Short-Term Progression of Diabetic Hard Exudates Monitored with High-Resolution Camera

To assess the progression of diabetic hard exudates over an 8-week period, using a high-resolution adaptive optics camera.

Prospective observational study.

Five eyes of three patients presenting diabetic maculopathy with hard exudates were studied. An area of clinically visible exudates was imaged sequentially using SD-OCT and high-resolution flood illumination adaptive optics for 2 months, on a weekly basis. A time-lapse video was obtained for each eye studied. Changes in terms of surface, number of free elements (foci), and central macular thickness were recorded.

Short-term modifications in terms of disposition, size, and number of exudates were observed. Two patterns of progression were identified: two eyes showed exudate dislocation concomitant with the regression of the underlying macular edema, with hard exudates being progressively replaced by a multitude of smaller foci. These exudates were labeled resorption exudates. In three other eyes with persistent diabetic macular edema, foci aggregated into larger exudates.

Diabetic hard exudate changes occurred over a short period of time but were not assessable clinically. Adaptive optics was able to document these subtle changes precisely. Further studies using this imaging modality may improve our understanding of the natural history of exudates and eventually help assess the efficacy of the various treatments available such as lipid-lowering drugs and anti-VEGFs injections.