Longitudinal analysis of the structural pattern of pseudophakic cystoid macular edema using multimodal imaging

Purpose To describe the relationship between pseudophakic cystoid macular edema (CME) progression and retinal structural changes observed by spectral-domain optical coherence tomography (SD-OCT) and fluorescein angiography. Methods Retrospective, consecutive, longitudinal imaging analysis of patients with acute pseudophakic cystoid macular edema. Two observers at two study centers evaluated all images and categorized the macular structural features based on the retinal layer involved with cystic changes and/or subretinal fluid. A time series of the structural pattern and visual acuity was constructed for 1-month intervals over a 6-month study period. Results Thirty nine patients presented with CME. The mean time since cataract extraction was 48 ±38 days (range 5–71). CME included inner nuclear layer (INL) cystic changes, outer plexiform layer (OPL) cystic changes, and subretinal fluid. Isolated INL changes were observed in four phakic fellow eyes. Isolated OPL morphology was not observed, and additional inner layers remained uninvolved. Resolution occurred rapidly following administration of periocular glucocorticoids, and typically demonstrated a reverse structural pattern or delayed subretinal fluid resolution. Isolated subretinal fluid or a combined INL and subretinal fluid structure indicated CME resolution. Conclusion Acute and recurrent pseudophakic CME involves a directional progression of the retinal layer involved with cystic changes and a clinical course. CME begins with INL cystic changes, progresses to combined INL and OPL morphology, and may continue to involve subretinal fluid. The inner nuclear layer is the most frequently involved layer, and isolated INL cysts may occur in phakic fellow eyes. A three-layer structure, the presence of OPL morphology, or isolated INL early in the postoperative period indicates disease activity.