Diabetic macular edema: classification, medical and laser therapy

Purpose. to propose and describe a new classification of diabetic macular edema (DME) based on its etiopathogenetic features and to present efficacy and safety data on medical and laser treatments currently used and under investigation. Methods. available literature on DME has been reviewed and information provided by contact lens biomicroscopy, fluorescein angiography and optical coherence tomomography has been combined; published data from trials and reports investigating effectiveness of medical and laser treatments were also analyzed. Results. DME was classified according to its main etiopathogenetic components: prevalently retinovascular, tractional and with taut attached posterior hyaloid, each of them having peculiar aspects on fundus, angiographic and tomographic examination. Focal laser treatment remains the only effective intervention, as shown by a large randomized controlled trial, but new less-invasive photocoagulation strategies (i.e., light laser photocoagulation and subthreshold micropulse diode laser) as well as pharmacological approaches (i.e., antioxidants, PKC inhibitors, aldose-reductase and AGE inhibitors, VEGF inhibitors, intravitreal triamcinolone) are emerging. Conclusions. based on our review a classification of DME was developed that may prove useful in making the appropriate treatment decision; the new laser and pharmacological treatments currently investigated are promising and need to be confirmed by large, controlled clinical trials.