Extramacular paracentral acute middle maculopathy-like retinal ischemia after vitrectomy for epiretinal membrane

To describe two cases of extramacular paracentral acute middle maculopathy (PAMM)-like retinal ischemia after vitrectomy with internal limiting membrane (ILM) peeling for epiretinal membrane (ERM).

Case 1 involved a 78-year-old woman with a history of hyperlipidemia and preoperative visual acuity (VA) of 20/20. Case 2 involved a 72-year-old man with a history of hypertension and hyperlipidemia, and preoperative VA of 20/32. In both cases, cataract surgery and vitrectomy with ILM peeling were performed for the unilateral ERM and cataract. On postoperative day 1, retinal whitening was observed at separate extramacular areas from ILM peeling in the macular region in both cases. Optical coherence tomography revealed a high-intensity reflection in the inner nuclear layer, and optical coherence tomography angiography showed a perfusion defect in the deep capillary plexus (DCP), which corresponded to the area of retinal whitening. Fluorescein angiography revealed no significant abnormalities, leading to a diagnosis of PAMM-like retinal ischemia. In Case 1, retinal whitening disappeared at postoperative week 2, and the corrected VA improved to 20/20 at postoperative month (POM) 6. In Case 2, retinal whitening resolved at POM 1 and POM 4.5, and VA improved to 20/16. However, both cases showed residual perfusion defects in some deep retinal vessels, accompanied by scotomas corresponding to these areas.

We observed two cases of extramacular PAMM-like retinal ischemia that developed after vitrectomy with ILM peeling. Although both cases showed improved VA, blood flow disturbances at the DCP level and associated visual field defects persisted.