Should the outcome of focal photocoagulation for center-sparing diabetic macular edema require expanding the definition of center involvement?

Photocoagulation may still be a therapeutic choice for center-sparing diabetic macular edema. We compared the visual evolution after photocoagulation, in eyes with focal diabetic macular edema, stratified per the location of thickening with optical coherence tomography. We evaluated people with type 2 diabetes and focal diabetic macular edema, before and three weeks after focal photocoagulation. We divided the sample by edema location: central (group1); paracentral (group 2) and pericentral (group 3) and compared the proportions of eyes with baseline visual impairment, visual improvement, and visual deterioration between groups; central edema was evaluated with logistic regression, as an explaining variable of baseline visual impairment and visual improvement. The study included 160 eyes: 77 in group 1, 20 in group 2, 63 in group 3; baseline visual impairment was more frequent in groups 1 and 2 (52.6%) than in group 3 (28.6%, p = 0.002, OR 2.77) and as common in groups 1 (51.9%) and 2 (55.0%, p = 0.8). The proportions of visual improvement and visual deterioration did not differ between groups (p > 0.05). The outcome after focal photocoagulation was similar in paracentral (considered center-sparing) and central macular edema; the definition of center involvement, which needs intravitreal antiangiogenics, should expand to include paracentral thickening.