Purpose: To identify factors associated with variability in anatomical and functional response of diabetic macular oedema (DMO) after 4 mg of intravitreal triamcinolone acetonide (ivTA), and for recurrence of macular oedema.
Design: Pooled analysis of individual data from two randomized controlled trials.
Methods: This was a multicentre study involving 107 eyes with DMO administered 4 mg ivTA. Predictive factors for response to treatment were evaluated with linear regression analysis. Factors associated with time to recurrence of oedema were studied with Cox proportional hazards modelling. Main outcome measures were maximum improvement in optical coherence tomography (OCT)-measured central foveal thickness (CFT) and best-corrected visual acuity (BCVA), final CFT and BCVA at 12 months and time to oedema recurrence.
Results: Greater reduction of retinal thickening occurred in eyes with worse baseline thickening (P < 0.001). There was also greater improvement of visual acuity in eyes with poorer preoperative BCVA levels (P < 0.001). Age, duration of oedema and previous macular laser treatment had no significant effect on maximal BCVA or CFT improvement. Eyes given 4 mg triamcinolone alone were more likely to develop recurrence of oedema at 12 months than those given a combination of 4 mg triamcinolone plus sequential laser (hazard ratio 2.60 [95% confidence interval: 1.45-4.67]).
Conclusion: Baseline OCT-measured retinal thickening and BCVA are important predictors of maximal anatomical and functional response of DMO to ivTA, respectively. Combination treatment strategy using sequential laser therapy may have a role in delaying recurrence of oedema after triamcinolone.