Diabetes mellitus (DM) is a serious debilitating and deadly disease causing significant mortality and morbidity globally. Diabetic macular oedema is the most common cause of visual loss in the working population.~In 1985, the Early Treatment Diabetic Retinopathy Study (ETDRS) demonstrated that focal (direct/grid) laser photocoagulation reduces moderate vision loss from diabetic macular oedema (DMO) by 50% or more. However, further studies have shown that photocoagulation can eventually result in complications leading to loss of central vision and decreased colour vision. Thus, many newer laser machines that claim to reduce the rate of complications have been developed over the years.~In this project, we plan to evaluate the usage of the micropulse 577 nm laser, which is a yellow light laser, and compare it to the conventional 532 nm green laser that is widely used. The 577 nm laser has a high affinity for oxyhemoglobin, a slightly lower affinity for melanin and almost no affinity for macular xanthophylls, as shown in the graph below.22,23,24,25 The yellow 577 nm light also scatters very little and does not cause photochemical reactions in the tissues.~The theoretical advantage of using the micropulse 577 nm yellow laser would be the reduced energy requirement to obtain the same results as with green 532 nm. This leads to less retinal toxicity and damage due to reduced absorption by the xanthophylls. Our aim in this project is to observe whether the theoretical advantage translates to a more effective treatment in reality.
The purpose of this study is to determine whether the new micropulse 577 nm yellow laser is a better treatment option compared to the conventional 532 nm green laser for diabetic macular edema.