Microvascular Changes In The Recurrent Cystoid Macular Edema Secondary to Posterior Noninfectious Uveitis on Optical Coherence Tomography Angiography

Abstract

BACKGROUND: Posterior uveitis represents the second most frequent type of uveitis (15-30% of all uveitis). Non-infectious posterior uveitis complicated with secondary cystoid macular edema (CME) negatively affected the visual prognosis.The objective of the current study is to determine possible microvascular changes that can cause a relapsing uveitis-CME through optical coherence tomography angiography (OCTA).METHODS: This is a case-control study, an evaluation of patients with secondary CME noninfectious posterior uveitis-related undergoing dexamethasone (DEX) implant. The visits following the DEX-implant were carried out 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 (24.3%) reviewed. RESULTS: Our investigation showed a reduction in superficial vessel plexus (SVP) measurements already within 2-month (84%), reaching 96.4% for up 1-year, however displaying an irregular profile in 69.6% of cases, persisting for up 1-year; the relapsing uveitis-CME eyes with irregular superficial foveal avascular zone (FAZ) profile were in 51%, while the SVP measurements reestablished in 100% of cases. Conversely, the deep vascular plexus (DVP) parameters restored occurred 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, a capillary rarefaction ring around the FAZ appeared in 80.4% of cases; the relapsing uveitis-CME eyes with abnormal DVP parameters were in 41% of cases, of which 92.1% showed a rarefaction ring had abnormal DVP.CONCLUSIONS: The use of OCTA allows to evaluate the retinal microvascular features, which could be the cause of the recurrence of CME in uveitis patients, despite the DEX-implant treatment. We suggested that the possibility of the recurrence of the uveitis-CME depends on the persistence of modifications of the superficial and deep layers, which we therefore consider appropriate to investigate. With this purpose it would be useful to introduce OCTA into the current imaging armamentarium in follow-up of patients with noninfectious uveitis-CME.