Purpose:
To assess the short-term effect of intravitreal Bevacizumab (IVB) in patients with macular edema (ME) secondary both to Diabetic Retinopathy and to Venous Occlusion (VO).
Methods:
Thirty-four eyes of 34 patients with ME were included in the study. There were 24 eyes with diabetic macular edema (DME) and 10 eyes with VO. Early Treatment of Diabetic Retinopathy Study (ETDRS) logMar visual acuity (VA) and Spectral Domain Optical Coherence Tomography (SD-OCT) foveal thickness, overall macular volume with Thickness Map Tab and eye-tracking follow-up of the central edema scan were performed at the day of IVB (T0), 1 day (T1) and 7 days (T2) after IVB. Statistical analysis was conducted using Stata 12.0 SE. Repeated Measures Analysis of Variance was used to determine statistical significance.
Results:
The SD-OCT average foveal thickness was 468.67 µm (SD 135.44, range 287 to 772) at T0; 429.00 µm (SD 118.74, range 235 to 740) at T1; 414.26 µm (SD 117.32, range 208 to 723) at T2. The average overall macular volume was 9.51 mm3 (SD 2.12, range 6.17 to 14.56) at T0; 8.97 mm3 (SD 2.12, range 5.36 to 14.09) at T1; 8.73 mm3 (SD 2.09, range 5.02 to 13.87) at T2. The average follow-up (AFU) T0-T1 was -32.85 µm (SD 30.04, range -142 to 6); AFU T1-T2 was -18.41 µm (SD 13.43, range -60 to 8). A statistically significant decrease was demonstrated in SD-OCT foveal thickness (p<0.0001; F 23.27) and overall macular volume (p<0.0001; F 21.84). Interestingly, there was a major reduction in ME from T0 to T1 rather than from T1 to T2. Although several patients referred a positive outcome within the first day after IVB, average improvements in VA were not statistically significant.
Conclusions:
We demonstrated a significant reduction in ME within the first day after IVB. Further studies using a larger sample of patients closely examined at different time points in the first month after IVB are needed to determine the period of greatest ME reduction and of ME recurrence after IVB. Better understanding ME response to IVB could suggest new injections intervals.
Keywords: macula/fovea • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)