Simple Vision Function Tests that Distinguish Eyes with Early to Intermediate Age-related Macular Degeneration.

PURPOSE: To present and compare baseline vision findings in eyes with early age-related macular degeneration (E-AMD), intermediate AMD (I-AMD), and age-similar participants with normal aging changes to the retina (No-AMD). METHODS: Two hundred and thirty-seven eyes of 125 individuals (66.4% female, mean age 75.3 years) were tested monocularly using several simple, rapid psychophysical tests: high contrast visual acuity, low contrast visual acuity at reduced luminance, contrast sensitivity, shape discrimination hyperacuity, colour vision, reading rate, and glare recovery. Retinal status was determined using colour fundus photographs that were graded according to the Beckman Initiative for Macular Research Classification Committee scale. Logistic regression analyses with generalized estimating equations were used to assess the association between each vision variable and AMD category, while taking into account the correlation between the two eyes. RESULTS: Three vision measures (contrast sensitivity [CS], shape discrimination hyperacuity [SDH], and colour discrimination [DesatCCS]) were significantly and independently associated with intermediate AMD. Relative Risk Ratios (RRR), 95% Confidence Intervals (in parentheses), beta coefficients, and significance (p) for the I-AMD vs. No-AMD model are: CS: RRR = 6.5 (1.91-22.0), beta = 1.87, p < .01; SDH: RRR = 2.34 (1.24-4.44), beta = 0.85, p < .001; DesatCCS: RRR = 1.43 (1.22-1.68), beta = 0.36, p < .001. Performance on these measures was significantly poorer for participants with I-AMD vs. No-AMD. CONCLUSIONS: Simple screening tests distinguish eyes with intermediate AMD from eyes with less severe AMD or normal aging changes. This suggests that these vision measures may be significant predictors of which participants will go on to develop advanced AMD.

Fixational microsaccades: A quantitative and objective measure of disability in multiple sclerosis.

BACKGROUND: Objective tools for prognosis and disease progression monitoring in multiple sclerosis (MS) are lacking. The visuomotor system could be used to track motor dysfunction at the micron scale through the monitoring of fixational microsaccades. AIMS: The aim of this study was to evaluate whether microsaccades are correlated with standard MS disability metrics and to assess whether these methods play a predictive role in MS disability. METHOD: We used a custom-built retinal eye tracker, the tracking scanning laser ophthalmoscope (TSLO), to record fixation in 111 participants with MS and 100 unaffected controls. RESULTS: In MS participants, a greater number of microsaccades showed significant association with higher Expanded Disability Status Scale score (EDSS, p < 0.001), nine-hole peg test (non-dominant: p = 0.006), Symbol Digit Modalities Test (SMDT, p = 0.014), and Functional Systems Scores (FSS) including brainstem (p = 0.005), cerebellar (p = 0.011), and pyramidal (p = 0.009). Both brainstem FSS and patient-reported fatigue showed significant associations with microsaccade number, amplitude, and peak acceleration. Participants with MS showed a statistically different average number (p = 0.020), peak vertical acceleration (p = 0.003), and vertical amplitude (p < 0.001) versus controls. Logistic regression models for MS disability were created using TSLO microsaccade metrics and paraclinical tests with ⩾80% accuracy. CONCLUSION: Microsaccades provide objective measurements of MS disability level and disease worsening.

The Impact of Presentation Mode and Technology on Reading Comprehension among Blind and Sighted Individuals.

SIGNIFICANCE: Technological advancements have made distributing reading materials in audio formats more common. Investigating how presentation mode impacts comprehension among sighted and blind individuals will inform the distribution of information to enhance comprehension. PURPOSE: The aims were (1) to investigate the hypothesis that reading comprehension is enhanced by increased physical engagement and cognitive effort through text or braille and (2) to explore how assistive technology impacts comprehension for blind individuals. METHODS: In a within-subjects design, 31 sighted and 34 blind participants read and listened to scientific passages and verbally answered free-response questions about what they read and heard. For sighted participants, passages were presented in text and human voice actor recordings. For blind participants, passages were presented with hard-copy braille, a refreshable braille display, voice actor recordings, and a screen reader. RESULTS: Comprehension scores were analyzed using mixed-effects regression and pairwise comparisons on the estimated marginal means. In study 1, the comprehension difference between text or hard-copy braille and the voice actor formats was assessed to address the first aim. Sighted participants had better comprehension with text (mean, 74.8%; 95% confidence interval [CI], 70.5 to 79.1%) than with a voice actor (mean, 69.7%; 95% CI, 65.4 to 74.0%; P = .02), and blind participants had superior comprehension with hard-copy braille (mean, 70.4%; 95% CI, 63.3 to 77.5%) than with a voice actor (mean, 61.9%; 95% CI, 54.7 to 69.0%; P = .03). In study 2, the comprehension differences among blind participants between the four formats were investigated to address the second aim. Comprehension was better with hard-copy braille (mean, 70.6%; 95% CI, 63.4 to 77.7%) than with a screen reader (mean, 60.7%; 95% CI, 53.5 to 67.9%; P = .02) and better with a braille display (mean, 69.7%; 95% CI, 62.5 to 76.9%) than with a screen reader (P = .04). CONCLUSIONS: Study 1 supports the hypothesis that more physically engaging tasks enhance comprehension, and study 2 suggests that listening to scientific materials using a synthesized voice may reduce comprehension ability compared with hard-copy braille and braille displays.

Effect of modulating braille dot height on reading regressions.

It is well known that people who read print or braille sometimes make eye or finger movements against the reading direction. The way these regressions are elicited has been studied in detail by manipulating linguistic aspects of the reading material. Actually, it has been shown that reducing the physical intensity or clarity of the visual input signal can also lead to increased regressions during reading. We asked whether the same might be true in the haptic realm while reading braille. We set the height of braille dots at three different levels (high, medium, and low) and asked adult blind, practiced braille readers to read standardized texts without any repetition of content. The results show that setting the braille dot height near the tactile threshold significantly increased the frequency of regressive finger movements. Additionally, at the lowest braille dot height, braille reading speed significantly diminished. These effects did not occur at braille dot heights that were closer to the height of standard braille (medium and high). We tentatively conclude that this effect may be due to a heightened sense of uncertainty elicited by perception near the threshold that seems to be common to the reading process, independent of the sensory input modality. Furthermore, the described effect may be a feature of a brain area that contributes to the reading process mediated by vision as well as touch.