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

Abstract

Epidemiology of age-related macular degeneration (AMD) is based on staging systems relying on color fundus photography (CFP). We aim to compare AMD staging using CFP to multimodal imaging with optical coherence tomography (OCT), infra-red (IR), and fundus autofluorescence (FAF), in a large cohort from the Epidemiologic AMD Coimbra Eye Study. All imaging exams from the participants of this population-based study were classified by a central reading center. CFP images were graded according to the International Classification and Grading System for AMD and staged with Rotterdam classification. Afterward, CFP images were reviewed with OCT, IR, and FAF and stage update was performed if necessary. Early and late AMD prevalence was compared in a total of 1616 included subjects. In CFP-based grading, the prevalence was 14.11% for early AMD (n = 228) and 1.05% (n = 17) for late AMD, nine cases (0.56%) had neovascular AMD (nAMD) and eight (0.50%) geographic atrophy (GA). Using multimodal grading, the prevalence increased to 14.60% for early AMD (n = 236) and 1.61% (n = 26) for late AMD, with 14 cases (0.87%) of nAMD and 12 (0.74%) of GA. AMD staging was more accurate with the multimodal approach and this was especially relevant for late AMD. We propose that multimodal imaging should be adopted in the future to better estimate and compare epidemiological data in different populations.

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

“…Subjects who participated in the Incidence study also had blood samples collected for genetic analysis. 20 – 23 We have previously reported on the genetic characterization of this cohort, and we found that rare and low-frequency variants in the CFH gene with damaging effects were more common in AMD cases (Farinha C, et al, unpublished data, 2021). The purpose of this study is to determine the association between the carrier status of rare genetic variants in the CFH gene and the phenotypic features in AMD patients who participated in the Incidence study.…”

“…Both FAF (488 nm) and IR images were acquired for field 2 at 30° (high resolution with ≥15 frames each). 23 …”

“…CFP image grading was supported by Retmarker AMD Research software (Retmarker SA, Coimbra, Portugal) according to the International Age-Related Macular Epidemiological Study Group Classification, while simultaneously analyzing the corresponding SD-OCT, IR, and FAF images in the Heidelberg Eye Explorer software (version 1.10.4.0) as previously reported. 21 , 23 , 25 , 26 …”

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

“…Recently, a multimodal approach has been recommended to comprehensively visualise AMD and help determine the best clinical management based on structural disease markers 12 . For drusen, several advanced eye imaging modalities such as infrared imaging (IR) 23 , 24 , green scanning laser ophthalmoscopy 25 , fundus autofluorescence (FAF) 26 , 27 and OCT 27 – 29 have been shown to be useful in differentiating different drusen subtypes 27 , 30 and a multimodal approach is suggested for improved accuracy of AMD staging 31 , 32 . Comparison of drusen segmentation between OCT and en face retinal images also show different advantages to each modality with the former useful for detection of large drusen areas while color fundus photographs (CFPs) are superior in detecting subtle changes in drusen 21 , 22 .…”

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

“…The environmental and nutritional risk factors associated with AMD prevalence were previously explored and reported (Cachulo et al, 2016; Raimundo et al, 2018). Subjects who participated in the 6.5‐year follow‐up visit for the estimation of incidence also had blood samples collected for further genetic characterization (Farinha et al, 2020).…”