Optical coherence tomographic hyperreflective foci in early stages of diabetic retinopathy

To analyze the presence of hyperreflective foci in Type 1 and Type 2 diabetic patients, separately, without clinically significant diabetic macular edema and visual impairment.

Noninvasive, observational prospective study. Seventeen and 19 consecutive Type 1 and Type 2 diabetic patients (33 and 38 eyes), respectively, were recruited. All patients had no clinically significant diabetic macular edema or visual impairment. Two age- and sex-matched control groups were also included. Patients underwent an ophthalmologic examination including spectral domain optical coherence tomography. Hyperreflective foci were counted considering horizontal B-scan passing through the fovea.

On spectral domain optical coherence tomography, patients affected by Type 1 and Type 2 diabetes had a mean of 7.5 ± 4.6 and 9.9 ± 4.5 hyperreflective foci, respectively. Subjects of control groups had a mean of 0.9 ± 0.8 and 1.7 ± 1.5 hyperreflective foci, respectively. Hyperreflective foci amount was statistically different between Type 1 and Type 2 diabetic groups (P = 0.032) and significantly higher in diabetic patients than in controls (P < 0.001). Hyperreflective foci amount was significantly higher in diabetic patients with a poor quality glycometabolic control (P < 0.001 and P = 0.016) or affected by hypertension (P = 0.008).

We reported the presence of hyperreflective foci in diabetic patients without diabetic macular edema and visual impairment. This spectral domain optical coherence tomography finding might be a useful marker for the diagnosis and the follow-up in the early stage of diabetic retinopathy.