Abstract
Purpose: :
To describe retinopathy findings in patients with diabetes on fundus autofluorescence (FAF) as compared to color fundus images.
Methods: :
Review of eyes from patients with type 1 and type 2 diabetes who underwent non-mydriatic telemedicine retinal screening exams with standard color imaging and green extracted monochromatic channel (550 nm) with a resolution of 12 Mega pixel (Canon CX-1 Hybrid Retinal Camera, Tokyo, Japan) and FAF imaging (exciter filter 530-580 nm and near infrared barrier filter 640 nm). All images were viewed on one computer with maximal brightness and resolution of 1280 x 800, in a dark room. Images were discarded if quality was considered suboptimal. Fundus color images were compared with FAF images for correlation of findings seen in non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR).
Results: :
Fifty eyes of patients with type 1 and type 2 diabetes were imaged from 2010 until present. Thirty-six demonstrated no diabetic retinopathy based on color imaging and FAF. On both imaging techniques, 11 patients met the criteria for NPDR and 5 demonstrated signs of severe NPDR or PDR. Intraretinal hemorrhages, microaneurysms, hard exudates, chorioretinal scars from photocoagulation, and pre-retinal hemorrhages were all apparent as areas of hypofluorescence on FAF. Hard exudates and pre-retinal fibrosis were more difficult to visualize on FAF compared to color imaging. Four patients with NPDR demonstrated markedly more FAF disturbance compared to color imaging. One patient had a hollenhorst plaque that was not noted on FAF.
Conclusions: :
Our results indicate that subjects with diabetes exhibit an array of abnormalities on FAF. In some NPDR eyes FAF disturbances can be more apparent than on color imaging. Additional study is warranted to further characterize FAF findings in eyes with diabetes and the utility of FAF as a tool in ocular telescreening.
Keywords: diabetic retinopathy • retina • imaging/image analysis: clinical