Efective treatment of diffuse diabetic macular edema by temporal grid pattern photocoagulation

BACKGROUND AND OBJECTIVE: To determine the effectiveness of laser grid pattern photocoagulation to the macula but not the papillomacular bundle for the treatment of diffuse diabetic macular edema. PATIENTS AND METHODS: Thirty-five eyes of 23 patients with diffuse diabetic macular edema underwent laser grid photocoagulation excluding the papillomacular bundle area. Best-corrected visual acuity by Snellen chart, foveal thickness using a retinal mapping program by optical coherence tomography (OCT), and mean deviation sensitivity by Humphrey automated central perimetry were investigated before and 1, 3, and 6 months after the treatment. RESULTS: Six months after treatment, the visual acuity was improved by 2 or more lines in 16 eyes (43%) and the foveal thickness decreased in 32 eyes (91%). The mean deviation worsened in 34 eyes (97%). There was a significant correlation between the improvement of visual acuity and the initial mean deviation, suggesting that a better visual acuity would be expected with a preoperative mean deviation of approximately -20 dB. CONCLUSION: Grid pattern photocoagulation without treatment to the papillomacular bundle area was effective in treating diffuse diabetic macular edema, especially in eyes with an initial mean deviation showing moderate dysfunction.