scholarly journals The Relationship Between Perifoveal L-Cone Isolating Visual Acuity and Cone Photoreceptor Spacing—Understanding the Transition Between Healthy Aging and Early AMD

2021 ◽  
Vol 13 ◽  
Author(s):  
Rigmor C. Baraas ◽  
Åshild Horjen ◽  
Stuart J. Gilson ◽  
Hilde R. Pedersen
Keyword(s):  
Outer Segment ◽  
Healthy Aging ◽  
Segment Length ◽  
Retinal Eccentricity ◽  
Cone Photoreceptor ◽  
Cone Structure ◽  
Age Related ◽  
Risk Of Progression ◽  
The Relationship ◽  
Cone Density

Background: Age-related macular degeneration (AMD) is a multifactorial degenerative disorder that can lead to irreversible loss of visual function, with aging being the prime risk factor. However, knowledge about the transition between healthy aging and early AMD is limited. We aimed to examine the relationship between psychophysical measures of perifoveal L-cone acuity and cone photoreceptor structure in healthy aging and early AMD.Methods and Results: Thirty-nine healthy participants, 10 with early AMD and 29 healthy controls were included in the study. Multimodal high-resolution retinal images were obtained with adaptive-optics scanning-light ophthalmoscopy (AOSLO), optical-coherence tomography (OCT), and color fundus photographs. At 5 degrees retinal eccentricity, perifoveal L-cone isolating letter acuity was measured with psychophysics, cone inner segment and outer segment lengths were measured using OCT, while cone density, spacing, and mosaic regularity were measured using AOSLO. The Nyquist sampling limit of cone mosaic (Nc) was calculated for each participant. Both L-cone acuity and photoreceptor inner segment length declined with age, but there was no association between cone density nor outer segment length and age. A multiple regression showed that 56% of the variation in log L-cone acuity was accounted for by Nc when age was taken into account. Six AMD participants with low risk of progression were well within confidence limits, while two with medium-to-severe risk of progression were outliers. The observable difference in cone structure between healthy aging and early AMD was a significant shortening of cone outer segments.Conclusion: The results underscore the resilience of cone structure with age, with perifoveal functional changes preceding detectable changes in the cone photoreceptor mosaic. L-cone acuity is a sensitive measure for assessing age-related decline in this region. The transition between healthy aging of cone structures and changes in cone structures secondary to early AMD relates to outer segment shortening.

scholarly journals Retinal factors of visual sensitivity in the human fovea

2021 ◽  
Author(s):  
Niklas Domdei ◽  
Jenny L. Reiniger ◽  
Frank G. Holz ◽  
Wolf Harmening
Keyword(s):  
Adaptive Optics ◽  
Outer Segment ◽  
Visual Sensitivity ◽  
Segment Length ◽  
Retinal Eccentricity ◽  
Small Spot ◽  
Steep Decline ◽  
Human Participants ◽  
Specialized Region ◽  
Cone Density

AbstractHumans direct their gaze towards visual objects of interest such that the retinal images of fixated objects fall onto the fovea, a small anatomically and physiologically specialized region of the retina displaying highest visual fidelity. One striking anatomical feature of the fovea is its non-uniform cellular topography, with a steep decline of cone photoreceptor density and outer segment length with increasing distance from its center. We here assessed in how far the specific cellular organization of the foveola is reflected in visual function. Increment sensitivity to small spot visual stimuli (1 x 1 arcmin, 543 nm light) was recorded psychophysically in 4 human participants at 17 locations placed concentric within a 0.2-degree diameter around the preferred retinal locus of fixation with adaptive optics scanning laser ophthalmoscopy based microstimulation. While cone density as well as maximum outer segment length differed significantly among the four tested participants, the range of observed threshold was similar, yielding an average increment threshold of 3.3 ± 0.2 log10 photons at the cornea. Thresholds were correlated with retinal eccentricity, as well as cone density and outer segment length. Biophysical simulation allowed to develop a model of foveal sensitivity based on these parameters, explaining at least 37% of the observed threshold variability. Based on high reproducibility in replicate testing, the residual variability is assumed to be caused by individual cone and bipolar cell weighting at the specific target locations.

scholarly journals Macular Pigment Optical Density and Photoreceptor Outer Segment Length as Predisease Biomarkers for Age-Related Macular Degeneration

2020 ◽  
Vol 9 (5) ◽  
pp. 1347 ◽  
Author(s):  
Norihiro Nagai ◽  
Sakiko Minami ◽  
Misa Suzuki ◽  
Hajime Shinoda ◽  
Toshihide Kurihara ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Optical Density ◽  
Outer Segment ◽  
Macular Pigment ◽  
Age Related Macular Degeneration ◽  
Segment Length ◽  
Macular Pigment Optical Density ◽  
Photoreceptor Outer Segment ◽  
Age Related ◽  
Fellow Eyes

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases; there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2® (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386; p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD < 0.65 and/or PROS length < 35 μm, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p < 0.001; 95% confidence interval, 3.50–60.4; odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.

The ageing photoreceptor

2007 ◽  
Vol 24 (2) ◽  
pp. 151-155 ◽  
Author(s):  
ALEXANDER CUNEA ◽  
GLEN JEFFERY
Keyword(s):  
Aging Process ◽  
Outer Segment ◽  
Retinal Disease ◽  
Segment Length ◽  
Rod Photoreceptor ◽  
Retinal Neurons ◽  
Rod Photoreceptors ◽  
Outer Segments ◽  
Age Related ◽  
Similar Density

With age many retinal neurons are lost. In humans the rod photoreceptor population in the perimacular region is subject to approximately 30% loss over life. Those that remain have been reported to suffer from extensive convolutions and localized swellings of their outer segments abnormally increasing their disc content and outer segment length. Here we examine quantitatively age-related changes in rat rod photoreceptors. The rat retina is ∼97% rod dominated. Here, aged rods showed significant reductions in outer segment length. The discs in their outer segments had a similar density, irrespective of whether they were young or old, however, in aged animals a higher proportion were misregistered. Surprisingly, in all of the tissue examined, we found no evidence for any convolution of outer segments or localized swelling as reported in humans, rather all remained straight. There are methodological differences between the research reported here and that undertaken on human retinae. There are also major differences in overall retinal architecture between humans and rodents that could contribute to differences in the aging process of individual cells. If it is the case that individual photoreceptors age differently in rodents compared to humans, it may pose significant problems for the use of this animal model in studies of ageing and age related outer retinal disease.

Early cone photoreceptor outer segment length shortening in RPGR X-linked retinitis pigmentosa

2020 ◽  
Author(s):  
Moreno Menghini ◽  
Jasleen K. Jolly ◽  
Anika Nanda ◽  
Laura Wood ◽  
Jasmina Cehajic-Kapetanovic ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Outer Segment ◽  
Segment Length ◽  
Cone Photoreceptor ◽  
Photoreceptor Outer Segment

scholarly journals The Relationship Between Social Support, Aging Expectations, and Health Behavior in Middle Age

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 409-409
Author(s):  
Hyun-E Yeom ◽  
Misook Jung ◽  
Eunyoung Park
Keyword(s):  
Social Support ◽  
Health Behavior ◽  
Social Relations ◽  
Healthy Aging ◽  
Cross Sectional Study ◽  
Middle Aged ◽  
Cross Sectional ◽  
Age Related ◽  
Attitudes Toward Aging ◽  
The Relationship

Abstract Midlife is a critical period when individuals need to actively engage in healthy behaviors for healthy aging. Although both social relations and attitudes toward aging are factors related to health behavior, little is known about their relationships based on age-related differences. The purposes of this study were to investigate the influence of social support affecting health behavior through expectations regarding aging and to examine how age affects the relationship. A cross-sectional study was conducted with data from 245 midlife Koreans (mean age= 51.5) collected by a self-administered survey. Data were analyzed using the PROCESS macro in SPSS. Social support was significantly related to expectations regarding aging (r= -.135, p=.034) and health behavior (r= .223, p&lt;.000). There was age-related difference in the relationship between social support and expectations regarding aging (β= .007, p=.038), indicating that the relationship was much stronger in the younger group. In addition, the influence of social support on health behavior through expectations regarding aging was significant in relatively young middle-aged individuals. Our findings emphasize the importance of supportive social relationships, which could affect expectations regarding aging linked to health behavior, especially for young middle-aged individuals. It is necessary to develop psycho-cognitive programs to activate social interaction and to improve positive attitudes toward aging for more active engagement in health behaviors in midlife individuals.

scholarly journals Age-dependent changes in mean and variance of gene expression across tissues in a twin cohort

2016 ◽  
Author(s):  
Ana Viñuela ◽  
Andrew A Brown ◽  
Alfonso Buil ◽  
Pei-Chien Tsai ◽  
Matthew N Davies ◽  
...  
Keyword(s):  
Gene Expression ◽  
Healthy Aging ◽  
Process Analysis ◽  
Strong Relationship ◽  
Methylation Array ◽  
Age Related ◽  
Age Dependent ◽  
Mean And Variance ◽  
The Relationship ◽  
Age Related Changes

AbstractGene expression changes with age have consequences for healthy aging and disease development. Here we investigate age-related changes in gene expression measured by RNA-seq in four tissues and the interplay between genotypes and age-related changes in expression. Using concurrently measured methylation array data from fat we also investigate the relationship between methylation, gene expression and age. We identified age-dependent changes in mean levels of gene expression in 5,631 genes and in splicing of 904 genes. Age related changes were widely shared across tissues, with up to 60% of age-related changes in expression and 47% on splicing in multi-exonic genes shared; amongst these we highlight effects on genes involved in diseases such as Alzheimer and cancer. We identified 137 genes with age-related changes in variance and 42 genes with age-dependent discordance between genetically identical individuals; implying the latter are driven by environmental effects. We also give four examples where genetic control of expression is affected by the aging process. Analysis of methylation observed a widespread and stronger effect of age on methylation than expression; however we did not find a strong relationship between age-related changes in both expression and methylation. In summary, we quantified aging affects in splicing, level and variance of gene expression, and show that these processes can be both environmentally and genetically influenced.

scholarly journals Deciphering the Relationship between Objective and Subjective Aspects of Recollection in Healthy Aging

2019 ◽  
Author(s):  
Adrien Folville ◽  
Arnaud D'Argembeau ◽  
Christine Bastin
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Healthy Aging ◽  
Subjective Experience ◽  
Lower Amount ◽  
Objective Measures ◽  
Aggregated Data ◽  
Mixed Effects Modeling ◽  
Age Related ◽  
The Relationship

Although healthy aging has been related to a decline in recollection as indexed by objective measures, the subjective experience of recollection seems to remain stable. To date, however, these age-related differences have only been examined using aggregated data across trials. In the current study, we investigated the relationship between subjective and objective measures of recollection on a trial-by-trial basis to determine whether the magnitude of this relationship was similar in young and older adults. Young and older participants were presented with a series of pictures that were associated with descriptive labels at encoding. At retrieval, they were cued with the labels and were asked to rate the vividness of their memory for the associated picture and to recall as many details of the picture as they could. On average, older adults assigned higher vividness ratings but recalled lower amount of specific episodic details than young adults. Mixed-effects modeling revealed that, across trials, the relationship between subjective (vividness) and objective (number of recalled details) recollection was stronger in young than in older participants. These findings provide evidence that older adults not only retrieve fewer episodic details but also spontaneously rely on these details to a lesser extent than young adults for judging the subjective quality of their memories.

scholarly journals Evaluating outer segment length as a surrogate measure of peak foveal cone density

2017 ◽  
Vol 130 ◽  
pp. 57-66 ◽  
Author(s):  
Melissa A. Wilk ◽  
Brandon M. Wilk ◽  
Christopher S. Langlo ◽  
Robert F. Cooper ◽  
Joseph Carroll
Keyword(s):  
Outer Segment ◽  
Segment Length ◽  
Surrogate Measure ◽  
Cone Density
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