Kinetics of central macular thickness reduction in patients with macular edema after intravitreal drug therapy

BACKGROUND The purpose of this study was to characterize central macular thickness and retinal volume following intravitreal injections using time domain and spectral domain optical coherence tomography (TD-OCT and SD-OCT, respectively). METHODS Nine patients with macular edema secondary to diabetes or retinal vein occlusion treated with intravitreal triamcinolone 4.0 mg and/or bevacizumab 1.25 mg were enrolled. Central macular thickness and volume was measured by SD-OCT and TD-OCT scan at baseline, and 1, 3, 6, 24, 48 hours, and 1 week postinjection. RESULTS Equations were derived to describe central macular thickness and volume reduction in the hours following intravitreal injection. Measurements of central macular thickness by SD-OCT were significantly reduced by 3 hours (P = 0.03) and retinal volume by 6 hours (P = 0.03). Central macular thickness measured 40.9 (28.6-53.2) μm thicker on the SD-OCT instrument while volume measured 3.47 (3.27-3.66) mm(3) higher. CONCLUSION Significant central macular thickness and volume reductions occur in the first hours after injection with triamcinolone and/or bevacizumab.