Validation of choroidal hyperreflective foci in diabetic macular edema through a retrospective pilot study

Choroidal hyperreflective foci (HCF) are novel spectral-domain optical coherence tomography (SDOCT) biomarkers in diabetic macular edema (DME). The present study intended to validate HCF and assess their role in the treatment outcome.

It was a retrospective, longitudinal, records-based pilot study recruiting consecutive patients of nonproliferative diabetic retinopathy with treatment naïve DME. Patients were treated with three intravitreal anti-vascular endothelial growth factor injections and followed by a pro re nata regimen.

A total of 43 eyes of 28 patients were included in the study. Eyes were divided into two groups. Group A (n = 19) comprised eyes with retinal hyperreflective foci (HRF) and group B (n = 24) had eyes with both HRF and HCF. The mean age of patients in group A and B was 58.5 ± 2.1 years and 55.2 ± 8.8 years, respectively. Mean best-corrected visual acuity at presentation was 0.38 ± 0.25 in group A and 0.59 ± 0.29 in group B (P = 0.01). Final BCVA was 0.35 ± 0.39 in group A and 0.47 ± 0.34 in group B (P = 0.3). External limiting membrane was intact in 19 out of 19 eyes in group A and two (8.3%) eyes in group B (P = 0).

Presence of HCF meant significantly worse initial BCVA compared to the eye that had HRF alone. The final BCVA was also worse in eyes with HCF compared to those with HRF and without HCF; however, the difference did not reach a significance level, probably pointing toward the fact that HCF and HRF are pathophysiologically identical. Further studies with a larger sample size and prospective design are needed to take these findings forward.