age of 69 years at time of surgery were evaluated. Correlation coefficients across the two visits were highest for ETDRS BCVA (0.97), tritan color vision testing (0.96), and low-contrast VA 5% (0.96), while the average t-statistic was largest for low-luminance deficit (4.2), ETDRS BCVA (4.1), and reading speed critical print size (3.7). ETDRS BCVA did not correlate with SD-OCT findings.

Conclusions

ETDRS BCVA can be considered a highly reliable and reproducible outcome measure. LLVA, protan color discrimination, contrast sensitivity, and reading speed may be useful secondary outcome measures.

Translational Relevance

This study provides guidance on the selection of visual function outcome measures for clinical trials of patients with macula-off RRD.

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

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

Contrast sensitivity function under three light conditions in patients with type 1 diabetes mellitus without retinopathy: a cross-sectional, case-control study

PURPOSE

To determine whether patients with type 1 diabetes mellitus (T1DM), without any sign of diabetic retinopathy, have any alteration in Contrast Sensitivity Function (CSF), in relation to patients without this disease, and whether CSF assessment in three different light conditions can be an effective test in the early detection of diabetic retinopathy.

METHODS

A prospective, cross-sectional, case-control study was preformed including 80 patients (40 with T1DM without diabetic retinopathy and 40 controls) between 11 and 47 years old. CSF was assessed at four spatial frequencies (3, 6, 12 and 18 cycles/degree) using the CSV-1000E test, under three light conditions: high (550 lx), medium (200 lx) and low (< 2 lx).

RESULTS

A lower CSF in the T1DM group was found at the three light conditions studied. The most spatial frequency affected was 18 cpd, 0.08 log units (p = 0.048) in high, 0.10 log units (p = 0.010) in medium (p = 0.010) and 0.16 log units (p < 0.001) in low-light conditions in mean CS values. The least spatial frequency affected was 3 cpd (p > 0.05 in all three light conditions).

CONCLUSION

Patients with T1DM, without diabetic retinopathy, presented a loss of CS to sine-wave gratings, with respect to people with the same characteristics without the disease, mainly at medium and high frequencies, and in medium and low-light conditions.

Impact of intravitreal injection therapy on contrast sensitivity in patients with nAMD and DME

PURPOSE

The study aims to evaluate changes in contrast sensitivity (CS) during therapy with intravitreal vascular endothelial growth factor (VEGF) inhibitors in patients with neovascular age-related macular degeneration (nAMD) and diabetic macular edema (DME).

METHODS

Prospective, uncontrolled, multicenter study on patients with neovascular AMD or DME who underwent intravitreal injection therapy with Ranibizumab, Aflibercept, or Bevacizumab was conducted. Best corrected visual acuity (BCVA) and CS measured by Mars Letter Contrast Sensitivity Test (MLCS) and Freiburg Visual Acuity and Contrast Test (FrACT) in logCS were evaluated before 3 consecutive VEGF inhibitor injections, which followed the pro renata regimen in treatment-naïve and pretreated eyes with a maximum of 9 injections. Correlation of MLCS and FrACT was calculated by the Spearman's rank correlation coefficient.

RESULTS

Eighty eyes of 74 patients (mean age 72.7; SD ± 9.96) were included. BCVA improved significantly from 0.44 (SD ± 0.21) logMAR to 0.38 (SD ± 0.23) logMAR by 0.06 (SD ± 0.14) logMAR values (p < 0.001). CS measured by MLCS increased significantly from 1.27 (SD ± 0.25) logCS to 1.39 (SD ± 0.22) logCS (p < 0.001). CS measured by FrACT also improved significantly from 1.22 (SD ± 0.32) logCS to 1.30 (SD ± 0.29) logCS (p = 0.035). A positive correlation between MLCS and FrACT was found (r = 0.389; p < 0.001). Despite statistical significance, results for BCVA, MLCS, and FrACT failed clinical significance. Overall best test results were achieved with MLCS.

CONCLUSIONS

Intravitreal injection therapy with VEGF inhibitors led to an improvement of BCVA and CS measured by MLCS and FrACT. MLCS was superior and more sensitive compared to FrACT and even BCVA to evaluate CS in elderly patients with macular pathology.

Quantification of Expected Information Gain in Visual Acuity and Contrast Sensitivity Tests

We introduce expected information gain to quantify measurements and apply it to compare visual acuity (VA) and contrast sensitivity (CS) tests. We simulated observers with parameters covered by the visual acuity and contrast sensitivity tests and observers based on distributions of normal observers tested in three luminance and four Bangerter foil conditions. We first generated the probability distributions of test scores for each individual in each population in the Snellen, ETDRS and qVA visual acuity tests and the Pelli-Robson, CSV-1000 and qCSF contrast sensitivity tests and constructed the probability distributions of all possible test scores of the entire population. We then computed expected information gain by subtracting expected residual entropy from the total entropy of the population. For acuity tests, ETDRS generated more expected information gain than Snellen; scored with VA threshold only or with both VA threshold and VA range, qVA with 15 rows (or 45 optotypes) generated more expected information gain than ETDRS. For contrast sensitivity tests, CSV-1000 generated more expected information gain than Pelli-Robson; scored with AULCSF or with CS at six spatial frequencies, qCSF with 25 trials generated more expected information gain than CSV-1000. The active learning based qVA and qCSF tests can generate more expected information than the traditional paper chart tests. Although we only applied it to compare visual acuity and contrast sensitivity tests, information gain is a general concept that can be used to compare measurements and data analytics in any domain.

Visual Characteristics of Adults with Long-Standing History of Dietary Exposure to Mercury in Grassy Narrows First Nation, Canada

Since the 1960s, Grassy Narrows First Nation (Ontario, Canada) has been exposed to methyl mercury (Hg) through fish consumption, resulting from industrial pollution of their territorial waters. This cross-sectional study describes the visual characteristics of adults with documented Hg exposure between 1970 and 1997. Oculo-visual examinations of 80 community members included visual acuity, automated visual fields, optical coherence tomography [OCT], color vision and contrast sensitivity. Median age was 57 years (IQR 51-63) and 55% of participants were women. Median visual acuity was 0.1 logMAR (Snellen 6/6.4; IQR 0-0.2). A total of 26% of participants presented a Visual Field Index inferior to 62%, and qualitative losses assessment showed concentric constriction (18%), end-stage concentric loss (18%), and complex defects (24%). On OCT, retinal nerve fiber layer scans showed 74% of participants within normal/green range. For color testing with the Hardy, Rand, and Rittler test, 40% presented at least one type of color defect, and with the Lanthony D-15 test, median color confusion index was 1.59 (IQR 1.33-1.96). Contrast sensitivity showed moderate loss for 83% of participants. These findings demonstrate important loss of visual field, color vision, and contrast sensitivity in older adults in a context of long-term exposure to Hg in Grassy Narrows First Nation.

Sex-Specific Interactions Between Hearing and Memory in Older Adults With Mild Cognitive Impairment: Findings From the COMPASS-ND Study

OBJECTIVES

Hearing loss (HL) in older adults is associated with a decline in performance on cognitive tasks and the risk of developing dementia. However, very few studies have investigated sex-related effects on these associations. A previous study of cognitively healthy older adults showed an association between HL and lower cognitive performance in females only. In the present study, we examined the effects of sex and hearing on cognition in individuals with mild cognitive impairment (MCI). We predicted that females with HL would be more likely to show poorer performance on the cognitive measures compared to females with normal hearing (NH), while cognitive performance in males would not depend on hearing. We further predicted that these auditory-cognitive associations would not depend on test modality, and would thus be observed in females for both auditory and visual tests.

DESIGN

Participants were 101 older adults with amnestic MCI (M = 71 years, 45% females) in the Canadian Consortium on Neurodegeneration in Aging (CCNA) COMPASS-ND study. Performance on the Montreal Cognitive Assessment (MoCA), Rey Auditory Verbal Learning (RAVLT), and Brief Visuospatial Memory Test-Revised (BVMT-R) was analyzed to investigate sex-related differences and/or hearing-related differences. Participants were categorized as having NH or HL using two different measures: pure-tone hearing screening results (normal based on a pure-tone threshold < 25 dB HL at 2000 Hz in the worse ear) and speech-in-noise speech reception thresholds (SRTs; normal < -10 dB SNR on the Canadian Digit Triplet Test [CDTT]).

RESULTS

Males and female groups did not differ in age, years of education, or other relevant covariates. Yet, females with better hearing on either pure-tone or speech-in-noise measures outperformed their worse hearing counterparts on the MoCA total score. Additionally, females with better hearing were more likely to recall several words on the MoCA delayed recall trial relative to those with worse hearing. Females with NH showed significant correlations between CDTT SRTs and both MoCA and RAVLT scores, while no correlations were observed in males. In contrast, males but not females showed an effect of hearing group on BVMT-R test status.

CONCLUSIONS

There were sex-specific differences in auditory-cognitive associations in individuals with MCI. These associations were mostly observed in females and on auditory tests. Potential mechanisms and implications are discussed.

Evaluating validity and reliability of the Arabic-version low-vision quality-of-life questionnaire

Low-vision quality-of-life questionnaire (LVQOL) has not been developed in the Arabic language, and none has been translated into Arabic. This study would demonstrate the effectiveness of the translated questionnaire. The English LVQOL was translated into Arabic (ARB-LVQOL) through five stages. A total of 52 low vision and 30 normally sighted individuals participated in this study. The internal consistency reliability, item-total correlation reliability, construct validity, convergent validity, discriminative validity, and respondent burden of the ARB-LVQOL were calculated. The translation team recommended that the ARB-LVQOL replicated the meaning of the LVQOL. The cultural differences were also noted during the translation process. Cronbach’s coefficient was α = 0.90 in both low vision (LV) and simulated groups. The item-total correlation ranged from 0.50 to 0.70 in both groups. The intra-class correlation coefficient indicated good test–retest reliability (LV group, ranged 0.82–0.93; control group ranged 0.83–0.94). The factor analysis, using varimax rotation, of the ARB-VQOL identified seven factors. A moderate to a strong relationship between the score of each domain with the total index score was observed, indicating an adequate convergent validity. The ARB-LVQOL discriminated between normally sighted and simulated low-vision participants and also to some extent between the simulated and real low-vision individuals. The respondent burden was less than 15 min in most responses. The ARB-LVQOL was found to relate well with patients’ visual functions and some patients’ characteristics, providing further evidence of the validity of ARB-LVQOL. The ARB-LVQOL showed psychometric properties analogous to the English version. The ARB-LVQOL could be used in clinical settings and research in adults with low vision in Arabic populations.

Luminance contrast preferences of people with a vision impairment for elements in the built environment

BACKGROUND: Standards for building elements recommend a minimum luminance contrast of 30%. The basis of this value and the metric originally used is not known. OBJECTIVE: To begin to provide an evidence base for the specification of minimum contrast in building elements. METHODS: Subjects with and without a vision impairment were characterized by visual acuity, contrast sensitivity, visual fields and color vision. On an iPad they rated the visibility, as a function of contrast, of simulated door frames, door handles, light switches and stair nosings as “Not visible at all”, “Poorly visible”, “Easily visible” and “Extremely easily visible”. RESULTS: The contrasts for each level of visibility were highly correlated with visual acuity and contrast sensitivity. A Principal Component analysis also verified the importance of visual acuity, contrast sensitivity and visual fields in rating visibility of simulations of building elements. The required contrast for door handles, light switches and stair nosings to attain the same ratings of visibility were very similar but less contrast was required for door frames. CONCLUSIONS: 30% Michelson contrast for building elements renders building elements only poorly visible for those with severe vision impairments. 65% luminance contrast is necessary for all elements to be “easily visible”. Some increase (not a decrease) on the present 30% requirement and encouragement to exceed this requirement would seem appropriate. The use of simulated objects facilitates a systematic examination of the effect of contrast, but the applicability of the results to real-life remains to be demonstrated.

The incidence of falls after first and second eye cataract surgery: a longitudinal cohort study

OBJECTIVE

To compare fall incidence, and visual acuity and refractive status, before surgery and after first and second eye cataract surgery.

DESIGN, SETTING

Prospective observational study in eight tertiary referral ophthalmology clinics in public hospitals in Sydney, Melbourne, and Perth.

PARTICIPANTS

People aged 65 years or more referred for bilateral age-related cataract surgery during 2013-16, followed for maximum of 24 months after study entry or until six months after second eye surgery, whichever was shorter.

MAIN OUTCOME MEASURES

Primary outcome: age- and sex-adjusted incidence of falls.

SECONDARY OUTCOMES

visual acuity and refractive error.

RESULTS

The mean age of the 409 included participants was 75.4 years (SD, 5.4 years); 220 were women (54%). Age- and sex-adjusted fall incidence prior to surgery was 1.17 (95% CI, 0.95-1.43) per year, 0.81 (95% CI, 0.63-1.04) per year after first eye surgery, and 0.41 (95% CI, 0.29-0.57) per year after second eye surgery. For the 118 participants who underwent second eye surgery and participated in all follow-up visits, age- and sex-adjusted incidence before (0.80 [95% CI, 0.55-1.15] falls per year) and after first eye surgery (0.81 [95% CI, 0.57-1.15] falls per year) was similar, but was lower after second eye surgery (0.32 [95% CI 0.21-0.50] falls per year). Mean habitual binocular visual acuity (logMAR) was 0.32 (SD, 0.21) before surgery, 0.15 (SD, 0.17) after first eye surgery, and 0.07 (SD, 0.15) after second eye surgery.

CONCLUSIONS

First eye surgery substantially improves vision in older people with cataract, but second eye surgery is required to minimise fall incidence. Timely cataract surgery for both eyes not only optimises vision in older people with cataract, but also reduces their risk of injury from falls.

Changes in contrast sensitivity after surgery for intermittent exotropia

To determine whether intermittent exotropia (IXT) surgery affects contrast sensitivity (CS), this retrospective study evaluated the changes in monocular and binocular CS and the binocular summation ratio (BSR) quantified as the ratio between the values of the binocular and the better monocular CS score (BSR = binocular CS score/better monocular CS score) after surgery for IXT. The subjects were patients who had undergone IXT-correcting surgery with a postoperative follow-up of > 3 months and had pre- and postoperative records of Mars CS test scores. In total, 64 patients (128 eyes) were evaluated. Both the binocular and monocular CS scores of the operated eyes were significantly worse on postoperative 1 day than the preoperative scores, but they were recovered after 1 week. The monocular CS scores of the operated eyes were significantly worse than those of the non-operated eyes until 1 week. There was no significant difference in monocular CS scores between the one-muscle and two-muscle surgeries and in binocular CS scores between the successful alignment and overcorrection groups even on the first day after surgery. The mean BSR was significantly decreased until postoperative month 1, however, recovered to preoperative levels after month 3. In conclusion, IXT-correcting surgery may temporarily worsen the CS, but it is recovered to preoperative levels. Thus, changes in CS in the immediate postoperative period after strabismus surgery should not be of concern.

Spatial frequency impacts perceptual and attentional ERP components across cultures

Culture impacts visual perception in several ways.To identify stages of perceptual processing that differ between cultures, we usedelectroencephalography measures of perceptual and attentional responses to simple visual stimuli.Gabor patches of higher or lower spatialfrequencywere presented at high contrast to 25 American and 31 East Asian participants while they were watching for the onset of aninfrequent, oddball stimulus. Region of interest and mass univariate analyses assessed how cultural background and stimuli spatial frequency affected the visual evoked response potentials. Across both groups, the Gabor of lower spatial frequency produced stronger evoked response potentials in the anterior N1 and P3 than did the higher frequency Gabor. The mass univariate analyses also revealed effects of spatial frequency, including a frontal negativity around 150 ms and a widespread posterior positivity around 300 ms. The effects of spatial frequency generally differed little across cultures; although there was some evidence for cultural differences in the P3 response to different frequencies at the Pz electrode, this effect did not emerge in the mass univariate analyses. We discuss these results in relation to those from previous studies, and explore the potential advantages of mass univariate analyses for cultural neuroscience.

Reliability of Several Glaucoma Tests in Patients With Boston Type 1 Keratoprosthesis

PURPOSE

Managing glaucoma after Boston type 1 keratoprosthesis (KPro) surgery remains challenging. We herein assessed the fitness of commonly used clinical tests to evaluate glaucoma in KPro eyes versus eyes with penetrating keratoplasty (PK) as controls.

METHODS

Sixteen patients with KPro and 14 patients with PK tested in an identical manner. After the 10-2 visual field with size V stimulus, intraocular pressure (IOP) was estimated with palpation by the first observer. Then, retinal nerve fiber layer (RNFL) thickness analysis was performed twice using optical coherence tomography by an ophthalmic photographer, before and after a short break. After the second observer estimated the IOP, the visual field was repeated. Finally, color photographs of the optic disk were captured by an ophthalmic photographer. The cup-to-disk ratio was assessed by 2 masked observers, at 2 different time points, in a random manner. Agreements between and within observers and reliability of repeated measurements were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman plots.

RESULTS

Inter-rater agreement of palpation IOP estimate was moderate for eyes with KPro (ICC = 0.47) and fair for eyes with PK (ICC = 0.27). Visual field and RNFL thickness showed high test-retest reliability in both KPro and PK eyes (ICC > 0.80 for both). Inter-rater agreement of cup-to-disk ratio assessments was substantial in eyes with both KPro (ICC = 0.62) and PK (ICC = 0.70).

CONCLUSIONS

The 10-2 visual field and RNFL thickness seem sufficiently repeatable and might allow the detection of glaucoma progression in KPro eyes. Such testing is important, given limited inter-rater agreement regarding the palpation IOP estimate.

Visual Function, Physical Function, and Activities of Daily Living in Two Aging Communities

Purpose

We report the distribution of visual acuity impairment (VAI), contrast sensitivity impairment (CSI) and their associations with physical health in an aging population.

Methods

In this cross-sectional analysis, VAI was categorized as mild (20/40-20/60) and moderate or greater (<20/60) in the better eye for distance and near vision. CSI was categorized as moderate (1.04-1.50 logCS) and severe or profound (<1.04 logCS). Physical outcomes included the short physical performance battery (SPPB) scores, self-reported quality of life (QoL) scores, physical limitations, difficulty with activity of daily living (ADL) and instrumental ADL (IADL). The associations between VAI and CSI with physical outcomes were explored overall and by community.

Results

There were 494 Black Jackson and 558 White Washington County participants. The mean age was 80 years, 63% were female, and 15% had VAIdistance presenting. Moderate or greater VAInear presenting was associated with higher prevalence of greater physical limitations (prevalence ratio, 1.25; 95% confidence interval, 1.09-1.44) and IADL difficulties (prevalence ratio, 1.77; 95% confidence interval, 1.32-2.38), but not ADL difficulties. Associations of VAIdistance presenting with physical limitations and lower SPPB scores, and CSI with physical limitations, IADL difficulties, lower QoL, and lower SPPB scores were found. A stratified analysis showed stronger associations in Jackson.

Conclusions

VAI and CSI were associated with poor physical health. These associations should be understood in the context of community differences.

Translational Relevance

Community-based factors may mitigate the impact of vision loss on physical outcomes. Public health endeavors are needed to address VAI and CSI to optimize physical health in the older adults with poor vision.

Patterns of Prevalence of Multiple Sensory Impairments among Community-Dwelling Older Adults

BACKGROUND

Much is known about individual sensory deficits among older adults, but there is a dearth of information about the prevalence of multiple concurrent sensory deficits in this population.

METHODS

We evaluated the prevalence of individual and multiple sensory impairments at the most recent clinic visit among participants aged 24 years and older in the Baltimore Longitudinal Study of Aging (BLSA) (hearing, vision, olfaction, proprioception, and vestibular function) and Atherosclerosis Risk in Communities Study (ARIC) (hearing, vision, olfaction). We compared observed prevalence of multiple sensory impairments with expected prevalence based on compounded probabilities of multiple impairments using Fisher Exact Tests. Also, we evaluated the comparability of different measures used between these two studies.

RESULTS

In both studies, the prevalence of each individual sensory impairment was common (>10%), and higher with older age, and the most common pattern of co-occurring sensory impairments was hearing and visual impairments (17.4% [BLSA]; 50.2% [ARIC]). In BLSA, the pattern that differed the most between observed and expected prevalence was combined hearing, vision, and olfactory impairments (observed 5.2% vs. 1.4% expected, p=0.01). In ARIC, this difference was much smaller (observed 8.1% vs. 7.2% expected, p=0.49).

CONCLUSIONS

Although concurrent hearing and vision impairments were the most common co-occurring deficits, combined hearing, vision and olfactory impairments are most likely to co-occur above chance, especially at older ages.

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.

Visual Performance and Cortical Atrophy in Vision-Related Brain Regions Differ Between Older Adults with (or at Risk for) Alzheimer's Disease

BACKGROUND

Visual impairment is associated with deficits in cognitive function and risk for cognitive decline and Alzheimer's disease (AD).

OBJECTIVE

The purpose of this study was to characterize the degree of visual impairment and explore the association thereof with cortical atrophy in brain regions associated with visual processing in individuals with (or at risk for) AD.

METHODS

Using the Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) dataset, we analyzed vision and brain imaging data from three diagnostic groups: individuals with subjective cognitive decline (SCD; N = 35), mild cognitive impairment (MCI; N = 74), and mild AD (N = 30). We used ANCOVAs to determine whether performance on reading acuity and contrast sensitivity tests differed across diagnostic groups. Hierarchical regression analyses were applied to determine whether visual performance predicted gray matter volume for vision-related regions of interest above and beyond group membership.

RESULTS

The AD group performed significantly worse on reading acuity (F(2,138) = 4.12, p <  0.01, ω 2 = 0.04) compared to the SCD group and on contrast sensitivity (F(2,138) = 7.6, p <  0.01, ω 2 = 0.09) compared to the SCD and MCI groups, which did not differ from each other. Visual performance was associated with volume in some vision-related structures beyond clinical diagnosis.

CONCLUSION

Our findings demonstrate poor visual performance in AD and that both group membership and visual performance are predictors of cortical pathology, consistent with the idea that atrophy in visual areas and pathways contributes to the functional vision deficits observed in AD.

Non-invasive electrical brain stimulation for vision restoration after stroke: An exploratory randomized trial (REVIS)

Background:

Occipital strokes often cause permanent homonymous hemianopia leading to significant disability. In previous studies, non-invasive electrical brain stimulation (NIBS) has improved vision after optic nerve damage and in combination with training after stroke.

Objective:

We explored different NIBS modalities for rehabilitation of hemianopia after chronic stroke.

Methods:

In a randomized, double-blinded, sham-controlled, three-armed trial, altogether 56 patients with homonymous hemianopia were recruited. The three experiments were: i) repetitive transorbital alternating current stimulation (rtACS, n = 8) vs. rtACS with prior cathodal transcranial direct current stimulation over the intact visual cortex (tDCS/rtACS, n = 8) vs. sham (n = 8); ii) rtACS (n = 9) vs. sham (n = 9); and iii) tDCS of the visual cortex (n = 7) vs. sham (n = 7). Visual functions were evaluated before and after the intervention, and after eight weeks follow-up. The primary outcome was change in visual field assessed by high-resolution and standard perimetries. The individual modalities were compared within each experimental arm.

Results:

Primary outcomes in Experiments 1 and 2 were negative. Only significant between-group change was observed in Experiment 3, where tDCS increased visual field of the contralesional eye compared to sham. tDCS/rtACS improved dynamic vision, reading, and visual field of the contralesional eye, but was not superior to other groups. rtACS alone increased foveal sensitivity, but was otherwise ineffective. All trial-related procedures were tolerated well.

Conclusions:

This exploratory trial showed safety but no main effect of NIBS on vision restoration after stroke. However, tDCS and combined tDCS/rtACS induced improvements in visually guided performance that need to be confirmed in larger-sample trials.

NCT01418820 (clinicaltrials.gov)

Topical Review: Perceptual-cognitive Skills, Methods, and Skill-based Comparisons in Interceptive Sports

SIGNIFICANCE

We give a comprehensive picture of perceptual-cognitive (PC) skills that could contribute to performance in interceptive sports. Both visual skills that are low level and unlikely influenced by experience and higher-level cognitive-attentional skills are considered, informing practitioners for identification and training and alerting researchers to gaps in the literature.Perceptual-cognitive skills and abilities are keys to success in interceptive sports. The interest in identifying which skills and abilities underpin success and hence should be selected and developed is likely going to grow as technologies for skill testing and training continue to advance. Many different methods and measures have been applied to the study of PC skills in the research laboratory and in the field, and research findings across studies have often been inconsistent. In this article, we provide definitional clarity regarding whether a skill is primarily visual attentional (ranging from fundamental/low-level skills to high-level skills) or cognitive. We review those skills that have been studied using sport-specific stimuli or tests, such as postural cue anticipation in baseball, as well as those that are mostly devoid of sport context, considered general skills, such as dynamic visual acuity. In addition to detailing the PC skills and associated methods, we provide an accompanying table of published research since 1995, highlighting studies (for various skills and sports) that have and have not differentiated across skill groups.

The Effect of Test Distance on Visual Contrast Sensitivity Measured Using the Pelli-Robson Chart

Purpose

The Pelli-Robson (PR) chart is widely used to measure clinical contrast sensitivity (CS). It is generally believed that PR testing distance is not critical. Here, we examine whether a closer test distance than the usual 1 meter might be better for patients with low vision.

Methods

PR CS was measured on two groups: low-vision students (<20 years old) and elder patients (>65 years old). Student PR was measured at 1 meter and at a closer distance d = visual acuity in log₁₀cy/deg (d = 1.5–logMAR). Elder PR was measured at 1 and 3 meters. Grating CS was also measured using the Ohio Contrast Cards (OCCs).

Results

Average CS was 0.398 log₁₀ units (over one line on the PR chart) higher at the closer distance than at 1 meter for the students, but there was no effect of 1 vs. 3 meters test distance for the elders. The equivalent spatial frequencies of the PR letters at 1 meter were near the acuity limits of students with low vision, but were near the peak of the elders’ CS functions. Especially for students with low vision, PR CS was below OCC CS, even when PR was tested at a closer distance.

Conclusions

PR CS should be measured at a distance in meters that is equal to the patient's letter acuity in cy/deg, or 1.5–logMAR.

Translational Relevance

Contrast sensitivity is highly associated with quality of life, and it is important to measure it accurately. Using a closer distance, or measuring grating CS, can reveal visual abilities missed when patients with low vision are tested using PR at 1 meter.

Visual outcomes of binocular implantation of a new extended depth of focus intraocular lens

Purpose:

To evaluate the visual outcomes of bilateral implantation of a new hydrophobic foldable extended depth of focus (EDOF) IOL.

Methods:

All cases undergoing phacoemulsification with bilateral implantation of Supraphob Infocus IOL between December 2017 and July 2018 at a tertiary eye care center were recruited in this prospective interventional study. The primary outcome measures were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA). Postoperative follow-up was done on day 1, 1 week, 1 month, and 3 months.

Results:

One hundred and four eyes of 52 patients with a mean age of 58.4 ± 9.3 years were included. The mean UDVA improved from 0.84 ± 0.32 logMAR preoperatively to 0.11 ± 0.08 logMAR at 3 months following surgery. At the final follow-up, the binocular UDVA, UIVA, and UNVA was 0.03 ± 0.07, 0.14 ± 0.06, and 0.36 ± 0.05 logMAR, respectively. The mean CS was 1.47 ± 0.06 logCS. The distance and near stereopsis was 90.2 ± 24.8 s of arc (arcsec) and 62.5 ± 19.4 arcsec, respectively. The mean total higher-order aberration (HOA), point spread function, and modulation transfer function were 0.30 ± 0.13, 0.07 ± 0.08, and 0.26 ± 0.07, respectively.

Conclusion:

The Supraphob Infocus EDOF IOL provides good unaided visual acuity for distance, intermediate, and near along with a high quality of vision as assessed by contrast sensitivity, HOAs, and stereoacuity. It may be a potential alternative to the currently available EDOF IOLs in providing good visual acuity at variable distances.

Repeatability of an automated ETDRS contrast threshold measurement

This technical report presents the repeatability of an automated Early Treatment Diabetic Retinopathy Study (ETDRS) contrast threshold (ETDRS-CT) test in participants (N = 40) with normal vision as well as in subjects with reduced visual acuity. The automated ETDRS-CT test showed good test-retest repeatability between the two administrations in both normal and reduced vision participants. Measurement at the retest yielded 0.05 log higher contrast sensitivity than at the first measurement, which might be due to a learning effect among participants.

Validation of an Automated Early Treatment Diabetic Retinopathy Study Low-contrast Letter Acuity Test

SIGNIFICANCE

Automated low-contrast letter acuity (LCLA) has several advantages: consistent luminance, reduced chance of individuals memorizing test letters, and convenient and accurate visual acuity reporting functions. Although automated LCLA might report slightly worse acuity than Sloan LCLA chart, considering its advantages, it may be a viable alternative to Sloan LCLA chart in clinical practice and research.

PURPOSE

The purpose of this study was to determine the repeatability of an automated LCLA measurement and its agreement with the Sloan LCLA chart test in normal participants and reduced-vision participants.

METHODS

Adult participants (n = 49) were measured with both automated Early Treatment Diabetic Retinopathy Study and Sloan LCLA tests, including normal and reduced-vision groups. Low-contrast letter acuity at two contrast levels (2.5 and 10%) was measured at 3 m in a random sequence with both LCLA tests. To test repeatability, participants were retested 1 week later. Repeatability of the two tests between two visits and agreement between automated and Sloan LCLA tests were evaluated using 95% limits of agreement.

RESULTS

In terms of the 95% limits of agreement, the repeatability of both tests was as follows: automated LCLA at 2.5%, ±0.26; automated LCLA at 10%, ±0.22; Sloan LCLA at 2.5%, ±0.23, and Sloan LCLA at 10%, ±0.16. The agreement of the two tests was as follows: ±0.19 at 2.5% and ±0.24 at 10%. The automated LCLA at 2.5 and 10% levels was generally reported one-half to one logMAR line lower than Sloan LCLA (mean differences, -0.04 at 2.5% and -0.13 at 10%; paired t test, P < .05).

CONCLUSIONS

The automated LCLA test shows fairly good test-retest repeatability at both 2.5 and 10% contrast levels. The agreement between the automated and the Sloan low-contrast letter acuity tests was comparable with test-retest agreement. Although the automated LCLA test reports slightly worse acuity than the Sloan LCLA test, it could be an appropriate alternative to the Sloan LCLA test.

Validation of visual acuity applications for teleophthalmology during COVID-19

PURPOSE

The objective of this study was to identify and validate smartphone-based visual acuity (VA) apps that can be used in a teleophthalmology portal.

METHODS

The study was conducted in three phases: A survey to investigate if the SmartOptometry App was easy to download, understand and test (phase I), an in-clinic comparison of VA measured in a random testing order with four tools namely COMPlog, Reduced Snellen near vision, Peek Acuity (Distance VA) and SmartOptometry (Near VA) (phase II) and a repeatability study on these 4 tools by measuring VA again (phase III). The study recruited the employees of our institute and adhered to the strict COVID-19 protocols of testing.

RESULTS

Phase I Survey (n = 40) showed 90% of participants used android phones, 60% reported that instructions were clear, and all users were able to self-assess their near VA with SmartOptometry App. Phase II (n = 68) revealed that Peek Acuity was comparable to COMPlog VA (P = 0.31), however SmartOptometry was statistically significantly different (within 2 log MAR lines) from Reduced Snellen near vision test, particularly for young (n = 44, P = 0.004) and emmetropic (n = 16, P = 0.04) participants. All the 4 tests were found to be repeatable in phase III (n = 10) with a coefficient of repeatability ≤0.14.

CONCLUSION

Smartphone-based apps were easy to download and can be used for checking patient's distance and near visual acuity. An effect of age and refractive error should be considered when interpreting the results. Further studies with real-time patients are required to identify potential benefits and challenges to solve.

A Comparative Study of Corneal Topography in Children with Autism Spectrum Disorder: A Cross-Sectional Study

Purpose: To investigate the corneal characteristics in individuals with autism spectrum disorder (ASD) and age-matched typical development (TD) participants. Methods: This cross-sectional, clinically based study compared children with ASD to age-matched TD participants. Corneal topography was measured with a portable EyeSys Vista system. The distance visual acuity (VA) and the contrast sensitivity (CS) were determined. The refractive error (RE) was assessed using a 2WIN autorefractometer. Results: A total of 31 children with ASD (mean age: 12.78 ± 4.49 years), and 60 participants with TD (mean age: 13.65 ± 3.56 years) were recruited. The two groups were similar in age (t = −2.084, p = 0.075) and VA (t = −0.35, p = 0.32). Most of the children with ASD had a significant amount of refractive errors (REs; range: +5.25 to −5.50 DS), and astigmatism was dominant (range: −0.25 to −4.50 DC). There was no statistically significant difference between both groups in terms of average corneal power (t = 1.12, p = 0.39). The children with ASD and participants with TD also did not differ significantly in terms of corneal shape descriptors (p > 0.05), such as corneal asphericity, inferior superior index, opposite sector index, and differential sector index. The spherical equivalent did not differ significantly between the ASD participants and participants with TD (t = 1.15, p = 0.15). There was a significant difference (p < 0.05) in the astigmatism component between the ASD participants and the participants with TD.

Capacity-limited resources are used for managing sensory degradation and cognitive demands: Implications for age-related cognitive decline and dementia

Older adults with sensory deficits are at higher risk for developing cognitive impairment and dementia. It remains uncertain if the link between sensory and cognitive functioning reflects a common underlying factor or whether sensory deficits directly undermine cognitive processing. This issue was addressed by comparing behavioral and event-related potential responses of 16 older and 16 young adults during a working memory paradigm that parametrically varied visual contrast level (100%, 69%, 22%) and cognitive task load (1-4 face pairs to remember). The groups were well-matched on demographic and neuropsychological variables; however, older adults had worse corrected visual acuity and contrast sensitivity. The study's major finding was an interaction between visual contrast level and task load on performance accuracy (percent of correct responses) and the allocation of resources for decision making/updating (as indexed by the P3b amplitude). The negative impact of degraded visual processing was greater at higher levels of task demand. This result suggests that a shared pool of processing resources is used to mediate cognitive operations and manage the processing of degraded images. The study also demonstrated that older adults reach the limits of their processing capacity at lower levels of task load. The interaction between visual degradation and task demand, accompanied by the age-related reduction in available processing resources highlight the increased vulnerability of older adults. Specifically, an age-associated decline in visual acuity and contrast sensitivity puts older adults at risk for depleting their limited resources in the service of processing degraded visual images. The results of this study underscore the potential importance of optimizing vision in older adults to help mitigate age-associated cognitive decline.

A New Contrast Sensitivity Test for Pediatric Patients: Feasibility and Inter-Examiner Reliability in Ocular Disorders and Cerebral Visual Impairment

Purpose

Assess feasibility and interexaminer reliability of a new test of contrast sensitivity (CS) for pediatric populations.

Methods

The Double Happy (DH) measures CS using a method similar to the Teller Acuity Cards. The schematic DH face is 16 degrees in diameter with features of 0.3 c/d and a channel frequency of 0.8 c/d. DH log₁₀ CS is in 0.15 log unit steps, 0.05 to 2.1. Participants were 43 unselected patients, ages 2 to 18 years: 23 were diagnosed with ocular disorders only; 20 were diagnosed with cerebral visual impairment (CVI). Two examiners measured DH log₁₀ CS. Visual acuity (VA) was also measured.

Results

All 43 participants were tested for binocular DH log₁₀CS. Cohen's kappa values for interexaminer reliability were fair. The between examiner ICC was +0.92 (P < 0.001). The mean difference between examiners was near zero, and the 95% CI was −0.44 to 0.45 log₁₀CS. DH log₁₀CS was near normal in the ocular disorder group and reduced in the CVI group. VA was reduced in both groups. DH log₁₀ CS and VA were correlated (r = −0.65). DH log₁₀ CS was a marginally better predictor of diagnosis than VA.

Conclusions

DH log₁₀CS test was successful in a diverse pediatric population diagnosed with ocular disorders or CVI. Interexaminer reliability was comparable to that of adults tested previously using the same stimuli and methods. Both CS and VA are reduced in CVI.

Translational Relevance

CS and VA both should be tested in pediatric clinical populations, especially in those at risk of CVI.

Visual and subjective outcomes following trifocal intraocular lens implantation in Iranian cataractous patients

BACKGROUND

The aim of this study was to evaluate visual and refractive outcomes and quality of vision after implantation of the AT LISA tri 839MP intraocular lens (IOL).

PATIENTS AND METHODS

This interventional clinical trial comprised 46 cataractous eyes of patients who underwent phacoemulsification with IOL implantation (mean age of 58.08 ± 11.01 years; range: 36-76 years old). Spherical equivalent (SE), uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected intermediate visual acuity (UIVA), corrected intermediate visual acuity (CIVA), uncorrected near visual acuity (UNVA), and corrected near visual acuity (CNVA) were measured 1, 3, and 6 months after surgery. Contrast sensitivity (CS) was measured at 6 months. Subjective quality of vision and presence of dysphotopsia by a short questionnaire were evaluated postoperatively.

RESULTS

At 6 months, the mean visual acuity was 0.08 ± 0.11, 0.03 ± 0.08, 0.07 ± 0.09, 0.02 ± 0.08, 0.05 ± 0.09, and 0.02 ± 0.08 LogMAR for UDVA, CDVA, UIVA, CIVA, UNVA, and CNVA, respectively. The mean values of SE were - 0.4728 ± 0.32D. These variables improved over time, yet significant changes were detected in UDVA (P = 0.009) and SE (P = 0.0001). The mean CS value was 1.74 ± 0.08. The mean scores (0% = no symptoms; 100% = strong symptoms/unable to perform activities) for glare and halos were 7.07 ± 0.22% and 8.70 ± 0.23%, respectively. These items were reduced over time. Patients' level of satisfaction mean score for performing activities was 96.66%.

CONCLUSIONS

The AT LISA tri 839MP IOL provides excellent uncorrected distance, intermediate and near vision, and CS. This IOL showed a minimal level of photic phenomena and a high level of patient satisfaction.

Functionally validated imaging endpoints in the Alabama study on early age-related macular degeneration 2 (ALSTAR2): design and methods

Background

Age-related macular degeneration (AMD), a leading cause of irreversible vision impairment in the United States and globally, is a disease of the photoreceptor support system involving the retinal pigment epithelium (RPE), Bruch’s membrane, and the choriocapillaris in the setting of characteristic extracellular deposits between outer retinal cells and their blood supply. Research has clearly documented the selective vulnerability of rod photoreceptors and rod-mediated (scotopic) vision in early AMD, including delayed rod-mediated dark adaptation (RMDA) and impaired rod-mediated light and pattern sensitivity. The unifying hypothesis of the Alabama Study on Early Macular Degeneration (ALSTAR2) is that early AMD is a disease of micronutrient deficiency and vascular insufficiency, due to detectable structural changes in the retinoid re-supply route from the choriocapillaris to the photoreceptors. Functionally this is manifest as delayed rod-mediated dark adaptation and eventually as rod-mediated visual dysfunction in general.

Methods

A cohort of 480 older adults either in normal macular health or with early AMD will be enrolled and followed for 3 years to examine cross-sectional and longitudinal associations between structural and functional characteristics of AMD. Using spectral domain optical coherence tomography, the association between (1) subretinal drusenoid deposits and drusen, (2) RPE cell bodies, and (3) the choriocapillaris’ vascular density and rod- and cone-mediated vision will be examined. An accurate map and timeline of structure-function relationships in aging and early AMD gained from ALSTAR2, especially the critical transition from aging to disease, will identify major characteristics relevant to future treatments and preventative measures.

Discussion

A major barrier to developing treatments and prevention strategies for early AMD is a limited understanding of the temporal interrelationships among structural and functional characteristics while transitioning from aging to early AMD. ALSTAR2 will enable the development of functionally valid, structural biomarkers for early AMD, suitable for use in forthcoming clinical trials as endpoint/outcome measures. The comprehensive dataset will also allow hypothesis-testing for mechanisms that underlie the transition from aging to AMD, one of which is a newly developed Center-Surround model of cone resilience and rod vulnerability.

Trial registration

ClinicalTrials.gov Identifier NCT04112667, October 7, 2019.

Luminance Contrast of Accessible Tactile Indicators for People With Visual Impairment

Australia is one of only two known countries with a safety standard specifying levels of contrast required to provide accessible environments for people with visual impairment. However, these requirements were not developed based on empirical research involving people with vision loss. We investigated whether the level of luminance contrast in Australian accessibility standards, 30%, is adequate for people with visual impairments to detect and identify discrete tactile ground surface indicators over a range of contrasts with the background flooring before contact. We found that the 30% luminance contrast is adequate for people with low vision, although they preferred higher contrast.

Pilot Outcomes of a Multicomponent Fall Risk Program Integrated Into Daily Lives of Community-Dwelling Older Adults

Objectives: To evaluate whether a fall prevention intervention reduces fall risk in older adults who have previously fallen. Design: Randomized controlled pilot trial. Setting: Participants' homes. Intervention: LIVE-LiFE, adapted from Lifestyle-Intervention Functional Exercise (LiFE) integrates strength and balance training into daily habits in eight visits over 12 weeks. The adaptations to LiFE were to also provide (a) US$500 in home safety changes, (b) vision contrast screening and referral, and (c) medication recommendations. Control condition consisted of fall prevention materials and individualized fall risk summary. Measurement: Timed Up and Go (TUG) and Tandem stand. Falls efficacy, feasibility, and acceptability of the intervention. Results: Sample (N = 37) was 65% female, 65% White, and average 77 years. Compared with the control group, each outcome improved in the intervention. The LIVE-LiFE intervention had a large effect (1.1) for tandem stand, moderate (0.5) in falls efficacy, and small (0.1) in the TUG. Conclusion: Simultaneously addressing preventable fall risk factors is feasible.

Sustained Gazing Causes Measurable Decline in Visual Function of Patients with Dry Eye

PURPOSE

To assess the effects of sustained gazing on visual function of dry eye patients.

DESIGN

Prospective, comparative before-and-after study.

METHODS

A total of 176 patients with dry eye and 33 control subjects ≥50 years old were included. Dry eye symptomatology along and clinical parameters were assessed. Out-loud reading speed was measured using the International Reading Speed Test (IReST) as words per minute (wpm). Reading speed was repeated using different IReST excerpts following 30-minute silent reading.

RESULTS

At baseline, there were no differences between dry eye patients and control subjects with respect to reading speed (172 vs 180 wpm, respectively; P = 0.21) or the time to read the excerpt (33 vs 30 seconds, respectively; P = 0.17). After silent reading, the dry eye patients had decreased reading speed and increases in the length of time to read the passage compared to baseline (161 vs 172 wpm, respectively; P = 0.002; and 38 vs 33 seconds, respectively; P < 0.001). The control subjects did not show significant differences for either parameter. There were significant differences with respect to both parameters between the dry eye and control groups after sustained gazing (161 vs 188 wpm, respectively; P = 0.006; and 38 vs 31 seconds, respectively; P = 0.003). Each 1-point increase in baseline corneal staining score (0-6) led to a 5-wpm reduction in reading speed (95% confidence interval, -8 to -1; P = 0.01).

CONCLUSIONS

Sustained gazing, such as in silent reading, has a measurable negative impact on visual performance of dry eye patients. Corneal staining represents a clinical parameter relevant to visual function.

Validation of an automated-ETDRS near and intermediate visual acuity measurement

BACKGROUND

The aim of this study was to determine the repeatability of an automated-ETDRS (Early Treatment Diabetic Retinopathy Study) near and intermediate visual acuity measurement in subjects with normal visual acuity and subjects with reduced visual acuity. The agreement of automated-ETDRS with gold standard chart-based visual acuity measurement was also studied.

METHODS

Fifty-one subjects were tested (aged 23 to 91 years; 33 subjects with normal visual acuity: 6/7.5 or better; 18 subjects with reduced visual acuity: 6/9 to 6/30). Near and intermediate visual acuity of one eye from each subject was measured with an automated tablet-computer system (M&S Technologies, Inc.) and Precision Vision paper chart in a random sequence. Subjects were retested one week later. Repeatability was evaluated using the 95 per cent limits of agreement (LoA) between the two visits.

RESULTS

Average difference between automated-ETDRS near visual acuity and near visual acuity by paper chart was 0.02 ± 0.10 logMAR (p > 0.05). Agreement of near visual acuity between automated-ETDRS and paper chart was good, with 95 per cent LoA of ±0.19 logMAR. Furthermore, automated-ETDRS near visual acuity showed good repeatability (95 per cent LoA of ±0.20). Mean difference between automated-ETDRS intermediate visual acuity and intermediate visual acuity by paper chart was 0.02 ± 0.10 logMAR (p > 0.05). Agreement of intermediate visual acuity between automated-ETDRS and paper chart was good, with 95 per cent LoA of ±0.20 logMAR. In addition, automated-ETDRS intermediate visual acuity had good repeatability (95 per cent LoA of ±0.16).

CONCLUSION

Automated-ETDRS near and intermediate visual acuity measurement showed good repeatability and agreement with the gold standard chart-based visual acuity measurement. The findings of this study indicate the automated visual acuity measurement system may have potential for use in both patient care and clinical trials.

Impact of Dry Eye on Prolonged Reading

SIGNIFICANCE

Patients with dry eye frequently report difficulty with reading. However, the impact of dry eye on reading has not been studied in detail. This study shows the unfavorable effect of dry eye on reading speed and offers mechanisms that may be responsible.

PURPOSE

The purpose of this study was to evaluate the impact of dry eye signs as well as symptoms on both short-duration out-loud and prolonged silent reading.

METHODS

This study included 116 patients with clinically significant dry eye, 39 patients with dry eye symptoms only, and 31 controls, 50 years or older. After the Ocular Surface Disease Index (OSDI) questionnaire, objective testing of dry eye (tear film stability studies, Schirmer's test, and ocular surface staining) was performed. Total OSDI score and two subscores (vision related and discomfort related) were calculated. A short-duration out-loud reading test and a 30-minute sustained silent reading test were performed. Reading speed for each test was calculated as words per minute (wpm) and compared across the three groups.

RESULTS

Patients with clinically significant dry eye read slower than controls measured with sustained silent reading test (240 vs. 272 wpm, P = .04), but not with short-duration out-loud reading test (146 vs. 153 wpm, P = .47). Patients with dry eye symptoms only did not have slower reading speed measured using either reading test as compared with controls. However, vision-related OSDI subscore independently was associated with slower reading speed (P = .02). Multivariable regression models demonstrated that each 1-point (between 0 and 6) increase in corneal staining score led to a 10-wpm decrease in sustained silent reading speed (P = .01).

CONCLUSIONS

This study demonstrates a significant negative impact of dry eye (particularly presence of corneal staining) on prolonged reading. Prolonged reading task may serve as an objective clinically relevant test to measure the impact of dry eye on vision-related quality of life.

The Effect of a Head-mounted Low Vision Device on Visual Function

SIGNIFICANCE

Head-mounted low vision devices have received considerable attention in recent years owing to rapidly developing technology, facilitating ease of use and functionality. Systematic clinical evaluations of such devices remain rare but are needed to steer future device development.

PURPOSE

The purpose of this study was to investigate, in a multicenter prospective trial, the short- and medium-term effects of a head-worn vision enhancement device (eSight Eyewear).

METHODS

Participants aged 13 to 75 years with stable vision (distance acuity, 20/60 to 20/400; visual field diameter >20°) were recruited across six sites. Data were collected at baseline (no device), at fitting (with device), and after 3 months of everyday use. Outcome measures were visual ability measured by the Veterans Affairs Low Vision Visual Functioning Questionnaire 48, distance acuity (Early Treatment Diabetic Retinopathy Study), reading performance (MNREAD chart), contrast sensitivity (MARS chart), face recognition, and a modified version of the Melbourne Low Vision Activities of Daily Living (ADL) Index.

RESULTS

Among the 51 participants, eSight introduction immediately improved distance acuity (0.74 ± 0.28 logMAR), contrast sensitivity (0.57 ± 0.53 log units), and critical print size (0.52 ± 0.43 logMAR), all P < .001, without any further change after 3 months; reading acuity improved at fitting (0.56 ± 0.35 logMAR) and by one additional line after 3 months, whereas reading speed only slightly increased across all three time points. The Melbourne ADL score and face recognition improved at fitting (P < .01) with trends toward further improvement at 3 months. After 3 months of use, Veterans Affairs Low Vision Visual Functioning Questionnaire 48 person measures (in logits) improved: overall, 0.84, P < .001; reading, 2.75, P < .001; mobility, 0.04, not statistically significant; visual information, 1.08, P < .001; and visual motor, 0.48, P = .02.

CONCLUSIONS

eSight introduction yields immediate improvements in visual ability, with face recognition and ADLs showing a tentative benefit of further use. Overall, visual ability, reading, and visual information showed greatest benefit with device use. Further studies need to examine benefits of practice and training and possible differential effects of underlying pathology or baseline vision.

Test-retest Variability of a Standardized Low Vision Lighting Assessment

SIGNIFICANCE

Systematic lighting assessments should be part of low vision evaluations. The LuxIQ has gained popularity as an assessment tool, but its reliability has not been examined independently and is necessary for evidence-based vision rehabilitation.

PURPOSE

Besides magnification, improved lighting levels are a common intervention in reading rehabilitation for individuals with low vision. Determining the appropriate lighting can be a complex and time-consuming task. The LuxIQ is a portable lighting assessment tool that can be used to systematically measure lighting preferences; however, there is little independent evidence to support its reliability in low vision rehabilitation.

METHODS

One hundred nine control subjects (age, 18 to 85 years) and 64 individuals with low vision (age, 27 to 99 years) adjusted both the luminance and color temperature parameters on the LuxIQ while viewing a sentence on the MNREAD at their preferred print size for continuous reading. After 30 minutes, they were asked to repeat the same measurements.

RESULTS

Using Bland-Altman plots, test-retest variability was calculated using the limits of agreement (LOAs). For illuminance, the LOA width was 2806 lux for control subjects and 2657 lux for visually impaired participants. For color temperature, the LOA width was 2807 K for control subjects and 2364 K for those with a visual impairment. Difference scores were centered near zero, indicating overall accuracy.

CONCLUSIONS

The measurement of lighting preference lacks the precision necessary for clinical utility, given that the LOA for luminance ranged more than 2600 lux, with normally sighted and low vision participants. Such variability translates into a range of approximately ±40 or 50 W in an incandescent light bulb, depending on the luminance level, making it clinically difficult to narrow down the options for evidence-based lighting recommendations. Next steps are to examine whether the reading behavior of low vision clients is positively affected by interventions that are based on LuxIQ recommendations.

Rifle Shooting for Athletes With Vision Impairment: Does One Class Fit All?

Revised evidence-based classification criteria introduced for shooting for athletes with vision impairment (VI shooting) suggest that athletes with impaired contrast sensitivity (CS) and visual acuity (VA) should be eligible for inclusion in the sport but should all eligible athletes compete against each other in the same "class" or is more than one class necessary? Twenty-five elite VI shooting athletes took part in the study. Two measures of visual function were assessed under standardized conditions: VA (using an ETDRS logMAR letter chart, and/or a BRVT chart) and CS (using both a Pelli-Robson chart and a Mars number chart). Shooting performance, in both prone and standing events, was measured during an international VI shooting competition. Fourteen of the 25 athletes had measurable VA, and for CS, 8 athletes had measurable function with the Pelli-Robson chart and 13 with the Mars chart. The remaining athletes had function not numerically measurable by the charts and were considered to have no residual vision. There was no indication that shooting performance varied with visual function, and individuals that had residual vision had no advantage over those without vision for either prone or standing shooting. The modifications made to VI shooting, including the use of auditory tones to guide the gun barrel, appear to have successfully rendered the sport equitable for all eligible athletes. Only one class is necessary for athletes. An improved method of measuring CS in athletes with profound VI would be advantageous.

Performance of a New-Generation Extended Depth of Focus Intraocular Lens-A Prospective Comparative Study

PURPOSE

The aim was to study the visual performance of a new refractive extended depth of focus (EDOF) intraocular lens (IOL).

DESIGN

Prospective, comparative study.

METHODS

Consenting patients with age-related cataract willing for bilateral cataract surgery within 2 weeks were implanted with the Supraphob EDOF IOL and those willing for 1 eye surgery were implanted with a monofocal IOL. The uncorrected and best-corrected distance, intermediate and near visual acuity, and contrast sensitivity were evaluated at 1 and 3 months postoperatively. We also inquired about glare, halos, difficulties in night driving, requirement for spectacles, and overall satisfaction with vision.

RESULTS

The Supraphob EDOF group (n = 72 eyes) and the monofocal IOL group (n = 54 eyes) were comparable with respect to all preoperative parameters including biometry, visual acuity, and cataract status. The mean age of participants was 58.4 ± 10.6 years. Both groups had similar distance vision but the EDOF group had significantly better intermediate (0.2 ± 0.2 logMAR vs 0.75 ± 0.19 logMAR, P < 0.001) and near vision (median = N6 vs N12, P < 0.001) compared to the monofocal group at 3 months. The contrast sensitivity was similar in both groups. Patients in the EDOF IOL group had much greater satisfaction for intermediate and near vision. Less than 10% patients reported glare, halos, and difficulty in driving at night in the EDOF group.

CONCLUSIONS

The Supraphob EDOF IOL was effective in improving the distance, intermediate and near vision in majority of patients, and retained good contrast sensitivity with most patients reporting excellent satisfaction.

Neuroanatomical substrates underlying contrast sensitivity

BACKGROUND

Contrast sensitivity (CS), a measurement of the ability to discriminate an object from its background, is an essential domain of visual functions. Eye aging or diseases are usually responsible for CS decline or impairment. However, whether neuroanatomical substrates are underlying CS is mostly unknown.

METHODS

High-resolution magnetic resonance imaging data of 100 healthy young subjects from the Human Connectome Project (HCP) dataset were used to calculate gray matter volume (GMV). CS was assessed using the Mars Contrast Sensitivity Test. A multiple regression analysis was used to investigate the relationship between CS and GMV in a voxel-wise manner within the whole gray matter.

RESULTS

The range of Mars_Final scores for the 100 participants was from 1.08 to 1.88, and we found significant positive correlations between the CS scores and GMV in the bilateral visual cortex. Precisely, the significant bilateral clusters were mainly located in bilateral V3A, with the superior parts extending to the bilateral posterior parietal cortex.

CONCLUSIONS

These findings suggest the critical role of the dorsal visual stream in CS processing, which may provide insights into the neuroanatomical mechanism of contrast sensitivity and its relation to some brain disorders.

A comparison of the contrast sensitivity function between age-matched phakic emmetropes and pseudophakic individuals with aspheric intraocular lenses

PURPOSE:

The purpose of this study is to compare the contrast sensitivity function (CSF) between eyes of age-matched individuals with aspheric intraocular lens (IOL) and emmetropia.

METHODS:

A prospective hospital-based case–control study in South India was conducted to study the CSF in the eyes of patients between the ages of 50–60 years. The CSF was compared between those with emmetropia and those implanted with an indigenous aspheric IOL. Twenty-five consecutive patients were recruited in both groups. The independent sample t-test was used for analysis.

RESULTS:

The mean age was 53.08 ± 1.96 years and 57.68 ± 2.85 years in normal emmetropes and emmetropic pseudophakic with aspheric IOL, respectively. The mean CSF showed a statistically significant difference (P < 0.000) between the normal emmetropic eyes and pseudophakic eyes with the values being 1.91 and 1.572, respectively.

CONCLUSION:

The CSF was significantly better in the eyes of age-matched normal emmetropes when compared to those with an aspheric IOL implanted.

Preventing falls among older fallers: study protocol for a two-phase pilot study of the multicomponent LIVE LiFE program

Background

Falls reflect sentinel events in older adults, with significant negative consequences. Although fall risk factors have been identified as intrinsic (e.g., muscle weakness, balance problems) and extrinsic (e.g., home hazards), most prevention programs target only intrinsic factors. We present the rationale and design of a home-based multicomponent fall prevention program—the LIVE LiFE program—for community-living older adults. The program adapts and expands the successful Lifestyle Intervention Functional Exercise (LiFE) program by adding home safety, vision contrast screening, and medication review. The specific aims of the study are to (1) adapt the LiFE program to a US context and expand it into a multicomponent program (LIVE LiFE) addressing intrinsic and extrinsic fall risks, (2) examine feasibility and acceptability, and (3) estimate program impact on multiple outcome measures to prepare for an efficacy trial.

Methods

The study involves two phases: an open-label pilot, followed by a two-group, single-blinded randomized pilot trial. Eligible participants are community-living adults 70+ years reporting at least one injurious fall or two non-injurious falls in the previous year. Participants are randomized in a 2:1 ratio to the program group (LIVE LiFE, n = 25) or the control group (written fall risk assessment, n = 12). The open-label pilot participants (n = 3) receive the program without randomization and are assessed based on their experience, resulting in a stronger emphasis on the participant’s personal goals being integrated into LIVE LiFE. Fall risk and balance outcomes are assessed by the Timed Up and Go and the 4-Stage Balance Test at 16 weeks. Additional outcomes are incidence of falls and near falls, falls efficacy, fear of falling, number of home hazards, and medications assessed at 16 weeks. Incidence of falls and near falls, program adherence, and satisfaction are assessed again at 32 weeks.

Discussion

By expanding and adapting the evidence-based LiFE program, our study will help us understand the feasibility of conducting a multicomponent program and estimate its impact on multiple outcome measures. This will support moving forward with an efficacy trial of the LIVE LiFE program for older adults who are at risk of falling.

Trial registration

ClinicalTrials.gov, NCT03351413. Registered on 22 November 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3114-5) contains supplementary material, which is available to authorized users.

Behind the Wheel: Process Evaluation of a Safe-Transport Program for Older Drivers Delivered in a Randomized Controlled Trial

This process evaluation explores relationships between program outcomes and intervention implementation in a trial evaluating "Behind the Wheel," an education-based safe-transport program for older drivers. Participants (intervention group) were 190 Sydney drivers aged ⩾75 years (M = 80 ± 4years). Process measures included fidelity, dose delivered, and received. Outcomes were self-reported driving regulation and objectively measured driving exposure. Relationships were explored using regression models. Older drivers who took ownership of driving retirement and self-regulation by developing plans were more likely to reduce their weekly driving, (β = 38 km, 95% confidence interval (CI) = [7.5,68.7]), and night driving (β = 7 km, 95% CI = [3.5, 10.4]). Drivers of older age (odds ratio [OR] = 1.1/year older, 95% CI = [1.05, 1.3]) had greater odds of developing driving retirement plans. Female drivers (OR = 2.7,95% CI = [1.1, 6.9]), drivers with poorer function (OR = 1.2/5-point decrease on DriveSafe, 95% CI = [1.04, 1.4]), and worse health (OR = 1.2/additional medication, 95% CI = [1.02, 1.5]) had greater odds of developing safe mobility plans. This program had greatest impact with older, lower functioning drivers. A stronger message was delivered and received, as intended, to older drivers with lower function and poorer health. Our logic model can help channel resources to drivers who benefit most.

Patient perspectives of cataract surgery: protocol and baseline findings of a cohort study

BACKGROUND

Patient-reported outcome measures (PROMs) are becoming increasingly recognised as a key component in assessing the relative effectiveness of cataract surgery. This manuscript presents the protocol methodology and baseline characteristics of a prospective cohort study investigating patient-centred predictors of cataract surgery outcomes.

METHODS

Patients with bilateral cataract (aged ≥ 50 years) scheduled for their first eye cataract surgery were recruited at four public hospitals and three private ophthalmology clinics in Sydney, Australia. Participants underwent a comprehensive assessment of clinical measures of vision (for example, visual acuity, contrast sensitivity) and PROMs prior to first eye surgery and three months after first and second eye surgery. The PROMs of interest included health-related quality of life, visual disability and satisfaction with vision.

RESULTS

The characteristics of the baseline cohort of 359 participants are reported in this manuscript. Enrolment occurred over a two-year period with the majority recruited from urban public hospitals (96 per cent, n = 345). Health-related quality of life was scored highly (80 out of 100). Self-reported visual disability was considered within normal ranges compared to cataract populations in other high-income countries (-0.94 logits). Three-quarters of participants (n = 263/351) were dissatisfied with their pre-operative vision.

CONCLUSIONS

There is a complex and wide range of patient-centred experiences prior to first eye cataract surgery in the public hospital setting. Gaining further insight into the patient perspective may allow eye health professionals to more appropriately time surgery, better manage patient expectations and provide direction for future prioritisation initiatives of cataract wait lists. Companion papers will follow, detailing results of surgery in terms of PROMs.