Clinical characteristics and long-term follow-up of extensive macular atrophy with pseudodrusen-like appearance in Japanese patients

To describe the clinical characteristics and long-term follow-up findings of extensive macular atrophy with pseudodrusen-like appearance (EMAP) in a Japanese cohort. This retrospective observational study analyzed Japanese patients diagnosed with EMAP who underwent genetic tests, which did not detect known pathogenic variants of inherited retinal dystrophies or age-related macular degeneration. Patients underwent comprehensive ophthalmic evaluations, including multimodal imaging (fundus autofluorescence and optical coherence tomography) and full-field electroretinography. This study included eight Japanese patients with EMAP, encompassing five males and three females. The mean follow-up period was 102.5 (range, 25–180) months. The mean best-corrected visual acuity declined from 0.18 to 1.08 logarithm of the minimum angle of resolution (right eye) over the follow-up period. Macular atrophy and peripheral paving-stone-like degeneration were present in 75% and 87.5% of patients, respectively. Rod responses were reduced in 62.5% of patients, and delayed flicker full-field electroretinography implicit times were observed in 62.5%. Longitudinal imaging suggested phenotypic changes in a limited number of cases including progression from a predominantly central pattern to confluent involvement in one patient. Japanese patients with EMAP exhibited structural and functional abnormalities during long-term follow-up that were consistent with broader retinal involvement extending beyond the macula. What is known ・Extensive macular atrophy with pseudodrusen-like appearance (EMAP) is a rare, rapidly progressive retinal disorder primarily reported in European populations, characterized by bilateral macular atrophy and widespread subretinal drusenoid deposits. ・Clinical data regarding EMAP in Asian populations, particularly long-term evolution, remain scarce. What is new ・This represents the first case series of EMAP in a Japanese population and provides descriptive long-term clinical observations over a follow-up period of up to 15 years. ・The study highlights pan-retinal functional deterioration, such as reduced rod responses and delayed flicker full-field electroretinography implicit times, which may accompany or even precede apparent structural changes.