[Visual prognosis and prognostic risk factors after photocoagulation for diffuse diabetic macular edema].
PURPOSE: To investigate the efficacy of photocoagulation for diffuse diabetic macular edema. SUBJECTS AND METHODS: One hundred and fifty eyes with diffuse diabetic macular edema were treated by laser photocoagulation (grid pattern photocoagulation, in some instances combined with direct photocoagulation) and followed up more than 1 year. The visual prognosis of these cases was retrospectively studied. RESULTS: The logarithm of the minimum angle of resolution (Log MAR) final visual acuity after photocoagulation was improved more than 0.2 levels in 62 eyes (41%) of a total 150 eyes, and in 60% of 87 eyes in which preoperative visual acuity had been less than 0.5. Average visual acuity after photocoagulation reached a plateau within three months after surgery, and 84% of the eyes with 0.5 or better preoperative visual acuity achieved 0.5 or better final visual acuity. There was correlation between visual prognosis and the following preoperative factors: preoperative visual acuity, hard exudates, fluorescein leakage, grid area, hyperlipidemia, and renal failure. CONCLUSIONS: Grid photocoagulation as a treatment for diffuse diabetic macular edema is effective to improve or maintain visual acuity. Alternative treatment such as vitrectomy should be considered after three-month observation on the outcome of grid photocoagulation.