Abstract
Purpose: :
to detect and describe the features of diabetic macular edema (DME) using a scanning laser ophthalmoscope with the darkfield mode of a 790-nm diode laser (Nidek F-10 retro-mode).
Methods: :
Patterns of DME have been identified and described in retro-mode images by two observers (MP and FO) by comparison with corresponding fluorangiographic images (FA). In a second phase different observers (MV and MT) were instructed to detect and classify patterns of edema in 20 consecutive DME eyes. Inter-observer agreement and agreement between retro-mode and FA images have been evaluated. Direct correlation with OCT images were also examined. Agreement was graded by Cohen’s kappa.
Results: :
two cystic patterns (petaloid and honeycomblike) and one diffuse pattern of edema have been identified in retro-mode images and confirmed by OCT. Inter-observer agreement to detect different patterns of edema was very high (Cohen’s Kappa: 0.92, SE: 0.08). The agreement between retro-mode and FA images for each observer was moderate (observer 1: Cohen’s kappa: 0.52, SE: 0.12; observer 2: Cohen’s kappa: 0.58, SE: 0.12). The agreement between retro-mode and FA images increased without reaching optimal values (observer 1: Cohen’s kappa: 0.68, SE: 0.13; observer 2: Cohen’s kappa: 0.75, SE: 0.12) when only cystic patterns were considered.
Conclusions: :
Retro-mode modality allows to detect and characterize DME. The relative low agreement with FA images in classifying different DME patterns may be explained considering the improved identification of cystic DME patterns in retro-mode images and the lack of characterization of diffuse edema compared to FA images.
Keywords: imaging/image analysis: clinical • edema • diabetes