Contributor: Gordon K. Klintworth
Macular edema is the main cause of visual impairment in patients with diabetes mellitus. It can be focal or diffuse and is readily demonstrated clinically with OCT. Fluorescein leakage with pooling of the dye in cystoid spaces can be seen on fluorescein angiography. The latter typically produces an area of hyperfluoresecence in the region of the macula that resembles the petals of a flower. Macular edema is a manifestation of numerous conditions including systemic diseases with retinal vasculitis [Behçet disease, sarcoidosis, uveomeningencephalitic syndrome, HLA-B27 arthritis [arthritis - HLA-B27], birdshot retinochoroidopathy, dominant cystoid macular edema, anterior uveitis [uveitis - anterior], intermediate uveitis [uveitis - intermediate], posteior uveitis [uveitis - posterior], multifocal choroiditis, tamoxifen retinopathy [retinopathy - tamoxifen]. Macular edema is almost invariably presentin eyes with an acute central retinal vein occlusion or retinal branch vein occlusion and it can resolve spontaneously over weeks or months in less severe cases. Cystoid macular edema [edema - cystoid macular] may occur as a side effect of sympathomimetics in phakic eyes and aphakic eyes. Macular edema can be treated with focal laser photocoagulation. Intravitreal triamcinolone acetonide is beneficial for cystoid macular edema secondary to uveitis and diabetic retinopathy. It also reduces macular thickening due to diffuse diabetic macula edema.