Age-Related Macular Degeneration Staging by Color Fundus Photography vs. Multimodal Imaging-Epidemiological Implications (The Coimbra Eye Study-Report 6)

Age-Related Macular Degeneration and Extramacular Drusen: Genetic Associations in the Coimbra Eye Study

Purpose

To explore the association between the genetics of age-related macular degeneration (AMD) and extramacular drusen (EMD) in patients with and without AMD.

Methods

We included 1753 eyes (912 subjects) with phenotypic characterization regarding AMD and EMD. Genetic sequencing and the genetic risk score (GRS) for AMD were performed according to the EYE-RISK consortium methodology. To test for differences in the GRS from EMD cases, AMD cases, and controls, a clustered Wilcoxon rank-sum test was used. The association of AMD, EMD, and the GRS was evaluated using logistic regression models adjusted for age and sex. Individual associations of common risk variants for AMD with EMD were explored.

Results

EMD were found in 755 eyes: 252 (14.4%) with AMD and 503 (28.7%) without. In total, 122 eyes (7.0%) had only AMD, and 876 (50.0%) were controls. EMD were strongly associated with AMD (odds ratio [OR], 3.333; 95% confidence interval [CI], 2.356-4.623; P < 0.001). The GRS was associated with an increased risk of AMD (OR, 1.416; 95% CI, 1.218-1.646; P < 0.001) but not with EMD. Individually, the common risk variants ARMS2 rs10490924 (P = 0.042), C3 rs2230199 (P = 0.042), and CETP rs5817082 (P = 0.042) were associated with EMD, after adjustment for AMD, sex, and age.

Conclusions

We found a strong association between EMD and AMD, suggesting a common pathogenesis. The GRS for AMD was not associated with EMD, but a partially overlapping genetic basis was suggested when assessing individual risk variants. We propose that EMD per se do not represent an increase in the global genetic risk for AMD.

Non-Neovascular Age-Related Macular Degeneration Assessment: Focus on Optical Coherence Tomography Biomarkers

The imagistic evaluation of non-neovascular age-related macular degeneration (AMD) is crucial for diagnosis, monitoring progression, and guiding management of the disease. Dry AMD, characterized primarily by the presence of drusen and retinal pigment epithelium atrophy, requires detailed visualization of the retinal structure to assess its severity and progression. Several imaging modalities are pivotal in the evaluation of non-neovascular AMD, including optical coherence tomography, fundus autofluorescence, or color fundus photography. In the context of emerging therapies for geographic atrophy, like pegcetacoplan, it is critical to establish the baseline status of the disease, monitor the development and expansion of geographic atrophy, and to evaluate the retina's response to potential treatments in clinical trials. The present review, while initially providing a comprehensive description of the pathophysiology involved in AMD, aims to offer an overview of the imaging modalities employed in the evaluation of non-neovascular AMD. Special emphasis is placed on the assessment of progression biomarkers as discerned through optical coherence tomography. As the landscape of AMD treatment continues to evolve, advanced imaging techniques will remain at the forefront, enabling clinicians to offer the most effective and tailored treatments to their patients.

Diagnostic accuracy of self-reported age-related macular degeneration in the ASPREE Longitudinal Study of Older Persons

BACKGROUND

The validity of findings from epidemiological studies using self-report of ophthalmic conditions depends on several factors. We assessed the diagnostic accuracy of self-reported age-related macular degeneration (AMD) among older Australians enroled in a primary prevention clinical trial and compared diagnostic accuracy between demographic subgroups.

METHODS

At baseline (2010-2015), Australian sub-study participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial, underwent bilateral two-field, 45° non-mydriatic colour retinal photography. Beckman classification of any-stage AMD was used as the reference standard diagnosis. Participants were asked whether a doctor had ever diagnosed them with "macular degeneration" (the index test) via a paper-based questionnaire as part of the ASPREE Longitudinal Study of Older Persons (ALSOP) within the first year of enrolment.

RESULTS

In total, 4193 participants were included (aged 70-92 years, 50.8% female). Of those, 262 (6.3%) reported having AMD and 92 (2.2%) were unsure. Retinal grading detected 2592 (61.8%) with no AMD, 867 (20.7%) with early, 686 (16.4%) with intermediate and 48 (1.1%) with late AMD (n = 1601 with any-stage AMD, 38.2%). Self-reported AMD had 11.4% sensitivity (95% CI 9.9-13.1) and 96.9% specificity (95% CI 96.2-97.6) for any-stage AMD, with 69.8% and 63.9% positive and negative predictive values. Sensitivity was higher among participants with late-stage AMD (87.5%), older participants (26.8%), and those with poorer vision (41.0%).

CONCLUSIONS

Although most participants with late-stage AMD were aware of having AMD, the majority with early and intermediate AMD were not. Therefore, findings from studies that rely on disease self-report should be interpreted with caution.

Prevalence and risk factors for age-related macular degeneration in a population-based cohort study of older adults in Northern Ireland using multimodal imaging: NICOLA Study

PURPOSE

To report prevalence and risk factor associations for age-related macular degeneration (AMD) and AMD features from multimodal retinal grading in a multidisciplinary longitudinal population-based study of aging in Northern Ireland.

STUDY DESIGN

Population-based longitudinal cohort study.

METHODS

Retinal imaging at the Norther Ireland Cohort for the Longitudinal Aging Study health assessment included stereo Colour Fundus Photography (CFP) (Canon CX-1, Tokyo, Japan) and Spectral-Domain Optical Coherence Tomography (SD-OCT) ((Heidelberg Retinal Angopgraph (HRA)+OCT; Heidelberg Engineering, Heidelberg, Germany). Medical history and demographic information was obtained during a home interview. Descriptive statistics were used to describe the prevalence of AMD and individual AMD features. Multiple imputation followed by multiple regression modelling was used to explore risk factor associations including relationships with AMD genetic risk score.

RESULTS

Retinal images from 3386 participants were available for analysis. Mean age of the sample was 63.4 (SD 9.01, range: 36-99). Population weighted prevalence of AMD using colour grading in those over 55 years was: no drusen: 6 0.4%; drusen <63 μm: 15.9%; drusen 63-125 µm: 13.7%; drusen >125 µm or pigmentary changes: 8.3%; late AMD: 1.6%. Prevalence of AMD features in those over 55 years was: OCT drusen 27.5%, complete outer retinal pigment epithelium and outer retinal atrophy (cRORA) on OCT was 4.3%, reticular drusen 3.2% and subretinal drusenoid deposits 25.7%. The genetic risk score was significantly associated with drusen and cRORA but less so for SDD alone and non-significant for hyperpigmentation or vitelliform lesions.

CONCLUSIONS

Multimodal imaging-based classification has provided evidence of some divergence of genetic risk associations between classical drusen and SDD. Our findings support an urgent review of current AMD severity classification systems.

Identifying geographic atrophy

PURPOSE OF REVIEW

Age-related macular degeneration (AMD) is one of the leading causes of blindness and can progress to geographic atrophy (GA) in late stages of disease. This review article highlights recent literature which assists in the accurate and timely identification of GA, and monitoring of GA progression.

RECENT FINDINGS

Technology for diagnosing and monitoring GA has made significant advances in recent years, particularly regarding the use of optical coherence tomography (OCT). Identification of imaging features which may herald the development of GA or its progression is critical. Deep learning applications for OCT in AMD have shown promising growth over the past several years, but more prospective studies are needed to demonstrate generalizability and clinical utility.

SUMMARY

Identification of GA and of risk factors for GA development or progression is essential when counseling AMD patients and discussing prognosis. With new therapies on the horizon for the treatment of GA, identification of risk factors for the development and progression of GA will become critical in determining the patients who would be appropriate candidates for new targeted therapies.

Common and rare genetic risk variants in age-related macular degeneration and genetic risk score in the Coimbra eye study

PURPOSE

To determine the contribution of common and rare genetic variants in age-related macular degeneration (AMD) in a Portuguese population from the Coimbra Eye Study (CES), and the genetic risk score (GRS).

METHODS

Participants underwent ophthalmologic examination and imaging. A centralized reading centre performed AMD staging. Genetic sequencing was carried out with the EYE-RISK assay. Sixty-nine single nucleotide polymorphisms (SNPs) were genotyped and tested for association with AMD. Case-control and progression-to-AMD analyses were performed using logistic regression to assess allelic odds ratio (OR) at a 95% confidence interval (CI) for each variant. GRS was calculated for cases/controls and progressors/non-progressors. Cumulative impact of rare variants was compared between cases/controls using logistic regression.

RESULTS

In case-control analysis (237 cases/640 controls) variants associated with risk of disease were: ARMS2 rs10490924, ARMS2_HTRA1 rs3750846, CFH rs35292876, SLC16A8 rs8135665, TGFBR1 rs1626340. Major risk variants ARMS2/HTRA1 rs3750846, CFH rs570618 and C3 rs2230199 had unexpected lower allele frequency (AF), and the highest risk-conferring variant was a rare variant, CFH rs35292876 (OR, 2.668; p-value = 0.021). In progression-to-AMD analysis (137 progressors/630 non-progressors), variants associated with risk of progression were ARMS2 rs10490924, ARMS2_HTRA1 rs3750846, CFH rs35292876. GRS of cases/controls was 1.124 ± 1.187 and 0.645 ± 1.124 (p-value < 0.001), and of progressors/non-progressors was 1.190 ± 1.178 and 0.669 ± 1.141 (p-value < 0.001). Higher proportion of pathogenic rare CFH variants was observed in cases (OR, 9.661; p-value < 0.001).

CONCLUSIONS

Both common and rare variants were associated with AMD, but a CFH rare variant conferred the highest risk of disease while three major risk variants had a lower-than-expected AF in our population originary from a geographic region with lower prevalence of AMD. GRS was still significantly higher in AMD patients. Damaging CFH rare variants were cumulatively more common in AMD cases.

Phenotypic Expression of CFH Rare Variants in Age-Related Macular Degeneration Patients in the Coimbra Eye Study

Purpose

To determine the association between rare genetic variants in complement factor H (CFH) and phenotypic features in age-related macular degeneration (AMD) patients from the Coimbra Eye Study (CES).

Methods

AMD patients from the Incidence CES (NCT02748824) underwent ophthalmologic examination and color fundus photography, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence, and near-infrared imaging. Multimodal phenotypic characterization was carried out in a centralized reading center. The coding and splice-site regions of the CFH gene were sequenced through single-molecule molecular inversion probe-based next-generation sequencing in association with the EYE-RISK consortium. Variants with minor allele frequency <0.05 resulting in splice-site or protein change were selected. Differences in phenotypic features between carriers and noncarriers were analyzed using generalized estimated equations logistic regression models, considering intereye correlations.

Results

We included 39 eyes of 23 patients carrying rare CFH variants and 284 eyes of 188 noncarriers. Carrier status was associated with having higher drusen burden in the macula in the inner Early Treatment Diabetic Retinopathy Study circle (odds ratio [OR], 5.44 [95% confidence interval {CI}, 1.61-18.37]; P = 0.006), outer circle (OR, 4.37 [95% CI, 1.07-17.77]; P = 0.04), and full grid (OR, 4.82 [95% CI, 1.13-20.52]; P = 0.033). In SD-OCT, a lower total macular volume and lower inner retinal layers' volume (OR, 0.449 [95% CI, 0.226-0.894]; P = 0.023; OR, 0.496 [95% CI, 0.252-0.979]; P = 0.043) and pigment epithelial detachments (PEDs) (OR, 5.24 [95% CI, 1.08-25.44]; P = 0.04) were associated with carrying a rare CFH variant. Carriers with subretinal drusenoid deposits (SDD) had the rare variant P258L in all cases except one.

Conclusions

We identified in our cohort phenotypic differences between carriers and noncarriers of rare variants in the CFH gene. Carriers had more severe disease, namely superior drusen burden, PEDs, and thinner retinas. The rare variant P258L may be associated with SDD. Carriers are probably at increased risk of progression.

Multispectral pattern recognition measures change in drusen area in age-related macular degeneration with high congruency to expert graders

Drusen are a hallmark lesion of age-related macular degeneration (AMD) and changes in their area and/or volume are strongly associated with disease progression. Assessment of longitudinal change in drusen size in clinical practice however is limited to a single commercial tool or manual inspection by clinicians. In this study we analysed change in drusen area in 33 eyes with intermediate AMD across two separate visits using a novel technique known as multispectral pattern recognition for en face retinal images from various imaging modalities (infrared (815 nm), fundus autofluorescence (488 nm) and green (532 nm) scanning laser ophthalmoscopy). We found 91% (30/33 eyes) agreement in the direction of drusen change for multispectral pattern recognition relative to expert graders who graded eyes as having drusen progression, regression or being stable. Multispectral pattern recognition showed 100% sensitivity (22/22 eyes) and 73% specificity (8/11 eyes). In comparison, we found only 70% (23/33 eyes) agreement in the direction of drusen change with a commercially available change analysis software, the Cirrus Advanced RPE Analysis relative to expert graders, with a sensitivity 64% (14/22 eyes) and specificity of 82% (9/11 eyes). Total drusen area or amount of change between visits had no significant effect on agreement. This suggests multispectral pattern recognition can quantify longitudinal change in drusen area from multimodal imaging with greater congruency to expert graders than a commercially available platform based on a single imaging modality. Considering the association of drusen area and disease progression, this method could aid clinical assessment and monitoring of AMD.

Retinal layer thicknesses and neurodegeneration in early age-related macular degeneration: insights from the Coimbra Eye Study

PURPOSE

This study aims to analyze the retinal layers and choroidal thickness in a large set of eyes with early age-related macular degeneration (AMD), in order to detect differences by stage suggestive of early neurodegeneration, and to explore biomarkers of different phenotypes.

METHODS

This study is a population-based, cross-sectional study. Patients from the incidence AMD study (NCT02748824) with early AMD (Rotterdam 2a, 2b, 3) were included. All performed spectral-domain optical coherence tomography (SD-OCT) (Spectralis, Heidelberg Engineering, Germany) and automatic segmentation of all retinal layers was obtained with built-in software. Manual correction was performed whenever necessary. The mean thicknesses (ETDRS grid) and volume of each layer were recorded. Subfoveal choroidal thickness was manually measured. Estimates for each layer thickness were calculated with linear mixed models and tested for pairwise differences between stages. Associations between layer thickness and microstructural findings were assessed by multivariate regression analysis.

RESULTS

The final cohort comprised 346 eyes (233 patients): 82.66% (n = 286) in stage 2a, 5.49% (n = 19) in stage 2b, and 11.85% (n = 41) in stage 3. A global tendency for lower/inferior thickness of the neuroretinal layers was found comparing stage 3 to 2a: retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) were inferior in the inner/outer ETDRS circles and the outer nuclear layer (ONL) and photoreceptors' segments layer in the central circle (p ≤ 0.002). The retinal pigment epithelium-Bruch's membrane (RPE/BrM) layer was thicker in stage 3 (p ≤ 0.001). Subretinal drusenoid deposits (SDD) were associated with thinner neuroretinal layers and choroid (p < 0.05).

CONCLUSIONS

Our results showed in a large population-based dataset that several inner and outer neuroretinal layers were thinner with a higher stage in early AMD. These findings support the existence of early and progressive neurodegeneration. Neuronal retinal layer thicknesses might thus be used as quantitative biomarkers of disease progression in AMD. The presence of SDD is possibly associated to more prominent and faster neurodegeneration.

Phenotypic and genetic variations between Asian and Caucasian polypoidal choroidal vasculopathy

PURPOSE

To compare phenotypic and genetic variations in polypoidal choroidal vasculopathy (PCV) between Caucasian and Asian patients.

METHODS

We analysed phenotypic and genotypic data from two sites, Association for Innovation and Biomedical Research on Light and Image, Portugal and Singapore National Eye Centre, Singapore. Baseline fundus photography, spectral domain-optical coherence tomography, indocyanine green and fluorescein angiography scans were analysed by respective reading centres using a standardised grading protocol. Single nucleotide polymorphisms across 8 PCV loci were compared between cases and controls selected from each population.

RESULTS

One hundred and forty treatment-naïve PCV participants (35 Portuguese and 105 Singaporean) were included. The Portuguese cohort were older (72.33±8.44 vs 68.71±9.40 years, p=0.043) and were comprised of a lower proportion of males (43% vs 71%, p=0.005) compared with the Singaporean cohort. Differences in imaging features include higher prevalence of soft drusen (66% vs 30%, p=0.004), lower prevalence of subretinal haemorrhage (14% vs 67%, p<0.001), smaller polypoidal lesion (PL) area (0.09±0.09 vs 0.76±0.93 mm², p<0.001), lower ratio of PL to branching vascular network area (3% vs 38%, p<0.001) and lower central retinal thickness (346.48±93.74 vs 493.16±212.92 µm, p<0.001) in the Portuguese cohort. CETP rs3764261 (OR 2.467; 95% CI 1.282 to 4.745, p=0.006) in the Portuguese population was significantly associated with PCV and CFH rs800292 (OR 1.719; 95% CI 1.139 to 2.596, p=0.010) in the Singaporean population, respectively.

CONCLUSION

Among Asian and Caucasian patients with PCV, there are significant differences in the expression of phenotype. We also identified different polymorphisms associated with PCV in the two populations.