Effects of aging in retinal image quality (original) (raw)
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Effects of aging on optical quality and visual function
Clinical and Experimental Optometry, 2016
Background: We assessed the effects of aging on visual function and optical quality in a healthy adult population and provide reference values for different age ranges. Methods: We conducted a prospective study with 198 healthy volunteers from 31 to 70 years of age. The best-corrected visual acuity (BCVA) and contrast sensitivity (CS) at 3, 6, 12 and 18 cycles per degree (cpd) frequencies were assessed, together with values of optical quality and intraocular scattering obtained with a double-pass system, specifically the modulation transfer function cutoff frequency (MTF cutoff), the Strehl ratio, the OQAS Values (OV) at contrasts 100%, 20% and 9% and the objective scatter index (OSI). We studied the progression of these variables with age and obtained standard values for optical quality and intraocular scattering parameters for four age groups: 31-40 years, 41-50, 51-60, and 61-70. Results: We found significant correlations between age and all variables analyzed and significant differences among the age groups considered except for CS (3 cpd) (p=0.067). Age decline particularly affected low-contrast parameters such as the OV 9% and the OSI, which decreased to 37% and 50% of their original value, respectively. The OSI was found to provide high sensitivity and specificity values when healthy and caratactous eyes were considered. The results suggest that optical deficits are compensated until 50 years of age with sensory and perceptual factors, since smaller changes were found for visual function than for objective measurements of optical quality and intraocular scattering. Conclusions: Psychophysical and objective variables evolved differently with age. Reference values can be used to determine normal limits of optical quality and intraocular scattering for diagnosis of ocular conditions.
Vision through Healthy Aging Eyes
Vision
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 man...
Aging and scotopic sensitivity
Vision Research, 1998
Scotopic sensitivity was compared in young and older adults in good eye health after individualized correction for age-related changes in lens density and control of pupil diameter. Unlike earlier studies on this topic, fundus photography and a grading scale were used to characterize macular health in the older sample. Twenty-four young adults (mean age 27) and 25 older adults (mean age 70 years) underwent scotopic sensitivity testing after 30 min of dark adaptation. Light sensitivity for a 450 nm target was measured at 4, 7, 32, and 38°both nasally and temporally along the horizontal meridian. Lens density was estimated using Sample's method. On average, older adults exhibited a 0.5 log unit decrease in sensitivity even with lens density taken into account, which did not vary with target eccentricity or nasal/temporal hemifield. Although 60% of older subjects exhibited fundoscopic signs of early age-related maculopathy (ARM), even those free from these signs demonstrated a half log unit sensitivity loss, suggesting that this impairment may represent a biological aging process. We found no psychophysical evidence that scotopic sensitivity loss in older adults with relatively good retinal health is accentuated in the peri-macula, even though anatomical studies on donor retinas from older adults have indicated that this area has heightened rod loss.
Aging, senile miosis and spatial contrast sensitivity at low luminance
Vision Research, 1988
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 Changes in Retinal Functional Topography
Investigative Ophthalmology & Visual Science, 2008
To perform a detailed topographical analysis of functional age-related changes over the retina. METHODS. Fifty-nine normal phakic subjects aged 10 to 69 years were divided into six groups, according to decade of age. mfERG traces were recorded from the central 60°of the retina, with a resolution of 61 and 103 scaled hexagons. Group medians of peak amplitude and latency of the first-and secondorder (first slice) responses were used to generate 3-D topographical maps. RESULTS. With age, there was a continuous loss of amplitude and delay of implicit time of the first-and the second-order response components, but the topography of the loss was not uniform across the retina. Trend analyses on ring group data showed a significant decrease in amplitude of first-and secondorder responses although the age relationship of second-order responses was more complex. The loss of first-order kernel amplitude was generally accompanied by a rise in implicit time. Second-order kernel latencies showed no uniform alteration with age. CONCLUSIONS. Consistent with previous work, a steady loss of amplitude and increase of implicit time was observed with age. The topographical 3-D data, however, reveal age-related functional alterations in the retina beyond those found in ring averages, suggesting that these are masked by the standard analysis. Thus, the choice of physiologically coherent regions of interest may increase the sensitivity of detecting age-related change in multifocal analysis of retinal function. (Invest Ophthalmol Vis Sci. 2008;49:5024 -5032)
Visual performance of aged subjects with tinted lenses
2005
We have analized the chromatic vision and the contrast vision of subjects older than 50 years wearing coloured lenses, in order to compare the performance of these kind of filters when used by this particular population. "PsychoWin 2.25" and "Cambridge Colour Test" (CCT) from Cambridge Research Systems were used to determine the contrast sensitivity function of these subjects and their chromatic discrimination thresholds around three stimuli. The results show that none of the filters studied performs optimally in both tests simultaneously, although the grey filter is the one which impairs performance in a lesser degree.
Purpose: The Central Vision Analyzer (CVA) is an interactive computer device that has been reported to measure functional resolution at fixation under contrast and luminance conditions and fixation times which mimic a number of vision tasks of day and evening activities. The program presents Landolt C's that are flashed at fixation for 250 msec and tumbled 1 of 4 directions; the program thresholds for the smallest C the position of which is correctly recognized. In sequential fashion, the CVA tests 3 mesopic environments (98% Michelson Contrast, MC, against a background of 1.6 cd/m2, 25% MC against 5 cd/m2, then 50% MC against 1.6 cd/m2) and 3 glare environments (98%, 10% and 8% MC, all against a background of 220 cd/m2). This report evaluates the impact of aging and optical correction method on the resolution acuity measured in normal eyes. Methods: The visual acuities measured in normal eyes with the CVA were compared among three age groups: 18-30, 31-50 and 51-65. Comparisons were made between the three age groups in emmetropic eyes and myopic or hyperopic eyes tested with both contact lens and spectacle correction. Results: In emmetropic eyes, a significant decline was found with aging in both the 25% and 50% MC mesopic modules with a borderline significant change in the 98% MC mesopic module (but greater than the test-retest reliability) while a significant improvement was observed with aging among the myopic eyes, approximately 0.15 logMAR. In both myopic and hyperopic eyes, a small decline in vision of 0.10 to 0.12 logMAR was observed with aging when corrected with contact lenses while with spectacles, visual acuity remained approximately stable, with both corrections producing a similar acuity in the oldest age group. Conclusions: This study demonstrates changes in the vision measured in real world environments that is associated with aging and appears in line with the reported worsening in lens optical density, retinal sensitivity, and tear film stability that occur with aging. Whether the effects continue to worsen beyond age 65 or change in alternative ways with pathologies associated with aging, remain to be studied.