Characterization of Diabetic Microaneurysms by Simultaneous Fluorescein Angiography and Spectral-Domain Optical Coherence Tomography

Abstract

PURPOSE To correlate spectral domain optical coherence tomography (SD-OCT) findings of perfused diabetic microaneurysms with leakage status on fluorescein angiography (FA) using simultaneous FA and SD-OCT. DESIGN Retrospective, observational case series. METHODS 173 microaneurysms were analyzed in 50 eyes (14 mild nonproliferative diabetic retinopathy (NPDR); 22 moderate NPDR; 9 severe NPDR; 5 proliferative diabetic retinopathy (PDR)) of 40 diabetic patients using simultaneous FA and SD-OCT. The characteristics of microaneurysms were evaluated by two masked observers using SD-OCT and correlated with leakage status on FA. RESULTS External diameter of microaneurysms averaged 104 microns (range 43 – 266 microns). Some microaneurysm centers (15/173, 9%) and the outermost extent of microaneurysms (113/173, 68%) were localized to the outer half of the retina. Almost all microaneurysms spanned more than 1 retinal layer (157/173; 91%). Most microaneurysms had an internal lumen with homogeneous reflectivity (109/173; 63%) and moderate reflectivity (87/173; 50%). Both retinal thickness through microaneurysms as well as the presence of adjacent hypo-reflectivity on SD-OCT correlated with increasing leakage status seen on FA (P < 0.001). Microaneurysms’ dimensions, percent depth within the retina, retinal layer location, and internal reflectivity by SD-OCT did not correlate significantly with FA leakage status. CONCLUSIONS Simultaneous FA and SD-OCT allows detailed characterization of perfused diabetic microaneurysms. Increased FA leakage of diabetic microaneurysms positively correlated with peri-aneurysm fluid and retinal thickness. Perfused microaneurysms seen by SD-OCT were localized deeper than the inner nuclear layer.

Characterization of the Middle Capillary Plexus Using Optical Coherence Tomography Angiography in Healthy and Diabetic Eyes

“…27-29 Two recent OCTA studies showed that microaneurysms are more often found in the DCP than in the SCP. 11, 24 It will be important to reassess these findings as they relate to the MCP, since these studies have used the preset, INL-splitting segmentation boundaries to study the location of microaneurysms.…”

Characterization of Microaneurysm Closure After Focal Laser Photocoagulation in Diabetic Macular Edema

“…7,8 Characterization of individual microaneurysms in DME following focal laser photocoagulation may increase our understanding of microaneurysm regression and provide insight to improve treatment approaches. In this study, we characterized individual microaneurysms in DME using simultaneous FA and SD-OCT following navigated focal laser photocoagulation.…”

Guidelines for the Management of Diabetic Macular Edema by the European Society of Retina Specialists (EURETINA)

“…More recently, the relationships between OCT and FA findings have been explored and the various characteristics related to each other indicating that both overlap and the complementarity of findings [13,14] . Simultaneous FA and SD-OCT allow improved characterization of DME features and allow distinction of perfused MA from nonperfused MA as well as the ability to localize fluid to different retinal layers [15] . In a recent study, abnormalities of choroidal perfusion were detected by indocyanine green angiography, and the combination of this imaging modality along with enhanced-depth OCT imaging and FA were reported as superior indicators of ocular perfusion status in diabetic eyes [16] .…”