Long term evolutions of hard exudates after anti-VEGF therapy for diabetic macular oedema

To evaluate longitudinal change in hard exudate (HEs) volume over 5-years following anti-VEGF treatment for diabetic macular oedema (DMO).

This study was a post-hoc analysis of structural optical coherence tomography (OCT) volume scans collected in the Diabetic Retinopathy Clinical Research Network Protocol T extension trial. A deep learning model was used to segment HEs and compute a HEs volume (mm³) for the entire OCT scan at baseline, 12, 24, 52, 104, 260 weeks (w). HEs volume was also quantified within the central subfield (CSF), inner ring (IR), and outer ring (OR) of ETDRS grid. Change in HEs over time was compared among treatment arms and a multiple regression analysis was used to evaluate the impact of HEs on visual outcomes relative to other biomarkers.

116 eyes were included (aflibercept: 44, bevacizumab: 30, ranibizumab: 42) in the final analysis. Across all studied regions, HEs significantly decreased through w52 (p < 0.001), and from w52 to w104, a further significant decrease was observed in the total macula and IR, though no additional reduction between w104 and w260. Change in VA at w260 was associated with baseline VA and w260 change in CST, but not with baseline HEs. At w52, HEs reduction was significantly greater with aflibercept and ranibizumab compared to bevacizumab, but no longer significant at w104 and w260.

Following anti-VEGF therapy, HEs decreased through w104, but stabilised after that, and initial differences among agents disappeared by two years. The change in HEs did not predict w260 visual outcomes.