Femtosecond laser photocoagulation for treatment of diabetic macular edema after vitrectomy. To evaluate the feasibility and effectiveness of micro-photocoagulation using the Nd:YAG picosecond laser for the treatment of diabetic macular edema after vitrectomy. Sixteen eyes with diabetic macular edema, who were not responsive to conventional laser photocoagulation, were prospectively treated by micro-photocoagulation with the Nd:YAG picosecond laser. Diabetic macular edema was classified as diffuse edema in five patients, cystoid edema in eight, and serous retinal detachment in three eyes. Eyes were followed up for 5.9 ± 2.2 months (range, 3-12 months). Retreatment was performed when any microaneurysm was seen on optical coherence tomography angiography. The visual acuity improved in 5/16 eyes, was unchanged in 10/16 eyes, and worsened in 1/16 eyes during follow-up. Microaneurysms were well coagulated in all eyes, but the area of laser scars decreased by 12.6 ± 5.2% at 6 months, 14.6 ± 4.9% at 12 months, and 16.7 ± 7.8% at 15 months. Visual acuity improvement was correlated with the reduction of retinal thickness (r = 0.76, P < 0.0001), but not with the reduction of the area of laser scars (r = -0.22, P = 0.42). These results suggest that micro-photocoagulation with the Nd:YAG picosecond laser may improve visual acuity and macular edema without further laser photocoagulation when it is performed at least once after the vitrectomy.