Abstract
Purpose:
Predicting response to therapy is an important aspect of patient care. We sought to identify baseline factors that predicted long-term visual outcomes in patients with visual impairment due to DME who received ranibizumab in the RESTORE core and extension study.
Methods:
RESTORE was a 12-month, phase III randomised, controlled, clinical trial that compared laser photocoagulation, ranibizumab 0.5mg, and ranibizumab 0.5mg combined with laser photocoagulation. Patients completing RESTORE were eligible for enrollment into the 24 month RESTORE extension study. Ranibizumab was administered as three monthly initiating doses, followed by as-needed dosing similar to the EU product label. At Month 12, all patients were eligible for ranibizumab 0.5mg as-needed. Change from baseline in best-corrected visual acuity (BCVA) at 36 months/LOCF was analysed using multivariate linear regression adjusting for baseline characteristics.
Results:
In both ranibizumab- and laser only-initially treated patients (n=166 and n=74 respectively), the baseline characteristic most strongly correlated (Inversely) with change in BCVA was baseline VA (p=0.0002 and p<0.0001 respectively). Older age, duration of both diabetes and DME were also significantly correlated with 36-month BCVA in ranibizumab-treated patients only (p=0.045, 0.013, and 0.045 respectively). Shorter duration periods for diabetes and also for DME were associated with better clinical responses to ranibizumab treatment. In patients initially treated with laser, but not in patients commenced on either of the ranibizumab regimens, baseline central retinal thickness correlated positively with change in BCVA (p=0.0063).
Conclusions:
Baseline BCVA was a strong predictor of BCVA changes over 36 months, so that patients with poorer VA achieved greater gains than those with better baseline vision. Other correlates varied by treatment modality, consistent with differing modes of action between ranibizumab and laser photocoagulation. Better responses in patients with more recently diagnosed DME highlights the need for prompt therapy.
Keywords: 499 diabetic retinopathy •
585 macula/fovea •
748 vascular endothelial growth factor