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Optometry and Vision Science : Official... Oct 2015To compare the static and dynamic accommodative responses measured with the WAM-5500 and the PowerRef-II autorefractors. (Comparative Study)
Comparative Study
PURPOSE
To compare the static and dynamic accommodative responses measured with the WAM-5500 and the PowerRef-II autorefractors.
METHODS
The dynamic and static monocular accommodative responses were measured with the WAM-5500 and the PowerRef-II instruments in 30 pre-presbyopic patients (23.66 [±3.19] years). The spherical equivalent was measured at 0.00, 2.50, and 5.00 diopters (D) of accommodative stimulation for the static measurements. The subjective refraction was also determined. Dynamic accommodation was measured for abrupt changes of stimulus vergence of 2.00 D. Mean and peak velocities of accommodation and disaccommodation were evaluated. For the PowerRef-II, dynamic measurements were calculated for sampling frequencies of 5 and 25 Hz.
RESULTS
For far distance static results, the differences between subjective and WAM-5500 measurements were 0.07 (±0.21) D (p = 0.093) and those between subjective and PowerRef-II measurements were 0.70 (±0.47) D (p = 0.001). The difference in the response measured with both instruments was 0.08 (±0.32) D (p = 0.194) for 2.50 D and -0.32 (±0.48) D (p = 0.001) for 5.00 D of stimulation. For the dynamic mode, the PowerRef-II at 25 Hz measured faster mean and peak velocities of accommodation and disaccommodation than the WAM-5500, with statistically significant (p < 0.05) differences of 0.68 (±1.01), 0.67 (±0.98), 1.26 (±1.19), and 1.42 (±1.53) D/s, respectively. With a sampling frequency of 5 Hz for the PowerRef-II, these differences, which were statistically significant (p < 0.05), were reduced to 0.52 (±0.90), 0.49 (±0.91), 0.83 (±1.07), and 0.83 (±1.31) D/s, respectively.
CONCLUSIONS
There is good agreement between subjective refraction and WAM-5500 measurements. In contrast, the PowerRef-II produced more hyperopic results. There were no differences among instruments at 2.50 D of static stimulation; however, differences were found at 5.00 D. In the dynamic measurements, the PowerRef-II measured faster velocities, partly attributed to the difference in the sampling frequency.
Topics: Accommodation, Ocular; Adult; Female; Humans; Male; Prospective Studies; Refractive Errors; Vision Tests; Visual Acuity; Young Adult
PubMed: 26258276
DOI: 10.1097/OPX.0000000000000685 -
Optometry and Vision Science : Official... Oct 2018The response of the pupil to a flash of light, the pupillary light reflex (PLR), is an important measure in optometry and in other fields of medicine that is typically...
SIGNIFICANCE
The response of the pupil to a flash of light, the pupillary light reflex (PLR), is an important measure in optometry and in other fields of medicine that is typically evaluated by qualitative observation. Here we describe a simple, portable, iPhone-based pupillometer that quantifies the PLR in real time.
PURPOSES
The purposes of this study were to describe a novel application that records the PLR and to compare its technical capabilities with a laboratory-based infrared (IR) camera system.
METHODS
Pupil sizes were measured from 15 visually normal subjects (age, 19 to 65 years) using an IR camera system and the Sensitometer test. This test elicits pupillary constriction using the iPhone flash, records pupil size using the camera, and provides measurements in real time. Simultaneous recordings were obtained with the Sensitometer test and IR camera, and two measures were calculated: (1) dark-adapted steady-state pupil size and (2) minimum pupil size after the flash. The PLR was defined as the difference between these two measures. Pupil size was also recorded during the redilation phase after the flash. Bland-Altman analysis was used to assess the limits of agreement between the two methods.
RESULTS
Statistically significant correlations between the IR and Sensitometer test measures were found for the PLR (r = 0.91, P < .001) and redilation size (r = 0.65, P = .03). Bland-Altman analysis indicated a mean PLR difference of 6% between these two methods. The PLR limit of agreement was 14%, indicating that 95% of subjects are expected to have IR and Sensitometer test measurements that differ by 14% or less. Bland-Altman analysis indicated a mean redilation size difference of 1% between the two methods; the limit of agreement was 5%.
CONCLUSIONS
There is excellent agreement between pupil responses recorded using the Sensitometer test and IR camera. The Sensitometer test provides a highly promising approach for simple, portable, inexpensive pupillary measurements.
Topics: Adult; Aged; Female; Humans; Light; Male; Middle Aged; Pupil; Reaction Time; Reflex, Pupillary; Smartphone; Vision Tests; Vision, Ocular; Young Adult
PubMed: 30234829
DOI: 10.1097/OPX.0000000000001289 -
Optometry and Vision Science : Official... Mar 2022Logarithmic reading charts provide standardized measures of reading performance. Here we show that existing charts provide equivalent assessments of visual aspects of...
SIGNIFICANCE
Logarithmic reading charts provide standardized measures of reading performance. Here we show that existing charts provide equivalent assessments of visual aspects of reading that are in good agreement with traditional measures of visual acuity and seem uninfluenced by cognitive (linguistic) factors.
PURPOSE
The aims of this study were to (1) determine the equivalence of logarithmic charts of sentence and word reading, (2) evaluate the relationship between reading chart performance and more traditional measures of visual assessment, and (3) establish the influence of linguistic factors on reading chart performance.
METHODS
In a sample of 82 normally sighted participants, we determined performance on the reading measures (e.g., reading acuity, reading speed, critical print size) of the following logarithmic charts of sentence and word reading: The Colenbrander English Continuous Text Near Vision Card, Radner Reading Chart, Minnesota Reading Acuity Chart, and Smith-Kettlewell Reading Chart. In doing so, we compared performance on reading measures between charts and with performance on more traditional measures of visual assessment (uncrowded and crowded letter acuity, stereoacuity, accommodation) and cognitive measures of word knowledge and ability (Wechsler Adult Intelligence Scale Vocabulary Subtest, National Adult Reading Test).
RESULTS
Factor analysis confirmed that performance on the reading measures (reading acuity, reading speed, critical print size) was equivalent across charts. Reading test performance was also related to more traditional measures of vision, the most consistent of which were significant associations between reading acuity and acuity for single-letter optotypes. There were no significant associations between reading chart performance and cognitive measures of word knowledge and ability.
CONCLUSIONS
The findings presented here suggest that logarithmic charts composed of sentences and words represent an alternative to traditional letter acuity testing. This is particularly the case for measures of reading acuity.
Topics: Accommodation, Ocular; Adult; Humans; Language; Reading; Vision Tests; Visual Acuity
PubMed: 35045563
DOI: 10.1097/OPX.0000000000001865 -
Cornea Aug 2015The aim of this study was to evaluate the visual function information obtained from multiple reading tests in a dry eye population.
PURPOSE
The aim of this study was to evaluate the visual function information obtained from multiple reading tests in a dry eye population.
METHODS
In this case-control, single-center clinical research center-based study, 15 subjects with dry eye (mean age 65 years) and 10 normal subjects (mean age 40 years) were included. The Standardized Mini-Mental Examination was given to assure that subjects had normal cognitive function. Reading tests were both sentence based (Radner reading acuity test, reading contrast sensitivity test at a fixed print size, and menu-reading test) and paragraph based (Wilkins test and International Reading Speed Texts [IReST]). Wilkins and IReST tests were slightly modified to increase difficulty and visual stress. The main outcome measures were cognitive function, fatigue, dry eye symptoms, reading acuity, reading rate, and blink rate.
RESULTS
Results showed significantly lower rates in all reading tests in subjects with dry eye than in normal subjects; in the age-matched subgroup, only the menu and contrast sensitivity tests lost significance. Fatigue was significantly related to the IReST test, both at normal and critical print sizes. Reflex tearing was monitored and shown to significantly decrease the reading rate. IReST scores were considered the baseline, and the percent change from one test to IReST was also used to differentiate dry eye and normal subjects. The blink rate, symptoms, and demographics were not significantly correlated with reading tests.
CONCLUSIONS
Reading is a relevant end point that differentiates dry eye and normal subjects. This study evaluated a variety of reading tests for relevance as a measurable assessment of visual function in dry eye disease.
Topics: Adult; Aged; Blinking; Case-Control Studies; Cognition; Contrast Sensitivity; Dry Eye Syndromes; Female; Humans; Intelligence Tests; Male; Middle Aged; Reading; Vision Disorders; Vision Tests; Visual Acuity
PubMed: 26075460
DOI: 10.1097/ICO.0000000000000490 -
The Journal of Pediatrics Feb 2022To test the association of material deprivation and the utilization of vision care services for young children.
OBJECTIVE
To test the association of material deprivation and the utilization of vision care services for young children.
STUDY DESIGN
We conducted a population-based, repeated measures cohort study using linked health and administrative datasets. All children born in Ontario in 2010 eligible for provincial health insurance were followed from birth until their seventh birthday. The main exposure was neighborhood-level material deprivation quintile, a proxy for socioeconomic status. The primary outcome was receipt of a comprehensive eye examination (not to include a vision screening) by age 7 years from an eye care professional, or family physician.
RESULTS
Of 128 091 children included, female children represented 48.7% of the cohort, 74.4% lived in major urban areas, and 16.2% lived in families receiving income assistance. Only 65% (n = 82 833) had at least 1 comprehensive eye examination, with the lowest uptake (56.9%; n = 31 911) in the most deprived and the highest uptake (70.5%; n =19 860) in the least deprived quintiles. After adjusting for clinical and demographic variables, children living in the least materially deprived quintile had a higher odds of receiving a comprehensive eye examination (aOR 1.43; 95% CI 1.36, 1.51) compared with children in the most materially deprived areas.
CONCLUSIONS
Uptake of comprehensive eye examinations is poor, especially for children living in the most materially deprived neighborhoods. Strategies to improve uptake and reduce inequities are warranted.
Topics: Child; Child, Preschool; Facilities and Services Utilization; Female; Health Services Accessibility; Healthcare Disparities; Humans; Infant; Longitudinal Studies; Male; Ontario; Social Class; Vision Disorders; Vision Tests
PubMed: 34687692
DOI: 10.1016/j.jpeds.2021.10.020 -
Aerospace Medicine and Human Performance Feb 2023Computerized color contrast sensitivity (CS) tests that aim to determine presence, type, and severity of color vision deficiency have been developed and are available,...
Computerized color contrast sensitivity (CS) tests that aim to determine presence, type, and severity of color vision deficiency have been developed and are available, but data on agreement between tests is lacking. The purpose of the present study was to determine data agreement between three computerized color vision tests. A total of 50 subjects, 25 color vision normal (CVN) and 25 color vision deficient (CVD), were tested with the Konan CCT-HD, NCI, and a modified version of the Innova CCT. Sensitivity and specificity were compared across systems as well as differences in log CS values and how these relate to standards used to classify occupational performance. Each test showed 100% sensitivity for detection of hereditary red-green CVDs as well as type (protan vs. deutan). Each test showed 100% specificity for confirming normal red-green color vision in CVNs. Innova CCT and NCI showed 100% specificity in CVNs and CVDs for S cone CS. Konan CCT-HD showed 96% specificity in CVNs and 92% in CVDs for S cone CS. These findings indicate that each test reliably identifies hereditary CVD and confirms normal color vision. However, the three tests differ slightly in log CS values used to determine pass/fail scores of red-green color vision using a 100-point scale, and all show that protans consistently score lower than deutans on cone CS. Hence, depending on the criterion used in occupational settings, a single score may not prove equitable for individuals who have a protan deficiency.
Topics: Humans; Color Vision; Color Perception Tests; Contrast Sensitivity; Color Vision Defects; Cardiovascular Diseases; Computers
PubMed: 36755001
DOI: 10.3357/AMHP.6118.2023 -
Translational Vision Science &... Mar 2021To examine the feasibility of saccadic vector optokinetic perimetry (SVOP), an automated eye tracking perimeter, as a tool for visual field (VF) assessment in infants.
PURPOSE
To examine the feasibility of saccadic vector optokinetic perimetry (SVOP), an automated eye tracking perimeter, as a tool for visual field (VF) assessment in infants.
METHODS
Thirteen healthy infants aged between 3.5 and 12.0 months were tested binocularly using an adapted SVOP protocol. SVOP uses eye tracking technology to measure gaze responses to stimuli presented on a computer screen. Modifications of SVOP for testing infants included adjusting the fixation target to display a short animation, increasing the stimulus size to equivalent to Goldmann V, and introducing a tiered test pattern strategy. Binocular, single-quadrant confrontation VF testing and Keeler preferential looking cards visual acuity testing was also performed.
RESULTS
Using multiple test attempts when required, all but the youngest infant (12 of 13 [92.3%]) successfully completed a 4-point screening test. Seven infants (53.8%) successfully completed the 12-point test, four (30.8%) successfully completed the 20-point test, and three (23.1%) successfully completed the 40-point test. The effect of multiple test attempts and the complexity of the test pattern (number of test points) on performance was investigated, including test completion rate, percentage of correctly seen stimuli, and average time per tested stimulus.
CONCLUSIONS
The modified SVOP test strategy allowed successful assessment of binocular VFs in healthy infants. Future data collection from larger cohorts of infants is needed to derive normative limits of detection and assess accuracy in detecting and monitoring infant VF abnormalities.
TRANSLATIONAL RELEVANCE
Eye tracking perimetry may provide a useful method of automated VF assessment in infants.
Topics: Feasibility Studies; Humans; Infant; Saccades; Vision Tests; Visual Field Tests; Visual Fields
PubMed: 34003948
DOI: 10.1167/tvst.10.3.14 -
Optometry and Vision Science : Official... May 2018This study suggests that it is possible for some patients with severe red-green color vision deficiency to do perfectly on the Farnsworth D15 test after practicing it.
SIGNIFICANCE
This study suggests that it is possible for some patients with severe red-green color vision deficiency to do perfectly on the Farnsworth D15 test after practicing it.
PURPOSE
The Farnsworth D15 is a commonly used test to qualify people for certain occupations. For patients with color vision deficiency, there may be high motivation to try to pass the test through practice to gain entry into a particular occupation. There is no evidence in the literature on whether it is possible for patients to learn to pass the D15 test through practice.
METHODS
Ten subjects with inherited red-green color vision deficiency and 15 color-normal subjects enrolled in the study. All subjects had anomaloscope testing, color vision book tests, and a Farnsworth D15 at an initial visit. For the D15, the number of major crossovers was determined for each subject. Failing the D15 was determined as greater than 1 major crossover. Subjects with color vision deficiency practiced the D15 as long as desired to achieve a perfect score and then returned for a second visit for D15 testing. A paired t test was used to analyze the number of major crossovers at visit 1 versus visit 2.
RESULTS
Color-normal subjects did not have any major crossovers. Subjects with color vision deficiency had significantly (P < .001) fewer major crossovers on the D15 test at visit 2 (mean/SD = 2.5/3.0), including five subjects with dichromacy that achieved perfect D15 performance, compared to visit 1 (mean/SD = 8.7/1.3).
CONCLUSIONS
Practice of the Farnsworth D15 test can lead to perfect performance for some patients with color vision deficiency, and this should be considered in certain cases where occupational entry is dependent on D15 testing.
Topics: Adult; Color Perception; Color Perception Tests; Color Vision; Color Vision Defects; Female; Humans; Learning; Male; Middle Aged; Prospective Studies
PubMed: 29683989
DOI: 10.1097/OPX.0000000000001218 -
Graefe's Archive For Clinical and... Jun 2024Visual function is a complex process in which external visual stimuli are interpreted. Patients with retinal diseases and prolonged follow-up times may experience... (Review)
Review
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.
Topics: Humans; Visual Acuity; Contrast Sensitivity; Macula Lutea; Retinal Diseases; Vision Tests; Dark Adaptation; Visual Field Tests; Quality of Life
PubMed: 37938378
DOI: 10.1007/s00417-023-06272-1 -
Clinical & Experimental Optometry May 2022A scoring criterion of three-or-more letters correct on a line results in the most equivalent visual acuity score to letter-by-letter scoring.
CLINICAL RELEVANCE
A scoring criterion of three-or-more letters correct on a line results in the most equivalent visual acuity score to letter-by-letter scoring.
BACKGROUND
Using the criterion of three-or-more letters correct on a line of five letters to measure a line visual acuity is common. In this study, different line acuity criteria are compared to letter-by-letter visual acuity scoring to determine which criterion is the most accurate as well as least variable.
METHODS
One eye each of 32 subjects was tested with high-contrast visual acuity charts at 4.88 m. Subjects had 16 acuities measured: 8 under normal conditions and 8 under a + 1.50D blur condition. For each set of 8, logMAR visual acuity results were obtained by retrospectively applying each of four scoring criteria twice: letter-by-letter acuity and three line acuities (three-or-more, four-or-more, or five correct on a line). Differences in means were analysed using repeated measures ANOVA with post-hoc Tukey testing. Test-retest variability was analysed via Bland-Altman analysis.
RESULTS
The mean visual acuities (in logMAR) were -0.10, -0.11, -0.07, and -0.01 for letter-by-letter, three-or-more correct, four-or-more correct, and all five correct, respectively. With blur, the mean visual acuities were 0.41, 0.39, 0.45, and 0.53 for the respective criteria. Under both normal and blur conditions, the different acuity scoring criteria resulted in significant differences (p < 0.001), except for the letter-by-letter and three-or-more criteria (p ≥ 0.18). Whereas the criteria resulted in similar test-retest variability under blur, the line acuity using a criterion of three-or-more letters correct resulted in the lowest test-retest variability under best-corrected conditions.
CONCLUSION
A line visual acuity scoring criterion of three-or-more letters correct on a line, whether with good visual acuity or poorer visual acuity due to defocus, provides the most similar acuity and test-retest variability compared to letter-by-letter visual acuity.
Topics: Humans; Retrospective Studies; Vision Disorders; Vision Tests; Visual Acuity
PubMed: 34139959
DOI: 10.1080/08164622.2021.1924625