Green or Yellow Laser Treatment for Diabetic Macular Edema

Abstract

Purpose: Explore differences in green compared with yellow focal/grid laser treatment on functional and anatomic endpoints in eyes with diabetic macular edema. Methods: Data from two randomized clinical trials were evaluated for differences in visual acuity (VA) and optical coherence tomography (OCT) parameters, eyes were assigned to sham injection+prompt laser, ranibizumab+prompt laser, or prompt laser only; among subgroups of eyes treated exclusively and electively with either green or yellow laser. Results: In the sham injection+prompt laser group, the mean VA letter score change for eyes receiving green and yellow laser treatment, respectively, was +2.4±14 and +5.1±13 at the 52-week visit (P = 0.06), and +2.4±15 and +6.0±13 at the 104-week visit (P = 0.13), with no corresponding evidence of differences in OCT thickness. When comparing wavelength groups in the ranibizumab+prompt laser and prompt-laser only groups, meaningful differences in VA and OCT thickness were not detected at 1 or 2 years. Conclusion: A trend towards improved vision outcome with yellow laser observed in one trial was not corroborated by anatomic outcomes or by the other trial. Without random assignment to different wavelengths controlling for bias and confounding, it is not possible to determine whether one wavelength is better than the other.