Hyperreflective Foci in Outer Retina Predictive of Photoreceptor Damage and Poor Vision After Vitrectomy for Diabetic Macular Edema

In Brief Purpose: To investigate the correlation between visual outcomes and preoperative hyperreflective foci in the outer retinal layers seen on spectral domain optical coherence tomography images in eyes that underwent vitrectomy for diabetic macular edema. Methods: We retrospectively reviewed 32 consecutive eyes that underwent vitrectomy for diabetic macular edema. Ten eyes had accumulated or many hyperreflective foci in the outer retinal layers preoperatively; 22 eyes did not have the pathology. The logarithm of the minimum angle of resolution and the junction between inner and outer segments were studied in the groups. Results: Logarithm of the minimum angle of resolution was significantly better in eyes without hyperreflective foci than in those with hyperreflective foci at 3 months and 6 months, and the last visit (P = 0.029, 0.010, and <0.001, respectively) compared with no differences at the baseline. Visual improvement was greater in eyes with no hyperreflective foci at the same time points. Seven eyes with hyperreflective foci had no junction between inner and outer segments at the final visit, whereas only 4 eyes with no foci had no junction between inner and outer segments (P = 0.004). However, the foveal thickness did not differ between the groups at any time. Conclusion: Preoperative hyperreflective foci in the outer retinal layers detected by spectral domain optical coherence tomography might predict the photoreceptor damage and a poorer prognosis after vitrectomy for diabetic macular edema. Logarithm of the minimum angle of resolution was significantly better in eyes without hyperreflective foci in the outer retinal layers than those with hyperreflective foci after vitrectomy for diabetic macular edema, compared with no differences at baseline. Eyes with preoperative foci had postoperative foveal photoreceptor damage, whereas foveal thickness did not differ between the groups.