Abstract
Purpose: :
To determine the sensitivity of fundus autofluorescence (FAF) in detecting macular edema (ME) due to diabetes and retinal vein occlusions using optical coherence tomography (OCT) as the reference standard.
Methods: :
Consecutive eyes with ME that had FAF and spectral-domain OCT imaging between December 15, 2009 and March 15, 2010 were reviewed. All eyes underwent imaging with both modalities at the same visit. Accurate foveal localization on OCT was verified by simultaneous infrared fundus image capture. FAF images were obtained in the 30 degree field of view mode. They were then evaluated for increased FAF (hyper FAF) compared with the normal FAF distribution, and the location of hyper FAF in relation to the center of the fovea. The OCT images were reviewed for the presence or absence of macular edema and, if present, for the location of macular edema on the OCT map in relation to the center of the fovea. Central subfield thickness, greatest macular thickness in the area of edema, and total macular volume were recorded.
Results: :
Thirty one eyes of 21 patients (11 males and 10 females) were included. The mean patient age was 57 years (range 41-65 years). Twenty nine eyes had diabetic ME as confirmed by clinical examination and OCT while the other two patients had ME due to retinal vein occlusions. One of the patients had both diabetes and a branch retinal vein occlusion (BRVO). The mean central subfield macular thickness on OCT was 422µm (range 251-1052 µm) and the mean total macular volume was 10.13 mm3 (range 8.03-14.57 mm3). On FAF imaging, ME was detected as hyper FAF in all eyes. The area of hyper FAF correlated with the area of macular thickening on the OCT map. In all eyes, inner segment-outer segment photoreceptor junction in the area of macular thickening was intact on OCT. Patients with diabetic ME were treated with either focal laser with or without panretinal photocoagulation or observation depending on the visual acuity. The two patients with vein occlusions and one with both diabetes and a BRVO were treated with a series of intravitreal bevascizumab injections.
Conclusions: :
In this pilot study, FAF was found to be a sensitive diagnostic tool in detecting the presence of macular thickening in ME and the location of macular thickening in relation to the foveal center. FAF may be used as a rapid, non-invasive tool in the diagnosis of macular edema caused by diabetes and retinal vein occlusions.
Keywords: imaging/image analysis: clinical • diabetic retinopathy