Immediate response to intravitreal treatment for macular edema due to diabetes and retinal vein occlusion

To objectively assess the immediate response to intravitreal treatment for macular edema and compare it across different agents.

This retrospective, comparative study included patients with macular edema due to diabetic retinopathy (DME) or vein occlusion who were treated with intravitreal injections of either steroids (triamcinolone acetonide or dexamethasone sustained release implant) or anti-vascular endothelial growth factor antibodies (VEGF). The central retinal thickness (CRT) and the best corrected visual acuity (BCVA) were measured 1 day after the injection and compared with immediate pre-injection values.

There were 79 eyes (57 patients) including 51 eyes with DME, 18 with branch retinal vein occlusion edema (BRVO-ME), and 10 eyes with central retinal vein occlusion edema (CRVO-ME). The intravitreal agents were triamcinolone acetonide (TA)(n = 15), dexamethasone sustained release implant (DEX)(n = 22), ranibizumab (n = 19), and bevacizumab (n = 23). Statistically significant improvement in CRT was seen in all injection groups (p < 0.05) while improvement in mean BCVA was significant only in the TA group (p = 0.009). The mean change in CRT was maximum with steroids than with anti-VEGFs; viz. 159.47 µ in TA, 115.45 µ in DEX, 86.10 µ in ranibizumab, and 78.78 µ in bevacizumab group. Least amount of change was noted in the spongy type of macular edema (18.73 µ) while improvement in mean BCVA was statistically significant only in the cystoid group (p = 0.01).

Comparatively, steroid agents showed better immediate response to therapy than anti-VEGFs. Maximum reduction in central retinal thickness was seen following triamcinolone acetonide injection. Cystoid edema showed better immediate response than spongy retinal thickening.