Functional, Anatomical and Patient-Reported Baseline Characteristics of the MACUSTAR Study

Abstract

Purpose : To report the baseline characteristics of the longitudinal MACUSTAR study, a European multi-center study to develop and validate structural, functional and patient-reported endpoints in intermediate age-related macular degeneration (iAMD) for use in interventional clinical trials, which is funded by the European Union’s Horizon 2020 program.

Methods : Participants with iAMD and neighbouring diseases stages (early, eAMD; late, lAMD) and participants with no AMD were recruited at 20 study sites across seven European countries and underwent a battery of structural, functional and patient-reported assessments according to manuals specifically developed for the MACUSTAR study. Diagnosis and AMD staging according to the Beckman classification were confirmed by a central reading center (GRADE). After completion of data cleaning for the full baseline cohort, we report the characteristics of the sample, spread of functional deficit and patient-reported Vision Impairment in Low Luminance (VILL) across AMD stages.

Results : A total of 718 individuals, mostly female (66%) were included (iAMD, n=585; eAMD, 34; lAMD, 43; no AMD, 56). The mean (SD) age at baseline was 71.9±7.0 years. 46 (7.9%) participants with iAMD had lAMD in the non-study eye. Reticular pseudodrusen were present in 159 (27.2%) with iAMD and pigmentary abnormalities present in 287 iAMD participants (49.1%). Incomplete and complete retinal pigment epithelial and outer retinal atrophy were present in 69 (11.8%) and 54 iAMD participants (9.2%), respectively. All visual function assessments and VILL subscale scores were worst in late AMD (p<0.0001 except rod intercept time, p=0.095). They were similar in eAMD to iAMD in most assessments except low-luminance acuity, contrast sensitivity, standardized reading speed and the VILL-reading subscale (p=0.04, 0.002, 0.0063 and 0.0006, respectively) and the overall ability of individual assessments to to discriminate iAMD from eAMD was poor (area under the curve ≤0.675).

Conclusions : The baseline data from the MACUSTAR study underline the highly heterogeneous nature of iAMD according to the structural Beckman classification. The MACUSTAR dataset provides a unique opportunity for more granular characterization of iAMD disease subgroups. The longitudinal part of MACUSTAR is ongoing and includes an assessment of the predictive value of the above features for disease progression.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.