Senile Miosis Research Articles

Theoretical foundations of the educational module aimed at providing students with a complex of knowledge, skills and abilities necessary for understanding the specifics of color communication of elderly people

The goal of the paper is to present the theoretical foundations of a unique training program aimed at providing students with a complex of knowledge, skills and abilities needed to understand the specifics of color communication in old and very old age. The objectives of the paper include an analytical review of the sources that have defined the program content, the structure of the educational module, and its methodological basis. The selection of research sources was carried out through the RSCI, Google Scholar, Scopus, and Web of Science systems. In the process of work the methods of theoretical and comparative analysis, systematization and generalization of materials were used. The authors provide a detailed analysis of the sources, which represent the dynamics of age-related physiological changes in color vision and examine their impact on color communication of elderly people. Each of the theoretical models included into the review makes a special contribution to the development of the problem. The experiments with colored glasses of K. Ishihara et al. provide an opportunity to feel the impact of age-related decline in visual ability on everyday life and habits of an aging person. The research of D.T. Lindsay and A.M. Brown helps to understand how aging of the eye influences perception of individual shades. The method of M.F. Hassan's research group simulates how elderly people see different color combinations and complex images. An optical google of T. Suzuki et al. enables young people to experience senile miosis in any environment in real time under different illuminance conditions. J.L. Hardy's et al. experiment explains why elderly people often do not realize that their color perception is changing. In the complex, all the studies presented in the review help students to better understand the specifics of color communication in old and very old age, and thus to form a sustainable complex of knowledge, skills and abilities necessary for improving the quality of color design projects, creating by young professionals for elderly people

Age‐dependent prediction of visible differences in displayed images

AbstractA comprehensive computational model of the human visual system has been developed to predict just‐noticeable differences between a pair of stimuli. The stimuli are provided as high‐dynamic‐range, multichannel images, containing accurate spectral and photometric description of the scene. In this work, we extend such a model to determine the effect of age on the sensitivity of the visual system. The extensions are based on the existing models of disability glare, aging of the crystalline lens, and reduced pupil size with age (senile miosis). We confirm findings from other studies that those optical effects cannot fully explain the effect of aging, and we attribute the remaining drop of sensitivity to neural changes. The complete model, including an empirical neural component, can well explain the differences in contrast sensitivity between old and young observers.

Effect of age on pattern-reversal visual evoked potentials in Indian population

Background and Aim: Functional declines of the visual system are probably the most obvious aging changes in humans. Normal non-pathologic aging causes senile miosis and media opacities which cannot entirely explain the age-related declines. Changes in the retina and its neuro-circuitary contribute to the visual decline, which can be evaluated by evoked potentials. We investigated the effects of age on various components of transient pattern-reversal visual evoked potentials (t-PRVEPs) and whether there is presence of any differential aging on t-PRVEPs in Indian population. Methods: Monocular t-PRVEPs of 292 eyes from 146 normal subjects living in Wardha, Maharashtra and whose age ranges from 1-75 years, were recorded on an evoked potential recorder. Differences in latencies and amplitude were analyzed using one way analysis of variance (ANOVA) and polynomial regressions. Results: Age affects the PRVEP components differently with the most significant changes encountered in the P100 amplitude. The present study demonstrated that statistically, at least 67% of these changes are contributed by age alone. Comparisons with studies abroad showed similar changes but suggest the existence of an aging difference in Indians by at least 5 years. Indian males and females also showed aging differences with the latter aging earlier by at least 6-7 years. Conclusion: We therefore conclude that Indians seem to age faster compared to other populations and further research on possible causes for this difference in aging is warranted.

Accommodation in phakic and pseudophakic eyes measured with subjective and objective methods

To measure accommodation subjectively and objectively and assess anterior segment changes during accommodation in phakic eyes and pseudophakic eyes. Department of Ophthalmology, Medical Health and Science Centre, University of Debrecen, Debrecen, Hungary. Case series. Subjective and objective accommodation measurements and pupillometry were performed in phakic and pseudophakic patients. Refraction and pupil diameter were recorded with different accommodation stimuli. Corneal higher-order aberrations (HOAs) and anterior chamber depths (ACDs) were detected with a rotating Scheimpflug camera. The mean age of the 44 patients in the phakic group was 36.34 years ± 16.6 (SD) and of the 27 patients in the pseudophakic group, 69.3 ± 9.98 years. The mean subjective accommodation was 4.49 ± 3.48 diopters (D) in phakic eyes and showed significant correlation with age, spherical aberration, changes in pupil diameter, and ACD. The mean subjective accommodation was 0.50 ± 0.28 D in pseudophakic eyes. In phakic eyes, the mean objective accommodation was 0.46 ± 1.02 D, 1.06 ± 1.33 D, and 2.2 ± 1.9 D with 2.0 D, 3.0 D, and 5.0 D, respectively, of stimulus. In pseudophakic eyes, measurable objective accommodation was recorded. In phakic eyes, the correlations were significant between these values and age, changes in ACD, pupil size, and corneal spherical aberration. In pseudophakic eyes, the only correlation was with the spherical equivalent value. The magnitude of accommodation was greater with subjective measures than objective measures. In pseudophakic eyes, senile miosis and HOAs can be regarded as underlying factors in subjective accommodation; however, objective accommodation is not clinically significant. No author has a financial or proprietary interest in any material or method mentioned.

Early ERPs to faces: aging, luminance, and individual differences

Recently, Rousselet et al. reported a 1 ms/year delay in visual processing speed in a sample of healthy aged 62 subjects (Frontiers in Psychology 2010, 1:19). Here, we replicate this finding in an independent sample of 59 subjects and investigate the contribution of optical factors (pupil size and luminance) to the age-related slowdown and to individual differences in visual processing speed. We conducted two experiments. In experiment 1 we recorded EEG from subjects aged 18–79. Subjects viewed images of faces and phase scrambled noise textures under nine luminance conditions, ranging from 0.59 to 60.8 cd/m2. We manipulated luminance using neutral density filters. In experiment 2, 10 young subjects (age < 35) viewed similar stimuli through pinholes ranging from 1 to 5 mm. In both experiments, subjects were tested twice. We found a 1 ms/year slowdown in visual processing that was independent of luminance. Aging effects became visible around 125 ms post-stimulus and did not affect the onsets of the face-texture ERP differences. Furthermore, luminance modulated the entire ERP time-course from 60 to 500 ms. Luminance effects peaked in the N170 time window and were independent of age. Importantly, senile miosis and individual differences in pupil size did not account for aging differences and inter-subject variability in processing speed. The pinhole manipulation also failed to match the ERPs of old subjects to those of young subjects. Overall, our results strongly suggest that early ERPs to faces (<200 ms) are delayed by aging and that these delays are of cortical, rather than optical origin. Our results also demonstrate that even late ERPs to faces are modulated by low-level factors.

Optical simulation of reduced retinal illuminance caused by senile miosis

In order to simulate elderly vision for young observers, we developed an optical goggle using filters whose transmittance optically simulates the senile miosis: reduction in retinal illuminance as a function of ambient illuminance. First, we measured the pupil size of young and elderly subjects (mean age were 21.8 and 67.1 years, respectively) under six illuminance conditions (from 0.03 to 4850 lx), and formulated the relationship between illuminance and pupillary area functions in both age groups. Next, the transmittance formulae for the filter simulating the senile miosis were derived based on the properties of the pupillary area and visual functions of the elderly and the young subjects including the effect of mydriasis induced by the reduction of light due to the filter in young observers. Finally, we developed a goggle-type simulator using active optical devices which enables young people to experience senile miosis in any environment in real time.

Ocular monochromatic aberration statistics in a large emmetropic population

The primary objective of this study was to explore the statistics of ocular higher-order aberrations in a nearly emmetropic population. The wavefront aberration of 393 eyes of 218 subjects was obtained under natural conditions using the WaveLight WaveFront Analyser. The spherical equivalent of eyes ranged between +0.75 and − 1.25 D, with the astigmatism being less than 0.75 D. Mean age was 33.0±4.8 years. Analysis was performed for a 6 mm pupil. A significant dispersion in all Zernike coefficients was found. Population average values of Zernike coefficients were almost zero, with the exemption of primary spherical ( µm) and oblique trefoil () aberrations. Mean higher-order RMS error was 0.26 µm, corresponding to an equivalent defocus of 0.20 D. An increase in higher-order RMS with age (at pre-presbyopic range) was found, which was accompanied by changes in coma-like aberrations, while spherical aberration remained unchanged. Emmetropic eyes appear to have on average lower individual and combined higher-order aberrations than previously reported values on myopic eyes. Although aberration levels at fixed pupil diameter increase with age, their effect on retinal image quality is possibly cancelled out by senile miosis.

Circadian rhythm dysfunction in glaucoma: A hypothesis.

The absence of circadian zeitgebers in the social environment causes circadian misalignment, which is often associated with sleep disturbances. Circadian misalignment, defined as a mismatch between the sleep-wake cycle and the timing of the circadian system, can occur either because of inadequate exposure to the light-dark cycle, the most important synchronizer of the circadian system, or reduction in light transmission resulting from ophthalmic diseases (e.g., senile miosis, cataract, diabetic retinopathy, macular degeneration, retinitis pigmentosa, and glaucoma). We propose that glaucoma may be the primary ocular disease that directly compromises photic input to the circadian time-keeping system because of inherent ganglion cell death. Glaucomatous damage to the ganglion cell layer might be particularly harmful to melanopsin. According to histologic and circadian data, a subset of intrinsically photoresponsive retinal ganglion cells, expressing melanopsin and cryptochromes, entrain the endogenous circadian system via transduction of photic input to the thalamus, projecting either to the suprachiasmatic nucleus or the lateral geniculate nucleus. Glaucoma provides a unique opportunity to explore whether in fact light transmission to the circadian system is compromised as a result of ganglion cell loss.

Aging effects on the identification of digitally blurred text, scenes and faces: Evidence for optical compensation on everyday tasks in the senescent eye

When older observers are defocused optically to the same reduced acuity levels as their younger adult counterparts they are better able to read distant text. This study sought to determine if this ability extended to intrinsically blurred (i.e., image-processed) stimuli of different types. Such an outcome suggests an explanation based on older persons’ greater experience with blurred stimuli; otherwise, one attributable to compensatory changes in the optic media of the older eye would be favored. Twelve young and 12 old healthy community-resident adult observers with excellent acuity were compared on their ability to identify low-pass filtered real words, nonsense words, scenes, and faces arranged in a sequence of decreasingly blurred images. Young observers were able to identify the images correctly earlier in the blur sequence than older adult observers, significantly so for both real and nonsense words. This finding suggests that compensatory changes in the eye’s optical media rather than older observers’ greater experience with blur accounts for their superior legibility performance with optically defocused text. While the image-enhancing effects of the age-related decline in pupil size (senile miosis) may be involved, further research is needed to clarify the mechanism(s) underlying this ability.

Psychophysical evidence for losses in rod sensitivity in the aging visual system.

Rod sensitivity was measured with a criterion-free psychophysical method at 10 deg in the horizontal meridian of the nasal field of the left eye on 26 young (mean age, 24.1 yr) and 14 older (mean age 72.6 yr) observers in good ocular health. A 1 deg, 90 msec stimulus was delivered by means of a free-viewing optical system under computer control. Stimulus wavelengths were chosen to have either significant (406 nm) or minimal (560 nm) absorption by the older lens. After correction for senile miosis and lens density, 0.39 log unit higher thresholds for the older observers remained and are interpreted as being due to neural factors.

Aging and pattern visual evoked potentials.

Visual abilities decline during senescence. Age-related declines cannot be attributed entirely to changes in optical factors (senile miosis and opacification of the ocular media) and must therefore be caused by changes in the visual pathways. Because pattern visual evoked potentials (VEPs) provide information regarding the sensory function and integrity of the visual system, recent research on age-related changes in VEPs is reviewed. The results of this review show that stimulus parameters of VEPs (luminance, contrast, spatial and temporal frequencies) modify the age-related changes in VEPs. The visual system consists of multiple, parallel channels which process different information. Therefore, it is hypothesized that aging may affect the specific functional subdivisions in the visual pathways differentially.

Age‐related changes in the color appearance of broadband surfaces

AbstractChromatic and achromatic components of 15 broadband surfaces were scaled by 15 younger (mean age = 21.3 yrs) and 15 older (mean age = 71.9 yrs) subjects. Colored surfaces were obtained from the OSA Uniform Color Scales and presented as 2°‐diameter test stimuli that were freely viewed. Stimuli were presented in a grey (L = 0) ganzfeld‐like hemisphere with an illuminant having a correlated color temperature of 6200 K. Five stimuli were presented at three lightness levels (L = −4, 0 and +4). Each lightness level included samples chosen so that one pair plotted approximately along a tritan axis in MacLeod‐Boynton receptor‐excitation space and another pair plotted on an axis of constant S‐cone stimulation. The appearance of each test stimulus was scaled using the hue terms red, green, yellow and blue, and in terms of the proportion of overall chromatic content. The results indicate that hue names were used similarly for the two groups of subjects, however, older subjects perceived all stimuli as having less chromatic content than demonstrated by younger observers. Differences between the two age groups in perceived chromatic content of the test stimuli progressively increased as the lightness and luminance levels of the test stimuli decreased. Results obtained from control experiments suggest that this difference between the two age groups is not due to the influence of senile miosis or lenticular senescence leading to variations in the illuminances and spectral compositions of the test lights reaching the retina. © 1993 John Wiley &amp; Sons, Inc.

The effects of ageing on the pattern electroretinogram and visual evoked potential in humans

We have recorded patterns electroretinograms (PERGs) and visual evoked potentials (VEPs) from 14 elderly subjects (mean age 72 yr) and 12 young subjects (mean age 21 yr) in response to stimulation by high contrast sinusoidal grating patterns of variable spatial frequency (at 9 Hz) and temporal frequency (at 1.7 c/deg). The major effect of ageing on the PERG was an aspecific reduction in amplitude (of about 40%) at most spatial and temporal frequencies, together with a small but systematic phase lag. Control measurements suggest that senile miosis may be responsible for the phase lag, but not for the reduction in amplitude. The effects of ageing on the VEP were more dramatic and depended on the spatial and temporal properties of the stimulus. VEP amplitudes (at 1.7 c/deg) were significantly lower for the aged at low temporal frequencies (below about 6 Hz), but were similar at high temporal frequencies. At 9 Hz, there was no effect of spatial frequency on VEP amplitude. At high temporal frequencies (above 10 Hz), the latencies of VEPs (estimated from the rate at which phase varied with temporal frequency) were similar for old and young (94 and 99 msec respectively). Below 10 Hz, however, the latencies of the old observers was much greater (153 compared with 108 msec). The second-harmonic phase of VEPs of the old but not the young decreased considerably with spatial frequency, by about 1.9π radians (52msec) over the range from 0.5 to 11 c/deg. The selective reduction in amplitude at low temporal frequencies, the longer latencies at low temporal frequencies and the phase lag at high spatial frequencies are consistent with the hypothesis that mechanisms sensitive to high spatial and low temporal frequencies are selectively degraded by ageing.

The human pattern ERG: alteration of response properties with aging.

The influence of aging on both the amplitude and the latency of transient and steady-state pattern electroretinograms (PERG's) was studied in 80 healthy participants ranging from 25 to 77 years of age (mean age, 55.3 years). Responses to counterphasing checkerboard patterns were recorded for each of 7 test conditions in which the spatial (i.e., check sizes 0.25, 0.50, 1.00, and 2.00 degrees) and temporal characteristics (i.e., counterphasing at either 2, 4, 8, or 16 rps) of the stimuli were varied. For both the transient and steady-state PERG's amplitude was inversely related to age (p less than 0.05 for each test condition). In general, PERG latency directly correlated with age, but this effect was less robust (p less than 0.05 for one transient condition and three of the four steady-state conditions). The influence of age on the spatial tuning of the PERG was minimal; the decrease in PERG amplitude and the increase in PERG latency as a function of age were essentially the same for all test conditions. However, the magnitude of the age-related reduction in PERG amplitude was observed to vary with temporal frequency, being largest for the steady-state condition (16 rps). The results from an experiment in which young subjects were tested while wearing opaque contact lenses with 2-mm artificial pupils suggest that senile miosis is a significant factor contributing to the age-related PERG amplitude and latency changes, but it does not fully account for the observed changes.

The influence of age on the pattern and flash visual evoked magnetic response (VEMR)

The visual evoked magnetic response (VEMR) was measured over the occipital cortex to pattern and flash stimuli in 86 normal subjects aged 15-86 years. The latency of the major positive component (outgoing magnetic field) to the pattern reversal stimulus (P100M) increased with age, particularly after 55 years, while the amplitude of the P100M decreased more gradually over the lifespan. By contrast, the latency of the major positive component to the flash stimulus (P2M) increased more slowly with age after about 50 years, while its amplitude may have decreased in only a proportion of the elderly subjects. The changes in the P100M with age may reflect senile changes in the eye and optic nerve, e.g. senile miosis, degenerative changes in the retina or geniculostriate deficits. The P2M may be more susceptible to senile changes in the visual cortex. The data suggest that the contrast channels of visual information processing deteriorate more rapidly with age than the luminance channels.

Neural contribution to spatiotemporal contrast sensitivity decline in healthy ageing eyes

Contrast sensitivity thresholds were measured over a range of spatial and temporal frequencies in both a group of young and older observers. Results demonstrate a significant reduction in contrast sensitivity of the older age group at all but the lowest combinations of spatial and temporal frequencies investigated. The senile miosis and reduced optical transmission of the older eye was then mimicked using the younger observers as subjects. This combined effect of reducing retinal illumination produced no significant change in sensitivity. These findings are discussed in terms of neural loss within the visual pathways with increasing age.

Aging, senile miosis and spatial contrast sensitivity at low luminance

The purpose of this study was to determine how aging affects spatial contrast sensitivity at low light levels and to examine whether senile miosis, which reduces retinal illuminance in the aged eye, underlies any observed sensitivity loss. Contrast thresholds for targets having a range of spatial frequencies were measured in young ( n = 13,M age= 24) and older ( n = 11,M age= 73) adults who were free from identifiable ocular pathology. Measurements were carried out at three luminance levels spanning a three log unit range. Results indicated that older adults' loss in contrast sensitivity not only increased with increasing spatial frequency, but also became more pronounced with decreases in luminance level. Additional threshold measurements where pupil diameter was varied indicated that senile miosis was not responsible for older adults' loss in spatial vision at any light level tested. Rather, older adults' miotic pupil tended to have a positive effect on their spatial vision in that it slightly improved their contrast sensitivity.

Age-related alterations in retinal function.

Age-related visual deficits that occur in the absence of recognized visual disease are frequently observed. Many of the optical factors contributing to these deficits have been delineated, but the contributing neurophysiological alterations have not been clearly defined. This investigation examined age-related variations in the retinal and cortical processing of visual information. Pattern-specific retinal potentials (pattern electroretinogram or PERG in this series) and cortical potentials (VECPs) were recorded from nine young visual normals (20-30 years) and nine healthy elderly individuals (70-80 years). All subjects had best corrected visual acuity of 20/30 or better. Checkerboard patterns (7.5-60 min. checks) were modulated in a counterphase mode (2.0 and 7.5 rps). PERGs and VECPs were simultaneously recorded. Significant age-related alterations in waveform amplitude and latency were observed for both biopotentials. The VECP alterations were largely the result of the reduction in retinal illumination associated with senile miosis, but this factor could not account for most of the observed PERG alterations. These results suggest that neurophysiological changes in the retina may underlie some of the visual deficits observed in healthy elderly adults.

Senile miosis: the possible contribution of disordered sleep and daytime sleepiness.

The contribution of disordered sleep and daytime sleepiness to senile miosis was investigated in 23 participants aged 60 to 80 years and 12 participants aged 21 to 40 years. All participants filled out questionnaires and were interviewed about their health, sleep, and daytime alertness. On this basis the older group was subdivided into a group of 13 participants with sleep disorders or daytime sleepiness and 10 participants without. All participants were studied with a computerized infrared television pupillometry system for 15 s in ambient lighting, 15 s after 5 min dark adaptation and with 5 light flashes. Pupil diameter after dark adaptation was significantly larger in the older group without sleep disorders than in the older group with sleep disorders (5.94 +/- .73 mm vs. 4.49 +/- .62 mm, M +/- SD, p less than .001). Significant partial correlation coefficients controlled for age were found between pupillary diameter and a variety of sleep variables. The data suggest that occult sleep disorders and daytime sleepiness may contribute to senile miosis.

Altered pattern evoked retinal and cortical potentials associated with human senescence.

Physiologically healthy elderly individuals often exhibit visual deficits which result from age-related changes in both the transmission characteristics of the ocular media and the functional properties of the neural elements in the visual pathway. Many of the age-related changes in the optical quality of the ocular media have been identified, but the age-dependent variations in visual neurophysiology have not been clearly delineated. This investigation examined age-related alterations in pattern-specific biopotentials generated in the human retina and visual cortex. Counterphasing (2.0 and 7.5 rps) patterns (7.5', 15', 30' and 60' checks) were used to simultaneously monitor pattern-reversal visual evoked potentials (PRVEPs). Young visual normals (20-30 years of age) and healthy elderly observers (70-80 years of age) with visual acuity of 20/30 or better were studied. All data were corrected for the effects of senile miosis on retinal illumination. Significant variations in the waveform characteristics of both biopotentials were noted for the elderly individuals. PRRP amplitude was uniformly reduced for all stimulus conditions. PRVEP amplitude reductions were also noted but were more stimulus specific than the PRRP amplitude reductions. No significant PRVEP or PRRP latency changes were observed. These results suggest that alterations in the physiological properties of neural elements in both the retina and visual cortex are associated with normal aging.