OCT Classification of Clinically Significant Macular Edema

Diabetic macular edema is the commonest cause of visual loss in patients with non proliferative diabetic retinopathy and a common cause of visual loss in PDR. According to Early Treatment Diabetic Retinopathy study, early detection and laser treatment of clinically significant macular oedema decreases the risk of moderate visual loss by 50%. Though laser has been the standard of care till recently, many new treatment modalities are now available in the management of CSME. Even in the ETDRS, many patients treated with laser did not improve and actually had a visual drop, especially those patients with diffuse CSME. Why laser should be effective in certain subgroup and not in others could not be explained at that time.