Microvascular changes in the recurrent cystoid macular edema secondary to posterior noninfectious uveitis on optical coherence tomography angiography

BACKGROUND: Posterior uveitis represents the second most frequent type of uveitis (15–30% of all uveitis). Noninfectious posterior uveitis complicated with secondary cystoid macular edema (CME) affects the visual prognosis negatively. The objective of the current study is to detect possible microvascular changes causing relapsing uveitis-related CME using optical coherence tomography angiography (OCTA). METHODS: This is an interventional, observational, retrospective study with 1 year follow-up. Patients with noninfectious, posterior uveitis-related CME undergoing dexamethasone (DEX) implant were evaluated. Following the DEX-implant were carried out control visits after 1 month, 2-months, 4-months, 6-months, and for up 1-year. A total of 76 eyes of 38 consecutive patients with noninfectious posterior uveitis were enrolled (consecutive sample). Complicated noninfectious posterior uveitis with secondary CME was diagnosed in 56 eyes of uveitis patients (73.7%) and reviewed. RESULTS: Our investigation showed (1) a reduction in superficial vessel plexus (SVP) measurements within 2-month (84%), reaching 96.4% for up 1-year, (2) an irregular profile of SVP in 69.6% of cases, persisting for up 1-year; relapsing uveitis-related CME eyes with irregular superficial foveal avascular zone (FAZ) profile were in 51%, while the SVP measurements reestablished in 100% of cases. Conversely, (3) the deep vascular plexus (DVP) parameters restored in a lower number of eyes within the 2-month (39.3%), remaining abnormal in 46.4% of cases for up 1-year; despite DVP restored in 53.6% of cases for up 1 year, (4) a capillary rarefaction ring around the FAZ appeared in 80.4% of cases; the relapsing uveitis-related CME eyes with abnormal DVP parameters were present in 41% of cases, of which 92.1% showed a rarefaction ring had abnormal DVP. CONCLUSIONS: The use of OCTA enabled the evaluation in detail of retinal microvascular changes. We suggested that the possibility of the recurrence of the uveitis-related CME depends on the persistence of modifications of the superficial and deep layers. In this regard, we propose to implement the current imaging armamentarium with OCTA for the follow-up of patients with noninfectious uveitis-related CME.