Age-related Macular Degeneration Participants Research Articles

Nocturnal hypoxia and age-related macular degeneration.

Nocturnal hypoxia is common, under-diagnosed and is found in the same demographic at risk of age-related macular degeneration (AMD). The objective of this study was to determine any association between nocturnal hypoxia and AMD, its severity, and the high-risk sub-phenotype of reticular pseudodrusen (RPD). This cross-sectional study included participants aged ≥50 years with AMD, or normal controls, exclusive of those on treatment for obstructive sleep apnoea. All participants had at home, overnight (up to 3 nights) pulse oximetry recordings and multimodal imaging to classify AMD. Classification of Obstructive Sleep Apnea (OSA) was determined based on oxygen desaturation index [ODI] with mild having values of 5-15 and moderate-to-severe >15. A total of 225 participants were included with 76% having AMD, of which 42% had coexistent RPD. Of the AMD participants, 53% had early/intermediate AMD, 30% had geographic atrophy (GA) and 17% had neovascular AMD (nAMD). Overall, mild or moderate-to-severe OSAwas not associated with an increased odds of having AMD nor AMD with RPD (p ≥ 0.180). However, moderate-to-severe OSA was associated with increased odds of having nAMD (odds ratio = 6.35; 95% confidence interval = 1.18 to 34.28; p = 0.032), but not early/intermediate AMD or GA, compared to controls (p ≥ 0.130). Mild OSA was not associated with differences in odds of having AMD of any severity (p ≥ 0.277). There was an association between nocturnal hypoxia as measured by the ODI and nAMD. Hence, nocturnal hypoxia may be an under-appreciated important modifiable risk factor for nAMD.

Accelerated Brain Atrophy, Microstructural Decline and Connectopathy in Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) has recently been linked to cognitive impairment. We hypothesized that AMD modifies the brain aging trajectory, and we conducted a longitudinal diffusion MRI study on 40 participants (20 with AMD and 20 controls) to reveal the location, extent, and dynamics of AMD-related brain changes. Voxel-based analyses at the first visit identified reduced volume in AMD participants in the cuneate gyrus, associated with vision, and the temporal and bilateral cingulate gyrus, linked to higher cognition and memory. The second visit occurred 2 years after the first and revealed that AMD participants had reduced cingulate and superior frontal gyrus volumes, as well as lower fractional anisotropy (FA) for the bilateral occipital lobe, including the visual and the superior frontal cortex. We detected faster rates of volume and FA reduction in AMD participants in the left temporal cortex. We identified inter-lingual and lingual-cerebellar connections as important differentiators in AMD participants. Bundle analyses revealed that the lingual gyrus had a lower streamline length in the AMD participants at the first visit, indicating a connection between retinal and brain health. FA differences in select inter-lingual and lingual cerebellar bundles at the second visit showed downstream effects of vision loss. Our analyses revealed widespread changes in AMD participants, beyond brain networks directly involved in vision processing.

Investigating the Spatiotemporal Summation of Perimetric Stimuli in Dry Age-Related Macular Degeneration.

To measure achromatic spatial, temporal, and spatiotemporal summation in dry age-related macular degeneration (AMD) compared to healthy controls under conditions of photopic gaze-contingent perimetry. Twenty participants with dry AMD (mean age, 74.6 years) and 20 healthy controls (mean age, 67.8 years) performed custom, gaze-contingent perimetry tests. An area-modulation test generated localized estimates of Ricco's area (RA) at 2.5° and 5° eccentricities along the 0°, 90°, 180°, and 270° meridians. Contrast thresholds were measured at the same test locations for stimuli of six durations (3.7-190.4 ms) with a Goldmann III stimulus (GIII, 0.43°) and RA-scaled stimuli. The upper limit (critical duration) of complete temporal summation (using the GIII stimulus) and spatiotemporal summation (using the RA stimuli) was estimated using iterative two-phase regression analysis. Median (interquartile range [IQR]) RA estimates were significantly larger in AMD participants (2.5°: 0.21 [0.09-0.41] deg2; 5°: 0.32 [0.15-0.65 deg2]) compared to healthy controls (2.5°: 0.08 [0.05-0.13] deg2; 5°: 0.15 [0.08-0.22] deg2) at all test locations (all P < 0.05). No significant difference in median critical duration was found in AMD participants with the GIII stimulus (19.6 [9.9-30.4] ms) and RA-scaled stimuli (22.9 [13.9-40.3] ms) compared to healthy controls (GIII: 17.0 [11.3-24.0] ms; RA-scaled: 22.4 [14.3-33.1] ms) at all test locations (all P > 0.05). Spatial summation is altered in dry AMD, without commensurate changes in temporal summation. The sensitivity of perimetry to AMD may be improved by utilizing stimuli that probe alterations in spatial summation in the disease.

The effects of age and central field loss on maintaining balance control when stepping up to a new level under time-pressure.

To investigate the effects of age and central field loss on the landing mechanics and balance control when stepping up to a new level under time-pressure. Eight older individuals with age-related macular degeneration (AMD), eight visually normal older and eight visually normal younger individuals negotiated a floor-based obstacle followed by a 'step-up to a new level' task. The task was performed under (1) no-pressure; (2) time-pressure: an intermittent tone was played that increased in frequency and participants had to complete the task before the tone ceased. Landing mechanics and balance control for the step-up task was assessed with a floor-mounted force plate on the step. Increased ground reaction forces and loading rates were observed under time-pressure for young and older visual normals but not for AMD participants. Across conditions, loading rates and ground reaction forces were higher in young normals compared to older normals and AMD participants. Young visual normals also demonstrated 35-39% shorter double support times prior to and during the step-up compared to older normals and AMD participants. All groups shortened their double support times (31-40%) and single support times (7-9%) in the time-pressure compared to no-pressure condition. Regarding balance control, the centre-of-pressure displacement and velocity in the anterior-poster direction were increased under time-pressure for young and older visual normals but not for AMD participants. The centre-of-pressure displacement and velocity in the medial-lateral direction were decreased for the AMD participants under time-pressure but not for young and older visual normals. Despite walking faster, AMD participants did not adapt their landing mechanics under time-pressure (i.e., they remained more cautious), whilst older and young adults with normal vision demonstrated more forceful landing mechanics with the young being most forceful. A more controlled landing might be a safety strategy to maintain balance control during the step-up, especially in time-pressure conditions when balance control in the anterior-posterior direction is more challenged.

Development and Pilot-Testing of a Patient Decision-Making Aid for Nutrition in Age-Related Macular Degeneration.

ObjectiveWe described the development and pilot-testing of an application based patient decision-making aid (PDA) for nutrition in age-related macular degeneration (AMD). Alpha-testing and beta-testing were performed to explore the PDA’s usability, acceptability, and comprehensibility in the design stage and in “real-life” conditions.MethodsA nutrition PDA was developed in this study by a multidisciplinary steering committee that consisted of ophthalmologists, nurses, nutritionists, and methodologists using a systematic development process. The PDA was based on a smartphone native installation and a free-to-use app. First, based on information from literature reviews and focus group interviews for needs assessment, we developed a decision aid prototype. Second, we conducted the alpha testing to explore the acceptability, usability, and comprehensibility of the PDA prototype among 18 AMD patients. Third, a before/after study was conducted to assess changes in the attitudes, risk perceptions, intentions, knowledge, decisional conflicts, and decision self-efficacy of 33 AMD patients.ResultsThe alpha test proved that the nutrition PDA is acceptable and usable. In the beta test, after the AMD participants used the PDA, their scores for knowledge [mean = 13.3, standard deviation (SD) = 2.92], attitude (mean = 18.97, SD = 2.19), decision self-efficacy (mean = 23.94, SD = 6.04), and preparation significantly increased (mean = 26.30, SD = 4.90), and their score for decisional conflict significantly decreased (mean = 10.15, SD = 3.66). There was no significant difference in anxiety (mean = 2.64, SD = 1.08) before and after the use of the PDA. The mean score in the system usability scale was above 70 (mean = 72.61; SD = 5.38), which indicates the good usability of the PDA. With regard to the PDA acceptability, the scores for satisfaction with its comprehensibility, satisfaction with its attractiveness, and satisfaction with its emotional support were 5.49 (SD = 1.03), 5.30 (SD = 1.40), and 4.91(SD = 1.07), respectively, which show its adequate acceptability.ConclusionOur study showed that the nutrition PDA was an acceptable and suitable instrument for AMD patients and fit the values of all its stakeholders. This study is an important step in supporting shared decision-making, which has the potential to provide a more patient-centered and value-based nutrition health system for individuals with different types of AMD.

Evaluation of Cone- and Rod-Mediated Parameters in Dark Adaptation Testing as Outcome Measures in Age-Related Macular Degeneration

To investigate the suitability of 6 rod- or cone-mediated dark adaptation (DA) parameters as outcome measures for clinical trials in age-related macular degeneration (AMD), including their retest reliability, association with age and disease severity, and measurable longitudinal change over time. Prospective, longitudinal study (Clinicaltrials.gov: NCT01352975). A total of 191 patients with AMD and older participants followed longitudinally over 5 years. Dark adaptation testing was performed using the AdaptDx dark adaptometer with a maximum test time of 40 minutes. A 2-part exponential-linear curve was fitted to obtain values for cone decay, cone plateau, time to rod-cone break, rod intercept time (RIT), rod adaptation rate (S2), and area under the curve. Intersession retest reliability was assessed in tests performed within 2 weeks using the Bland-Altman analysis. The relationship of DA parameters with age, AMD severity, and reticular pseudodrusen (RPD) presence was evaluated using linear mixed models. Retest reliability, association with disease severity, and longitudinal change of 6 DA parameters. A total of 1329 DA curves were analyzed. Rod intercept time was the parameter that showed the greatest reliability (intraclass correlation coefficient of 0.88) and greatest association with age, AMD severity, and RPD (marginal R2 of 0.38), followed by the rod-mediated parameters area under the curve and rod-cone break. Cone plateau appeared constant at lower RIT values but increased with progressive rod dysfunction (RIT > 22.8 minutes) with a slope of 0.07 log units per 10 minutes RIT prolongation. Therefore, it might provide additional information in the advanced stages of AMD. Age-related macular degeneration severity and RPD presence are each associated with large differences in multiple DA curve parameters. In addition, substantial differences in some parameters occur with age, even accounting for AMD severity and RPD status. This supports the 2-hit hypothesis of age and disease status on DA (and perhaps AMD pathophysiology itself). Of the DA parameters, RIT has the highest retest reliability, closest correlation with AMD severity and RPD, and largest longitudinal changes. This underscores the suitability of RIT as an outcome measure in clinical trials. The cone plateau increases only in advanced stages of kinetic rod dysfunction, indicating rod dysfunction preceding cone dysfunction and degeneration in the temporal sequence of pathology in AMD.

Association of Dietary Nutrient Intake with Early Age-Related Macular Degeneration in Japanese-Americans.

Lifestyle factors may be associated with the development of age-related macular degeneration (AMD), in addition to demographic and genetic factors. The purpose of this cross-sectional study is to elucidate the association between nutrient intake and AMD in the Japanese-American population living in Los Angeles. We conducted a medical survey of Japanese immigrants and their descendants living in Los Angeles, including interviews on dietary habits, fundus photography, and physical examinations. Participants were classified into early AMD and control groups on the basis of fundus photographic findings. Consequently, among the 555 participants, 111 (20.0%) were diagnosed with early AMD. There were no late-stage AMD participants. Multivariate logistic regression analysis showed that the intake of animal fat and saturated fatty acids (SFA) was positively associated with early AMD (p for trend = 0.01 for animal fat, p for trend = 0.02 for SFA), and the intake of vegetable fat, total carbohydrate, simple carbohydrate, sugar, and fructose was inversely associated with early AMD (p for trend = 0.04 for vegetable fat, p for trend = 0.046 for carbohydrate, p for trend = 0.03 for simple carbohydrate, p for trend = 0.046 for sugar, p for trend = 0.02). Our findings suggest that excessive animal fat and SFA intake increases the risk for early AMD in Japanese-Americans whose lifestyles have been westernized.

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

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.

Serum Levels of ARMS2, COL8A1, RAD51B, and VEGF and their Correlations in Age-related Macular Degeneration.

Many factors including genetic and environmental are responsible for the incidence of Age-related Macular Degeneration (AMD). However, its pathogenesis has not been clearly elucidated yet. This study aimed to estimate the Age-Related Maculopathy Susceptibility 2 (ARMS2), Collagen type VIII Alpha 1 chain (COL8A1), Rad 51 paralog(RAD51B), and Vascular Endothelial Growth Factor (VEGF) protein levels in serum of AMD and control participants and to further investigate their correlation to understand AMD pathogenesis. For this case-control study, 31 healthy control and 57 AMD patients were recruited from Advanced Eye Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. A blood sample was taken and serum was isolated from it. ELISA (enzyme-linked immunosorbent assay) was used for the estimation of proteins in the serum of patients. ARMS2 and COL8A1 levels were significantly elevated in the AMD group than in the control group. The highest levels of ARMS2, COL8A1, and VEGF proteins were recorded for the wet AMD sub-group. The study results endorsed significant positive correlation between these following molecules; ARMS2 and COL8A1 (r = 0.933, p < 0.0001), ARMS2 and RAD51B (r = 0.704, p < 0.0001), ARMS2 and VEGF (r = 0.925, p < 0.0001), COL8A1 and RAD51B (r = 0.736, p < 0.0001), COL8A1 and VEGF (r = 0.879, p < 0.0001), and RAD51B and VEGF (r = 0.691, p < 0.0001). The ARMS2 and COL8A1 levels were significantly higher and RAD51B was significantly lower in the AMD group than controls. Also, a significant statistical correlation was detected between these molecules, indicating that their interaction may be involved in the pathogenesis of AMD.

Genomic-Metabolomic Associations Support the Role of LIPC and Glycerophospholipids in Age-Related Macular Degeneration.

Purpose:Large-scale genome-wide association studies (GWAS) have reported important single nucleotide polymorphisms (SNPs) with significant associations with age-related macular degeneration (AMD). However, their role in disease development remains elusive. This study aimed to assess SNP–metabolite associations (i.e., metabolite quantitative trait loci [met-QTL]) and to provide insights into the biological mechanisms of AMD risk SNPs.Design:Cross-sectional multicenter study (Boston, Massachusetts, and Coimbra, Portugal).Participants:Patients with AMD (n = 388) and control participants (n = 98) without any vitreoretinal disease (> 50 years).Methods:Age-related macular degeneration grading was performed using color fundus photographs according to the Age-Related Eye Disease Study classification scheme. Fasting blood samples were collected and evaluated with mass spectrometry for metabolomic profiling and Illumina OmniExpress for SNPs profiling. Analyses of met-QTL of endogenous metabolites were conducted using linear regression models adjusted for age, gender, smoking, 10 metabolite principal components (PCs), and 10 SNP PCs. Additionally, we analyzed the cumulative effect of AMD risk SNPs on plasma metabolites by generating genetic risk scores and assessing their associations with metabolites using linear regression models, accounting for the same covariates. Modeling was performed first for each cohort, and then combined by meta-analysis. Multiple comparisons were accounted for using the false discovery rate (FDR).Main Outcome Measures:Plasma metabolite levels associated with AMD risk SNPs.Results:After quality control, data for 544 plasma metabolites were included. Meta-analysis of data from all individuals (AMD patients and control participants) identified 28 significant met-QTL (β = 0.016−0.083; FDR q-value < 1.14 × 10−2), which corresponded to 5 metabolites and 2 genes: ASPM and LIPC. Polymorphisms in the LIPC gene were associated with phosphatidylethanolamine metabolites, which are glycerophospholipids, and polymorphisms in the ASPM gene with branched-chain amino acids. Similar results were observed when considering only patients with AMD. Genetic risk score–metabolite associations further supported a global impact of AMD risk SNPs on the plasma metabolome.Conclusions:This study demonstrated that genomic–metabolomic associations can provide insights into the biological relevance of AMD risk SNPs. In particular, our results support that the LIPC gene and the glycerophospholipid metabolic pathway may play an important role in AMD, thus offering new potential therapeutic targets for this disease.

Determinants of concern about falling in adults with age-related macular degeneration.

To investigate the prevalence and level of concern about falling (CF) among older people with vision impairment due to age-related macular degeneration (AMD) compared to a visually normal control group, and to identify determinants of CF for the AMD group. Participants included 133 older people: 77 with AMD (mean age=80.5±6.2years), and 56 controls (mean age=75.4±5.3years). Binocular visual acuity, contrast sensitivity and visual fields were measured, and CF was assessed using the Falls Efficacy Scale - International (FES-I). Data were also collected for sensorimotor function (postural sway, sit-to-stand, knee extensions, walking speed, proprioception), and neuropsychological function (reaction time, symptoms of anxiety and depression) using validated tests and scales. Concern about falling scores were higher for AMD participants compared to control participants (mean±S.D. 24.6±8.0 vs 21.6±5.7, p=0.02, respectively), although these findings failed to reach significance when adjusted for age (p=0.16). Among AMD participants, multivariable models showed that greater CF was associated with reduced contrast sensitivity (p=0.02), slower sit-to-stand times (p<0.001) and higher anxiety scores (p<0.001); these factors explained 40% of the variance in CF (p<0.01). Levels of CF in older people with AMD were not found to be elevated by their disease status alone, but rather by the extent of vision loss. Levels of CF in those with AMD were associated with various visual, sensorimotor and neuropsychological factors. These findings will assist clinicians in identifying those at greatest risk of developing high CF and inform the design of future intervention programmes for this population.

Object search in neovascular age‐related macular degeneration: the crowding effect

BackgroundVisual search, an activity that relies on central vision, is frequent in daily life. This study investigates the effect of spacing between items in an object search task in participants with central vision loss.MethodsPatients with neovascular age‐related macular degeneration (AMD), age‐matched controls, and young controls were included. The stimuli were displays of four, six and nine objects randomly presented in a ‘crowded’ (spacing 1.5°) or ‘uncrowded’ (spacing 6°) condition. For each of 96 trials, participants were asked to search for a predefined target that remained on the screen until the response was recorded. Accuracy, search time, and eye movements (number of fixations and scan path ratio) were recorded.ResultsCompared to older controls, accuracy decreased by 31 per cent and search time increased by 61 per cent in AMD participants. Ageing also affected performance with a lower accuracy by 13.5 per cent and longer search times by 46 per cent in older compared to younger controls. Increasing the spacing between elements increased accuracy by 21 per cent in AMD participants but it had no effect in older and younger controls. Performance was not related to visual acuity or to duration of neovascular AMD, but search time was correlated to the lesion size in the ‘crowded’ condition.ConclusionsObject search is ubiquitous in daily life activities. When visual acuity is irrevocably reduced, increasing the spacing between elements can reliably improve object search performance in patients.

Relationship between neural functional connectivity and memory performance in age-related macular degeneration

Age-related macular degeneration (AMD) has been linked to memory deficits, with no established neural mechanisms. We collected resting-state brain functional magnetic resonance imaging and standardized verbal recall tests from 42 older adults with AMD and 41 age-matched controls. We used seed-based whole brain analysis to quantify the strength of functional connectivity between hubs of the default mode network and a network of medial temporal regions relevant for memory. Our results indicated neither memory performance nor network connectivity differed by AMD status. However, the AMD participants exhibited stronger relationships than the controls between memory performance and connectivity from the memory network hub (left parahippocampal) to 2 other regions: the left temporal pole and the right superior/middle frontal gyri. Also, the connectivity between the medial prefrontal cortex and posterior cingulate cortex of default mode network correlated more strongly with memory performance in AMD compared to control. We concluded that stronger brain-behavior correlation in AMD may suggest a role for region-specific connectivity in supporting memory in the context of AMD.

NATURAL HISTORY OF QUANTITATIVE AUTOFLUORESCENCE IN INTERMEDIATE AGE-RELATED MACULAR DEGENERATION

To investigate differences in quantitative autofluorescence (qAF) imaging measurements between eyes with and without large drusen, and whether qAF measurements change over time in the eyes with large drusen. Eighty-five eyes from participants with bilateral large drusen and 51 eyes from healthy participants underwent qAF imaging at least once, and the age-related macular degeneration participants were reviewed 6-monthly. Normalized grey values at 9° to 11° eccentricity from the fovea were averaged to provide a summary measure of qAF values (termed qAF8). In a multivariable model, qAF8 measurements were not significantly different between age-related macular degeneration eyes with large drusen and healthy eyes (P = 0.130), and qAF8 measurements showed a decline over time in the age-related macular degeneration eyes (P = 0.013). These findings add to the body of evidence that qAF levels are not increased in eyes with large drusen compared with healthy eyes, and qAF levels show a significant decline over time in the age-related macular degeneration eyes. These findings highlight how the relationship between qAF levels and retinal pigment epithelium health does not seem to be straightforward. Further investigation is required to better understand this relationship, especially if qAF levels are to be used as an outcome measure in intervention trials.

Prevalence and new onset of depression and anxiety among participants with AMD in a European cohort

To investigate the prevalence and new onset of depression and anxiety among subjects with age-related macular degeneration (AMD) and its association with AMD in a large European cohort with relatively good visual acuity. 11,834 participants enrolled in the German population-based Gutenberg Health Study were studied. AMD was diagnosed by grading of fundus photographs. Depression and anxiety were assessed with the Patient Health Questionnaire and the Generalized Anxiety Disorder-2 Scale, respectively. Logistic regression analyses were performed and adjusted for several parameters. 1,089 (9.2%) participants were diagnosed having AMD. Prevalence of depression in AMD and non-AMD participants was 7.2% and 8.0%, respectively and prevalence of anxiety was 4.2% and 7.0%, respectively. New onset of depression and anxiety at 5-year follow-up in AMD subjects was 2.6% and 3.6%, respectively. AMD was not associated with depression (OR 0.93; CI 95% 0.70–1.20; p = 0.62). AMD was associated with less anxiety (OR 0.67; CI 95% 0.47–0.93; p = 0.02). This is the first study analyzing both prevalence and new onset of depression and anxiety in AMD subjects. AMD- and non-AMD participants had a similar prevalence and new onset of depression in our population-based sample. Participants without AMD had a higher prevalence of anxiety. AMD was not associated with depression.

Modified images reflecting effects of age‐related macular degeneration on perception of everyday scenes

BackgroundDepictions of vision with age‐related macular degeneration (AMD) in public information material typically show a central region of absolute vision loss. Patients with early and moderate disease frequently do not report this. We aimed to measure how a group of people with AMD perceive everyday scenes in order to produce accurate depictions.MethodsWe report on six people aged 65–82 years with monocular AMD (visual acuity +0.04 to +1.64 logMAR) and normal vision in the fellow eye. Participants viewed four images monocularly, alternating between eyes. The image was digitally altered to approximate participants’ descriptions of their perception with the affected eye. The altered image was viewed with the unaffected eye, and compared with the original image viewed with the affected eye. This was repeated iteratively until a perceptual match was achieved between the modified image/unaffected eye and the original image/affected eye.ResultsFor five AMD participants with visual acuity +0.04 to +0.50 logMAR the modified images did not resemble those in current public information material. Image modifications required to achieve perceptual similarity with the affected eyes included localised distortion, contrast reduction and blur. Widespread colour desaturation was also required in some cases. One participant with advanced geographic atrophy reported an absolute positive scotoma, similar to existing depictions.ConclusionsVision in people with AMD may not conform to the common depiction of a central region of absolute vision loss. The accurate representations of AMD patients’ vision produced in this study will enable better understanding of the visual consequences of AMD.

The effect of non-neovascular age-related macular degeneration on face recognition performance

PurposeThere is a well-established research base surrounding face recognition in patients with age-related macular degeneration (AMD). However, much of this existing research does not differentiate between results obtained for ‘wet’ AMD and ‘dry’ AMD. Here, we test the hypothesis that face recognition performance is worse in patients with dry AMD compared with visually healthy peers.MethodsPatients (>60 years of age, logMAR binocular visual acuity 0.7 or better) with dry AMD of varying severity and visually healthy age-related peers (controls) completed a modified version of the Cambridge Face Memory Test (CFMT). Percentage of correctly identified faces was used as an outcome measure for performance for each participant. A 90% normative reference limit was generated from the distribution of CFMT scores recorded in the visually healthy controls. Scores for AMD participants were then specifically compared to this limit, and comparisons between average scores in the AMD severity groups were investigated.ResultsThirty patients (median [interquartile range] age of 76 [70, 79] years) and 34 controls (median age of 70 [64, 75] years) were examined. Four, seventeen and nine patients were classified as having early, intermediate and late AMD (geographic atrophy) respectively. Five (17%) patients recorded a face recognition performance worse than the 90% limit (Fisher’s exact test, p = 0.46) set by controls; four of these had geographic atrophy. Patients with geographic atrophy identified fewer faces on average (±SD) (61% ± 22%) than those with early and intermediate AMD (75 ± 11%) and controls (74% ± 11%).ConclusionsPeople with dry AMD may not suffer from problems with face recognition until the disease is in its later stages; those with late AMD (geographic atrophy) are likely to have difficulty recognising faces. The results from this study should influence the management and expectations of patients with dry AMD in both community practice and hospital clinics.

Reading Speed and Reading Comprehension in Age-related Macular Degeneration

To evaluate the impact of age-related macular degeneration (AMD) on short out-loud and sustained silent reading speeds, and reading comprehension. Prospective, cross-sectional. Setting: Wilmer Eye Institute. Literate, native-English speakers with and without AMD. AMD participants had better-eye visual acuity (VA) <20/32 and >20/100, while controls had binocular VA >20/32. MNRead was used to assess short-duration out-loud reading speed. Sustained silent reading test was used to evaluate sustained silent reading speeds, while reading comprehension was assessed based on silent reading test text. MNRead maximum reading speed, sustained-silent reading speed, and comprehension score. Analyses included 24 AMD patients and 22 controls. In age-adjusted regressions, AMD participants, compared to controls, read 46 words per minute (wpm) slower on MNRead (95% confidence interval [CI]:-66,-26, P < .001), but there was no difference in sustained reading speeds between groups (β= 0.99, 95% CI:-41.8, 43.8, P= .96). In other models, there was a decrement of 12.6 wpm on MNRead per 0.1 worsening logMAR (95% CI:-18.7,-6.6, P < .001), but VA was not associated with a decrement in sustained reading speed (β=-10.1, 95% CI:-22.4, 2.1, P=.10). However, AMD participants had substantially lower comprehension scores than controls (53% vs 85% correct, P < .001), and each 1-line VA decrement was associated with 5.9% lower comprehension score (95% CI:-9.1,-2.7, P= .001). AMD patients read slower than controls when forced to read out loud. When asked to read silently over a longer duration, both groups read at similar speeds, though AMD patients demonstrated substantially lower comprehension scores, suggesting that they chose to sacrifice comprehension for speed.

Effects of Magnification on Emotion Perception in Patients With Age-Related Macular Degeneration.

Individuals with low vision often experience difficulties in performing tasks of daily living, such as face perception. This leads them to having difficulties with social interactions, as they can no longer correctly perceive the emotion of others. The present study investigated the effects of magnification on face perception in participants with age-related macular degeneration (AMD), and their ability to detect and categorize emotions. It was hypothesized that patients with AMD would be less accurate in comparison to healthy controls, but that magnification would improve their performance to that of controls. Faces containing happy, angry, or neutral emotion were both doubled (equivalent of arm's length distance) and decreased by half in size (equivalent of across the street). The ability to detect and to discriminate emotional content was compared between 20 AMD patients and 7 age-matched controls. Eye movements were recorded while conducting both tasks. Regardless of stimulus size, when compared to controls, we observed that individuals with AMD consistently performed with lower accuracy in both emotion detection and categorization tasks. Moreover, having images undergo a 2-fold increase in size did improve performance, but did not equate AMD participants' performance to that of the controls in either the emotion detection or categorization task. Eye movements in AMD participants were highly variable in position compared to controls. The data suggest that magnification alone does not appear to be the answer for improving emotion perception within individuals with low vision. Next steps should include an evaluation of the effects of viewing strategy.

Object crowding in age-related macular degeneration.

Crowding, the phenomenon of impeded object identification due to clutter, is believed to be a key limiting factor of form vision in the peripheral visual field. The present study provides a characterization of object crowding in age-related macular degeneration (AMD) measured at the participants' respective preferred retinal loci with binocular viewing. Crowding was also measured in young and age-matched controls at the same retinal locations, using a fixation-contingent display paradigm to allow unlimited stimulus duration. With objects, the critical spacing of crowding for AMD participants was not substantially different from controls. However, baseline contrast energy thresholds in the noncrowded condition were four times that of the controls. Crowding further exacerbated deficits in contrast sensitivity to three times the normal crowding-induced contrast energy threshold elevation. These findings indicate that contrast-sensitivity deficit is a major limiting factor of object recognition for individuals with AMD, in addition to crowding. Focusing on this more tractable deficit of AMD may lead to more effective remediation and technological assistance.