Longitudinal follow-up of two patients with isolated paracentral acute middle maculopathy

Objective: To describe longitudinal retinal changes in two cases of isolated paracentral acute middle maculopathy (PAMM). Case series: We reported two cases (64 and 67-year-old men) with isolated PAMM, who were followed-up for over 5 and 2.5 years, respectively. Both cases exhibited similar clinical natural histories. The first examinations took place several days after onset, with funduscopy showing that both cases exhibited paracentral scotoma with good visual acuity and small gray lesions, while optical coherence tomography (OCT) showed the presence of a hyperreflective band that ranged from the inner plexiform layer to the outer plexiform layer (OPL). The lesions became unremarkable within 1 month. The hyperreflective band also became unremarkable and was limited to the inner nuclear layer (INL) within 1 month, with the band disappearing within several months. Subsequently, OCT showed there was a thin and irregular INL and OPL, an excavated change of the inner retinal surface, along with outer nuclear layer (ONL) thickening. After several years, OCT angiography demonstrated normal flow of macular capillaries in the superficial capillary plexus, and decreased flow in the lesion with dilation of the capillaries around the area in the deep capillary plexus (DCP). Focal serous retinal detachment (SRD) occurred in one case after 4-5 years. Conclusion: Our findings indicated that long-term retinal changes in PAMM resulted in excavation of the inner retinal surface, INL thinning, ONL thickening and abnormal vasculature, especially in the DCP. Focal SRD may be a rare complication that can present at 4 years after onset.