Hyperreflective foci as biomarkers for inflammation in diabetic macular edema: Retrospective analysis of treatment naive eyes from south India

Purpose: The aim of this study was to analyze the factors associated with hyperreflective foci (HRF) in diabetic macular edema (DME) in treatment naive eyes. Methods: This retrospective observational study included 131 eyes of 91 treatment naive patients with DME. Details of ophthalmological examination with duration of vision loss and systemic parameters were noted. The spectral-domain optical coherence tomography (SD-OCT) images were analyzed for number and location of HRF and the associated imaging biomarkers. Results: Inner retinal (IR) HRF were seen in 88 eyes (67%), outer retinal (OR) in 28 (21%), and subretinal (SR) in 12 (9%). The IR had (7.1 +/- 7) HRF, the OR (6.5 +/- 4.8), and SR (3.9 +/- 2.9). A greater proportion of eyes with HRF also had subretinal fluid (SRF), significantly higher blood pressure and lower serum triglycerides. Univariate linear regression analysis showed women (3 HRF greater vs. men, P = 0.04), eyes with cystoid spaces (2.95 more HRF vs. no cystoid spaces, P = 0.02), and SRF (2.96 more HRF vs. no SRF, P = 0.007) had more HRF, whereas higher triglycerides (1 HRF lesser per 50 mg lower TGL, P = 0.03) had lesser. Conclusion: Our study highlights the importance of HRF as an imaging biomarker in DME suggesting an inflammatory origin. Long-term observations of large cohorts with automated analysis can give more insights.

Automated summary

The study found significant associations between the location and number of HRF in eyes of DME patients and the presence of SRF, higher blood pressure, and lower serum triglycerides in most eyes. Factors such as gender, presence of cystoid spaces, and SRF in eyes were also correlated with the number of HRF.