Table 5. Diabetic Retinopathy Clinical Research Network Focal/Grid Laser (Both Focal and Grid Treatment Are Applied When Laser for Diabetic Macular Edema is Considered).

Circumstances to Consider Edema threatening or involving the center of the macula, including any of the following: Optical Coherence Tomography (OCT) central subfield thickness ≥2 standard deviations than the norm (e.g., ≥250 μm on Stratus OCT) Edema within 500μm of the center of the macula Edema associated with lipid within 500μm of the center of the macula, or edema ≥1 disc area within 1 disc area of the center of the macula ≥13 weeks since focal/grid laser has been given Direct Focal/Grid Treatment Direct laser to all microaneurysms in areas of retinal thickening between 500 an 3000μm from the center of the macula Direct laser to all microaneurysms in areas of retinal thickening between 300 an 500μm of center of macula if center-involved edema persists after an initial session of focal/grid laser, but generally not if the visual acuity is better than 20/40 50μm to 60μm spot size 0.05 to 0.1 second duration Green to yellow wavelengths Endpoint of laser burn: change color of microaneurysm or at least a mild gray-white burn evident beneath microaneurysm. Grid laser is applied to all areas with edema not associated with microaneurysms between 500μm and 3000μm superiorly, nasally and inferiorly from the center of macula and between 500μm and 3500μm temporally from the center of the macula, separating laser burns at least 2 burn widths apart, again with a 50μm to 60μm spot size and 0.05 to 0.1 second duration.