Purpose: To investigate the correlation between the hyperreflective foci (HF) on spectral domain optical coherence tomography at the baseline and visual outcomes after intravitreal bevacizumab injections in different patterns of diabetic macular edema.
Methods: We retrospectively reviewed the medical records of 97 eyes (80 patients) with diabetic macular edema that were treated with intravitreal bevacizumab injection. The eyes were categorized into three groups by optical coherence tomographic features: diffuse retinal thickening, cystoid macular edema, and serous retinal detachment. The baseline and final best-corrected visual acuity, foveal thickness, the number of HF, and status of the external limiting membrane and the ellipsoid zone were evaluated and compared among the three groups.
Results: The number of HF in all retinal layers was reduced in patients with diabetic macular edema after treatment. In multivariate regression analysis, the final visual acuity was associated with baseline visual acuity (P = 0.004) and number of outer retinal HF (P = 0.004) in the diffuse retinal thickening group, baseline visual acuity (P = 0.002) and number of outer retinal HF (P < 0.001) in the cystoid macular edema group, and baseline number of inner and outer retinal HF (P = 0.041, P = 0.025, respectively) in the serous retinal detachment group. The baseline number of the outer retinal HF was correlated with the final visual acuity, ellipsoid zone disruption length, and external limiting membrane disruption length in all three groups.
Conclusion: The number of HF in outer retinal layer on spectral domain optical coherence tomography at baseline might predict the final visual acuity in all three patterns of diabetic macular edema groups.