Vision through Healthy Aging Eyes

As life expectancy grows, so too will the number of people adversely affected by age. Although it is acknowledged that many conditions and diseases are associated with age, this mini-review will present a current update of the various visual changes that generally occur in healthy individuals disregarding the possible effects of illness. These alterations influence how the world is perceived and in turn can affect efficiency or the ability to perform ordinary daily tasks such as driving or reading. The most common physical developments include a decreased pupil size and retinal luminance as well as changes both in intercellular and intracellular connections within the retina along the pathway to the visual cortex and within the visual cortex. The quantity and the physical location of retinal cells including photoreceptors, ganglion and bipolar retinal cells are modified. The clarity of intraocular organs, such as the intraocular lens, decreases. These all result in common visual manifestations that include reduced visual acuity, dry eyes, motility changes, a contraction of the visual field, presbyopia, reduced contrast sensitivity, slow dark adaptation, recovery from glare, variation in color vision and a decreased visual processing speed. Highlighting these prevalent issues as well as current and possible future innovations will assist providers to formulate treatments and thereby conserve maximum independence and mobility in the modern mature population.

Left Turns by Older Drivers With Vision Impairment: A Naturalistic Driving Study

Background and Objectives Older drivers are over-represented in collisions at intersections while making left turns across oncoming traffic. Using naturalistic driving methods, we evaluated the association between vision impairment and their left turn characteristics. Research Design and Methods In this prospective, observational study, vision impairment as defined by visual acuity, contrast sensitivity, visual processing speed, visual field sensitivity and motion perception was assessed in drivers ≥70 years old. Data acquisition systems were installed in their personal vehicles recording video and vehicle kinematics. Driving during everyday life was recorded for six months. Data analysts evaluated a temporal data window surrounding randomly selected left turns at four-way intersections. Left turn traversals and turning behavior were evaluated in terms of age-adjusted associations with vision impairment. Results The sample consisted of 151 older drivers. The number of turns studied was 473; 265 turns were rated as unsafe traversals, and 201 as problematic turning behavior. Drivers with slowed visual processing speed and visual field impairment were less likely to exhibit unsafe traversals (p< 0.05); those with worse contrast sensitivity, slowed visual processing speed, and visual field impairment were less likely to exhibit problematic turning behavior (p <0.05). Discussion and Implications Using naturalistic driving, our study suggests older drivers with vision impairment exhibit better performance in making left turns than those without deficits, which contradicts older driver studies on left turns using driving simulators and on-road driving evaluations. Our findings suggest more cautious and self-regulatory behavior which are consistent with older visually impaired drivers’ commonly expressed concerns about their driving difficulties. Translational Significance In contrast to previous older driver studies using driving simulators and on-road driving evaluations, our study suggests that in everyday life older visually-impaired drivers exercise caution in left-turn behavior across oncoming traffic as compared to those who are normally sighted.

Analysis of Color-Specific Visual Processing Speed Differences in Division 1 College Football Players

IntroductionThe University of Cincinnati has been doing NeuroVisual Training (NVT) as part of an injury prevention and performance enhancement program since 2010. We recently noticed that some athletes have substantial differences in visual reaction time based on color, specifically red versus green. We set out to assess if they may have had any color processing deficiencies.MethodsWe identified 4 out of 107 screened athletes with deficiencies in their ability to react to green compared to red. After identifying these color deficiencies, we developed a protocol to assess and manage the said deficiencies. The protocol included assessing for color blindness with the Ishihara plates, color Visual Evoked Potentials (cVEP), and color-based visual reaction times.ResultsNone of the individuals had color blindness based on the Ishihara plates. There were significant differences in visual reaction times for red and green with red being significantly slower. cVEP mean red P100 latency was 115.5 ± 3.2 ms versus 104.4 ± 1.3 ms for green, and mean voltage was 7.30 ± 1.4 µV versus 9.20 ± 1.4 µV for green. DiscussionNVT is becoming a mainstream means to improve performance and safety for athletes in competitive sports. It was interesting to note that high caliber athletes in a division 1 college football program were showing relatively slow visual reaction times. We were able to train them to a higher level of NVT proficiency once we included color-based tasks that best suited their ability to see and process quickly. People performing NVT on athletes may wish to be aware of and consider checking for color processing deficiencies such that one can train the athletes to the highest level possible.

Alertness Training Increases Visual Processing Speed in Healthy Older Adults

In this study, we investigated whether alertness training in healthy older adults increases visual processing speed (VPS) and whether functional connectivity in the cingulo-opercular network predicts training gain. Using the theory of visual attention, we derived quantitative estimates of VPS before and after training. In Study 1, 75 healthy older adults participated in alertness training, active-control training, or no training ( n = 25 each). A significant Group × Session interaction indicated an increase in VPS in the alertness-training group but not in the control group, despite VPS not differing significantly between groups before training. In Study 2, 29 healthy older adults underwent resting-state functional MRI and then participated in alertness training. Pretraining functional connectivity in the cingulo-opercular network correlated with the individual training-induced change in VPS. In conclusion, results indicate that alertness training improves visual processing in older adults and that functional connectivity in the cingulo-opercular network provides a neural marker for predicting individual training gain.

Visual fixations rather than saccades dominate the developmental eye movement test

When children have visual and/or oculomotor deficits, early diagnosis is critical for rehabilitation. The developmental eye movement (DEM) test is a visual-verbal number naming test that aims to measure oculomotor dysfunction in children by comparing scores on a horizontal and vertical subtest. However, empirical comparison of oculomotor behavior during the two subtests is missing. Here, we measured eye movements of healthy children while they performed a digital version of the DEM. In addition, we measured visual processing speed using the Speed Acuity test. We found that parameters of saccade behavior, such as the number, amplitude, and direction of saccades, correlated with performance on the horizontal, but not the vertical subtest. However, the time spent on making saccades was very short compared to the time spent on number fixations and the total time needed for either subtest. Fixation durations correlated positively with performance on both subtests and co-varied tightly with visual processing speed. Accordingly, horizontal and vertical DEM scores showed a strong positive correlation with visual processing speed. We therefore conclude that the DEM is not suitable to measure saccade behavior, but can be a useful indicator of visual-verbal naming skills, visual processing speed, and other cognitive factors of clinical relevance.

Cognitive Function in Multiple Sclerosis Patients Based on Age, Gender, and Education Level

Multiple sclerosis (MS) is defined as an inflammatory, progressive, and autoimmune disease in the central nervous system, recognized by its subsequent demyelination and neurodegeneration. Cognitive disorders are among the most severe problems in patients with MS, affecting their personal and professional life. This study is aimed to evaluate memory and visual learning, visual processing speed, and spatial perception in MS patients based on age, gender, and level of education. This cross-sectional study was carried out on 42 MS patients (based on McDonald’s criteria). The level of disability in patients was assessed using EDSS, and cognitive performance was evaluated by the use of judgment of line orientation (JLO), symbol digit modalities test (SDMT), and revised brief visuospatial memory test (BVMT-R). In this study, patients were within the age range of 20-51 years, 73.8% of which were female, and 61.9% had academic degrees. According to the classes of independent variables (gender, education level), no significant difference was observed in the mean scores of dependent variables (JLO, SDMT, and BVMR-T scores) (P>0.05). In addition, age as a confounding variable had no impact (P>0.05). In addition, gender and level of education had no significant interaction (P>0.05). According to the results of the study, age, gender, and education level had no significant effect on memory and visual learning, visual processing speed, and spatial perception.